[mythtv-commits] Ticket #4535: mytharchive encodes multiple audio streams to mpeg2 incorrectly
MythTV
mythtv at cvs.mythtv.org
Sat Jan 26 11:02:04 UTC 2008
#4535: mytharchive encodes multiple audio streams to mpeg2 incorrectly
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Reporter: thrantastic at gmail.com | Owner: paulh
Type: patch | Status: new
Priority: minor | Milestone: unknown
Component: mytharchive | Version: head
Severity: low | Mlocked: 0
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I recently exported a recording with 2 audio streams and they ended up
getting switched around (as it seems mythtranscode is wont to do from time
to time). Upon further investigation, however, it seemed that mytharchive
was selecting the correct streams in the right order when encoding, but
they were still coming out wrong when the file was demuxed and then
remuxed.
Finally I discovered that ffmpeg was not mapping the streams as requested
by mythburn.py because it was being called with slightly incorrect
arguments. Multiple audio streams being added with ffmpeg requires
multiple -acodec, -ab, etc. switches, one for each stream. Mythburn.py was
not doing this, so ffmpeg did not re-order the streams as requested, and
in fact was transcoding the wrong one to ac3 which is why it got chosen
during the demuxing/remuxing process.
I have attached a patch that correctly adds the audio switches for a
second audio stream. It duplicates the parameters being used for the first
stream, so no changes are needed to the encoding profiles. This patch was
successful in exporting the troublesome file I mentioned earlier and
doesn't seem to have broken anything, but it has not received much testing
beyond that.
--
Ticket URL: <http://svn.mythtv.org/trac/ticket/4535>
MythTV <http://svn.mythtv.org/trac>
MythTV
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