RepoMirrors/ffmpeg
1
0
Fork 0
mirror of https://git.ffmpeg.org/ffmpeg.git synced 2024-12-18 13:35:13 +00:00
Code Issues Projects Releases Wiki Activity

ape: Unbreak adaptcoeffs computation

Browse Source 
And simplify and explain the expression.

Fault introduced in f3fdef108e

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
This commit is contained in:
Luca Barbato 2016-04-21 16:09:38 +02:00 committed by Derek Buitenhuis
parent 5b9a4476e3
commit dd4fb2339f
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
libavcodec/apedec.c
View File

@ -1284,8 +1284,16 @@ static void do_apply_filter(APEContext *ctx, int version, APEFilter *f,
/* Update the adaption coefficients */ /* Update the adaption coefficients */
absres = FFABS(res); absres = FFABS(res);
if (absres) if (absres)
*f->adaptcoeffs = ((res & INT32_MIN) ^ ((~0UL) << 30)) >> *f->adaptcoeffs = APESIGN(res) *
(25 + (absres <= f->avg*3) + (absres <= f->avg*4/3)); (8 << ((absres > f->avg * 3) + (absres > f->avg * 4 / 3)));
/* equivalent to the following code
if (absres <= f->avg * 4 / 3)
*f->adaptcoeffs = APESIGN(res) * 8;
else if (absres <= f->avg * 3)
*f->adaptcoeffs = APESIGN(res) * 16;
else
*f->adaptcoeffs = APESIGN(res) * 32;
*/
else else
*f->adaptcoeffs = 0; *f->adaptcoeffs = 0;