DV conversion playback on HDTV

[fitzy626]

I am looking to get the best quality (reasonable quality = 1G/hr) from my DV captures so i can playback on my HD LCD.
I am using WD Media Player TV Live so it plays all kinds of codecs. I am playing around with h264 and Xvid codecs.
I am using IMtoo HD Video Converter to convert my DV AVIs.
My questions are:
1. Is there an optimal Video size (I've tried 720X480, 640X480 and even 320X240) If i keep the bit rate constant and change the video size, there is little or no real quality difference when viewing the different files on my LCD. Why??
2. Bit rate seems to be the only thing that affects quality (and file size) but is there a diminishing return if you increase the bit rate to 10,000kbps). What is the optimal settings based on video size
3. Does change GoP affect quality
4. I did enable De-interlacing and this removed all artifacts and jagginess to the video.
5. I read that Q-scale affects compression and quality but again lowering the value to say 6 (deom 25) does not change the filesize
6. Are there different codecs or programs i should be using to perform the conversion.


thanks, any help is appreciated.

[edDV]

You didn't say if this is camcorder video. I'll assume you mean 720x480i/29.97 (59.94 fields per second) DV.

In that case the answer is MPeg2, 720x480i, lower field first with average VBR between 5-9 Mb/s (depending on quality desired) with MP2 or AC-3 audio at ~256Kb/s. So far my experiments with interlace h.264 show lower quality unless similar bit rates are used. An h.264 bob deinterlace to 59.94p will require equal to more bit rate with no quality improvement.

My questions are:
1. Is there an optimal Video size (I've tried 720X480, 640X480 and even 320X240) If i keep the bit rate constant and change the video size, there is little or no real quality difference when viewing the different files on my LCD. Why?

You mean for DV direct playback? If so.
a. The camera never had full 720 horizontal resolution. Most consumer models don't.
b. The TV deinterlace + upsize can't hold the quality. Detail gets processed out.
c. The sample video didn't have sufficient horizontal detail. Leaves or grass are a worse case.

2. Bit rate seems to be the only thing that affects quality (and file size) but is there a diminishing return if you increase the bit rate to 10,000kbps). What is the optimal settings based on video size

For MPeg2, >8000kbps starts to show deminishing returns. High action (e.g. sports) will show improvement above 9000kbps.

3. Does change GoP affect quality

Longer GOP is one potential strategy so long as you don't try to edit later. Experiment with action shots.

4. I did enable De-interlacing and this removed all artifacts and jagginess to the video.

But it also cut in half the motion increments and added blur unless you used bob deinterlace. Most camcorder video suffers from deinterlace. That is why I recommend interlace MPeg2.

5. I read that Q-scale affects compression and quality but again lowering the value to say 6 (deom 25) does not change the filesize

Depends on action, noise and frame detail.

6. Are there different codecs or programs i should be using to perform the conversion.

Some choices
a. MPeg2 interlace - optimal for DV. 120Hz HDTV sets will like it.
b. h.264, VC-1 interlace - no real file size benefit.
c. h.264, wmv progressive - deinterlace artifacts, not compatible with 120/240Hz HDTV processing.

[edDV]

PS: A question not asked is levels correction.

Most consumer DV/HDV/AVCHD camcorders record hot whites over the 16-255 range. If you want these to appear similar contrast to normal TV, you should reduce nominal whites down to level 235. A few overshoots above 235 (e.g. bright cloud detail or lights) are OK. Black at 16 will match broadcast and DVD black.

[fitzy626]

yes the DV capture is from a camcorder. I am not playing DV-AVI on my TV. I would like to convert first using the best codec and software to perform this. Which software are you suggesting - can you please include the link.
I didn't understand the answer why when i play around with the video size, it has no real impact on quality when played back on hd tv, why is that. there is also no change in the file size which i find strange because every post i read says bit rate and video size affect the file size.

[edDV]

yes the DV capture is from a camcorder. I am not playing DV-AVI on my TV. I would like to convert first using the best codec and software to perform this. Which software are you suggesting - can you please include the link.

You would use a typical DV format edit program (e.g. Premiere, VideoStudio, Vegas, etc.) or separate MPeg2 encoder.

What software do you have?

I didn't understand the answer why when i play around with the video size, it has no real impact on quality when played back on hd tv, why is that. there is also no change in the file size which i find strange because every post i read says bit rate and video size affect the file size.

What is your camcorder model? What is your HDTV model?

If the camcoder is capable of full 6.75MHz 720x480 detail, then you should see a difference vs. 640. If not, convert 720x480 (DVD compatible) to 640x480 (not DVD compatible) and use 88% the bit rate you would have used. If you can't see a difference at 524x480 (digital cable quality), your camcorder or TV must be a low performer.

[fitzy626]

My camcorder is panasonic PV-GS13 and i have already captured the DV using Nero9/Nero Vision. Captured AVI has following characteristics.
Format: DV/DVCPRO NTSC
Video: 640X480
Audio 32Khz
FPS: 29.97
Data Rate i think is ~30mbps

I already have the AVI file. Right now i need to convert,so what codec, software and settings should i use to obtain near AVI uncompressed quality. Right now im trying to keep the converted file to under 1GB/hr of conversion.

HD TV is Samsung 46 LCD however for testing right now I am using a Sanyo 19" LCD with component cables connected to the WD Media player.