Re: [Mjpeg-users] Converting Large DV to MPEG-1 and MPEG-2

[Steven M. S. <sm...@2B...>]

On Mon, 12 Jan 2004, George Kola wrote:

> from 1 hr DV) showing up as only ~16 minutes in windows media player. I tried 
> video lan player, and it found  ~18 minutes in that same mpeg file. But the 
> bad thing was with the mpeg in which windows media player found the full 1 
> hour, video lan player only found ~49 minutes. I am able to play the full 1 

	I'm curious - when you say "found NN minutes" are you referring to
	an onscreen/menu clock/timer or did you sit and play the movie and
	time it?   Did, for example, 'vlc' only play for 18 minutes and then
	declare the end of file and "movie ended"?
	
> smil2yuv -i 2 ../test.avi 2>smil.err | y4mscaler -S option=sinc:4 -O preset=VCD 
> 2>y4m.err | mpeg2enc -f 1  -o test.m1v 2>mpegenc.err 1>mpeg2nc.out
> 
> ++ WARN: [y4mscaler] Source active region clipped by projection of target.
> **ERROR: [y4mscaler] Cannot make progressive stream from interlaced.
> **ERROR: [y4mscaler]  (Try '-I ilace=TOP_ONLY/BOTTOM_ONLY'; see manpage.)
> 
>        What should I do ?. I seem to be de-interlacing with -i 2 in smil2yuv. 

	You should try y4mscaler's suggestion :)

	Add "-I ilace=BOTTOM_ONLY" before the "-S option".

> Should I use -I ilace=TOP_ONLY or BOTTON_ONLY ?. which is better ?. I had 
> used yuvscalar

	Flip a coin.   Doesn't matter which you pick.  When going from 
	480 interlaced to 240 progressive one of the fields has to go away.
	Doesn't matter which one.

> smil2yuv ../test.avi | yuvscaler -O VCD | mpeg2enc -f 1 -o test.m1v
> 
>          That worked fine. What does yuvscalar do for de-interlacing ?.Which 
> is better.

	No, it's just silently tossing one of the fields - I don't know which
	one it picks.

>           Steven, can you please email me the script you have for encoding to 
> MPEG-4. It would be very useful. I also have a problem with the mencoder 

	Hmmm, it should have been attached to one of the mail items I sent
	yesterday (or was it the day before).     I'll send that privately.

> encoded file playing in quicktime on Mac OS. If I install the 3ivx codec, I 
> can see the video but not the audio. Is it possible to make the MPEG-4 both 

	3ivx?   Never heard of it.  I usually just use MPlayer to play movies
	on OS/X but have used the Quicktime Player on occasion.

> problem with VBR MP3 in avi. I am using ABR mp3 in the MPEG4 avi. Is there a 
> work-around. Any pointers would be greatly appreciated.

	Yes, a number of players have trouble with VBR mp3.   For use with
	the Quicktime player I create a MP4 container instead of AVI and use
	AAC audio instead of MP3 (the tool I use can put mp3 into a MP4
	container - just haven't tried it yet since AAC sounds better at lower
	bitrates).   It's a bit of a chore to build but the mpeg4ip project
	(mpeg4ip.sf.net) has command line tools for manipulating MP4 files.
	The audio's encoded with faac (www.audiocoding.com as I recall).

> > mpeg2enc -f 3 -4 1 -2 1 -q 5 -b 7500 -V 300 -P -K tmpgenc -E -8 -g 6 -G 18
> >
>         I gave that a shot and it looks better. Thanks. I also find that 

	Welcome.

> if the MPEG-2 is scaled to full screen, I see interlacing artifacts. What is 

	Fact of life on a computer monitor ;(   Some players have deinterlacing
	logic - xine has the capability, so does MPlayer (I forget the
	exact option).   Or sit back a little further and let the distance
	blur things ;)

> the best way to get rid of them. I had not used -i 2 in smil2yuv. I have 
> started doing that now. Is that enough or should I do something else.

	That does not do deinterlacing.   -i 2 tells smil2yuv to emit 
	4:1:1 data rather than doing the 4:1:1 to 4:2:0 conversion.   y4mscaler
	does a MUCH better job of chroma conversion - that's the reason to
	use -i 2 and y4mscaler -O chromass=.   You do not want to deinterlace 
	before encoding - that'll ruin the video rather completely.  Do the 
	deinterlacing at playback time.

	Cheers,
	Steven Schultz