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vcd_on_mac

DV, DVD and (XS)VCD on a Macintosh memo and cookbook

http://www.sjoki.uta.fi/~shmhav/SVCD_on_a_Macintosh.html Updated: 20070520

Matti Haveri

<http://www.sjoki.uta.fi/~shmhav/SVCD_on_a_Macintosh.html> Updated: 20070520

Matti Haveri <mattiDOThaveriATsjokiDOTutaeiroskaaDOTfi> remove ei roskaa

Contents:

SVCD vs VCD vs DVD

DVD and (X)SVCD encoding and authoring

Other info

More info about (XS)VCD and DVD

Acknowledgements


SVCD vs VCD vs DVD [back to Contents]

Why SVCD? For one thing, CD burners are still much more common than DVD burners so you may already have the hardware and software to encode video that you can conveniently play on a regular DVD player or send via snailmail or via the Internet to relatives etc. Provided the DVD player supports SVCD, that is. VideoHelp lists many DVD players that should be SVCD compatible but try before you buy.

SVCD is high quality compared to VCD but low quality compared to DVD. DVDs have much larger capacity than CDs so it is possible to use higher bitrates and resolutions to gain better quality video. A 80 minute CD holds about 798 MB but a DVD can hold 4.7(-8.5-9.4-17) GB of MPEG data.

DVD and SVCD use MPEG2 while VCD uses MPEG1 video encoding. Unlike VCD, SVCD can take advantage of interlaced video which shows smoother motion on TV.

DVD's video bitrate is up to 10036 kb/s (=9.8 Mb/s) while SVCD is 2441 kb/s (=2500000 b/s = 2,4 Mb/s) and VCD is only 1125 kb/s (=1152000 b/s = 1.1 Mb/s). You can fit about 40 minutes of highest quality SVCD on a CD.

DVD resolution is up to PAL/NTSC 720x576/480 pixels while SVCD is 480x576/480 and VCD is only 352x288/240.

You can make a non-standard SVCD a.k.a. XSVCD with DVD-like bitrates and/or resolution but it may not play on all DVD players and not all DVD players understand standard SVCDs anyway. XSVCDs and CVDs are even possible to later rip, concatenate and burn as DVDs (see the chapter "CVD vs SVCD vs DVD").

What's SVCD? <http://www.videohelp.com/svcd.htm>

Super Video CD Overview <http://www.iki.fi/znark/video/svcd/overview/>

The Super Video CD FAQ <http://www.iki.fi/znark/video/svcd/faq/>

I've now switched mainly to DVDs but many (XS)VCD principles apply also to DVD. You can use the many (XS)VCD applications also for DVD.


DVD and (X)SVCD encoding and authoring [back to Contents]

  • System requirements

Most of the used software needs at least Mac OS X 10.2. A fast CPU is recommended for MPEG2 encoding: my old '97 PowerMacintosh 8600/G4 450 and mpeg2enc compress 1 minute of DV to progressive PAL SVCD MPEG2 in about 10 minutes (via MPEG2 Works) so you need a lot of time or a faster Mac. G3 processor is very slow in MPEG encoding.

  • Encode MPEG video and audio

For (X)SVCD you have to encode your QuickTime movie into movie.mpv (MPEG2 video) and movie.mp2 (MPEG1 layer 2 audio). Alternative suffixes for these video and audio formats are .m2v and .m1a.

The source can be a QuickTime movie such as a plain iMovie DV stream *.dv, a DV-encoded QT movie *.mov etc. Usually you want to concatenate plain DV streams into a single file with original iMovie quality by exporting them as a DV-encoded QT movies (PAL/NTSC 720x576/480). In iMovie 2 you can do this by choosing in iMovie "File/Export Movie.../To QuickTime/Full Quality, Large" or just "File/Export Movie.../For iDVD" which is the same thing.

In iMovie 3 and 4 you don't have to export the movie anymore because each time you do a save in iMovie, a little reference .mov file is created inside the iMovie project folder. You save a lot of time and disk space by using this tiny reference .mov as your input file.

The hardest part is encoding the video into MPEG2. One good MPEG2 encoder is mpeg2enc in mjpeg tools. Many (XS)VCD encoding GUI applications (MPEG2 Works, ffmpegX, iVCD, MediaPipe etc) use mpeg2enc as their MPEG2-video encoding engine and mp2enc as their MPEG1-audio encoding engine so you don't have to use the command line interface. You can use many of these tools also for DVD encoding.

Compiling mpeg2enc on Mac OS X (ctrl-click to download mpeg2enc) <http://mjpeg.sourceforge.net/MacOS/>

MJPEG HOWTO <https://sourceforge.net/docman/display_doc.php?docid=3456&group_id=5776>

- MPEG2 Works ($10) is a nice GUI front-end to mpeg2enc and other SVCD tools. It is designed to output plain vanilla SVCD or DVD so there is a minimum amount of settings making this is a very good choice for those that don't want to fiddle with plethora of obscure options that may ruin the video if incorrectly used. MPEG2 Works doesn't currently support interlaced output and the aspect ratio isn't exactly preserved with Half-D1 (PAL/NTSC 352x576/480) resolution.

- ffmpegX ($15) is a nice GUI front-end to mpeg2enc and other (X)SVCD tools so encoding, multiplexing and authoring is user friendly. It has many user-configurable options so you can tweak the output in many ways. ffmpegX doesn't currently support interlaced output and the aspect ratio isn't exactly preserved with Half-D1 (PAL/NTSC 352x576/480) resolution. Notice that with 4:3 input (DV) resolutions you must uncheck Options/Letterbox so that ffmpegX doesn't unnecessarily add black borders to the left and right.

- MMT-EZ ($0) seems also to be a nice GUI front-end to mpeg2enc and many other tools including a DVD/CD burner.

- iVCD ($30) also uses mpeg2enc as its MPEG encoding engine although it offers only basic (S)VCD encoding and authoring for people who don't want to fiddle with many obscure options. At least in PAL the field dominance is wrong and the other v1.1.3 bug seems to be that at least in a PAL DV to SVCD the encoded MPEG2 has unnecessary black bars at the left & right where a simple 720x576 to 480x576 scaling would have been correct.

- Toast Titanium ($100) is a good 1st choice for (S)VCD and DVD encoding, authoring, and burning because you need a disk burner anyway and it is easier to use than some cheaper CD/DVD burners. AFAIK Toast Titanium 7 uses MainConcept MPEG encoder. Toast can be used to encode MPEG1 files, too: make a VCD project and Save As Disk Image..., mount the disk image, copy the /MPEGAV/*.DAT to the desktop and rename it as *mpg.

- MediaPipe (currently $0) has also mpeg2enc is packaged inside its MPEGEncoder.mpipe, which you can configure and use as a command line utility either directly via MediaPipe's or indirectly via MissingMPEG Tools' graphical user interfaces.

Unfortunately MediaPipe hasn't been updated for a long time and some of its components do not work with new Mac OS X versions. So sadly it is now obsolete.

Despite other tools' user friendliness I used to prefer to encode (XS)VCD via MediaPipe for the flexibility it offered. It is currently the only mpeg2enc-based GUI encoder that supports interlaced output which has smoother motion on a TV compared to progressive output. MediaPipe is also currently the only encoder which can be configured to maintain the correct aspect ratio with output resolutions like PAL/NTSC 352x576/480. Encoding with MediaPipe is flexible but somewhat complicated so I have moved MediaPipe instructions to another page. There are preconfigured MediaPipe templates for DVD and (XS)VCD encoding.

A quick review of more expensive DVD- and MPEG-encoding options: iDVD (comes bundled with a new Mac or $80 bundled with other iLife '05 applications) is easy to use, it has good quality, and it has also nice-looking DVD authoring built-in. Toast Titanium ($100) has a decent MPEG encoder and a basic authoring built-in. DVD Studio Pro & Compressor provide more options for encoding and authoring but the $500 price is quite high for an average user. MainConcept MPEG Encoder is easy to use, it has good quality and plenty of options for tweaking but the $249 price may be too high for an average consumer looking for more encoding options (custom bitrates, resolutions etc) than iDVD can provide. BitVice Lite ($149) has slightly less options for tweaking but the price is right. Quality-wise, Digigami MegaPEG.X Batch ($240) and Digigami MegaPEG.X QT ($240) are identical. The latter is a QuickTime Export plug-in which allows one to output MPEG straight from iMovie, QuickTime Player etc. Digigami's default settings may be too smooth and fuzzy for some people so adjust the settings as needed. Digigami MegaPEG.X Batch's bitrate and quantization chart is a very nice feature (it actually reads the bitrate info from demultiplexed m2v). Also the previously mentioned mpeg2enc variants can be used for DVD encoding. LaCie FastCoder ($249) currently supports only NTSC. Cleaner, Heuris are other options for MPEG encoding.

You can increase the MPEG quality with a 2/3-pass encoder which first analyzes the video content and then proceeds to encode it but this takes longer than a 1-pass method. mpeg2enc does not currently support 2-pass encoding.

A quick review about the role of I, P and B frames in compression: I-frames (intra frames) stand alone; they rely on no other frames for proper decoding. P-frames (forward predicted frames) are predicted in a single direction: they rely on the previous I or P frame for motion compensation. B-frames (bidirectionally predicted frames) are placed between pairs of IP frames (display order). B-frames can be reconstructed using both information from the I or P frame earlier in time and the I or P frame occurring later in time. Each of these three types of frames has an approximate cost in bits to the encoder. Generally speaking, if you study the statistics of IPB frame sizes, P-frames take about twice as many bits to compress as B-frames. And I-frames take twice as many bits to compress as P-frames. I-frames are the most expensive. GOP starts with an I-frame. B-frames follow either the I-frame or a single P-frame. Only one P frame at a time.

To make a standard SVCD you must scale and encode the input QuickTime file to PAL/NTSC 480x576/480 MPEG2 file at a maximum of 2500 kb/s. You can fit about 40 minutes of SVCD video on a 700MB CD with this bitrate. If you deviate from those resolutions or 2500 kb/s bitrate you make a nonstandard SVCD a.k.a. XSVCD which may not play on your DVD player. Besides, not all DVD players can play standard SVCDs anyway. Try a known-good VCD- and a SVCD-disk before you buy a DVD player.

After you have encoded MPEG2 you can optionally check and play the file with VLC media player or with the QuickTime Player if you have bought the $20 QuickTime MPEG-2 Playback Component from Apple.

iDVD and Toast Titanium have a MPEG encoder, DVD authoring and a DVD burner built-in. Toast Titanium ($100) or Sizzle ($0) can be used to author encoded MPEGs as video-DVDs (see below). DVD Studio Pro ($500) has much more options at a price.

You can easily make a SVCD where you can select tracks with your DVD player remote, just as if you were using a commercial DVD disk. Just get VCD Builder (donationware) and optionally also compose a starting menu with track names and graphics to the beginning of the SVCD. Also Toast Titanium supports SVCD authoring.

It is better to keep single MPEGs relatively short (max ~40 minutes) because in long MPEGs the audio may get slightly out-of-sync and shorter MPEG chunks are easier to manage and re-encode at lower bitrate if the CD's capacity is exceeded. VCD Builder allows you author smaller MPEGs to a single CD and break individual MPEGs into chapters so you can conveniently play them via the DVD player's remote control (check the right chapter times with QuickTime Player from the input movie or the MPEG files ( MPEG-2 Playback Component is required for MPEG2 movies)).

