[libav-devel] [PATCH] mp3: fix start band index for block type 2 in 8kHz audio

Kostya Shishkov kostya.shishkov at gmail.com
Wed May 16 19:56:56 CEST 2012


On Wed, May 16, 2012 at 01:33:12PM -0400, Sean McGovern wrote:
> On Wednesday, May 16, 2012, Kostya Shishkov <kostya.shishkov at gmail.com>
> wrote:
> > In hybrid frames long window part ends at 36 samples for most of the cases
> > but at 72 for 8kHz case. For some reason decoder assumed it's 48 or even
> 36
> > samples, which caused wrong bitstream decoding for such blocks.
> >
> > l3_25207.mpg from conformance suite demonstrates it the best.
> > ---
> > As a side note, remaining distortion in that file is caused by incorrect
> > stereo reconstruction.
> >
> 
> Hi Kostya,
> 
> Does this have an associated test?
> 
> If not, can/should we add one?

Of course it doesn't but it's easy to add.
http://streams.videolan.org/Mpeg_Conformance/ftp.iis.fhg.de/ contains lots of
short streams that should cover every aspect of MP3 decoder.
But let's admit it - nobody cares.


More information about the libav-devel mailing list