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| author | Paul Wilkins <paulwilkins@google.com> | 2011-01-10 16:41:53 +0000 |
|---|---|---|
| committer | Paul Wilkins <paulwilkins@google.com> | 2011-01-10 16:41:53 +0000 |
| commit | cf7c4732e5be5c881a49f778ba011ea5d656f66e (patch) | |
| tree | e6f2bfaf19b45feee4c240cf1ac3d4f99dc7ab90 /vp8/encoder/firstpass.c | |
| parent | 405499d835a4a01fe09bc5ea01a2e7e77aaef8da (diff) | |
| download | libvpx-cf7c4732e5be5c881a49f778ba011ea5d656f66e.tar libvpx-cf7c4732e5be5c881a49f778ba011ea5d656f66e.tar.gz libvpx-cf7c4732e5be5c881a49f778ba011ea5d656f66e.tar.bz2 libvpx-cf7c4732e5be5c881a49f778ba011ea5d656f66e.zip | |
Two Pass VBR change
Further experiment with restriction of the Q range.
This uses the average non KF/GF/ARF quantizer, instead
of just relying on the initial value. It is not such a strong constraint
but there may be a reduced risk of rate misses.
Change-Id: I424fe782a37a2f4e18c70805e240db55bfaa25ec
Diffstat (limited to 'vp8/encoder/firstpass.c')
| -rw-r--r-- | vp8/encoder/firstpass.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/vp8/encoder/firstpass.c b/vp8/encoder/firstpass.c index 48899162d..4d259c676 100644 --- a/vp8/encoder/firstpass.c +++ b/vp8/encoder/firstpass.c @@ -989,6 +989,19 @@ static int estimate_max_q(VP8_COMP *cpi, double section_err, int section_target_ //Q = cpi->oxcf.cq_target_quality; } + // Adjust maxq_min_limit and maxq_max_limit limits based on + // averaga q observed in clip for non kf/gf.arf frames + // Give average a chance to settle though. + if ( (cpi->ni_frames > + ((unsigned int)cpi->total_stats->count >> 8)) && + (cpi->ni_frames > 150) ) + { + cpi->maxq_max_limit = ((cpi->ni_av_qi + 32) < cpi->worst_quality) + ? (cpi->ni_av_qi + 32) : cpi->worst_quality; + cpi->maxq_min_limit = ((cpi->ni_av_qi - 32) > cpi->best_quality) + ? (cpi->ni_av_qi - 32) : cpi->best_quality; + } + return Q; } static int estimate_q(VP8_COMP *cpi, double section_err, int section_target_bandwitdh, int Height, int Width) @@ -2121,7 +2134,7 @@ void vp8_second_pass(VP8_COMP *cpi) cpi->common.Width); // Limit the maxq value returned subsequently. - // This increases the risk of overspend if the initial + // This increases the risk of overspend or underspend if the initial // estimate for the clip is bad, but helps prevent excessive // variation in Q, especially near the end of a clip // where for example a small overspend may cause Q to crash |