On Fri, 11 Mar 2005, Matti Haveri wrote:
> PAL/NTSC 352x288/240 is a valid DVD resolution but I'm unsure whether
> I should encode it as MPEG1 or MPEG2.
MPEG1
> Some sources say that only MPEG1 is correct while other sources seem
> to indicate that also MPEG2 is OK?
Since you've either de-interlaced or tossed away one of the fields
there's nothing to be gained by using MPEG2 for a small frame size.
> Which MPEG1 -f option should I use: 0 = Generic MPEG1, 1 = standard
> VCD, 2 = VCD? (-f 8 seems to be the only correct choice for a MPEG2
> to be used in a DVD)? Or does this matter much anyway??
MPEG1 is technically limited to about 1800Kb/s for DVD use. I forget
exactly where I saw that but I know that DVD Studio Pro3 imposes
that limit.
The point is moot though since at 352x288/240 ~1Mb/s is more than
sufficient.
"-f 1" would be ok but that does impose a 1152Kb/s limit and do some
other stuff peculiar to VCDs that you don't need.
GENERIC MPEG1 (-f 0) would probably be the best choice. You'll
need to specify the bitrate and probably need to give a VBV (-V 46).
DVD use of MPEG1 is, from what I've seen, primarily for menu
backgrounds or buttons with video clips playing in them.
> What about -S and -B settings?
You could put -S at some very high number if you're concerned about
the length.
I wouldn't worry about the -B setting since it's just used to
calculate when the start a new file - since you're going for
"no limit" (create a single file) the -B default is fine.
> Deinterlaced the source DV and cropped 720x576 to 704x576 and scaled
> it to 352x288.
y4mscaler will do that automagically I believe.
> mpeg2enc -v 0 -f 0 -F 3 -n p -a 2 -b 1875 -I 0 -r 16 -q 8 -V 224 -g 9
> -G 15 -N -S 4000 -B 230
>
> I used mp2 audio @ 384 kb/s although that may be too much compared to
> the rather low video bitrate that I used in the test.
I've found 224 is usually more than adequate but 192 can be used to
save some space.
When I need to create a DVD with extended play time I use the MPEG-2
and the 1/2 D1 (sometimes called "CVD") frame size of 352x480/576
That's a very good compromise between the "VCD" size where 3/4 of the
information is being tossed away (704->352 and 480 -> 240 basically
is losing 3/4 of the information). With 352x480/576 less is being
discarded. And yes, 352x480/576 is a valid DVD frame size that all
DVD players have to accept ;)
Cheers,
Steven Schultz
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