VCD Builder automatically launches and configures Multitrack CD-ROM XA in Roxio Toast (commercial) after it has processed the input MPEGs.

For best results scale or crop your Menu source images to a 4:3 size (iMovie exports stills as 4:3 PAL 768x576 or NTSC 640x480) with apps like Graphic Converter or Photoshop (you may have to configure your DVD player to get the correct aspect ratio on a TV).

CDRW disks may be more DVD-player compatible than CDR disks. Notice that not all DVD players can play SVCDs so try before you buy.

Congratulations, you're done! Now try the disk in your standalone DVD player before rushing to do longer projects.


Other info [back to Contents]

  • CVD vs SVCD vs DVD

Before rushing to make SVCDs you may also consider the CVD (China Video Disc) and low- and high-resolution XSVCD formats because they are easier to export to DVDs later.

What is CVD? First, CVD predates SVCD. 2nd, "Chaoji VCD", which roughly translates to "Super VCD" is like a compatibility specification for players -- a Chaoji VCD player must be able to play back SVCD, CVD, VCD 2.0, VCD 1.1 and CD-DA discs.

Super Video CD Overview <http://www.iki.fi/znark/video/svcd/overview/>

Today all "SVCD compatible" standalone PAL DVD players are actually compatible with Chaoji VCD players. This means that both CVD and SVCD formats are supported.

On the other hand, the "SVCD compatible" standalone Region 1 NTSC DVD players in U.S. are not forced to include CVD compatibility. The reason is simple: Those players are not used in China, even in theory (as is the case with Region 2 PAL players). Only half of the "SVCD compatible" R1 DVD players are currently (200206) compatible with CVD. Most of them are made in southeast asia, and they use C-Cube's microchips.

So why CVD-resolution (or high-resolution XSVCD) instead of a standard SVCD?

CVD video differs from SVCD basically only by its slightly lower horizontal resolution (PAL/NTSC 352x576/480 vs 480x576/480). This resolution also happens to be one legal resolution, a.k.a. half D1, for DVD video. (Like a SVCD, CVD also uses VBR MPEG2 video encoding with up to 2441 kb/s (=2500000 b/s = 2,4 Mb/s) bitrate).

So the benefit of encoding CVDs is that you can use your PAL/NTSC 352x576/480 MPEG2 files on CVDs today and on DVDs tomorrow, without any picture re-encoding or re-scaling (you just need to multiplex them with DVD specs). This is not possible with SVCD, because its resolution (480x576/480), isn't compatible with DVD video. So SVCD files need re-encoding if you want to burn them on DVD later. (There are ways to convert SVCDs to DVDs without re-encoding, but that creates something like an "xDVD" and many players do not support such discs. The most common problem is a picture with totally wrong aspect ratio or blank picture in the right side of the TV screen!). With CVD you don't have that kind of problems, and your DVD authoring programs accept your CVD files!

CVD audio uses the same 44.1 kHz MPEG1 layer 2 audio as SVCD, but more than 80% of the DVD standalones produced after 1999, which are also compatible with Chaoji Video CD players, can play also 48 kHz audio on CVDs and SVCDs. So, if your DVD standalone supports 48 kHz CVD audio, you may want to encode 48 kHz audio in the first place, especially if you intend to later transfer the CVDs to DVDs because DVD uses 48 kHz audio.

CVD, SVCD and VCD will all go away the day DVD burners become mainstream and the DVD media becomes as cheap as CDRs are today. But all those standards are based on MPEG so you may prepare yourself with DVD in mind by encoding CVD or low- or high-resolution XSVCD with 48 kHz audio so they can be easily transferred to DVD in the future. Of course you get better quality by re-encoding to DVD with higher DVD bitrates _if_ you still have the original material. You can also continue to use your old SVCDs but transferring and concatenating them to higher capacity DVDs has its benefits, too.

Legal DVD resolutions are PAL/NTSC 720x576/480, 704x576/480, 352x576/480 for MPEG2 and 352x288/240 for MPEG1 so you can transfer these resolutions also to DVD if you want. My Pioneer 444 PAL DVD player accepts all these resolutions on XSVCD as well as PAL 352x288 XSVCD MPEG2.

Using MPEG1 layer 2 audio (a.k.a. M1A or MP2) is non-standard in NTSC but can be played back on many DVD players, so check whether your DVD player supports it or whether you must use compressed AC3 or uncompressed PCM audio.

So basically you need to decide whether to encode:

1) standard SVCD PAL/NTSC 480x576/480 with 44.1 kHz audio

2) low resolution 352x576/480 XSVCD a.k.a. CVD with 48 kHz audio (1st choice for XSVCD)

3) high resolution 720x576/480 XSVCD with 48 kHz audio

4) high resolution 704x576/480 XSVCD with 48 kHz audio

5) low resolution 352x288/240 X(S)VCD with 48 kHz audio

Standard SVCD is more compatible with DVD players but those X(S)VCD-resolutions can be more easily transferred and concatenated to real DVDs later.

PAL/NTSC 704x576/480 may be a good choice for originally analog sources (analog-to-DV capture from a TV-tuner, for example) because the original analog active image width is PAL 702 or NTSC 711 and the 704 XSVCD width crops the unnecessary black borders from the 720 width DV image.

CVD: What is it, how to test it & what to expect! <http://www.videohelp.com/forum/userguides/98177.php>

A Quick Guide to Digital Video Resolution and Aspect Ratio Conversions <http://www.iki.fi/znark/video/conversion/>

Q: My DVD-recorder can burn PAL/NTSC 352x288/240 MPEG1 as a video-DVD, but QuickTime Player displays only black video from the VOB? A: You might have also noticed that QuickTime Player erroneusly reports your file as MPEG2 when it, in fact, is just MPEG1 in a MPEG2-style container. If you open the file with MPEG Streamclip, you can see the video and also use the Show Stream Info -command to see that it is really MPEG1. You can fix the MPEG container issue if you demultiplex the file and then remultiplex it with MPEG Streamclip. Then also QuickTime Player shows the video in it.

miniDVD a.k.a. cDVD is a DVD video written onto a CD-R(W) instead of a DVD disc. A miniDVD can only hold about 15 minutes of DVD quality video on a 700 MB CD-R(W).

Not many standalone DVD players will play miniDVD -- see the list for miniDVD compatible players. Computers can play the miniDVD if the CD/DVD drive supports at least 8x CD-R/W reading speed. A workaround for computers with slower drives is to copy the VIDEO_TS folder to the harddisk and play it from there.

Toast Titanium can create a miniDVD. Go through the same process you would to create a DVD, however when prompted for a blank DVD insert a blank CD instead.

Avoid "garbage in, garbage out": Take care that your original video is high quality. If possible, use good illumination and a tripod so the MPEG2 encoder can focus on relevant movement on the video. Familiarize yourself with the camcorder's settings.

You can minimize the loss of quality on long 60-90 minute XSVCDs by using widescreen format or by converting the material to black & white. If you prefer color, the movie must be "clean", meaning almost no noise. Progressive output is less blocky than interlaced but progressive movement is jerkier on TV. Reducing the output resolution also diminishes blockiness but the image may not be as crisp. Animations may look ugly because there is noise around fast moving clean lines. The blocking artifacts are most noticable on backgrounds like sky. The material should contain as little visible vegetation and water as possible...

Q: OK, I have now successfully burned SVCDs. But how can I retrieve the MPEG2s back from the SVCDs if I want to use them later in other projects?

- Ripping is fast and easy with Toast Titanium: insert the (XS)VCD and choose Recorder/Disc Info... A list of tracks will appear. Select the Video track and save the MPEG from there.

If you want to burn DVD-compatible XSVCD to a DVD, you must demultiplex and author the ripped MPEG and remultiplex it with DVD specs. Toast does all this and also authoring automatically.

To re-burn as DVD in Toast: select Video/DVD-Video (or SVCD or VCD), add the ripped MPEG and burn it to a DVD. If Toast sees that the MPEG conforms to the DVD spec it doesn't re-encode it (the re-multiplexing and authoring phases are fast) so there is no quality loss. Toast may sometimes unnecessarily start to slowly re-encode valid DVD or (S)VCD MPEGs -- demultiplexing the MPEG to .m2v and .m1a (a.k.a. .mp2) may fix this.

- VCD Copy X (donationware) can rip the tracks off of a VCD or SVCD as *.dat files, which can AFAIK just be renamed as *.mpg and re-burned as SVCDs. (Compared to the original *.mpg the *.dat file contains some additional navigation information the SVCD needs).

- Another alternative for ripping is MissingMediaBurner. MissingMediaBurner has to compete with the Finder for access to the CDR(W) so put a blank CDR(W) to the CD-burner but leave the drive tray still open. In MissingMediaBurner choose Device: CD-R/RW, Driver: generic-mmc-raw (you may have to experiment with your setup). Choose the Output Folder in the RIP DISK panel, check Raw mode, press the Rip-button and immediately close the CD-burner's tray. You get something like mycd.bin as an output file. Launch GNU vcdtoolsX and use its vcdXrip to open mycd.bin and generate *.mpg files that you can author and re-burn as SVCDs with VCD Builder and Toast.

- Here is another way to rip via Toast (the other Toast method is faster because here the MPEG must be demultiplexed so Toast doesn't try to re-encode it): select CD/DVD Copy (and the desired CDRW) in Toast and File/Save as Disc Image... Rename the saved disc image *.toast to *.bin and use vcdXrip in GNU vcdtoolsX to extract the MPEGs from it.

- If necessary, you can demultiplex the *.dat or *.mpg files with MPEG Streamclip, MPEG2 Works, ffmpegX or MoreMissingTools' MPG DEMUX, and remultiplex and reuse them as *.mpg files.

MPEG is a delivery format, not an editing format, but occasionally you may want to edit MPEG files or import them to iMovie. I'd suggest you try MPEG Streamclip first and see if it does the job for you.

- MPEG Streamclip ($0) converts MPEG files (including transport streams) into muxed, demuxed, DV, QuickTime, AVI, MP4 or H.264 video or TIFF still frames, so you can easily import them in iMovie, Final Cut Pro, DVD Studio Pro and Toast Titanium. MPEG2 conversions require the $20 Apple's QuickTime MPEG-2 Playback Component (you can buy it online from Apple, but you already have it if you use either Final Cut Pro 4/HD or DVD Studio Pro). MPEG Streamclip also includes a player to set In and Out points, and perform a partial conversion. It does not read encrypted VOB files. It can open and convert also DV, MOV, AVI, MP4, H.264, DivX or WMV files (DivX and WMV need 3rd party add-ons).

To convert a DVD or MPEG to DV with MPEG Streamclip (v1.8 or later): Open a desired .VOB on a DVD (DVD/VIDEO_TS/VTS_01_1.VOB, for example) or a MPEG file. Select the In/Out points if you want to extract just a portion of the video. Choose "File/Export to DV.../Compression: DV (DV25)". Choose "Split DV stream in Segments" if the content is more than 9 minutes 27 seconds because iMovie 1-4 can't reliably handle longer clip files and it might be a good idea to limit the converted .dv file's size anyway (segmented clips play seamlessly in iMovie). MPEG Streamclip can optionally resample audio to 48 kHz which DV (and DVD) use (use this option when converting (S)VCD 44.1 kHz audio for DV). You can import the converted .dv to iMovie or save it directly into iMovie project's Media folder to save time and HD space (iMovie prompts you what to do with the clip when the project is opened. Notice that iMovie HD 5 now stores its project folder as a package -- MPEG Streamclip can save straight into the package's /Media folder!). As a nice touch MPEG Streamclip correctly adds 8+8 black pixels to the sides when converting PAL/NTSC 352x576/480 half D1 or 704x576/480 MPEG to 720x576/480 DV.

