shithub: libvpx

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vp9-aqmode=3: Reduce condition below which we turn off delta-qp.

Add TODO to consider turning-off more smoothly.

Change-Id: Id6dd4c5c515f5b09c388af965eb27dbe24924362

--- a/vp9/encoder/vp9_aq_cyclicrefresh.c

+++ b/vp9/encoder/vp9_aq_cyclicrefresh.c

@@ -60,6 +60,8 @@

 }

 // Check if we should turn off cyclic refresh based on bitrate condition.

+// TODO(marpan): May be better in some cases to just reduce the amount/delta-qp

+// instead of completely shutting off.

 static int apply_cyclic_refresh_bitrate(const VP9_COMMON *cm,

                                         const RATE_CONTROL *rc) {

   // Turn off cyclic refresh if bits available per frame is not sufficiently

@@ -67,10 +69,10 @@

   // with number of seg blocks, so compare available bits to number of blocks.

   // Average bits available per frame = avg_frame_bandwidth

   // Number of (8x8) blocks in frame = mi_rows * mi_cols;

-  const float factor = 0.25;

+  const float factor = 0.15;

   const int number_blocks = cm->mi_rows  * cm->mi_cols;

   // The condition below corresponds to turning off at target bitrates:

-  // (at 30fps), ~12kbps for CIF, 36kbps for VGA, 100kps for HD/720p.

+  // (at 30fps), ~8kbps for CIF, 20kbps for VGA, 60kps for HD/720p.

   // Also turn off at very small frame sizes, to avoid too large fraction of

   // superblocks to be refreshed per frame. Threshold below is less than QCIF.

   if (rc->avg_frame_bandwidth < factor * number_blocks ||