On Mon, 24 May 2004, Heber Vazquez wrote:
> I record using one AverDVD (www.aver.com) pci.
>
> lav2yuv +n foo_movie0*.avi | yuvdenoise -F -f | mpeg2enc -n n -f 8 -q 2 -P -I 0 -4
> 1 -2 1 -o foo_video.m2v ;
> I want to know if are any other setting to optimize more my videos, I try to use
> 640x480 but when convert to mpeg2enc the compression are similar to the 352x480
> settings.
-q 2 is not a good idea. Values below 4 are usually not
recommended - there have been reports of artifacts (overflow in the
MMX DCT/iDCT implementation if memory serves me correctly). I've
used -q 3 on an Altivec based system without problem - but the files
are much larger and the quality isn't noticeably better than -q 4.
With lower -q values you may also want to increase the bitrate from
the default of 7500 to something like 8200 or so. '-b'
Increasing the search radius from the default of 16 to 24 with -r may
also be useful.
Optionally adding a "-E -8" to the encoding command line - that can
help reduce the bitrate without visible side effects.
640x480 isn't a permitted DVD frame size - I would be surprised if
the DVD played in a standalone DVD player.
From
http://www.dvddemystified.com/dvdfaq.html#3.4
the list of picture resolutions are given as:
Allowable picture resolutions are:
MPEG-2, 525/60 (NTSC): 720x480, 704x480, 352x480, 352x240
MPEG-2, 625/50 (PAL): 720x576, 704x576, 352x576, 352x288
MPEG-1, 525/60 (NTSC): 352x240
MPEG-1, 625/50 (PAL): 352x288
Nary a 640x480 anywhere to be found ;)
Take the 640x480 1:1 (mjpeg cards generate square pixels) and resample
to 704x480 10:11 (NTSC) pixels with y4mscaler. Adding this step
before mpeg2enc should perform the task:
y4mscaler -I sar=1:1 -O sar=10:11 -S option=sinc:4 -O size=704x480
y4mscaler can be found at:
http://www.mir.com/DMG/Software/y4mscaler.html
Cheers,
Steven Schultz
-------------------------------------------------------
This SF.Net email is sponsored by: Oracle 10g
Get certified on the hottest thing ever to hit the market... Oracle 10g.
Take an Oracle 10g class now, and we'll give you the exam FREE.
http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click
_______________________________________________
Mjpeg-users mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/mjpeg-users