MPEG Streamclip can join similar MPEG files: The joined files must have the same PIDs, the same start codes, and the same audio/video properties (that is, they must come from the same source or channel). Using "Convert to MPEG" before joining the files can be helpful, because it changes PIDs and start codes to a default value. The preferred method to join streams is to Copy one stream in MPEG Streamclip, open another stream and Paste it there. This method checks that the joined streams indeed are compatible. Another method is to put the MPEGs in the same folder, and rename them so that they sort as desired in list view. Then select them via MPEG Streamclip's "File/Open Files..." dialog box (Shift- or Command-click to select multiple MPEGs). Then choose "Edit/Fix Timecode Breaks". After this MPEG Streamclip should report the combined length of all MPEGs (check the Log Window if you want to know whether any timecode breaks were found). Then choose "File/Convert to MPEG... or /Save As..." to save them in a single file. If the video transition between two files looks bad, you can use the Cut command to improve it. You can join very different and incompatible MPEGs with this latter method so the end result is not guaranteed to work.

MPEG Streamclip can also edit MPEG files. Just set In/Out points (with I/O keys), Cut unwanted material off and choose "File/Convert to MPEG...". You can also Cut/Copy selections to other parts of the same stream or open another compatible stream and Paste it there. Shift-dragging the playhead can also be used to define a selection. Option + arrow keys jump to the beginning/end or In/Out points. You can use the Trim-command to more closely see a part of the video before cutting, then choose Revert Trimming to see all material. JKL-keys can be used to enable fast forward or reverse playing. The scroll wheel works also; with the Option key it scrolls 1 second per click. See the manual for more details on how to jump in single frame, GOP, 1 second, 10 second or 1 minute chunks when searching a specific spot in the video.

Editing and trimming can be accurate only if In and Out are both on keyframes because MPEG Streamclip edits to the GOP, not to the frame. For DVD and (XS)VCD the maximum GOP size is PAL 15 and NTSC 18 frames, so the editing accuracy can be up to about 0.6 seconds. You can advance to the previous or next keyframe (i.e. I-frame, the beginning of each GOP or Group Of Pictures) with the Up/Down arrow keys -- you can also use the Edit/Go to Keyframe command to see where the In and Out points really are when editing (the In point is included in the selection, the Out point is not included). Shift + Up/Down arrow keys allow fine-tuning the selection to the GOP.

Among other things, MPEG Streamclip can demultiplex VOB or MPEG into .m2v video and .aiff, .ac3 or .m1a (a.k.a .mp2) components. It can also easily be used to multiplex video and audio files together: just place similarily named .m2v and .aiff, .ac3 or .m1a files in the same folder, drop the .m2v file on MPEG Streamclip, and convert them to MPEG with PCM, .ac3 or .m1a audio. If necessary, MPEG Streamclip can encode new .m1a audio at 192-384 kb/s. Notice that MPEG Streamclip doesn't multiplex VOB-compatible files for performance reasons, so the DVD authoring app has to re-multiplex them.

MPEG Streamclip can also change the aspect ratio, scale, center, letterbox, un-letterbox, crop, add borders, deinterlace, change field dominance, adjust brightness, contrast, saturation and volume of the converted video.

MPEG Streamclip 1.5.1 is compatible with DreamBox or Topfield TF5000PVR/TF5500PVR DVB set-top boxes, FireWire, Ethernet, USB and DVD devices like Elgato EyeTV digital video recorders, ReplayTV digital video recorders, the Humax PVR-8000 set-top box, the Panasonic SV-AV100 camcorder, the JVC Everio camcorder, the Sony T1 camera, the Panasonic VDR-M70 and the Hitachi DZ-MV230 camcorders. It is also compatible with MPEG-2 devices supported by DVHSCap and VirtualDVHS (free applications available from Apple as part of the FireWire SDK for developers); namely, the Sony IP7/MicroMV, the Sony HDR-FX1, the JVC GR-HD1 camcorders; the JVC HM-DH30000U and the Mitsubishi HD-2000U video cassette recorders; the Samsung SIR-T165 set-top box.

Check the MPEG Streamclip Guide at its Help menu for more details.

You can import the edited MPEGs to Toast Titanium, DVD Studio Pro or Sizzle 0.5b2 (some prefer Sizzle 0.1 because it can make DVDs which start playing as soon as you insert the disc, whereas Sizzle 0.5 demands you put in a menu. v0.1 might also be more reliable. There may also be differences in what audio formats each version likes and dislikes), and burn them directly, with no encoding time and no loss of quality. (Notice that iDVD doesn't accept MPEG as its input).

If you still have Toast 6, please update it least to version 6.0.9 as previous versions could alter audio/video sync of muxed MPEG files. Some versions of Toast may have trouble burning some MPEGs with mp2 audio -- a workaround is to demultiplex the MPEG to m2v and m1a (or aiff) with MPEG Streamclip and burn them. Toast may lose audio sync or be too picky and reject some MPEGs -- a workaround is to demultiplex the MPEG to m2v and aiff with MPEG Streamclip and burn them. Toast 7 now also features a preference to prevent the lengthy and lossy re-encoding -- enable it if you know the MPEG is valid for a DVD or (S)VCD. Converting to "Headed" MPEG via MPEG Streamclip adds a special header to the MPEG file that lets you import unsupported frame sizes into Toast 6 or 7 and skip recompression. However, DVDs made from "headed" MPEG files are not guaranteed to work with all players.

Toast accepts MPEGs, VOBs and VIDEO_TS folders as its input. Use Toast's Video/Advanced/DVD-Video setting (not the "DVD-Video from VIDEO_TS" setting if you want to burn several such items to a single DVD. Delete unnecessary items (such as unwanted DVD menus from old DVDs), change the description of the titles and the DVD itself to something that makes sense and burn the new DVD. This results in Toast authoring a new VIDEO_TS folder that has a title menu of the videos from your other VIDEO_TS folders or their contents. Toast basically treats the VOB sets as MPEG video. Toast adds the AUDIO_TS folder as part of its authoring process so you don't need to do anything other than drag the folders to Toast so it can find the videos.

You can also author the MPEGs which Toast rejects with Sizzle. On the other hand, Sizzle may not like the PCM audio in MPEG ripped from an iDVD-encoded disk -- a workaround is to convert such MPEGs to use mp2 audio with MPEG Streamclip.

Short Sizzle manual: Click "Add Title" and one-by-one select the desired MPEG files you want on the DVD. Then, with the "TOC Menu 1" still selected in the "Item" list, choose an existing button on Sizzle's preview screen, click "Edit Button", choose Action "Jump to menu...", select "Destination" and the desired MPEG, and edit the "Button Label" text as desired. For more MPEGs, choose "Add Button" and repeat as above. * If you want to break the MPEG as chapters: Play the MPEG in some other application and make notes for the desired chapter point times (there is no GUI for this in Sizzle). Then in Sizzle, select the MPEG in the "Item" list, the "Chapters" tab and "+" to add chapters (the first chapter is always at 00:00:00.00). Then on Sizzle's preview screen click the chapter button, "Edit button", Action: "Jump to chapter..." and Destination: and a desired chapter time. Choose "Add Button" and repeat for the remaining chapter points you have added. When you are finished click "Save Disc Image". * If you want to test the DVD image before burning: Mount the .dmg image by double-clicking it and launch the /Applications/DVD Player to test it. * Burn the DVD via Toast Titanium: Select Copy/Image File, select the .dmg Sizzle created, and hit Record. Or burn using the Disk Utility: Choose images/Burn... and select the .dmg Sizzle created, and click "Burn".

- ffmpegX ($15) can also convert .VOB or .mpg to .dv. It works OK but its installation and interface can be too overwhelming.

- VisualHub ($23) also uses open source components such as ffmpeg as its engine. It can convert between many codecs: iPod, PSP, DV, DVD, Tivo, AVI, MP4, WMV, MPEG and Flash. It has presets for easy use and it is targeted for people that "just want to get the job done". Advanced panel lets you modify the settings. Batch Processing of multiple files. Xgrid support: use the power of every Mac on your network for batch encoding.

- DVDxDV ($25) can convert DVD-disks, VIDEO_TS folders and .VOB files to DV-encoded .mov files. iMovie 4 users should be aware that the audio is converted to 32 kHz when it imports DV-encoded .mov files (this is fixed in iMovie HD).

- DropDV ($40) can convert MPEG1 and MPEG2 streams to .dv.

- Cinematize ($60) can convert a DVD or a VIDEO_TS folder (not plain .VOB or .mpg) to .dv or QuickTime. There is a 15 day demo limited to 10 second content.

- In Toast Titanium ($100), select the Video tab, add the *.mpg or *.VOB files or drag a DVD or a VIDEO_TS folder to Toast's window, select the files in the list, choose Disc/Export Video... and Toast converts them with audio to DV streams. The converted files may even be on the (X)SVCD or DVD disk so no ripping is needed.

- A simple option to convert a DVD to DV is to just connect the DVD-player's analog outputs to a DV camcorder and convert the analog signal to DV.

- HandBrake can't output to DV but it can convert VIDEO_TS folder, DVD image or real DVD with AC-3, LPCM or MPEG audio tracks to MP4 (MPEG-4 or H.264), AVI or OGM with AAC, MP3, Vorbis or AC-3 pass-through. It supports chapter selection, basic subtitle support (burned into the picture), integrated bitrate calculator, deinterlacing, cropping and scaling and grayscale encoding.

Here are some other apps for MPEG encoding, editing or authoring:

- Capty MPEG Edit EX ($50) for Mac OS 9/X can do frame-accurate MPEG2 (not VOB or MPEG1) editing with 48 kHz PCM, AC3 or M1A single audio streams. It does this by converting a GOP to uncompressed video at the point of the edit. It supports all legal DVD resolutions. It can join different MPEGs to a single MPEG file and write as DV stream or MOV.

- Capty MPEG Edit Mac OS X can edit MPEGs frame-accurately (as opposed to GOP-accurately), so it must re-encode some frames (if you clip off an I-frame it must be re-encoded). It only accepts muxes of .m2v & .mp2/.pcm. It is a Japanese application, and unfortunately there is no english localization at the moment (Capty MPEG Edit EX may be a very similar app). It is a newer iteration of the english software that came with the ADS USB Instant DVD hardware MPEG encoder.

- Capty DVD/VCD 2 ($70) can encode and author single- or dual-layer video-DVDs as well as VCDs. It also accepts MPEG sources, does Dolby Digital encoding, offers 25 customizable motion menu templates, provides the ability to specify chapter points and chapter menus, and creates DVD slide shows that can display photo titles as well as have background music. Here is a CaptyDVD 2.0 quick tour.

- Pixe VRF Browser ($50) for Mac OS 9/X can view, edit and export video from a VR format DVD-RAM or DVD-RW or from a VIDEO_TS folder to DVD authoring applications. Pixe VRF Browser may be unnecessary if you have Toast 7 because its only real value is in extracting MPEGs from VR-mode DVDs recorded on a standalone DVD recorder or a DVD camcorder. It will not read MPEG files directly. There is a short review here. The data from VRF Browser is compatible with Pixela's Capty MPEG Edit EX, enabling detailed editing of frame by frame video and audio data. Unlike Capty MPEG Edit EX it doesn't play audio or allow preview of edits.

