[mythtv-users] DVB to DVD

Ian Trider iantri at gmail.com
Sat Apr 2 20:28:10 UTC 2005


On Apr 2, 2005 7:23 AM, Tom Hughes <tom at compton.nu> wrote:
> Is there any way of converting a DVB MPEG stream to a DVD MPEG stream
> without reencoding and without losing the audio sync information from
> the PTS data in the original stream? If I can also edit the stream to
> remove bits then that would be even better.
> 
> Everything I've seen says to use avidemux, but that doesn't seem to
> want to open a DVB PS stream, any every way I've found to convert
> the PS stream to something it can open seems to involved reencoding
> and/or loss of audio sync.

A bit of background for those who don't know:

System-type MPEG streams contain timing information ("PTS data") that
aligns the video and audio.  In the event of adverse events; i.e.
frame drops or reception problems, everything should keep on going in
sync perfectly, because the data stream correlates audio to video.

That said, you probably won't be able to use DVB MPEG-2 video on DVD
without reencoding anyway, since (most) DVB broadcasts are not in a
DVD-Compliant format, that being {352,704,720}x480, 9.8mbit max
(combined audio and video), audio being 48khz PCM, AC3, or Mpeg Layer
II (technically only in PAL players).  Replace 480 with 576 in PAL
countries.  Some DVD players will take non-compliant formats if the
video file is patched to indicate it is a compliant resolution, but
this is a Bad Idea(TM) since it won't work on many players.

To the best of my knowledge, you can't transform DVB PS to DVD PS 
anyway without demuxing to seperate audio and video streams.

To keep the audio in sync, you are going to need software that is
simply not available in Linux. If you want to just demux the streams
and end up with synced audio and video, you can use PVAStrumento in
Windows, which is free -- it, based on the PTS data, calculates how
many audio or video frames it must drop or add to keep everything
proper.  From here you can reencode to a DVD-compliant format.

If you want to cut sections from the file, VideoRedo is an MPEG2
editor that does this while performing the same corrections as
PVAStrumento (but, IMHO, does a better/more seamless job).  It is
shareware, USD$59 I think.  It does the header patching trick as well,
I believe, but again, you'll probably need to reencode anyway.

You might be able to get PVAStrumento to work in WINE, I don't know.
-- 
Ian Trider
iantri at gmail.com


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