[FFmpeg-cvslog] avcodec/mpegvideo_enc: Avoid fine lambda steps in VBV retry code when RD is not in use

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Sep 22 20:17:40 2015 +0200| [31623e9d1ea960035cee59839e016397a559dab3] | committer: Michael Niedermayer

avcodec/mpegvideo_enc: Avoid fine lambda steps in VBV retry code when RD is not in use

Reduces the number of times the vbv retry code is used and should have no
effect on quality

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=31623e9d1ea960035cee59839e016397a559dab3
---

 libavcodec/mpegvideo_enc.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c
index 8aca1d0..76eb40f 100644
--- a/libavcodec/mpegvideo_enc.c
+++ b/libavcodec/mpegvideo_enc.c
@@ -1824,16 +1824,18 @@ vbv_retry:
         if (avctx->rc_buffer_size) {
             RateControlContext *rcc = &s->rc_context;
             int max_size = FFMAX(rcc->buffer_index * avctx->rc_max_available_vbv_use, rcc->buffer_index - 500);
+            int hq = (s->avctx->mb_decision == FF_MB_DECISION_RD || s->avctx->trellis);
+            int min_step = hq ? 1 : (1<<(FF_LAMBDA_SHIFT + 7))/139;
 
             if (put_bits_count(&s->pb) > max_size &&
                 s->lambda < s->lmax) {
-                s->next_lambda = FFMAX(s->lambda + 1, s->lambda *
+                s->next_lambda = FFMAX(s->lambda + min_step, s->lambda *
                                        (s->qscale + 1) / s->qscale);
                 if (s->adaptive_quant) {
                     int i;
                     for (i = 0; i < s->mb_height * s->mb_stride; i++)
                         s->lambda_table[i] =
-                            FFMAX(s->lambda_table[i] + 1,
+                            FFMAX(s->lambda_table[i] + min_step,
                                   s->lambda_table[i] * (s->qscale + 1) /
                                   s->qscale);
                 }