- MPEG Append ($50, the Mac OS 9 version is free) can combine MPEG files for DVD authoring applications like DVD Studio Pro.


...Many older MPEG tools handled only video and they are described below mainly for historical curiosity. To preserve audio you had to laboriously demultiplex audio and video to separate files and convert them separately to *.aif audio and *.dv video which you can import to iMovie and join there or combine in QuickTime Player:

1. Demultiplex MPEG to separate audio and video files:

You can do this with either MPEG2 Works, ffmpegX, MoreMissingTools' MPG DEMUX or mpgtx GUI (all use mpgtx as their demuxing engine. Note that for some reason iTunes can't currently convert MPEG audio if it is demultiplexed with bbDEMUX so use mpgtx for demuxing).

Demultiplexing yields *.mp2 as an audio file and either something like *.m2v (MPEG2) or *.m1v (MPEG1) as a video file. Don't throw the video file away because you convert it to DV later.

2. Convert *.mp2 audio to uncompressed 48 kHz 16 bit stereo *.aif which iMovie can import:

a) With iTunes you can convert the demuxed *.mp2 audio file to an uncompressed 48 kHz 16 bit stereo *.aif file, and import it to iMovie where you can combine it with the DV video you get in the next step. You can import the converted *.aif file via iMovie 3's Audio tab straight from the iTunes Library or locate and import the converted *.aif file to iMovie 2.

(You can select the AIF format in iTunes/Preferences/Importing, and define the folder where the *.aif is saved via iTunes/Preferences/Advanced. In iTunes select File/Add to Library... to add the .mp2 to the playlist, then select the .mp2 and choose iTunes/Advanced/Convert Selection to AIFF. You can then copy the .aif file from the iTunes folder elsewhere via the Finder or import it via iMovie 3's Audio tab).

b) You may also convert the *.mp2 to WAV with MPEG2 Works and use QuickTime Pro to export it as uncompressed 48 kHz 16 bit stereo AIFF.

c) You may also convert *.mp2 to *.aif with SoundApp although it isn't currently Mac OS X native.

3. Convert MPEG video to DV video: You can do the MPEG to DV conversion with tools like DiVA or MediaPipe.

a) DiVA is more user friendly but it doesn't exactly preserve the correct aspect ratio with resolutions like PAL/NTSC 352x576/480 (standard SVCD resolutions and DVD 720x576/480 are OK). DiVA doesn't require you to demultiplex the MPEG before converting it to another video format.

Set DiVA not to crop the MPEG and set it to scale to PAL/NTSC 720x576/480 in its main window. Set Compression to DV-PAL or DV/DVCPRO-NTSC with Best Quality and PAL/NTSC 25/29.97 fps.

b) With MediaPipe you have more control so you can maintain the correct aspect ratio even with weird MPEG resolutions. I have some preconfigured MediaPipe MPEG-to-DV templates. You can use the templates to convert _demultiplexed_ MPEG back to DV (the pipes don't have a demultiplexer so you have to demultiplex the MPEG first!). There are templates to convert MPEG resolutions PAL 352x288, 352x576, 480x576, 704x576 and 720x576 and NTSC 352x240, 352x480, 480x480, 704x480 and 720x480 to DV.

Note that some DV<->MPEG conversions require you to crop or add borders before or after scaling to maintain the correct aspect ratio. Check the original MPEG's resolution with tools like mpgtx GUI because QuickTime Player may report wrong MPEG resolutions.

A Quick Guide to Digital Video Resolution and Aspect Ratio Conversions <http://www.iki.fi/znark/video/conversion/>

c) By the way, iMovie 3 can import MPEG1 video if you drop the MPEG1 file to the iMovie timeline or shelf. MPEG-2 Playback Component is required for iMovie 3 MPEG2 importing or MPEG2 playing via QuickTime Player. Anyway, currently the converted MPEG files lack audio and the quality isn't as good as with DiVA or MediaPipe because in PAL, the output DV file every other frame is duplicated so the resultant video is jerky. Also in PAL the diplayed 720x540 must be resized to 720x576 in QuickTime Player to avoid distortion in interlacing. With DiVA or MediaPipe the converted DV quality is good and interlacing is preserved well with MPEG2 files.

4. Import to iMovie and join the converted video and audio:

a) Open the output DV-encoded QuickTime video file with QuickTime Pro and export it as a PAL or NTSC DV stream (with iMovie 3 you can skip this step). Import it to iMovie and combine with the imported *.aif audio.

b) Or, in QuickTime Pro paste the audio to the video track with the Add Scaled command to make video and audio sync.

Another commercial but expensive option to MPEG-to-DV conversion is to use Cleaner which should export also audio.

Methods a & b are quick 'n dirty, method c yields the best quality but you need the $20 Apple MPEG-2 Playback Component for it.

a) Play the DVDwith VLC media player and choose Video/Snapshot or take a screenshot via Command-Shift-3 (the whole screen) or Command-Shift-4 (a selection). You can also use /Applications/Utilities/Grab to take a screenshot.

b) Play the DVD with /Applications/DVD Player and take a screenshot. Regular screenshot doesn't work with the DVD Player but you can take a screenshot using the command "screencapture -c" with /Applications/Utilities/Terminal: when you press the Return-key, the screen image is placed onto the clipboard, including whatever image was paused or played in the DVD player. Use Edit/Paste with your choice of image editor. You can also take the screenshot with utilities like Snapz Pro X. Also Capture Me and DVD Capture support DVD still capture.

c) Open the desired .VOB in the DVD (DVD/VIDEO_TS/VTS_01_1.VOB, for example) or a MPEG with MPEG Streamclip. Scroll to the desired frame with the arrow keys and choose File/Export Frame.../Frame Size: 4:3 or 16:9, Pixel Aspect: Computer Graphics. Choose "Deinterlace Video" if there are motion-induced interlacing lines ( i.e. horizontal comb lines) in the video and if you don't want them in the image. As a nice touch MPEG Streamclip correctly scales the frame so that the correct aspect ratio is maintained.

Toast Titanium ($100) can burn (S)VCD from a bin and cue image file pair.

MissingMediaBurner (cdrdao as its engine) is a cheaper alternative to Toast.

Some things to remember about slideshows:

1. Standard video resolution is only PAL/NTSC 720x576/480 so the original megapixel stills have to be downsampled to this low resolution quality no matter what (you can optionally include the original images to the DVD-ROM part of the DVD so they can be viewed on a computer with no quality loss, though). The MPEG encoding will also degrade quality on video-DVDs.

High-Definition Video (HDV) resolution is somewhat better: in iMovie HD it is either 1280x720 (720p) or 1440x1080 (1080i) so you may want to try them instead of standard definition DV when working with iMovie HD. Notice that iDVD doesn't currently support HDV so you can't use it for this task.

2. iMovie display is just a preview so always judge the quality on a TV or via the QuickTime Player.

3. QuickTime Player has low quality playback of DV clips by default. You have to turn on high quality playback of the clip to see all quality (in QT 7 you do this via enabling "Window/Show Movie Properties/Video Track/Visual Settings/High Quality" setting -- do not enable "Single Field" or "Deinterlace" because they deinterlace playback. You can also set "QuickTime Player 7/Preferences.../General/Use high quality video setting when available" to check the "High Quality" box by default (notice that the "Single Field" or "Deinterlace" boxes may have been saved to the file so sometimes you must take care to uncheck them).

Notice also that older versions of QuickTime Player do not automatically scale the rectangular pixel video to square pixel computer display so the aspect ratio may look incorrect (you must scale NTSC 720x480 to 646x480 and PAL 720x576 to 788x576 to see the correct aspect ratio).

Notice also that you may see normal interlacing comb lines in QuickTime Player.

4. iMovie 4, 5 and 6 have a bug which may ruin still images: When you send the project to tape or to iDVD, DON'T let iMovie render the clips -- that's where you get irreversible jaggies! On the other hand, slow-motion clips and reversed clips NEED rendering to prevent flicker. Luckily there are workarounds for this nasty old bug: You get smoother slow-motion and reversed effect with 3rd party applications so slow-motion clips don't need iMovie's rendering. You can also convert still images to good quality video with Photo To Movie or Still Life or by tweaking iMovie's Ken Burns effect so they don't need iMovie's rendering either.

5. Notice that if an image is TOO sharp, this may cause flickering in thin sharp vertical lines when viewed on an interlaced TV. This is caused by the fact that a thin and sharp 1-line vertical object is visible only half of the time and even a 2-line vertical object may seem to jump up and down on an interlaced TV (see interlace flicker, see also this related article about the issue). The flicker is most prominent with "high frequency" images, i.e. images with lots of thin and sharp edges (buildings, wires etc). On the other hand, "soft" images (faces etc) are not affected.

iMovie doesn't properly blur the images so they tend to flicker badly on a TV. Also thin vertical lines tend to "live" with the Ken Burns effect. One clumsy workaround is to apply a small (1 pixel or so) Gaussian blur to the input images. Just using a smaller resolution (640x480) in the input images also prevents flicker but the images may appear slightly fuzzy instead (and you really should not much zoom into such low resolution image with Ken Burns!). I recommend bicubic downsampling via a Photoshop batch; also iPhoto's downsampling produces similar results. ...but I wouldn't currently use iMovie for slideshows because all this is very clumsy... Luckily there are some good 3rd party apps to the rescue:

Some applications intentionally slightly blur images to reduce the flicker. Photo To Movie's higher quality export setting does this and the results are very good. Also in Toast Titanium 7 the slideshows don't flicker.

As a side-note, here and here are good pages describing how to make good-looking titles to your video.

6. Notice that some operations will actually convert the slideshow into video. In a real DVD slideshow without transitions the stills are encoded to MPEG2 I-frames and each frame is displayed several seconds. This will take very little space (about 30-224 kB per image depending on its content). On the other hand, all the fancy transitions between slides have to be converted to video running PAL/NTSC 25/29.97 frames per second. This takes A LOT more space. In the same manner in an iMovie "slideshow" ALL the material is converted to video which takes even more space. There may also be slight "MPEG pumping" in the encoded stills if they are converted into video with iMovie and then encoded as MPEG for the DVD.

The advantage of doing the slideshow in iMovie is that this allows more precise control of the content compared to iDVD: in iDVD the slide duration affects all slides at once, selected songs will only play through and then loop, etc (DVD Studio Pro allows more variation). The DVD specification has a 99 slide limit per slideshow, but you can have many such slideshows on a single DVD. A iDVD slideshow offers the viewer a way to manually advance and go backwards the photos, but if you want to control what the viewer sees then stick with iMovie. iMovie (maybe combined with Photo To Movie and Still Life for even better flexibility) allows you to vary things like slide timing and music fades and basically give you control over how things are presented. You can use the iMovie chapters as usual to break the slideshow into smaller chunks.

7. For best results crop your input still images to some 4:3 aspect ratio (768x576, 1024x768, 2048x1536 etc) with apps like GraphicConverter or Photoshop. You may have to configure your DVD player to get the correct aspect ratio on a TV.

iMovie HD puts black bars to the left & right when it imports 4:3 images (this is the correct thing to do and iMovie HD does it almost right). If you want no black borders to the imported still images in 4:3 video projects, you must crop the input images so that their aspect ratio is NTSC 720x528 or PAL 788x576 or some larger multiple of those figures (NTSC 1024x751, 2048x1502, 2095x1536 etc, or PAL 1024x749, 2048x1497, 2101x1536 etc). If you want no black borders to the imported still images in 16:9 video projects, their aspect ratio must be NTSC 874x480 or PAL 1050x576 or some larger multiple of those figures.

