[FFmpeg-devel] [PATCH] Fix distortion problem in MPEG1/2 video
michaelni at gmx.at
Tue May 14 14:50:30 CEST 2013
On Tue, May 14, 2013 at 03:49:08PM +0900, Heesuk Jung wrote:
> I'm sorry for late response and update my feedback for this issue.
> * Background of my suggestion
> - I believe that many files by pod encoder don't need full parsing option
> low possibility need full parsing.
> : As you know and so I concerned performance loss for many normal files.
> - And I tried to generalize this issue to slove problem ans I realized
> root cause is wrong frame size information of header.
> Ans so I suggest that we decide full parsing after checking frame length
> within 7 frames.
> * Full Parsing Enable/Disable speed test
> 1) Test file
> - I selected high bitrate file to clarify this issue.
> - Input #0, avi, from
> encoder : PotEncoder
> Duration: 00:00:59.23, start: 0.000000, bitrate: 25067 kb/s
> Stream #0:0: Audio: mp3 (U / 0x0055), 44100 Hz, stereo, s16p,
> 96 kb/s
> Stream #0:1: Video: mpeg2video (Main) (MPG2 / 0x3247504D), yuv420p,
> 1280x720 [SAR 1:1 DAR 16:9], 29.97 fps, 29.97 tbr, 29.97 tbn, 59.94 tbc
> 2) Test Environment
> - Intel(R) Core(TM) i5-3317U CPU @ 1.70GHz
> - 8GB RAM, 256GB SSD
> 3) Test Method
> - I evaluated the below excuting time at 5 times.
> - time ./ffprobe ~/download/ProblemMedia/AVI/\[3\]_tp_MPEG2_MP3.avi
> 4) Evaluate time result
> - Full Parsing
> 1 2 3 4 5
> real 0m0.051s 0m0.054s 0m0.053s 0m0.056s 0m0.054s 0m0.0536s
> user 0m0.040s 0m0.032s 0m0.036s 0m0.036s 0m0.032s 0m0.0352s
> sys 0m0.008s 0m0.020s 0m0.016s 0m0.016s 0m0.020s 0m0.016s
> - Header Parsing
> 1 2 3 4 5
> real 0m0.046s 0m0.049s 0m0.047s 0m0.050s 0m0.048s 0m0.048s
> user 0m0.044s 0m0.020s 0m0.024s 0m0.032s 0m0.028s 0m0.0296s
> sys 0m0.004s 0m0.028s 0m0.020s 0m0.016s 0m0.020s 0m0.0176s
> 5) Summary
> - Test result is about 6ms(Total video duration is 59s) difference
> between Full parsing and header parsing.
> I hope your feedback and thanks
This does not look statistically significant
try yourself: http://www.graphpad.com/quickcalcs/ttest1/
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Democracy is the form of government in which you can choose your dictator
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