shithub: libvpx

Download patch

ref: 37293583cd53f2bf8a5ff32018bf6e3f3ff6ad04
parent: 3fedf4a59bbe8e879e611012fdd0dd3de7cad1af
author: Marco <[email protected]>
date: Wed Sep 30 14:27:49 EDT 2015

Stabilize the encoder buffer from going too negative.

For screen-content mode, with frame dropper off, put a limit
on how low encoder buffer can go.

Under hard slide changes, the buffer level can go too low and then
take long time to come back up (in particular when frame-dropping
is not used), which will affect the active_worst and target frame size.

Change-Id: Ie9fca097e05cd71141f978ec687f852daf9de332

--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -271,6 +271,13 @@
 
   // Clip the buffer level to the maximum specified buffer size.
   rc->bits_off_target = VPXMIN(rc->bits_off_target, rc->maximum_buffer_size);
+
+  // For screen-content mode, and if frame-dropper is off, don't let buffer
+  // level go below threshold, given here as -rc->maximum_ buffer_size.
+  if (cpi->oxcf.content == VP9E_CONTENT_SCREEN &&
+      cpi->oxcf.drop_frames_water_mark == 0)
+    rc->bits_off_target = VPXMAX(rc->bits_off_target, -rc->maximum_buffer_size);
+
   rc->buffer_level = rc->bits_off_target;
 
   if (is_one_pass_cbr_svc(cpi)) {