[H-GEN] CD Burner software

[Christopher Biggs]

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Paul Gearon <pag at PISoftware.com> moved upon the face of the 'Net and spake thusly:

> Well Chris made the perfectly good suggestions of transcode and mencoder.
> There's lots of others out there which provide more/less/different
> functionality to these (eg. mjpegtools).  Sourceforge is your friend in
> this.

Yeah, I forgot mjpegtools.    That suite is the only one mentioned so
far that is aimed toward *editing* video.   The others are really just
for playback and format conversion.

If you want to edit your video on disk, definitely give mjpegtools a
look.   There's also an editor/manipulator called "avidemux" which can
edit .AVI files in-place.

> But my reason for writing was to ask about the file formats you mention.
> AVI is a framework for encapsulating video and audio streams such that
> they can be played back together.  The video is often MPEG (either 1, 2 or
> 4) but may be other things.  The audio can be mp3, ac3, or several others.
> DivX is MPEG-4 video with MP3 audio... though the spec is a little loose.
> Anyway, AVI doesn't actually describe the type of video you have.

This is all correct.  The AVI format has better support for metadata
(oddball codec types, bitrates etc.) than the MPEG container format,
so it tends to get used even when the underlying video/audio streams
are all MPEG standard.    With an mpeg system stream you're pretty
much limited to the standard mpeg codecs.

The annoying part is that consumer-device (dvd player etc.) take-up of
the ability to play .avi format has been really slow (due to patents,
maybe?), so if you want to be portable, you need vanilla mpeg.

> The AVI from a video camera has a video stream which is a form of "Motion
> JPEG" (every frame is individually compressed as a seperate JPEG image).
> I can't remember the audio type (MP3?).  The MPEG files used by VCDs are a
> raw MPEG video stream (either MPEG-1 or MPEG-2), and a raw MPEG audio
> stream in a seperate file.  By their nature, the raw streams are seperate
> as they aren't in a multiplexing file (like AVI or Quicktime) to glue them
> together.

No, VCD is multiplexed into one stream.    

The multiplexing of video and audio into an "MPEG system stream" while
remaining within the contstraints of the VCD format is in my
experience the hardest thing about making VCDs.  Many of the
multiplexers assume your playback platform is a PC with semi-infinite
buffering capability, while most consumer VCD players have pitiful
buffer space and thus lose audio sync if the system stream is not
multiplexed *just* so.

> The conversion to raw MPEG streams for use with VCD tools, VCD imager, and
> their ilk, is easily found on the web pages for Transcode and Mjpegtools.
>
> http://mjpeg.sourceforge.net/
> http://www.theorie.physik.uni-goettingen.de/~ostreich/transcode/

One more point...for some reason it's really hard to go from
variable-bitrate (and even frame-rate!) streams like Real Media and
Quicktime to VCD, without losing audio sync.   Mplayer and transcode
seem to be rather poor at that.   

If anyone has had much luck with RM-to-VCD, I have a bunch of old
files "stuck" in RM format that I'd like to "rescue"....
(mencoder can theoretically do it, but audio sync is off by several
minutes at the end of a 30 minute clip).

--cjb


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