Technical trivia: The PAL/NTSC resolution for still images is in DVD 720x576/480 (encoded as MPEG2 I-frames), in SVCD it is MPEG2 704x576/480 or 480x576/480 and in VCD it is MPEG1 704x576/480 or/and 352x288/240 (for a VCD, you may actually multiplex a high-resolution still and a low-resolution still together into the same system stream).

-iDVD can make DVD slideshows with optional transitions between images.

-Toast Titanium 7 ($100) can make good quality no-flicker (S)VCD and DVD slideshows with menus and with either automatic or manual advance.

-Ulead DVD PictureShow ($30) can create VCD or DVD slideshow using photos, video, music, narration, captions and customizable menu backgrounds. It also automatically blurs the images so they don't flicker on a TV.

-VCD Builder (donationware) can easily make VCD slideshows. Just create a new sequence in your project, and then drop the pictures onto the sequence and wait a while for VCD Builder to do its job. By default, the pictures are displayed for 5 seconds before moving on to the next picture. You can change this by double-clicking on the sequence to bring up the sequence edit window. Select all images you want to change, and then enter a new value in the Wait box. You can also change the scaling of the image, I prefer to uncheck TV-safe borders.

-MissingMpegSlideshow can convert images to a VCD or SVCD slideshow. Put MissingMpegSlideshow in the same folder as MissingMpegTools.

Q: How can I use iMovie projects as an input for MPEG Streamclip or JES Deinterlacer?

A1: If necessary, select the desired contiguous clips in the iMovie timeline and export them to a .dv file via File/Export.../QuickTime/Full Quality/Share selected clips only. Then use that .dv file as an input.

A2:You can also use the whole iMovie project as an input: Quit iMovie. In MPEG Streamclip choose File/Open Files.../All Files; then navigate to the "iMovie _project/Cache/Timeline Movie.mov" and use that tiny reference movie as an input. Also JES Deinterlacer can similarily "drill" into the iMovie project package when opening files for input.

With MPEG Streamclip and JES Deinterlacer it is also do a quick import of the processed files back into iMovie. That method works with iMovie 1-6. Just remember to take care that the .dv clip you are dropping in the Media folder is REALLY a plain DV stream .dv clip and that it is of the same video standard (PAL/NTSC) as the iMovie project. With other apps you can use the Finder to drop the processed files to the iMovie project package's /Media folder.

JES Deinterlacer ($0) is a very good quality PAL<->NTSC converter for .dv and QuickTime files. The conversion quality is much better than with QuickTime, iMovie or iDVD which distort or lose interlacing and skip frames (NTSC -> PAL) or duplicate frames (PAL -> NTSC) when adjusting for the differences in frame sizes and frame rates. JES Deinterlacer preserves interlacing and intelligently blends fields so the movement is smooth. Daniel Slagle's iMovie FAQ has detailed JES Deinterlacer instructions for PAL<->NTSC conversion.

Notice that JES Deinterlacer doesn't output audio if the source is DVD/VOB/MPEG. It can also output only as .dv or QuickTime, not as MPEG. As a workaround you can first convert DVD/VOB/MPEG to .dv or .mov with other apps and convert THAT to the other video standard with JES Deinterlacer. Then re-encode it as MPEG, if necessary. Doing this involves MPEG->DV->MPEG conversion so you should use a high bitrate in the re-encoding to avoid artifacts.

MPEG Streamclip ($0) can also convert PAL<->NTSC. Just switch the "Standard: " in the export settings. Also remember to check "Interlaced Scaling" (to prevent distorted interlacing) and "Frame Blending" (to compensate the different rame rates so you get smoother motion).

The conversion output with JES Deinterlacer and MPEG Streamclip is different so do a test and decide which you like better. In JES Deinterlacer the motion may be somewhat smoother than in MPEG Streamclip but the difference isn't very big. MPEG Streamclip seems to more blend neighbouring frames than JES Deinterlacer. MPEG Streamclip also completely loses the interlacing lines in some scenes when it blends frames. JES Deinterlacer always keeps interlacing lines visible.

Atlantis 2 ($195) is another PAL<->NTSC converter. Nattress Standards Conversion ($100) is a PAL<->NTSC plugin for Final Cut -- here is a review about it. Also Digigami MegaPEG.X Batch ($240) can do video standards conversion.

MPEG2 Works can convert VOBs or MPEGs with AC3 or MP2 audio between NTSC<->PAL via its "VOB/VOB PAL <-> NTSC Conversion" command. If the VOB contains PCM audio you must convert it to use MP2 audio with MPEG Streamclip's "File/Convert to MPEG with MP2 audio..." command first. Notice that most PAL equipment can play NTSC so you may not need to convert NTSC DVDs at all. Notice also that the video standards conversion quality isn't as good as when converting .dv files with JES Deinterlacer.

- BTW, a proper PAL<->NTSC conversion needs more than a simple 720x576<->720x480 scaling, but luckily the error is very small and goes unnoticed unless looked for. The correct conversion should do the following:

PAL DV to NTSC DV conversion: scale 720x576 to 729x486 and crop it to 720x480.

NTSC DV to PAL DV conversion: scale 720x480 to 711x569 and pad it to 720x576.

iMovie can render slow-motion, fast-motion and reversed video but you get better quality and more options with 3rd party utilities:

When iMovie renders a slow-motion scene it just duplicates each frame so the movement gets jerky. You get smoother motion with 3rd party utilities like JES Deinterlacer or Slow Motion Smoother.

iMovie skips frames and deinterlaces its fast-motion effect. You get smoother motion and more options with JES Deinterlacer.

iMovie HD 5's reversed effect deinterlaces video so the movement gets jerky with interlaced material. You get smoother motion in reversed video with JES Deinterlacer (or with iMovie 4 which did this correctly).

JES Deinterlacer (freeware) instructions for slow-motion, fast-motion and reversed video:

Input: If you want to render the whole iMovie HD timeline movie, you save time and harddisk space by using iMovie's tiny reference movie as an input: Quit iMovie and open JES Deinterlacer. Open its Input tab, press "Choose...", navigate to the iMovie_project/Cache/Timeline Movie.mov and select it as an input.

You can export selected continuous iMovie HD clips as a standalone .dv file via iMovie's File/Share.../QuickTime/Full Quality -command and use the .dv file as an input for JES Deinterlacer. This is also a safer way because sometimes using the reference movie as an input may be produce errors.

Slow-motion and fast-motion: In JES Deinterlacer's Project tab select "Project kind: Standards conversion". Select "Custom" and set "Movie speed: 0.5" for 0.5x slow-motion, 2 for 2x fast-motion and so on for other speeds. You can select speed ratios in the range of 0.1-10x with 0.01 decimal precision (with v2.7.1 the 0.1x may stall and with 0.2x the audio is out of sync. 0.25-10x are OK). THEN set the other options:

For NTSC use "Settings/Height: 480, Width: 720, Frame rate: 29.97".

For PAL use "Settings/Height: 576, Width: 720, Frame rate: 25".

Check "Blend" and let "Scale only" remain unchecked.

In the Output tab set "Video output/Compressor/Export: DV Stream.../DV Format: DV, Video Format: NTSC/PAL, Scan Mode: Interlaced, Aspect ratio: 4:3/16:9, Audio Format: Unlocked/Locked, Rate: 48.000 kHz".

Let "Progressive (out)" remain unchecked. (Leave the other options as defaults).

Select the output folder via "Put..." and click "OK" to start processing.

You can optionally check the Output tab's "Progressive (out)" -- with this option the movement is slightly jerkier.

JES Deinterlacer can smooth slow-motion by doing a "Both fields" a.k.a. "bob" deinterlacing. This method deinterlaces each video field (or half frame) and reconstructs a full progressive frame from it, so you get 2x more frames and 2x smoother motion. Notice that this "bob" deinterlacing trick doesn't work in progressive video because there are no temporally different video fields to take advantage of. Notice also that if you shoot with slow shutter speeds (PAL 1/25 or NTSC 1/30 second shutter speed or slower) you effectively get progressive video so use 1/50 or 1/60 or faster shutter speeds so you get different interlaced fields. After these temporally unique fields and frames have run out, JES Deinterlacer starts to blend them together with different opacities.

JES Deinterlacer features pitch preserving sound track for the altered speed. iMovie doesn't preserve pitch for altered speed so you can use iMovie-rendered soundtrack and combine it with JES Deinterlacer-rendered video if you prefer the audio that way. Or render the audio track with some audio application. Audacity allows you to change the speed (and hence the length) of audio but it does affect the pitch and tempo. Amazing Slow Downer can slow down audio with no pitch change.

* There happens to be another JES Deinterlacer option which outputs 0.5x slow-motion. You can enable this "Deinterlace Both fields with Double movie duration" by choosing in the Project tab "Project kind: Deinterlace", Check "Both fields" and "Double movie duration". With this setting you can quickly extract all temporally unique fields in an interlaced video and convert them into frames. (This is equivalent to the Standards conversion with the settings "Frame rate = same, no scaling, Movie speed = 0.5, Telecine, Progressive out").

Notice that NTSC users may not be able to choose the DV Stream Export in JES Deinterlacer via the "Deinterlace Both fields with Double movie duration" method because, as a bug, iMovie HD sometimes exports .dv files with slightly non-standard reported frame rates such as 29.975 instead of 29.970. This prevents JES Deinterlacer to set the DV Stream as its export option. The workaround for NTSC users is to set the equivalent 0.5x slow-motion via the Standards conversion dialog as described above.

You get special fast-motion effects by mixing JES Deinterlacer's "Blend" or "Telecine" and "Progressive" or "Interlaced" output options. Different material and different fast-motion ratios may need different options so run a test and see what you like the best. As a general guideline the Blend & Interlaced is very nice with somewhat fuzzy image and smooth motion (several interlaced frames are blended in a single frame). Blend & Progressive combination is may also be nice because it makes the camcorder pans and shakes more fuzzy (several frames are deinterlaced and blended in a single frame). Telecine & Interlaced is crisp but also jerkier (every Nth interlaced frame is preserved). Telecine & Progressive may often be too jerky (every Nth frame is deinterlaced and preserved).

Reversed: In JES Deinterlacer's Project tab select "Change field dominance" and "Reverse movie".

In the Output tab set "Video output/Compressor/Export: DV Stream.../DV Format: DV, Video Format: NTSC/PAL, Scan Mode: Interlaced, Aspect ratio: 4:3/16:9, Audio Format: Unlocked/Locked, Rate: 48.000 kHz".

Let "Progressive (out)" remain deselected to enable interlaced output and smoother motion. (Leave the other options as defaults).

Select an output folder via "Put..." and click OK to start processing.

Import to iMovie: You can use iMovie's File/Import... to import the .dv files but you save time and HD space with the following method if the files are big: Quit iMovie. Let JES Deinterlacer save its output (MUST be .dv!) straight into iMovie_project/Media -folder. Alternatively you can also just move the output .dv file to that folder (open the iMovie project package by control-clicking it and choosing Show Package Contents in the Finder). When you then launch iMovie, it prompts you that "Some stray files were found in the project, and were moved into iMovie's Trash. Would you like to view the Trash contents?". Move the clip(s) from the Trash to the Timeline or to the Shelf.

