avi codec quality

[EAO]

I'm capturing using Virtual VCR.

After trying both Huffyuv and Picvideo mjpeg, I have settled on mjpeg.

But I firmly believe that the codecs behave differently in different PC's because I have rebuilt - and installed different o/s's - in my PC enough to have viewed the differences when using the same codec.

There is a huge compression difference between mjpeg 19 and mjpeg 20.

I was wondering if there was a different codec or hack that would allow something like setting mjpeg 19.5. Huffyuv is close, but it has fast motion issues for me, so I'm wondering if there are alternatives that someone out there has tried and liked.

My goal is to capture from sat TV at 720x480 in NTSC, and then convert to DVD. I would like to keep these captures, so quality is an issue.

[SaSi]

Just a thought.

Isn't satelite TV digital? I don't know if it is in the states or if different channels have different medium, but if it is digital (i.e. MPEG2), you could use something like a DVB recorder setup and record directly the MPEG2 transmission, demux the system stream into ES and use them to author a DVD.

[duhmez]

Huffyuv is lossless, and can't have fast motion isues. (As long as you don't choose >export yuy2 then it is totally lossless)

huffyuv is like a zip file, it contains the data as rendered by the capture hardware, pixel by pixel.

[EAO]

I was capping huffyuv using yuy2. When I switched to rgb24, I would drop frames. If you have any suggestions, I'll experiment.

FYI - This is a fresh install of winxp pro. No service pack. No critical updates. It has been much more stable in terms of dropped frames than when I add all the other junk. All possible services are turned off - sys restore, indexing, etc.

[trevlac]

Huffyuv is lossless, and can't have fast motion isues. (As long as you don't choose >export yuy2 then it is totally lossless)

Can you explain to me wht a 'fast motion issue' is?

Huffyuv can capture YUY2 and RGB lossless. If you input as RGB and convert to YUY2 the conversion causes some minor loss. This type of conversion can take place:
-Inside your card (if you ask for anything but a YUV output)
-In Huffyuv if you ask it to compress RGB as YUV
-When Huffyuv outputs a YUV compressed file to something like VDub which wants only RGB.

You should capture as YUY2 and only edit in Avisynth if you are concerned about colorspace conversions. Your encoder may even cause a conversion.

[EAO]

Sorry I wasn't clear.

On this particular instance, it was from sat TV source. There was a small plane flying moderatley high over a rural countryside. The shot was from high enough off the ground that the scene was moving without blurring. Trees , grass land, etc. If you've seen any of the Lord Of the Rings movies, it was similar in pace to the scene shots they did in the air. Not too fast. Everything in focus.

When I watched the .avi on the monitor, the scene had a very slight but noticeable jitter. Like it couldn't keep up and would skip frames when necessary. (No dropped frames reported by virtualvcr) I have never seen that in any huffyuv capture before, but there it was. Not something I want to deal with after a capture. I have never seen it in a picvideo capture, so the decision for me was easy.

[trevlac]

I think this is a preview issue. The data is captured as long as no dropped frames. Search for huffyuv preview to be sure.

[bottle-necked]

I've used Huffy alot and I've also captured off DirectTV and I couldn't help but wonder if that 'jitter' you talked about wasn't in the original transimission instead of so much in your captured video. Sometimes you couldn't ask for a better video input than DirectTV but then again there are times their transmission is really bad, like VCD or worse. I've seen shows the audio didn't even match the video on 'live' TV from them. You talk about having trouble capturing video!!

I tend to find their movie channels, Encore, to have better quality than say 'TNT, but this isn't always the case. I suppose they sometimes use copies of copies or are very limited on bandwidth.

Anyway, I don't have any negetive comments about Huffy. Picvideo I've tried a few times and it's alright, but for the price.... lol

[duhmez]

Perhaps your isses is only during payback from huffy. Decoding huffyuv takes alot more cpu than encoding it, and its moving massive amounts of data. if this is the issue then its a non issue. I recommend you compress your huffy into somehitng else then play it, i bet the motion issues yua re talking about go away.

[trevlac]

Perhaps your isses is only during payback from huffy. Decoding huffyuv takes alot more cpu than encoding it, and its moving massive amounts of data. if this is the issue then its a non issue. I recommend you compress your huffy into somehitng else then play it, i bet the motion issues yua re talking about go away.

This is what I ment. Sorry I said preview. I ment playback.

[EAO]

I gotcha. Makes sense. In your opinion does the huffyuv codec produce a better image than picvideo mjpeg at setting 19?

I'll try it on an RW and see what happens.

[schematic2]

I found pic to give a very close second to huffyuv in its highest quality setting...

[duhmez]

technically pic at its highest setting is lossless is it not?
been a while since I used it though.
And yes pic @ 19 is a very nice quality and decent filesize. i do not however like the price when there's huffy, I'll just spend the extra cash I save on hard drive space

[SaSi]

technically pic at its highest setting is lossless is it not?
been a while since I used it though.
And yes pic @ 19 is a very nice quality and decent filesize. i do not however like the price when there's huffy, I'll just spend the extra cash I save on hard drive space

MJPeg is compressing each frame as a separate JPG picture. Picture quality goes just like JPG compression quality goes.

Mjpeg is a good codec for capture-->edit as it compresses all pictures as self-contained frames. No interpolated or predicted frames. This is good for editing, as you can cut at your heart's desire.

Hufyuv is a good codec for the same purpose as it doesn't introduce another step of quality loss (relevant for high quality source and less important for VHS capture) but also more appropriate when for whatever reason your system cannot cope with the CPU load of compression. Hufyuv requires less CPU than Mjpeg or Divx but much more disk space.

If you have a powerful CPU (P4/2.0GHz or more) you might want to try DivX with a constant quality setting of 2 or less (1 is max quality) and a keyframe interval of 1. This makes DivX behave like Mjpeg compressing frames to jpeg at MPEG4 style. It might be an answer to some problems.