[Ffmpeg-devel][PATCH] Possible bug in bmp decoder

[Diego Biurrun]

On Mon, Jan 29, 2007 at 11:32:13PM +0000, M?ns Rullg?rd wrote:
> Michael Niedermayer <michaelni at gmx.at> writes:
> 
> > On Mon, Jan 29, 2007 at 03:05:17PM +0100, Michel Bardiaux wrote:
> >> Reimar Doeffinger wrote:
> >> >On Mon, Jan 29, 2007 at 02:18:47PM +0100, Michel Bardiaux wrote:
> >> >>Alex Beregszaszi wrote:
> >> >>>>...
> >> >>>>    switch(depth){
> >> >>>>    case 24:
> >> >>>>        for(i = 0; i < avctx->height; i++){
> >> >>>>            memcpy(ptr, buf, n);
> >> >>>>            buf += n;
> >> >>>>            ptr += linesize;
> >> >>>>        }
> >> >>>>        break;
> >> >>>>...
> >> >>>>
> >> >>>>Should it not be memcpy(ptr, buf, linesize) ?
> >> >>>n probably means input linesize, while linesize is the output linesize.
> >> >>Yes.
> >> >>
> >> >>>I guess 24bit BMP doesnt stores the padding 1 byte.
> >> >>Actually it does, see
> >> >>
> >> >>    /* Line size in file multiple of 4 */
> >> >>    n = (avctx->width * (depth / 8) + 3) & ~3;
> >> >>
> >> >>and that's why I am suspicious.
> >> >
> >> >Neither is right, avctx->width * (depth >> 3) is the right value.
> >> 
> >> Yes. Patch attached.
> >
> > looks ok assuming mans has no objections
> 
> Fine by me, assuming it is correct.  I don't have any specs or samples
> at hand.

Somebody provide me with a proper commit message and I'll apply this
patch.

Diego