[FFmpeg-user] Zeranoe Windows builds spiking CPU to 100% randomly

Jan Ehrhardt phpdev at ehrhardt.nl
Wed Jul 11 22:56:40 CEST 2012

Andy Sheen in gmane.comp.video.ffmpeg.user (Wed, 11 Jul 2012 20:12:25 +0100):
>ffmpeg -y -loglevel info -i 7416_20120706232700.mpg -r 25 -ss 0:0:0 -t
>0:10:00 -map 0:0 -pass 1 -vcodec libx264 -b 1200k -threads 8 -f mp4 -an nul
>3 times and averaging gives
>head   (version N-42432-gb27c7d7)  382fps
>0.11.1  (ffmpeg version 0.11.1)    379fps

Your version (thanks for the dl) was certainly quicker than my 20120706
build, but that was the one with the 20% delay (see the other thread).

On my testdata your 20120710 version was some (2-10) fps slower than my
0.11.1 build, but we will not argue over such tiny differences.

Depending on your sourcefiles there might be a speed gain of 20% if
you compile as x64. I got such figures, but cannot be sure all of the
PC's in my project are 64-bit.

What still strikes me: on my most troublesome file (50i PAFF interlaced
Canon HF M306 recording) the ancient Mencoder-33883 is as quick as or
even faster than the fastest FFmpeg. See output below.

Mycoder-33883 = Sherpya's build with some mods and additions by me.


BTW. Both FFmpeg and Mencoder are incorrect about the input framerate.
They think it is 25, but for a correct transcode it should be 50.

U:\utils>echo 22:41:03,63 ffmpeg-20120710-w32

U:\utils>ffmpeg-20120710-w32 -r 50 -i T:/PRIVATE/AVCHD/BDMV/STREAM/00005.MTS -vf
 scale=384:288 -aspect 4:3 -sws_flags bicubic -threads 0 -vcodec wmv2 -b:v 320k
-acodec wmav2 -ab 64k -ar 44100 -y output.wmv   2>output.log

U:\utils>echo 22:41:55,79 exit

U:\utils>echo 22:41:55,80 mycoder-r33883

U:\utils>mycoder-r33883.exe -fps 50 -mc 0 -noskip -ofps 25 -vf scale=384:288 -sw
s 2 -lavdopts fast:threads=4 -of lavf -lavfopts format=asf -ovc lavc -lavcopts v
codec=wmv2:vbitrate=320:vglobal=1 -oac lavc -lavcopts acodec=wmav2:abitrate=64:a
global=1 -af volnorm -o outputm.wmv T:/PRIVATE/AVCHD/BDMV/STREAM/00005.MTS  1>>o
** MUXER_LAVF *****************************************************************
REMEMBER: MEncoder's libavformat muxing is presently broken and can generate
INCORRECT files in the presence of B-frames. Moreover, due to bugs MPlayer
will play these INCORRECT files as if nothing were wrong!

Unsupported PixelFormat 61
Unsupported PixelFormat 53
[asf @ 00d676d8]Codec for stream 0 does not use global headers but container for
mat requires global headers
[asf @ 00d676d8]Codec for stream 1 does not use global headers but container for
mat requires global headers

U:\utils>echo 22:42:47,64 exit

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