catalin.muresan at astral.ro
Fri Mar 28 13:25:12 CET 2003
On Fri, Mar 28, 2003 at 01:35:47AM -0500, Yan Seiner wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> OK, Thanks everyone!
> I now have the ability to take my PAL tapes, run them through my
> PAL/NTSC tape deck, edit them to cut the cruft out, and play them back!
> Here's a collection of my *limited* and probably erroneous wisdom.
> Hopefully this will be useful to other newbies as a starting point:
> grabbing videos from a regular VHS:
> mencoder -tv
> -ofps 29.97 -ovc xvid -xvidencopts bitrate=800 -oac mp3lame -lameopts
> vbr=3 -o movie5.avi
are you sure that your BT878 card doesn't know PAL so you don't have
to do the conversion ?
> There's no reason to use a greater than 320x240 resolution on the
> capture since 240 is the resolution of a VHS tape. (I tried the
> recommended 352x240 but it came out squished.) This may be different
you could try to encode with lavc and use the aspec=1.33 option or
playback with aspect=1.33
> for S-Video; ordinary composite is 240 lines of resolution.
> A word on resolution: if your resolution is not a multiple of 16,
> strange things will happen. Like a field of green with your image
> smushed into the top 3 lines. Or other, equally strange things. Why?
> I have no idea. I'm guessing it has to do with the compression used.
> For display on a normal TV, make sure your resolution is at a 4:3 ratio.
MPEG specifies that the image is split in 16x16 blocks which are
encoded, not the image as a whole, so the encoder (or the player ?)
compensates the missing info.
> For some strange reason, I have to specify a much higher bitrate for
> cartoons (800) than live action (500) to get comparable quality. Again,
try also (for lavc) vhq:v4mv, or some kind of noise reduction (-vop
pp=tn) or something else, also try not to use width=320:height=240, use
instead width=640:height=480 and -vop pp=tn/lb,scale=320:240
(documentation.html - 2.4.3 Examples)
> I guess this has to do with the compression used. Or possibly it's an
> artifact of the PAL to NTSC conversion and the multiple
> analog-digital-analog conversions that happen with my setup. (analog PAL
> - digital conversion inside deck - analog NTSC - composite in to
> computer - digital). YMMV.
More information about the MPlayer-users