[MPlayer-dev-eng] [PATCH] problems with AAC decoding

[Dan Oscarsson]

When upgrading to current snapshot I detected that a previous playable
mpeg-ts-file with LATM/AAC now no loger worked and another that have
never worked, now did. It looks like you now try ffmpeg for AAC decoding
before internal faad. My analysis indicates that when ffmpeg decoding is
tried, it reads the audio data stream, and when it failes and faad is
tried the stream is not restarted so faad finds a header in a new place.
This is why (I think) a previously non-working file now works.

I found out that the ad_faad.c did not probe for LATM and that is why it
often failed to decode LATM/AAC from DVD-T TV-streams. Attached is a
patch for that. Now it tries to find a LATM header first and then the
other types of AAC headers. At least my tests show that it handles
LATM/AAC stream better than before. But due to ffmpeg is tried first and
does not restore audio stream to its starting point in case of failure,
you have to use -ac faad, to change the order so it can work.

I hope some of you who better understands how the audio decoder probing
is intended to work can fix so ffmpeg decoder can also be tried without
next decoder gets wrong position in audio stream to try its probes on.

   Dan


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