From 454cbc96b7c81109b1d7fd24df1da99ba30f5207 Mon Sep 17 00:00:00 2001
From: John Koleszar <jkoleszar@google.com>
Date: Tue, 19 Apr 2011 14:05:27 -0400
Subject: [PATCH] Limit size of initial keyframe in one-pass.
Rather than using a default size of 1/2 or 3/2 seconds for the first
frame, use a fraction of the initial buffer level to give the
application some control.
This will likely undergo further refinement as size limits on key
frames are currently under discussion on codec-devel@, but this gives
much better behavior for small buffer sizes as a starting point.
Change-Id: Ieba55b86517b81e51e6f0a9fe27aabba295acab0
---
vp8/encoder/onyx_if.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/vp8/encoder/onyx_if.c b/vp8/encoder/onyx_if.c
index cbaab5fb01..4208f1fe4d 100644
--- a/vp8/encoder/onyx_if.c
+++ b/vp8/encoder/onyx_if.c
@@ -1459,10 +1459,6 @@ static void init_config(VP8_PTR ptr, VP8_CONFIG *oxcf)
cpi->avg_frame_qindex = cpi->oxcf.worst_allowed_q;
// Initialise the starting buffer levels
- cpi->oxcf.starting_buffer_level =
- rescale(cpi->oxcf.starting_buffer_level,
- cpi->oxcf.target_bandwidth, 1000);
-
cpi->buffer_level = cpi->oxcf.starting_buffer_level;
cpi->bits_off_target = cpi->oxcf.starting_buffer_level;
@@ -1635,6 +1631,10 @@ void vp8_change_config(VP8_PTR ptr, VP8_CONFIG *oxcf)
// Convert target bandwidth from Kbit/s to Bit/s
cpi->oxcf.target_bandwidth *= 1000;
+ cpi->oxcf.starting_buffer_level =
+ rescale(cpi->oxcf.starting_buffer_level,
+ cpi->oxcf.target_bandwidth, 1000);
+
// Set or reset optimal and maximum buffer levels.
if (cpi->oxcf.optimal_buffer_level == 0)
cpi->oxcf.optimal_buffer_level = cpi->oxcf.target_bandwidth / 8;
@@ -2661,16 +2661,17 @@ static int pick_frame_size(VP8_COMP *cpi)
if (cpi->pass == 2)
vp8_calc_auto_iframe_target_size(cpi);
- // 1 Pass there is no information on which to base size so use bandwidth per second * fixed fraction
else
#endif
- cpi->this_frame_target = cpi->oxcf.target_bandwidth / 2;
-
- // in error resilient mode the first frame is bigger since it likely contains
- // all the static background
- if (cpi->oxcf.error_resilient_mode == 1 || (cpi->compressor_speed == 2))
{
- cpi->this_frame_target *= 3; // 5;
+ /* 1 Pass there is no information on which to base size so use
+ * bandwidth per second * fraction of the initial buffer
+ * level
+ */
+ cpi->this_frame_target = cpi->oxcf.starting_buffer_level / 2;
+
+ if(cpi->this_frame_target > cpi->oxcf.target_bandwidth * 3 / 2)
+ cpi->this_frame_target = cpi->oxcf.target_bandwidth * 3 / 2;
}
// Key frame from VFW/auto-keyframe/first frame
--
GitLab