generic-library/vpx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Remove the frame rate factor for key frame size.

Browse Source 
When temporal layers is used (i.e., number_of_layers > 1),
we don't use the frame rate boost for setting the key
frame target size. The factor was forcing the target size to be
always at its minimum (2* per_frame_bandwidth) for low frame rates
(i.e., base layer frame rate).

Generally we should modify or remove this frame rate factor;
for now we turn if off for number_of_layers > 1.

Change-Id: Ia5acf406c9b2f634d30ac2473adc7b9bf2e7e6c6
This commit is contained in:
Marco Paniconi 2012-02-22 14:39:17 -08:00
parent 2b0aee4b5d
commit 507ee87e3e
1 changed files with 10 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
vp8/encoder/ratectrl.c
View File

@ -392,10 +392,16 @@ static void calc_iframe_target_size(VP8_COMP *cpi)
int Q = (cpi->common.frame_flags & FRAMEFLAGS_KEY)
? cpi->avg_frame_qindex : cpi->ni_av_qi;
// Boost depends somewhat on frame rate
kf_boost = (int)(2 * cpi->output_frame_rate - 16);
// Boost depends somewhat on frame rate: only used for 1 layer case.
if (cpi->oxcf.number_of_layers == 1) {
kf_boost = (int)(2 * cpi->output_frame_rate - 16);
}
else {
// Initial factor: set target size to: |2.5 * per_frame_bandwidth|.
kf_boost = 24;
}
// adjustment up based on q
// adjustment up based on q: this factor ranges from ~1.2 to 2.2.
kf_boost = kf_boost * kf_boost_qadjustment[Q] / 100;
// frame separation adjustment ( down)
@ -403,6 +409,7 @@ static void calc_iframe_target_size(VP8_COMP *cpi)
kf_boost = (int)(kf_boost
* cpi->frames_since_key / (cpi->output_frame_rate / 2));
// Minimal target size is |2* per_frame_bandwidth|.
if (kf_boost < 16)
kf_boost = 16;