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AAC encoder: ANMR, avoid empty search ranges

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Avoid generating broken paths when some bands have an
empty search space.
This commit is contained in:
Claudio Freire 2015-12-04 22:56:34 -03:00
parent 7a4652dd5d
commit 293c170f59
1 changed files with 12 additions and 2 deletions
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14
libavcodec/aaccoder.c
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@ -261,9 +261,9 @@ static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
}
//minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
q0 = coef2minsf(q0f);
q0 = av_clip(coef2minsf(q0f), 0, SCALE_MAX_POS-1);
//maximum scalefactor index is when maximum coefficient after quantizing is still not zero
q1 = coef2maxsf(q1f);
q1 = av_clip(coef2maxsf(q1f), 1, SCALE_MAX_POS);
if (q1 - q0 > 60) {
int q0low = q0;
int q1high = q1;
@ -279,6 +279,12 @@ static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
q1 = q1high;
}
}
// q0 == q1 isn't really a legal situation
if (q0 == q1) {
// the following is indirect but guarantees q1 != q0 && q1 near q0
q1 = av_clip(q0+1, 1, SCALE_MAX_POS);
q0 = av_clip(q1-1, 0, SCALE_MAX_POS - 1);
}
for (i = 0; i < TRELLIS_STATES; i++) {
paths[0][i].cost = 0.0f;
@ -327,6 +333,10 @@ static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
maxscale = coef2maxsf(qmax);
minscale = av_clip(minscale - q0, 0, TRELLIS_STATES - 1);
maxscale = av_clip(maxscale - q0, 0, TRELLIS_STATES);
if (minscale == maxscale) {
maxscale = av_clip(minscale+1, 1, TRELLIS_STATES);
minscale = av_clip(maxscale-1, 0, TRELLIS_STATES - 1);
}
maxval = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], s->scoefs+start);
for (q = minscale; q < maxscale; q++) {
float dist = 0;