JES Deinterlacer supports also chapters in iMovie projects: To do so, you must quit iMovie and use the iMovie_project/Shared Movies/iDVD/*.mov as an input. You must also save as a DV-encoded .mov (NOT as .dv stream as in the previous instructions) via JES Deinterlacer's Output tab's "Video output/Compressor/Direct: DV-PAL/NTSC". Then use that as an input for iDVD.

Notice that JES Deinterlacer may stall if it is hidden (via Hide Others command, for example) so avoid doing that when it is active. If JES Deinterlacer acts up, you may need to quit JES Deinterlacer and delete its preference and log files (~/Library/Preferences/JES Deinterlacer Prefs and nl.jes.deinterlacer.plist and ~/Library/Logs/JES Deinterlacer log). Then log out/in and try again.

You can render slow-motion also with Slow Motion Smoother ($15):

Slow Motion Smoother is an iMovie 2-4 plug-in which can smooth slow-motion clips. Unfortunately Slow Motion Smoother 1.1.2 isn't yet compatible with iMovie HD 5. It seems to first do a "bob" deinterlacing with its "Camcorder" mode. In its "File" mode or with <0.5x slow-motion clips it blends frames together so movements appear fuzzy but the motion is smooth.

This can be useful if you have shot some footage in 4:3, but now want to include it in a "widescreen" 16:9 video (or vice versa).

iMovie HD letterboxes the material when converting 4:3<->16:9, but a) it can't preserve interlacing and b) the colors get a washed-out look. You get better quality by doing the conversion with MPEG Streamclip which can do the conversion with letterboxing and also without letterboxing (but with cropping, of course). MPEG Streamclip can also preserve interlacing. See here how to process iMovie clips with 3rd party apps.

Q: How can I convert 4:3 DV or MPEG to 16:9 DV?

A: Open the DV or MPEG clip with MPEG Streamclip and choose "File/Export to DV.../Aspect Ratio: 16:9, Zoom: X/Y aspect ratio 0,75". A letterbox will be added, but you can remove it by also entering in the field "%" a magnifying factor of 133.3 % -- notice that then you must also check either "Interlaced Scaling" or "Deinterlace Video" to prevent interlacing artifacts.

Q: How can I convert 16:9 DV or MPEG to 4:3 DV?

A: Open the DV or MPEG clip with MPEG Streamclip and choose "File/Export to DV.../Aspect Ratio: 4:3, Zoom: X/Y aspect ratio 1,333 -- check also either "Interlaced Scaling" or "Deinterlace Video" to prevent interlacing artifacts". A letterbox will be added, but you can remove it by entering in the field "%" a magnifying factor of 133.3 % and leaving the X/Y aspect ratio at 1 -- check also either "Interlaced Scaling" or "Deinterlace Video" to prevent interlacing artifacts.

With MPEG Streamclip exporter's two fields "Center" you can move the picture center horizontally and vertically if you so desire. Negative values move the center to the left or to the top and positive values to the right or to the bottom. You can check the how many pixels you should use by first saving a frame from the video via File/Export Frame.../Unscaled. Then measure the pixel dimensions of the exported image in some image editing application.

The "Interlaced Scaling" in MPEG Streamclip MUST be enabled in some circumstances. If you are scaling interlaced material to a different height, you must tell MPEG Streamclip to preserve interlacing and scale each video field separately by checking "Interlaced Scaling". If you don't, interlacing will be badly distorted in the scaled movie, and you get many visual artifacts. The alternative is to enable "Deinterlace Video". On the other hand, using "Interlaced Scaling" with progressive movies isn't recommended because it produces a little quality loss (blurring). But if the video contains interlaced AND progressive material you must enable "Interlaced Scaling" because interlacing artifacts are much more readily seen than the slight blurring in the progressive part of the material.

Notice that currently MPEG Streamclip loses the embedded timecode when doing DV-to-DV conversions.

Q: Analog-to-DV conversion adds narrow black borders to the left & right (and some analog "head switching" noise to the bottom). How can I crop them out?

A: If you view the output on a TV, then the overscan will automatically crop the borders out. But if you view the output on a computer monitor, you might want to crop them out. You can do this with MPEG Streamclip (see here how to process iMovie clips with 3rd party apps):

For non-DV output (usually you want this for computer playback) you can simply use suitable "Cropping: " values in MPEG Streamclip's export settings. Notice that with DV input a few pixels are automatically cropped because of the rectangular to square pixel conversion so do a test for the desired cropping values. Leave the "Scale" unchecked so the original aspect ratio is preserved. BTW, if you choose a DV frame size as an output, the "Scale" option has no effect and the picture is always scaled to match the input resolution -- this is why you must Zoom into the image to preserve the correct aspect ratio with DV output:

For DV output you must do the cropping by using a suitable Zoom % value. For example: with PAL you can use magnifying factor of ~103% and for NTSC ~102% (the sampling matrix vs actual active picture size is PAL 720x576 vs 702x576 and NTSC 720x480 vs 710.85x486: so you can calculate an approximate magnifying factor for PAL 720/702*100=102.6% and for NTSC 720/710.85*100=101.3%). Fine-tune these values, if necessary.

The "Interlaced Scaling" in MPEG Streamclip MUST be enabled in some circumstances. If you are scaling interlaced material to a different height, you must tell MPEG Streamclip to preserve interlacing and scale each video field separately by checking "Interlaced Scaling". If you don't, interlacing will be badly distorted in the scaled movie, and you get many visual artifacts. The alternative is to enable "Deinterlace Video". On the other hand, using "Interlaced Scaling" with progressive movies isn't recommended because it produces a little quality loss (blurring). But if the video contains interlaced AND progressive material you must enable "Interlaced Scaling" because interlacing artifacts are much more readily seen than the slight blurring in the progressive part of the material.

  • How can I pad video to the TV safe area (and preserve interlacing) [back to Contents]

When you view video on a TV, then the TV's overscan will usually crop about 10% of the image in horizontal and vertical dimensions (i.e. 5% from all sides).

The Picture Safe (a.k.a. action safe) area is the largest region of screen that viewers are likely to see. The Text Safe (a.k.a. caption safe) area defines the boundaries of the area in which vital information such as logos, text and menus can be placed. The Picture Safe margins are generally considered 10% (i.e. 5% from all sides). The Text Safe margins are 20% (10% from all sides).

You should take this into account while shooting the video. Usually the camcorder's LCD screen is set to similar overscan most TVs have. But you can also later pad the video to the TV safe area with MPEG Streamclip (see here how to process iMovie clips with 3rd party apps):

If you want to pad the video 10%, just set MPEG Streamclip to use a Zoom factor of 90% while exporting to DV. Then use this padded .dv to the iMovie and iDVD projects.

The "Interlaced Scaling" in MPEG Streamclip MUST be enabled in some circumstances. If you are scaling interlaced material to a different height, you must tell MPEG Streamclip to preserve interlacing and scale each video field separately by checking "Interlaced Scaling". If you don't, interlacing will be badly distorted in the scaled movie, and you get many visual artifacts. The alternative is to enable "Deinterlace Video". On the other hand, using "Interlaced Scaling" with progressive movies isn't recommended because it produces a little quality loss (blurring). But if the video contains interlaced AND progressive material you must enable "Interlaced Scaling" because interlacing artifacts are much more readily seen than the slight blurring in the progressive part of the material.

BTW, iDVD 5 pads 20% of the image (10% from all sides), when it is set to output TV safe slideshows (via iDVD/Preferences/Slideshow/Always scale slides to TV Safe area). This iDVD setting affects only slideshows, not video. If you want the same padding for video, just set MPEG Streamclip to use a Zoom factor of 80%.

Q: I have a tiny 320x240 square pixel video clip that I want to convert to DV in its original size (such a tiny resolution may look bad if upsampled to fill the larger PAL/NTSC 720x576/480 matrix).

A: Do the padding by using a suitable Zoom % value in MPEG Streamclip while exporting to PAL/NTSC DV. You can calculate this via the vertical resolutions ratios: with PAL you can use Zoom factor of 42% [=(240/576)*100] and with NTSC 50% [=(240/480)*100].

(The padding could also be done via masks with QuickTime Player (see here, here and here), but using MPEG Streamclip could be easier for most people and it also automatically preserves the correct aspect ratio when converting square pixels to rectangular and vice versa).

  • How can I rotate video (and preserve aspect ratio and interlacing) [back to Contents]

- Q: I have vertical, square pixel progressive video from a still image camera. When I import it to iMovie, the clip is stretched horizontally. How can I maintain the correct aspect ratio?

- Q: How can I rotate rectangular pixel DV material 90° while maintaining the correct aspect ratio and interlacing?

Open the video with MPEG Streamclip (see here how to process iMovie clips). Then export via File/Export to DV... with Compression: DV (DV25) and Standard: PAL/NTSC. In the "Rotation" options you can choose to rotate the picture by 90°, 180° and/or flip (mirror) it. For 90° rotation, aspect ratio and scale factor will be preserved, resulting in a cropped and letterboxed picture. With 4:3 pictures you can then apply a 133.3% zoom to remove letterboxing, or a 75% zoom to get the full frame without cropping. Interlacing will be preserved if "Interlaced Scaling" is enabled.

Other tools:

...it is also possible to use iMovie HD's Mirror effect to mirror video: Select the clip, click the Effects tab and choose Mirror. Slide the Horizontal slider all the way to the Right and Apply the Effect. Or open the DV clip in QuickTime Player Pro 7 and mirror it (via Window/Show Movie Properties/Video Track/Visual Settings/Flip_Rotate). Then do a File/Export.../Movie to DV Stream/DV-PAL or NTSC, 48.000 kHz. Both methods work for interlaced material.

...it is also possible to use iMovie HD's Mirror effect to turn the video upside down: Select the clip, click the Effects tab, choose Mirror. Slide the Vertical slider all the way to the "Bottom" side and Apply the Effect. Sadly this iMovie HD Effect works properly only with progressive material -- with interlaced material the field order gets wrong and the output motion flickers badly on a TV.

...it is possible to do the rotation in the QuickTime Player Pro by adding a 4:3 mask to the clip (see here, here and here), but using MPEG Streamclip as described above is easier and it is also more flexible. There is also a free cf/x turn clip iMovie plug-in, but it has some limitations: It doesn't properly work with interlaced input because also the interlacing lines are simply rotated and this doesn't look good on a TV! So you should use it only for progressive material or deinterlace the input. It can't rotate the material without cropping and it doesn't preserve the correct aspect ratio when rotating rectangular pixels.

Why was interlacing invented? The image on an old CRT (cathode ray tube) TV decays very quickly, and scanning at a low frequency like 25/30 Hz produces noticeable flicker and tires the eyes quickly. A scan rate of at least 50Hz is required for comfortable viewing, with 80Hz or more being preferable. This mismatch could be solved by displaying the signal at a higher scan rate than its frame rate, but that would require using a frame buffer, a method that did not become feasible until the 1980s. Therefore, the interlacing method was adopted. Instead of displaying a sequence of frames, the screen displays a sequence of "fields". One field contains only the odd-numbered lines (forming the odd field), and the next contains only even-numbered lines (forming the even field). Because of persistence of vision, pairs of fields are perceived at the same time, giving the appearance of a full frame. Interlacing reduces the required bandwidth in half, without losing vertical resolution in quiet areas (in motion areas you don't notice very much anyway, because it's moving 50/60 times per second).

So interlacing is a way to display the nonmoving parts with full resolution and the moving parts with half resolution, but fluidly. It's a very clever way to cut bandwidth without sacrificing much quality. Interlaced material has smoother motion on an interlaced TV compared to deinterlaced/progressive material.

