On Sat, 5 Nov 2005, [UTF-8] Bernhard Fr??hmesser wrote:
> > ...deteriorated and is in need of color correction...
>
> Yep, definitely. Which color correction tool are you using (yuvcorrect? :-) )
No, it's not yuvcorrect. Care to make another guess? :) [Hint: it
is often abbreviated FCP]
> I use version 1.8.0 here.
Good!
> With your version below it works, but i have still used y4mscaler too as
> only with y4mshift this will result in a big big black border on the
> right and on the top.
Well, it's your video so if you want to distort the picture that's
your right. What you're doing is scaling from 564 up to 576 or
1.021 (576/564) so the image is distorted about 2% vertically.
What I do is try to center the active image area inside the frame
(with ~8pixels black borders on the left and right). Then crop to
704xN (where N is 480 for me, but 576 for "PAL"). 704x480 (576) is
a valid DVD framesize and that will remove most of the side borders.
> y4mscaler -O size=720x576 -I active=720x564+0+12
Should have had "-O sar=src" added to prevent scaling 564 -> 576
In general I've found that upscaling interlaced material is NOT
a good thing to do - degrades the picture quality.
If the final output is for "DVD" (and viewing on a TV) there are a
couple things to keep in mind: 1) TVs overscan so if you center the
active picture area in the frame you will NOT see ~8pixel black borders
and 2) most TVs are interlaced
> This is the result of following command(s):
> y4mdenoise -t 3 -z 3 | y4munsharp | mpeg2enc -f 8 -4 1 -2 1 -q 6 -b 4500
> -K tmpgenc -E -10 -o videotest24.liste
Is there a reason for such a low bitrate and quality setting? -q 5
and a bitrate of 6000 (or even the default of 7500) would look
better I think.
> The second picture comes from this command(s):
>
> lav2yuv 24.liste | yuvcorrect -Y CONFORM | y4mshift -n -8 -N 8 |
> y4mscaler -O size=720x576 -I active=720x564+0+12 | yuvmedianfilter |
> y4mdenoise -t 4 -z 3 | mpeg2enc -f 8 -4 1 -2 1 -q 6 -b 4500 -K tmpgenc
> -E -10 -o video24_2.mpg
> So i don't see that much difference between the two, and it still looks
I would not expect a big difference between "-t 4" and "-t 3".
Another thing you might try is the newly rewritten 'yuvdenoise' - it
does both spatial and temporal processing (y4mdenoise is temporal
filtering only).
> somehow to be interlaced (pay attention on the ppl on the picture and on
Well, it was interlaced input and no 'yuvdeinterlace' program was run
so it is not surprising that the output is interlaced.
:)
Remember #2 above - video (TVs) are interlaced but computer monitors
are progressive. Yes, there are progressive scan TV sets but they
are not as common as interlaced TVs. Play the DVD on a TV and the
video will look fine (slightly off on the aspect ratio - round objects
will appear slightly wrong).
> I remember in version 1.6.2 of the mjpegtools i used yuvdenoise -F which
> worked very well to deinterlace (for myself), is there anything i can do
> here to get rid of that lines in the video ...
Playback software (MPlayer, vlc, etc) have deinterlacing capability -
have you tried deinterlacing at playback time? If you're going to
make a DVD then leave the interlacing as it is and just deinterlace
when playing on a computer.
If you're only going to play on a computer then you are not
constrained to 720x576 - you can pick any size that is divisible
by 16 and encode as "generic MPEG-2" (-f 3).
> and to improve quality a bit more? ... there might be not much i can do...
I have a few suggestions ;)
Use an S-Video cable from the VCR to the capture card (probably need
a better VCR with S-Video output). OR use a analog->digital conversion
unit with very good 3D Y/C filters (Canopus ADVC300 for example, some
TBCs can also perform this function).
Use a higher bitrate - I think "-b 7500 -q 5" is a good starting point.
Crop to 704xN - that will save ~2% on the encoding time and save a
few bits (which can be used for the image rather than the borders).
Preprocess the data with FCP - I've found the filters and plugins for
very effective (especially the color correction and level adjustments).
For encoding try something like this:
(shift/center as needed ) |
y4mscaler -v0 -O sar=src -O size=704x576 |
yuvmedianfilter -f -t 0 -R 1 |
yuvdenoise -s 4,5,5 -g 64,255,255 -t 3,3,3 |
y4munsharp | \
mpeg2enc -f 8 -D 10 -E -10 -q 5 -K tmpgenc -4 1 -2 1 -o output.m2v
I'm sure others have methods that work well, maybe they'll share ;)
Cheers,
Steven Schultz
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