From: Ronald S. Bultje Date: Tue, 24 Jul 2012 21:23:12 +0000 (+0000) Subject: vp8: Replace x*155/100 by x*101581>>16. X-Git-Tag: n1.1-dev~9^2~710 X-Git-Url: http://git.ffmpeg.org/gitweb/ffmpeg.git/commitdiff_plain/48098788c240f678222d45db79aff38f494f3df5 vp8: Replace x*155/100 by x*101581>>16. Idea stolen from webp (by Pascal Massimino) - because it's Cool. Signed-off-by: Derek Buitenhuis --- diff --git a/libavcodec/vp8.c b/libavcodec/vp8.c index d0e2a0c..a662f8a 100644 --- a/libavcodec/vp8.c +++ b/libavcodec/vp8.c @@ -249,12 +249,13 @@ static void get_quants(VP8Context *s) } else base_qi = yac_qi; - s->qmat[i].luma_qmul[0] = vp8_dc_qlookup[av_clip_uintp2(base_qi + ydc_delta , 7)]; - s->qmat[i].luma_qmul[1] = vp8_ac_qlookup[av_clip_uintp2(base_qi , 7)]; - s->qmat[i].luma_dc_qmul[0] = 2 * vp8_dc_qlookup[av_clip_uintp2(base_qi + y2dc_delta, 7)]; - s->qmat[i].luma_dc_qmul[1] = 155 * vp8_ac_qlookup[av_clip_uintp2(base_qi + y2ac_delta, 7)] / 100; - s->qmat[i].chroma_qmul[0] = vp8_dc_qlookup[av_clip_uintp2(base_qi + uvdc_delta, 7)]; - s->qmat[i].chroma_qmul[1] = vp8_ac_qlookup[av_clip_uintp2(base_qi + uvac_delta, 7)]; + s->qmat[i].luma_qmul[0] = vp8_dc_qlookup[av_clip_uintp2(base_qi + ydc_delta , 7)]; + s->qmat[i].luma_qmul[1] = vp8_ac_qlookup[av_clip_uintp2(base_qi , 7)]; + s->qmat[i].luma_dc_qmul[0] = 2 * vp8_dc_qlookup[av_clip_uintp2(base_qi + y2dc_delta, 7)]; + /* 101581>>16 is equivalent to 155/100 */ + s->qmat[i].luma_dc_qmul[1] = (101581 * vp8_ac_qlookup[av_clip_uintp2(base_qi + y2ac_delta, 7)]) >> 16; + s->qmat[i].chroma_qmul[0] = vp8_dc_qlookup[av_clip_uintp2(base_qi + uvdc_delta, 7)]; + s->qmat[i].chroma_qmul[1] = vp8_ac_qlookup[av_clip_uintp2(base_qi + uvac_delta, 7)]; s->qmat[i].luma_dc_qmul[1] = FFMAX(s->qmat[i].luma_dc_qmul[1], 8); s->qmat[i].chroma_qmul[0] = FFMIN(s->qmat[i].chroma_qmul[0], 132);