From 32fa7725d288dcbdb6997130f1ca6edbcad25e1a Mon Sep 17 00:00:00 2001 From: Alex Converse Date: Thu, 6 May 2010 20:18:36 +0000 Subject: [PATCH] Make the faac inspired quantizer search make sense for a slightly narrower definition of "make sense." Originally committed as revision 23035 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/aaccoder.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/libavcodec/aaccoder.c b/libavcodec/aaccoder.c index e19fa38..d30f854 100644 --- a/libavcodec/aaccoder.c +++ b/libavcodec/aaccoder.c @@ -763,7 +763,7 @@ static void search_for_quantizers_faac(AVCodecContext *avctx, AACEncContext *s, const float *scaled = s->scoefs + start; const int size = sce->ics.swb_sizes[g]; int scf, prev_scf, step; - int min_scf = 0, max_scf = 255; + int min_scf = -1, max_scf = 256; float curdiff; if (maxq[w*16+g] < 21.544) { sce->zeroes[w*16+g] = 1; @@ -797,21 +797,23 @@ static void search_for_quantizers_faac(AVCodecContext *avctx, AACEncContext *s, } prev_scf = scf; curdiff = fabsf(dist - uplim[w*16+g]); - if (curdiff == 0.0f) + if (curdiff <= 1.0f) step = 0; else - step = fabsf(log2(curdiff)); + step = log2(curdiff); if (dist > uplim[w*16+g]) step = -step; + scf += step; + av_clip_uint8(scf); + step = scf - prev_scf; if (FFABS(step) <= 1 || (step > 0 && scf >= max_scf) || (step < 0 && scf <= min_scf)) { - sce->sf_idx[w*16+g] = scf; + sce->sf_idx[w*16+g] = av_clip(scf, min_scf, max_scf); break; } - scf += step; if (step > 0) - min_scf = scf; + min_scf = prev_scf; else - max_scf = scf; + max_scf = prev_scf; } start += size; } -- 2.7.4