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

[D Richard Felker III]

On Mon, Mar 22, 2004 at 10:24:59AM +0100, Alban Bedel wrote:
> Hi D Richard Felker III,
> 
> on Sun, 21 Mar 2004 22:04:49 -0500 you wrote:
> 
> > On Sun, Mar 21, 2004 at 06:07:50PM -0800, Nehal wrote:
> > > for some reason, the current code skips the first frame of 
> > > mp3 files (using any decoder), i'm assuming this is a bug 
> > > as i can't see any good reason for this.
> > 
> > It was added intentionally to avoid hearing pops at the beginning of
> > some files. Of course this is an incorrect, idiotic fix. 100l to
> > someone...
> 
> pops ?? lol it's really not the pb. Way too often the first
> frame is buggy and initialize mp3lib with totaly wrong parameters.
> So you end up playing at 11050Hz some nice 48000Hz, etc And that
> happend with a really significant amount of files :(((
> 
> A better fix is welcome ;) Anyway in betewen someone changed the
> ad_mp3lib to skip the first frame. So with mp3 files the first 2
> valid frames are skipped now.
> 
> > > this probably isn't noticeable with most files, but i have 
> > > a couple of test cases that have audible sound data in the 
> > > first frame. if someone wants, email me and i'll send you 
> > > the starting part of the files for testing purposes.
> > > 
> > > please apply the patch that i've attached
> > 
> > Please send a patch that fixes whatever bug is causing the first frame
> > to be decoded as a horrible pop in many files, and we'll gladly apply
> > this patch too.
> 
> I'll strongly advice a VERY EXTENSIVE testing (including loads of stuff
> encoded with old encoders) before renableing the decoding of the first
> frame.

All other apps handle it fine, so it must be a bug in MPlayer, not the
file. Maybe the first frame of the file is broken, but it's easy to
detect that it's broken and MPlayer just fails to detect that...

Rich