[Ffmpeg-devel] [PATCH] MS-GSM support: draft for review

[Michael Niedermayer]

Hi

On Mon, Nov 06, 2006 at 05:10:22PM +0100, Michel Bardiaux wrote:
> Michael Niedermayer wrote:
> >Hi
> >
> >On Mon, Nov 06, 2006 at 04:32:53PM +0100, Michel Bardiaux wrote:
> >>There are some pending issues:
> >>
> >>1. Still no configure control except --xable-libgsm. IMHO this is a 
> >>separate issue and can be done in a later patch.
> >>
> >>2. Whether the rename gsm to toastgsm is a good idea is very debatable.
> >
> >iam against the rename
> >
> >and the rename makes reviewing the changes below hard (ill wait for a
> >patch without that before ill review it)
> >
> >[...]
> 
> Ecco.

[...]
>  #define GSM_BLOCK_SIZE 33
> +#define MSGSM_BLOCK_SIZE 65
>  #define GSM_FRAME_SIZE 160
>  
> -static int libgsm_init(AVCodecContext *avctx) {
> +static int gsm_init(AVCodecContext *avctx) {

sensless rename, and the whole patch is full of these

also upon closer ispection the new "codec" seems to be the same as the old
except that 2 260bit (note not a multiple of 8) are packed together into one
65 byte packet instead of each padded to a multiple of 8 (=33 byte)
this is nasty, MS programmers should be shot for this
the solution is IMHO a AVParser which splits these packet pairs before the
gsm decoder

for encoding a AVBitstreamFilter could be written which merges 2 packets
together if encoding is needed

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is