How to make high quality MPEG4 video

[Steve O'Hara-Smith]

On Mon, 8 Sep 2003 00:28:53 +0900 (JST)
sugiura at kt.rim.or.jp (Sugiura Shiro) wrote:

SS> In article <20030902183709.7534858c.steve at sohara.org>
SS> steve at sohara.org writes:
SS> 

SS> >> 	That seems too low. What version of FreeBSD are you running ?
SS> >> There was an update merged to stable on 17 June this year that
SS> >fixed a> nasty problem with the bktr sync signalling at full
SS> >resolution YUV.
SS> 
SS> I use 5.1-CURRENT-20030812.

	You'll have that patch then :)

SS> I tried to turned off HTT on BIOS, and rebuild kernel without SMP ,
SS> then it likes so better. 

	Hmmm, ISTR there being some options to fiddle with ffmpeg's use
of SSE, MMX and the like. It may be worth fiddling with them if this kind
of thing makes a difference :(

SS> ---------------------------------------------------------------------
SS> ----(1)% ffmpeg -r 29.97 -s 640x480 -ac 2 -ar 48000 -ab 256 -acodec
SS> mp3 -vcodec \
SS>  mpegvideo -b 8000 -tvstd ntsc tv.mpg
SS> 
SS>   PID USERNAME PRI NICE   SIZE    RES STATE    TIME   WCPU    CPU
SS>   COMMAND 648 sugiura    8    0 11912K 10256K nanslp   0:52 49.88%
SS>   49.61% ffmpeg
SS>  
SS> (2)% ffmpeg -s 640x480 -tvstd ntsc -vcodec mpeg4 -b 2000 -acodec mp3
SS> -ac 2 \
SS>   -ab 256 -r 29.97 -f avi TV.avi
SS> 
SS>   PID USERNAME PRI NICE   SIZE    RES STATE    TIME   WCPU    CPU
SS>   COMMAND 657 sugiura  100    0 13092K 11588K RUN      1:47 36.77%
SS>   36.77% ffmpeg

	A little odd, I'd expect mpeg4 production to be slightly more
CPU intensive than mpeg1 - but these figures look reasonable. Presumably
these did not work well in some way - what happened ?

SS> (3)% ffmpeg -r 29.97 -s 640x480 -ac 2 -ar 48000 -acodec pcm_s16le
SS> -vcodec \ rawvideo -tvstd ntsc TV.avi
SS> 
SS>   PID USERNAME PRI NICE   SIZE    RES STATE    TIME   WCPU    CPU
SS>   COMMAND 685 sugiura    8    0 10064K  7216K nanslp   0:12 13.83%
SS>   13.62% ffmpeg
SS> ---------------------------------------------------------------------
SS> ----
SS> 
SS> I recorded TV like (3) , then I want to encode to MPEG4 using ffmpeg.
SS> But, I can't encode like following;
SS> 
SS> ---------------------------------------------------------------------
SS> ----% ffmpeg -t 30 -r 29.97 -s 640x480 -ac 2 -ar 48000 -acodec
SS> pcm_s16le \
SS>  -vcodec rawvideo -tvstd ntsc TV.avi

	The only difference is the -t 30 right ?

	Timer problems ??? Try kern.timecounter.method=1 in /etc/sysctl.conf
and a reboot to check.

SS> Is there any options to encode MPEG4?

	Well, for me it just works :)

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