From f7e187d3626f029490b8b619fb80da1b0e77dcfe Mon Sep 17 00:00:00 2001 From: John Koleszar Date: Thu, 4 Nov 2010 15:05:45 -0400 Subject: improve average framerate calculation Change Ice204e86 identified a problem with bitrate undershoot due to low precision in the timestamps passed to the library. This patch takes a different approach by calculating the duration of this frame and passing it to the library, rather than using a fixed duration and letting the library average it out with higher precision timestamps. This part of the fix only applies to vpxenc. This patch also attempts to fix the problem for generic applications that may have made the same mistake vpxenc did. Instead of calculating this frame's duration by the difference of this frame's and the last frame's start time, we use the end times instead. This allows the framerate calculation to scavenge "unclaimed" time from the last frame. For instance: start | end | calculated duration ======+=======+==================== 0ms 33ms 33ms 33ms 66ms 33ms 66ms 99ms 33ms 100ms 133ms 34ms Change-Id: I92be4b3518e0bd530e97f90e69e75330a4c413fc --- vp8/encoder/onyx_int.h | 1 + 1 file changed, 1 insertion(+) (limited to 'vp8/encoder/onyx_int.h') diff --git a/vp8/encoder/onyx_int.h b/vp8/encoder/onyx_int.h index 81e32f031..134e03075 100644 --- a/vp8/encoder/onyx_int.h +++ b/vp8/encoder/onyx_int.h @@ -399,6 +399,7 @@ typedef struct int inter_frame_target; double output_frame_rate; long long last_time_stamp_seen; + long long last_end_time_stamp_seen; long long first_time_stamp_ever; int ni_av_qi; -- cgit v1.2.3