Progressive scan is used in computer monitors. It is also becoming increasingly common in high-end television equipment, which is often capable of performing deinterlacing so that interlaced video can still be viewed. Advantages of progressive scan include: 1. Subjectively increased vertical resolution. The perceived vertical resolution of an interlaced image is usually equivalent to multiplying the active lines by about 0.6. This explains, for example, why HDTV standards such as 1080i (1440x1080, interlaced) in most cases deliver a poorer subjective quality than 720p (1280x720, progressive). 2. No flickering of narrow horizontal patterns. 3. Simpler video processing equipment. 4. Easier compression.

A computer monitor is a progressive device so the best way to evaluate interlacing is to watch the video on an interlaced 50Hz PAL or 60Hz NTSC TV. Make sure that the DVD player or some other video source isn't set for progressive playback. New flat panel LCD or plasma TVs may also default to progressive display so consult its manual whether interlaced output is possible. AFAIK the 100Hz PAL TVs deinterlace the displayed image so you may not be able to properly judge interlacing using them. I recently bought a new TV and avoided the 100Hz models because although they don't flicker, they may produce irritating artifacts to the image.

You can check whether the material is interlaced or progressive and look for flaws in interlacing also on a computer monitor:

Many computer applications have deinterlaced playback by default so that the average user doesn't get upset about the comb lines. To evaluate interlacing you must set the playback quality to display the video fields (i.e. those comb lines in motion scenes).

With .dv or .mov clips you can use QuickTime Player Pro:

Open the clip in QuickTime Player Pro. By default QuickTime Player has low quality deinterlaced playback of DV-encoded clips -- you have to turn on high quality playback of the clip to see all quality. In QT 7 you do this via enabling "Window/Show Movie Properties/Video Track/Visual Settings/High Quality" setting -- do not enable "Single Field" or "Deinterlace" because they deinterlace playback. You can also set "QuickTime Player 7/Preferences.../General/Use high quality video setting when available" to check the "High Quality" box by default (notice that the "Single Field" or "Deinterlace" boxes may have been saved to the file so sometimes you must take care to uncheck them).

With MPEG/VOB/DVD clips I usually do not use QT Player because it has a nasty feature to imitate 4:3 aspect ratio in MPEG files. This is bad in PAL because 720x576 is automatically scaled to 720x540 -- this distorts interlacing because the image is vertically scaled (in NTSC it is horizontally scaled from 720x480 to 640x480 so this doesn't affect the interlacing appearance). I could prevent the distortion by scaling the MPEG display to the native resolution in QT Player but instead I use MPEG Streamclip which shows the MPEG/VOB clips pixel for pixel after the "Window/Resize to Full Frame" command is used.

Then look closely at the interlacing pattern in moving scenes: the interlacing comb lines should be evenly and "beautifully" arranged. If you don't see comb lines in moving scenes the material is progressive. Some encoding applications may distort the interlacing pattern and this is guaranteed to show in motion scenes when watched on a TV. Sometimes interlacing distortion is difficult to spot on a computer monitor but deinterlacing first the other and then the other field off will usually reveal this (you can do this by copying a frame to apps like GraphicConverter and deinterlacing it there via Effect/Even Field Lines and Odd Field Lines or some equivalent command).

Now, the interlacing might look even and OK on a computer monitor but some apps may put the fields into wrong order. Spotting this wrong field dominance (see also here) is difficult on a computer monitor so I always check it via an interlaced 50Hz PAL or 60Hz NTSC TV when testing video applications. The wrong field dominance produces a dreadful zigzag effect on a TV so it is very easy to see.

Viewing the final output on a TV will best reveal interlacing problems but even then some users might have trouble seeing whether the material is interlaced or progressive to begin with. I have a 1 minute test clip that I'm VERY familiar with. It consists of smooth camcorder pans and I can readily tell if some issue in the workflow has made the material progressive because then the pans are not smooth but get that jerky progressive "film" look.

So the existence of interlacing is more readily seen on a computer monitor by those comb lines in moving scenes but the field dominance is best to evaluate on a TV.

BTW, field dominance is actually an incorrect term; it should be Field Order instead. Top First is the Upper, Odd field, field 1, the first line of the scan, which is actually half a line, the equivalent of upper. Bottom First is the Lower, Even field, field 2, the second line, actually the first full line, and the equivalent of lower.

DV material is bottom field first. HDV is top field first. A DVD can be either way: iDVD uses bottom field first but commercial DVDs are often top field first. So there is a chance that the field dominance can sometimes be incorrect if the DV editing and DVD encoding applications don't properly take care of it.

Notice that a slow camcorder shutter speed will essentially produce progressive video (so PAL 1/25s or NTSC 1/30s or slower shutter speeds yield progressive video) because both video fields are temporally the same.

(Notice also that, as a QT bug, sometimes the playback quality setting of the input file can determine the output quality. For example: If you have .dv clip whose playback quality is set for deinterlacing (or field blending) AND it is scaled from its native resolution, and you export it as .dv via QT Player Pro, THEN the exported video is deinterlaced (or the fields are blended). iMovie HD's reference movie is such an example, so make sure the 3rd party MPEG encoder you are using doesn't deinterlace the output footage behind your back! Sometimes only the deinterlaced playback setting of the input file is needed to trigger the unwanted deinterlacing of the output file. These kinds of things shouldn't happen so beware!).

Sometimes you might want to deinterlace video. You can deinterlace iMovie HD projects and other clips with JES Deinterlacer:

If you want to render the whole iMovie HD timeline movie, you save time and harddisk space by using iMovie's tiny reference movie as an input: Quit iMovie and open JES Deinterlacer. Open its Input tab, press "Choose...", navigate to the iMovie_project/Cache/Timeline Movie.mov and select it as an input.

You can export selected continuous iMovie HD clips as a standalone .dv file via iMovie's File/Share.../QuickTime/Full Quality -command and use the .dv file as an input for JES Deinterlacer. This is also a safer way because sometimes using the reference movie as an input may be produce errors.

In JES Deinterlacer select Project/Deinterlace. Choose the output format via Output/Export/DV Stream... (the right video standard should be selected automatically). Select the output folder via Output/Put... Click Output/OK to start the conversion. All the other settings can be at their defaults.

Notice that JES Deinterlacer may stall if it is hidden (via Hide Others command, for example) so avoid doing that when it is active. If JES Deinterlacer acts up, you may need to quit JES Deinterlacer and delete its preference and log files (~/Library/Preferences/JES Deinterlacer Prefs and nl.jes.deinterlacer.plist and ~/Library/Logs/JES Deinterlacer log). Then log out/in and try again.

Also MPEG Streamclip can deinterlace DV, MOV, MPEG, AVI, MP4, H.264 etc (MPEG1/2 is not an output option, and only some movies can be saved as MP4 or AVI).

There is a small difference in the deinterlaced output between JES Deinterlacer and MPEG Streamclip so do a test and decide which you like better.

Other interlacing-related stuff:

Q: How can I do interlaced animations?

A: Make progressive animation at PAL/NTSC 50/59.94 fps, then reinterlace with JES Deinterlacer to get a 25/29.97 fps interlaced version for TV. Open the progressive and double frame rate video with JES Deinterlacer and choose: Input tab/Progressive (in), and Project tab/Reinterlace/Defaults. Then choose Output tab/Export/DV Stream.../DV, PAL or NTSC and 48 kHz -- this re-combines the video fields back into a single frame with normal frame rate!

Q: How can I change field dominance of a .dv clip from top field first to bottom field first? DV uses only bottom field first so top field first video flickers badly on a TV.

A: Open the .dv clip with JES Deinterlacer: Input tab/check "Top field first (in)", Project tab/Change field dominance, Output tab/Export/DV Stream.../DV, PAL or NTSC, 48.000 kHz. (BTW, here is another route to turn interlaced material upside down (the result is identical to that in the previous paragraph): 1. Open the clip in JES Deinterlacer and choose: Input tab/uncheck "Top field first (in)" -- i.e. use the Defaults for that pane, Project tab/Change field dominance, Output tab/Direct/DV-PAL or DV-NTSC. 2. THEN turn the clip upside down with QuickTime Player Pro, and choose: File/Export.../Movie to DV Stream/Options.../DV, PAL or NTSC, 48.000 kHz.)

Standard definition video (DV and DVD) uses rectangular pixels. On the other hand, the computer display uses square pixels. To further complicate the matter, for historical reasons there is some "extra room" around the actual video frame. That is a mess that produces all kinds of errors when people try to calculate the aspect ratios! Read all about it here. A short summary:

The sampling matrix of standard definition NTSC DV is 720x480. Notice that inside (and outside!) of it the actual active picture size is 710.85x486. Weird but true.

Standard definition DV uses rectangular pixels -- the pixel aspect ratio for NTSC is 4320:4739 = ~0.912. So the pixels aren't square and you have to scale the image to see the correct proportions. iMovie and a TV set do this automatically but sometimes the poor user might see an unscaled image and think something is seriously wrong...

Now, to see the correct proportions you have to scale rectangular pixels to square pixels. You do that by multiplying the horizontal pixel count by the pixel aspect ratio:

So the NTSC square pixel horizontal sampling matrix becomes 720 x (4320:4739) = ~656.

So you should scale 4:3 NTSC 720x480 rectangular pixel sampling matrix to 656x480 square pixels to see the correct proportions on a computer monitor (many applications cheat and scale to 640x480 but luckily the error is so small that it goes unnoticed unless looked for).

The same calculation applies also to the NTSC actual active picture size: 710.85 x (4320:4739) = 648.

So the NTSC rectangular pixel actual active picture size 710.85x486 corresponds 648x486 square pixels which is EXACTLY 4:3!! THAT is the 4:3 ratio we talk about!

The same applies to PAL, too. For PAL DV the sampling matrix is 720x576, but the actual active picture size is 702x576. The pixel aspect ratio is 128:117 = ~1.094 for both.

So you should scale 4:3 PAL 720x576 rectangular pixel sampling matrix to 788x576 square pixels to see the correct proportions on a computer monitor (many applications cheat and scale to 768x576 but luckily the error is so small that it goes unnoticed unless looked for).

The same calculation applies also to the PAL actual active picture size: 702 x (128:117) = 768.

So the PAL rectangular pixel actual active picture size 702x576 corresponds 768x576 square pixels which is EXACTLY 4:3!! THAT is the 4:3 ratio we talk about!

The same principles apply to 16:9 widescreen, too. Just remember that 4:3 and 16:9 material use the same resolution (NTSC 720x480 or PAL 720x576 sampling matrix) -- they are just scaled differently for display. For the 16:9 calculations you have to multiply the 4:3 figures by (16:9):(4:3) = 4:3 = ~1.33:

So with 16:9 NTSC the actual active square pixel picture size is 864x486; i.e. 16:9 -- THAT is the 16:9 ratio we talk about!

So you should scale 16:9 NTSC 720x480 sampling matrix to 875x480 square pixels to see the correct proportions on a computer monitor.

With 16:9 square pixel PAL the actual active picture size is 1024x576; i.e. 16:9 -- THAT is the 16:9 ratio we talk about!

So you should scale 16:9 PAL 720x576 sampling matrix to 1050x576 square pixels to see the correct proportions on a computer monitor.

Now, didn't all that make sense! ;-)

A quick note about HDV (see also here and here):

The sampling matrix of HDV 1080i is 1440x1080, and its pixel aspect ratio is 4:3 = ~1.33, so for square pixel display it must scaled to 1920x1080.

