[MPlayer-dev-eng] Re: [PATCH] don't skip first mp3 frame

[Reimar Döffinger]

Hi,

> > > > > > > i downloaded the broken-first-frame.mp3 and tested it,
> > > > > > > apparently the starting position skips the header if it
> > > > > > > doesn't start at the beginning of the file. it then searches
> > > > > > > for the next header data(which in this case, it finds what it
> > > > > > > thinks is a frame header inside the audio data of first frame
> > > > > > > which is why it incorrectly detects it as 48000)
> > > > > > > 
> > > > > > > anyways here is a revised patch, plays the mp3 fine now
> > > > > > > 
> > > > > > > Nehal
> > > > 
> > > > My mp3-detection patch should have fixed that. ad_mp3lib.c still skips
> > > > the first frame, but this seems to be intented.?
> > > 
> > > if it does, it's a bad/broken intention. frames should never be
> > > skipped.
> > 
> > See libmpcodecs/ad_mp3lib.c, line 49. I think there were/are some broken
> > MP3 encoders that create only trash for the first frame or something
> > like that...
> 
> no, the idiotic demuxer was starting at the wrong place in the file
> making the decoder see the wrong data as the "first frame"... there's
> no other decoder that has to discard the first frame when playing
> mp3s, so mplayer shouldn't have to do it either...

So the questions is: Does the demuxer now work correctly? Should this be
removed?

Greetings,
Reimar Döffinger