Re: [Mjpeg-users] mplex not recognizing mpeg1 from mencoder

[<ro...@ub...>]

On Fri, Jan 02, 2004 at 04:29:54PM -0800, Steven M. Schultz wrote:
> 
> On Fri, 2 Jan 2004 ro...@ub... wrote:
> 
> > Currently I am using mjpegtools 1.6.1.92 to convert movies to
> > SVCD. How faster is the CVS version compared to the version I
> > have installed? Is it stable for SVCD production? I am thinking
> > about installing it and trying it.
> 
> 	It's been so long since I've run what was 1.6.1.92 that I don't know
> 	exactly what the difference in speed was.

I do not think 1.6.1.92 is that old. If I am not wronk, it has been
released by the end of November.

> 	Actually most of the speed up was done by changing the defaults to
> 	omit B frames ("-R 0"), leave '-I' as 0 (which is the default in
> 	ffmpeg - that's one place it gained a lot of speed) instead of 1 and
> 	a few other minor things.

Those options are there in the 1.6.1.92 release and they really
spead things up. I have been using them. I have also been using
the "-E n" with n being a value between -15 and -4, in order
to get smaller files. Do you think this is a good idea?
It seems that the small (in absolute value) values for n
dos not affect the quality that much.

> 	I've done a few CVDs (352x480 instead of 480x480) and for casual 
> 	viewing they are great and allow for much longer play time on a single
> 	disc.  I managed, finally, to get a 90minute concert onto 1 CD-R.  For
> 	computer playing that needs to stay within a 2GB avi size limit the
> 	CVD resolution will be of great value too.   And the encoding at 352x480
> 	is quite fast.

What does change in CVD compared to SVCD encoding? Only the frame size?
What I have been doing for NTSC SVCDs is bring the frame size to the
aspect ratio 4:3 by adding black borders at the top and bottom of the
video image, and then resize it to 480x480 while setting the aspect
ratio to 4:3. For example, if the movie is 672x272 (2.47:1), I add
black borders at the top and at the bottom of height 116 each, giving
a frame size of 672x504. Then I resize it to 480x480 and set the
aspect ratio to 4:3. What would be the procedure for a CVD target
in this example?

Regards.

Romildo