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

[D Richard Felker III]

On Wed, Oct 20, 2004 at 10:15:10PM +0200, Reimar Döffinger wrote:
> 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...

rich