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SUBMAN1
03-15-07, 02:10 PM
I haven't got into this yet, but I think it may be one of my next targets. Take lower quality content for example and upsample it using a Lanzcos 4 engine for example. I am fluent in Scenarist, but I am not sure what the latest tools are for HD content. Anyway, here is a blog I see that deals with the subject incase anyone is also interested in learning how to Author HD DVD:

http://blogs.msdn.com/ptorr/default.aspx

-S

Gizzmoe
03-15-07, 02:59 PM
Take lower quality content for example and upsample it using a Lanzcos 4 engine for example.
But thatīs going to take ages, like one second per frame or so, depending on the resolution, plus the time to recode it... :hmm:

SUBMAN1
03-15-07, 03:35 PM
But thatīs going to take ages, like one second per frame or so, depending on the resolution, plus the time to recode it... :hmm:
Nah! Just use AVISynth and it will do it close to real time. It is of course - CPU dependant.

A sample script for recorded TV that would work for turning content into 720p:
LoadPlugin("D:\Temp\dgmpgdec148\DGDecode.dll")
LoadPlugin("D:\Temp\dgmpgdec148\Decomb.dll")
mpeg2source("dgd2vfile.d2v")
FieldDeinterlace() |assuming recorded TV is pure interlaced material, turning it into progressive material
Lanczos4Resize(1280,720) |assuming 852x480 content here, making 1280x720 and still maintaining proper aspect ratio while upsampling with a very sharp 4 tap engine.

An optional thing would be to add the Crop (x,x,x,x) command to the end if you do not care about maintaing 1280x720 for proper sizing.

-S

Some info on this filter:

Lanczos4Resize is closely related to LanczosResize (correct name: Lanczos3Resize). The latter uses 2*3=6 lobes and the former 2*4=8 lobes to do the resizing. The result is that Lanczos4Resize produces sharper images. Especially usefull when upsizing a clip.
Interpolation Tap Size (taps parameter)
"For upsampling (making the image larger), the filter is sized such that the entire equation falls across 4 input samples, making it a 4-tap filter. It doesn't matter how big the output image is going to be - it's still just 4 taps. For downsampling (making the image smaller), the equation is sized so it will fall across 4 *destination* samples, which obviously are spaced at wider intervals than the source samples. So for downsampling by a factor of 2 (making the image half as big), the filter covers 2*4=8 input samples, and thus 8 taps. For 3x downsampling, you need 3*4=12 taps, and so forth.
Thus the total number of taps you need for downsampling is the downsampling ratio times the number of lobes (thus Tx downsampling and LanczoskResize results in T*2*k taps). And practically, one needs to round that up to the next even integer. For upsampling, it's always 4 taps." Source: [avsforum post] (http://www.avsforum.com/avs-vb/showthread.php?s=&postid=4760581#post4760581).
Lanczos4Resize is a short hand for LanczosResize(taps=4).

Gizzmoe
03-15-07, 03:47 PM
Nah! Just use AVISynth and it will do it close to real time. It is of course - CPU dependant.
Close to real-time for decoding 852x480 material, resizing it to 1280x720 and recoding it to MPEG4/H.264??? :hmm: Which CPU do you have?

Iīd once recoded a standard 720x400 MPEG-2 to H.264 using x264 (multi-threaded) with VirtualDub and my X2 4600, it was like 13 fps on average. I prefer XviD/H.263, single-pass with Q2.5, itīs quite a bit faster.

The x264 VfW codec:
http://deaththesheep.uni.cc/

SUBMAN1
03-15-07, 05:26 PM
Close to real-time for decoding 852x480 material, resizing it to 1280x720 and recoding it to MPEG4/H.264??? :hmm: Which CPU do you have?

Iīd once recoded a standard 720x400 MPEG-2 to H.264 using x264 (multi-threaded) with VirtualDub and my X2 4600, it was like 13 fps on average. I prefer XviD/H.263, single-pass with Q2.5, itīs quite a bit faster.

The x264 VfW codec:
http://deaththesheep.uni.cc/
It helps to have more cache for large files, so I bought a 4400+ instead. I also prefer Xvid for AVI's, though CCE SP is my main MPEG-2 encoder. AVISynth though is very fast for frame serving. Nothing is faster that I know of. I even use it for serving VirtualDUB. Also, the tighter the script, the faster the frame serving as well.

-S

PS. By the way, H.264 is the future I think. Or at least it is in a good position to be.