[MPlayer-dev-eng] [PATCH] fix mpg123 resync (for massive seeking)

[Ivan Kalvachev]

On 4/30/12, Thomas Orgis <thomas-forum at orgis.org> wrote:
> Hi,
>
> Ivan noticed that, on some files, wild seeking can provoke hangup of
> the mpg123 decoder. I tracked that down to mpg123_getformat()
> triggering premature parsing of the next frame which may have not
> been provided yet. I fixed the offending code in mpg123 for the upcoming
> release and also prepared attached patch that prevents this from the
> mplayer side.
>
> As a bonus, it actually simplifies the code by avoiding unnecessary
> calls to mpg123_getformat() --- 12 lines less, yay! ;-)
>
> Please test (Ivan with the special trigger video) and apply.

Patch committed.

The patch seems to work as advertised.
However sometimes I see some debug messages and parser errors. (no
audible artifacts or skips, it resumes normal play as it should)

We talked about the possibility of avi demuxer returning garbage,
that could confuse the mpg123 parser. In your investigation have you
found any clues if this might be true? Was mpg123_getformat() confused
by completely normal packages?

Is it possible that e.g. packets cut mp3 frames at strange places
(e.g. at half) and this causes the problems.

Best Regards