The sampling matrix of HDV 720p is 1280x720, and its pixel aspect ratio is 1:1 so it uses square pixels.

Besides MPEG-encoding, MPEG2 Works and ffmpegX have also many (XS)SVCD and DVD tools for getting MPEG info, multiplexing, demultiplexing, audio processing and authoring.

mpgtx GUI (based on the mpgtx command line tool) shows MPEG info and splits, joins and demuxes MPEG 1/2/3.

MoreMissingTools has many MPEG tools with a spartan GUI interface.

DVD Imager can be used to make a burnable DVD video image file from a VIDEO_TS folder. You can then create a new DVD disk using the Burn command in Disk Copy. DVD Imager is an Applescript Studio GUI wrapper for Jörg Schilling's mkisofs binary executable.

myDVDEdit can change the DVD's aspect option from 4:3 to 16:9 auto letterbox. Basically it's IFOedit on your Mac. You can use it to set the aspect flag on a DVD VIDEO_TS folder, among many other features. Now iDVD 4 and Toast users can set the flag for 16:9 before you burn the DVD and it will play at 16:9 on the set-top players.

Digigami Mpressionist.X ($1000) can analyze MPEG and report peaks in bitrate and quantization as well as many other details. Also Digigami MegaPEG.X ($240) can show the bitrate and quantization. A cheaper alternative is Bitrate Viewer ($0 or $30) which runs OK in Virtual PC. MacDVDBitrateParanoia can show the bitrate graph of an authored DVD.

JAW MPEG2Splitter ($15) lets you split huge MPEG-2 (video stream only, i.e. the .m2v kind) files in smaller chunks of size specified by user. It is also possible to extract a single segment of the file, given the starting and ending offset. The procedure can be fully manual, assisted, or fully automated.

Some iMovie and iDVD fixes and resources: how to fix a corrupted iMovie project file, file fixers for lost TYPE and CREATOR codes for iMovie project files after they have been stored on non-HFS+ a.k.a. Mac OS Extended volumes, iMovie FAQ, iDVD FAQ, iMovie 4 bugs, iMovie HD 5 bugs, iMovie HD 6 bugs and iMovie - The Missing Manual. iDVD 5 sets some bits in the widescreen .IFO and .BUP files incorrectly -- this link explains the workaround. iDVD 3 added chapter support, but it originally worked only with chapters generated in iMovie (not chapters created from scratch in QuickTime Player, for example) -- this link explains the geeky stuff behind this behaviour. Metadata Hootenanny is a viewer/editor for all the spiffy metadata you can put into QuickTime movies. Among other things, v1.1.5 lets you add or edit Chapter Tracks, which are a cool little feature of the QuickTime container format that is seldom used.

JES Deinterlacer is a very nice deinterlacer. It is also a very good quality PAL<->NTSC converter for QuickTime files. It can also do "bob" deinterlacing, i.e. convert both fields in an interlaced video frame into two separate frames so you can duplicate the framerate or get a slow-motion effect. Features: deinterlace movies (half height, normal height, double frame rate, blend). Change field dominance. Trim, shift, simple color correction. Change encoding (RGB gamma, video range, full range). Fix jagged edges. Carbon application for Mac OS 9.2.2 and Mac OS X.

iMovie FAQ - Smooth Slow Motion <http://www.danslagle.com/mac/iMovie/tips_tricks/6016.shtml>

Oak Street Software has a handy AppleScript that can automatically split DV clips into smaller 9 minute chunks which iMovie 1-4 can handle. You can edit the script to other durations. The script works otherwise OK but it seems the Mov2DVparts script currently drops a frame at every split seam except the very first seam. Unfortunately the script no longer works with QuickTime 7. Update: MovieSplit replaces Mov2DVparts, and it does work with Quicktime 7 and should also work with 5 or 6. The old Mov2DVparts is still included for users of older versions of Quicktime, although MovieSplit is faster, because it only splits the movie, it does not convert to DV stream. (I haven't yet had time to evaluate the updated script).

Notice that 1 B = 8 b (i.e. 1 byte = 8 bits), 1 Mb = 1024 kb, 1 kb = 1024 b and so on. Notice also that for data rates the multiplier is usually 1000 instead of 1024, so 1 Mb/s = 1000 kb/s, 1 kb/s = 1000 b/s and so on. For example: mpeg2enc uses 1000 as a multiplier in its settings so when you enter 2500 kb/s in its settings, then 2500000 b/s is used (= 2441 kb/s if 1024 was used as a multiplier). You can also use the Bit Calculator.


DVD example:

The following formula calculates the video bitrate to use to fill up a DVD disc based on the selected audio bitrate:

Video Rate [in bps] = (598566666 / Time [in minutes]) - Audio Rate [in bps]

For example, assuming a 90 minute video with 192 kb/s audio:

Video Rate = 598566666/90 - 192000 = 6650741 - 192000 = 6458741 b/s = 6459 kb/s.

In this case, allowing about 5% headroom for authoring a simple title, a 6000 kb/s average video bitrate would nearly fill the DVD. For the maximum bitrate, try 8500 kb/s, which is about 50% above the average bitrate setting and will produce good balanced results throughout the video.

Uncompressed PCM audio is 1536 kb/s [(48000 samples/s) x (16 bits/sample) x (2 channels)] so it is 8x larger than 192 kb/s compressed audio! For example: with PCM audio the video bitrate must be dropped to ~6000 kb/s @ 80 minutes, while with 192 kb/s compressed audio the corresponding length is 95 minutes.

Or in other words:

As a general guideline you can use this checklist when choosing a bitrate for a DVD:

Total size of a DVD disk = 4700000000 B (this equals ~4482 MB or ~4.4 GB with 1024 as the multiplier).

Subtract 5% (= 235000000 B) as a reserve for .ifo, .bup, and UDF info.

Subtract audio. With 192 kb/s .m1a audio this is 1440000 B/minute and 129600000 B/90 minutes (1000 as the multiplier).

Subtract the still menus; about 100000 B/menu.

For example, assuming a 90 minute video with 192 kb/s audio and 3 menus:

4700000000 - 235000000 - 129600000 - 300000 = 4335100000 B

That is equal to:

4335100000 B / 90 min = 802796 B/s = 6422370 b/s = 6422 kb/s (1000 as the multiplier).

So you can use about 6422 kb/s to encode the video.

If you have motion menus, transitions, and so on then they take up space that needs to be taken into account, too.


(XS)VCD example is slightly different because the disk is burned in a different format:

1x audio-CD speed is 75 sectors/s so a 80 minute audio-CD has 80 min * 60 s/min * 75 sectors/s = 360000 sectors (and a 74 minute CD has 333000 sectors).

SVCD data is stored on a CD-ROM XA "Mode 2-Form 2 block" format with 2352 B sector size. 2324 B of a sector is used for the actual MPEG2-data, and the remaining 28 B is used for minor error detection etc.

So a 80 minute CD holds 360000 sectors * 2324 B/sector = 836640000 B / (1024 * 1024) B/MB = ~797.9 MB of MPEG2 data. Likewise, a 74 minute CD holds ~738.0 MB of MPEG2 data.

(The same way a 80 or 74 minute audio CD which uses the whole 2352 B sector for audio data holds as much as ~807.5 or ~746.9 MB of audio data. On the other hand, a computer data CD uses only 2048 B of a 2352 B sector for data so a 80 or 74 minute CD holds only ~703.1 or ~650.4 MB data because more space of a sector is used for error correction etc).

A SVCD needs some overhead for non-MPEG2 data. You can calculate the overhead in sectors by (number_of_non_ISO_tracks * 150) + 450. For example: with 5 MPEG2s the overhead is (5 * 150) + 450 = 1200 sectors / (75 sectors/s) = 16 seconds (with 2352 B sector size). (Possible segment items and application data, if any, go into the ISO track and take up an additional total_ISO_data B : 2048 B/sector).

The maximum sector rate for the SVCD is 2x, so the maximum speed for the MPEG2-data is 2 x 75 sectors/s = 150 sectors/s = 150 sectors/s * 2324 B/sector = 348600 B/s = 2788800 b/s = 2723,4375 kb/s. This is the maximum _total_ (video + audio + 1-2% muxing mplex overhead + possible padding) MPEG2 bitrate.

So the maximum bitrate for a SVCD's MPEG2's video is 2691 kb/s (with the minimum 32 kb/s for audio). An audio bitrate of 224 kb/s leaves a maximum of 2499 kb/s for video. Audio bitrate can be 32-384 kb/s. Deviating from these values may produce disks that play poorly on some DVD players, especially if the video bitrate is other than about 2500 kb/s. Notice that actually the maximum standard SVCD video bitrate (mpeg2enc -f 4) is precisely 2500000 b/s = 2441 kb/s.

To _roughly_ figure out which video bitrate you should use to fit 60 minutes of SVCD on a 80 minute CD with 224 kb/s audio, you can use this equation:

(80 * 60 * 75 * 2324 * 8 / 1024 / 60 / 60) - 224 = 1592 kb/s, or more briefly:

(80 * 43575 / 32 / 60) - 224 = 1592 kb/s.

Or to fit 60 minutes of SVCD on a 80 minute CD with 128 kb/s audio:

(80 * 43575 / 32 / 60) - 128 = 1688 kb/s for video, which may be a better combination with low bitrates.

There is also a 1-2% mplex overhead so you may want to divide the calculated video bitrate by 1.01-1.02.

That kb/s should be the correct number to use with -b in mpeg2enc with constant bitrate (omitting -q from mpeg2enc sets CBR). Notice that this calculation only works if you have a CBR stream. If you have a variable bit rate VBR MPEG1/2 or SVCD, your calculation will always be wrong because currently you cannot determine the final size of a VBR stream (-q sets VBR in mpeg2enc). Maybe a 2-pass VBR option in mpeg2enc will make this possible in the future. With VBR the output size depends heavily on the material (fast or slow moving) and on the quality of the material.

So at the moment it is usually best to encode parts of a video as single streams (1st part from the beginning to the first commercials, 2nd from that commercials to the next commercials and so on, for example). If in the end the whole video doesn't evenly fit on a given amount of CDs, you have to reencode only one or a few sections with other bitrates or just drop the audio bitrate. You may also specify the MB where the stream is marked for splitting in mpeg2enc settings.

Bitrate Calculator <http://www.videohelp.com/calc>


More info about (XS)VCD and DVD [back to Contents]

RNC's great SVCD pages <http://homepage.mac.com/rnc/>

There is a nice page describing Digital Video Resolution and Aspect Ratio Conversions. The low-resolution XSVCD and CVD scaling and cropping values were calculated using this info:

A Quick Guide to Digital Video Resolution and Aspect Ratio Conversions <http://www.iki.fi/znark/video/conversion/>

This BBC link is also very helpful in understanding rectangular and square pixels.

VideoHelp Mac video forum <http://www.videohelp.com/forum/viewforum.php?f=9>

VCDImager <http://www.vcdimager.org/>

MediaPipe forum <http://mediapipe.sourceforge.net/Forum/>

DiVA forum <http://forums.3ivx.com/>

Acknowledgements: [back to Contents]

First Paul Hagstrom et al and then RNC prompted me to explore SVCD in a time when SVCD tools for the Mac were still rare. Their pioneering efforts have benefited us all.

Paul Hagstrom: VCD subpage <http://www.bu.edu/linguistics/UG/hagstrom/vcd.html>

-end-

vcd_on_mac.txt · Last modified: 2007/06/07 12:42 by nik