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avcodec/mpeg12enc: extend QP range to 28 for non linear quantizers

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Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer
2015-07-30 04:42:16 +02:00
parent 9723d439fd
commit bf2474c74f
2 changed files with 31 additions and 9 deletions
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30
libavcodec/mpegvideo_enc.c
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@@ -163,9 +163,29 @@ void ff_convert_matrix(MpegEncContext *s, int (*qmat)[64],
static inline void update_qscale(MpegEncContext *s)
{
s->qscale = (s->lambda * 139 + FF_LAMBDA_SCALE * 64) >>
(FF_LAMBDA_SHIFT + 7);
s->qscale = av_clip(s->qscale, s->avctx->qmin, s->avctx->qmax);
if (s->q_scale_type == 1) {
int i;
int bestdiff=INT_MAX;
int best = 1;
static const uint8_t non_linear_qscale[] = {
1,2,3,4,5,6,7,8,9,10,11,12,14,16,18,20,24,26,28
};
for (i = 0 ; i<FF_ARRAY_ELEMS(non_linear_qscale); i++) {
int diff = FFABS((non_linear_qscale[i]<<(FF_LAMBDA_SHIFT + 7)) - (int)s->lambda * 139);
if (non_linear_qscale[i] < s->avctx->qmin || non_linear_qscale[i] > s->avctx->qmax)
continue;
if (diff < bestdiff) {
bestdiff = diff;
best = non_linear_qscale[i];
}
}
s->qscale = best;
} else {
s->qscale = (s->lambda * 139 + FF_LAMBDA_SCALE * 64) >>
(FF_LAMBDA_SHIFT + 7);
s->qscale = av_clip(s->qscale, s->avctx->qmin, s->avctx->qmax);
}
s->lambda2 = (s->lambda * s->lambda + FF_LAMBDA_SCALE / 2) >>
FF_LAMBDA_SHIFT;
@@ -616,9 +636,9 @@ FF_ENABLE_DEPRECATION_WARNINGS
}
if (s->q_scale_type == 1) {
if (avctx->qmax > 12) {
if (avctx->qmax > 28) {
av_log(avctx, AV_LOG_ERROR,
"non linear quant only supports qmax <= 12 currently\n");
"non linear quant only supports qmax <= 28 currently\n");
return -1;
}
}