HDTV to High Quality Xvid

[drj]

I was hoping for some help and some critiques in trying to get the highest quality xvid avi from high definition digital cable captures. I have seen the type of quality you can get from this type of conversion and was hoping to reach that level and beyond. My goals are to have full 1080p avi with 5.1 sound. So far I have been getting pretty good results with the average size file of 1,400 for a 45 min show.<O</O
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My method is 1<SUP>st</SUP> I run my .ts through mpeg2repair<O></O>
2<SUP>nd</SUP> demux with DGIndex<O></O>
Then I run this avisynth script through VDM:<O></O>
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[code]<O></O>
Tfm()<O></O>
Tdecimate()<O></O>
RemoveGrain(mode=1)<O></O>
RemoveGrain(0,11)<O></O>
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Then I run a 2 pass encode with the video and audio demuxed from DGIndex. I set the target size according to a ratio, basically 1 min = roughly 38 mbs. <O></O>
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Some of the specific questions I have are:<O></O>
How does my avisynth script look? Any advice one way or the other? <O></O>
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What are the precise settings in VDM to achieve the high quality encodes that I am trying to achieve. I have read through 3 guides about what each setting does, but not any advice on what the settings should be, and how it affects overall quality. Things like should I use BVOPs? I think that I understand how they are used. Basically they take information from the frame ahead and the frame behind and compresses them, right? So those 2 frames that this info comes from, does that get dropped? <O></O>
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I’ve read about the quantization and different quantization matrices; one for high bitrate, low bitrate, ultra low, and so on. Is there one that any uses to encode high quality hdtv captures to xvid. <O></O>
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How about quantizer restrictions? I’ve read for min that 2 is better than 1, because 1 results in big file size with not much more quality than 2. So isn’t max 31 too high for what I am trying to do? <O></O>
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Is it a good idea to use VHQ mode 4? I am not worried about encoding times at all, I’ve got time, as long as we’re not talking about days and days. <O></O>
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I am not even sure if tweaking these settings will make that much of a difference. Will it? <O></O>
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I’ve had some issues where my encodes get a bit jumpy / blocky (hard to describe) in high motion and pan and scan scenes. Like something is flashing in between frames horizontally. There are no artifacts on the frames when I look at them one by one, but when played in succession, I guess it isn’t as smooth and nice as when there isn’t any motion or little motion. Any ideas to remedy this?<O></O>
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Here are 2 links to 10 secs of my encodes thus far if anyone is interested. <O></O>
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http://www.filecrunch.com/file/~7ed61y<O></O>
Right before the first guy swings you’ll see what I am talking about in terms of high motion scene problems that I am experiencing, and then other guy retaliates.<O></O>
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http://www.filecrunch.com/file/~tlgoo6<O></O>
And again as the last building is in a panning shot you’ll see it again. <O></O>
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I know that quality is a subjective term, so I guess I can put it this way. If I am willing to set aside up to 1,400 mbs per file, what settings should I use to get really great visually appealing results?<O></O>
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Any advice or information would be so appreciated.
This forum rocks. Thanks. <O></O>
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I do apologize for the length of this post. Sorry. <O></O>
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Happy holidays. <O></O>

[anonymez]

with the average size file of 1,400 for a 45 min show

grainy 1080p at less than 4mpbs is terrible (well, in my eyes) for mpeg4 AVC, let alone ASP.

How does my avisynth script look? Any advice one way or the other?

i really couldn't tell you. as you say, quality is subjective. i like to preserve grain, for example

Things like should I use BVOPs?

yes. a little dated, but an interesting read

Is it a good idea to use VHQ mode 4?

it's not a bad idea. at 4mpbs 1080p, it can only be good

I’ve had some issues where my encodes get a bit jumpy / blocky (hard to describe) in high motion and pan and scan scenes. Like something is flashing in between frames horizontally

downloaded and played the first clip, seems like a problem on your end. which player/renderer/decoder?

If I am willing to set aside up to 1,400 mbs per file, what settings should I use to get really great visually appealing results?

if 3.5-4mpbs is as high as you're willing to go, resize to 720p and use x264 instead (in which case you may also like to take a look at MeGUI-- vdubmod hasn't been updated in a while)

if you wish to keep it 1080p, go for 10mbps x264

[drj]

@ anonymez
Thanks for taking the time and replying to my questions. I really appreciate your initiative and you informative responses and addressing my questions.

I am re-reading the unofficial xvid guide and running some more tests. I'll keep you posted once I have some better perspective of what I am doing and after sufficiently experimented with all these settings.

Again, thanks. Your input was great, very helpful, and quite insightful.

drj

[drj]

@ anonymez

What script do you use to preserve grain? Does my encode look grainy to you, or bad in your eyes in any way?

player = it happens on both VLC and WMP11
codec = xvid 1.1.2

I’m pretty sure that it isn’t a problem with playing the file, because if you load the file into VDM and advance each frame with the [RIGHT] key, you will see it also.

Not sure what you mean by renderer? Can you clarify?

So do you think x264 is a better way to encode vs. Xvid? What kind of file size would I expect if I used x264 with 10mbps x264 is an average 45 minutes clip has 61,000 frames?

I just don’t see much media out there that is encoded with x264, that’s why I’m asking.

Thanks again.

drj

[anonymez]

What script do you use to preserve grain?

usually nothing more than mpeg2source, colormatrix and crop in the script

player = it happens on both VLC and WMP11
codec = xvid 1.1.2

could you describe the problem? you describe jumpiness and blockiness in your original post (both of which i see) but they're two different problems. i don't know much about US HDTV broadcasts, but aren't they progressive 24fps?

So do you think x264 is a better way to encode vs. Xvid? What kind of file size would I expect if I used x264 with 10mbps x264 is an average 45 minutes clip has 61,000 frames?

x264 has a hard time preserving grain at low-medium bitrates compared to xvid, but offers higher compression. file size (video only, in megabytes) = (10*45*60)/8 = 3375mb

[drj]

@ anonymez

could you describe the problem? you describe jumpiness and blockiness in your original post (both of which i see) but they're two different problems. i don't know much about US HDTV broadcasts, but aren't they progressive 24fps?

I am capturing from the high def channels. As far as I can tell, the frame size is 1920x1080, the frame rate is 29.97. I know that the channels are telecined (right term?) because I can see the interlacing artifact on the untouched video, which is removed by using the script that I mentioned.

I used the term blockiness / jumpiness because well, it really isn’t either one, but maybe a combination? There are no blocks per say, like pixilation effects, and the file plays smooth as silk, but in scenes with high motion or pans and scans, there is something there. I guess the best way that I can describe it is it looks like a black line jumps across the screen horizontally, very, very quickly. But no lines in the individuals frames. So maybe the frames don’t match up exactly so when played in succession, you see something. I don‘t know??? Maybe a frame dropped where it shouldn’t have???
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In the scenes that I uploaded, right before the punches are exchanged in the first clip (clipff) and in the second clip as the scene pans upward on the last building (clipb) you’ll see what I am referring to.