[MPlayer-users] ASF files with YUV4MPEG

[Matthew W. Miller]

On Sun, Jul 20, 2003 at 03:46:12PM +0200, Attila Kinali wrote:
>On Tue, 8 Jul 2003 12:33:47 -0700 (PDT) Jonathan Bartlett 
><johnnyb at eskimo.com> wrote:
>> I have an ASF file that I'm trying to re-encode into MPEG1 Video.  I'm
>> using yuv4mpeg to work on it. ... these files don't have a "frame
>> rate", they just have a delay on each frame for the period it's
>> supposed to be up for.
>Please use -ofps

He can't!  -ofps is an mencoder option.  The only way to output in
yuv4mpeg format is with mplayer -vo yuv4mpeg, which is suboptimal for
twiddly-frame-rate formats like ASF because it doesn't duplicate/toss
out frames to achieve a steady frame rate.  Yet another wishlist item
for mplayer-G2, as if A'rpi isn't sick to death of them already. :)
	Which still doesn't solve Jonathan Bartlett's conundrum.
	Mr Bartlett, I suggest you use the latest CVS versions of
MPlayer and ffmpeg/libavcodec with the super secret (you have to read
ffmpeg's documentation to find out about it ;) ) lossless ffv1 codec to
achieve a steady-framerate output movie with a minimum of detail loss,
e.g.:

$ mencoder -oac copy <-vf scale and whatever else> -ovc lavc -lavcopts
vcodec=ffv1:vstrict=-1 -ofps <framerate> -o output.avi input.asf

	Expect video bitrates of 5000-6000 kbit/s with this.  Also,
since I'm going under the stupid facile assumption that by 'MPEG-1' you
mean you're preparing for a VideoCD, remember that the NTSC VideoCD
framerate is 30000/1001, or 29.9700299700299700... and the NTSC film
VideoCD framerate is 24000/1001, or 23.9760239760239760... .
	Play it back to ensure that you don't get any sync screwups. 
(If you *do* then, um, look over there!  Something shiny!)  If you don't
get any audio at *all*, and mplayer's messages claim there is no
audiotrack in the output movie, redo the encode with '-oac pcm' instead
of '-oac copy'.  You have disk space to burn, right?
	If it plays back successfully then you can go on to mplayer -vo
yuv4mpeg and fiddle with all of that sort of thing.  Good luck.
-- 
Matthew W. Miller <mwmiller at columbus.rr.com>