Convert captured image to divx, advice needed.

[tonyrobbo]

Can anybody help this divx noob?

I have a very good capture from an interlaced pal motor race from digital tv at 720x576, 49 mins in length using the picvideo codec at 19 setting.

I now want to convert it to divx5 but am unsure of the settings to use, i would like to deinterlace, but is not essential, image quality is the most important thing.

I did a 2 pass encode using virtualDub:

1st pass @1900
2nd pass @1900 Max @19000
Encode as progressive
Use GMC
Use Bidirectional encoding
all other setting are default

VirtualDub Filters:

Resize to 640x480 (precise bicubic a=0.75)
Deinterlace MAP


Are these settings correct, how could i improve image quality?
Do i need to use any other filters and are they in the right order?

Thanks

[teegee420]

I would set the bitrate to max on the first pass next time. De-interlacing is definitely a must for Divx. You captured from digital TV so I imagine picture quality is excellent, so there shouldn't be any need to apply additional filters to improve the image. Are you not happy with how your Divx file turned out?

[tonyrobbo]

Thanks for the suggestion teegee420, i will try that.

As for the quality of the divx, i did expect it to be a little better.
Should i move the motion setting towards high motion as well next time, because i left it in the middle.

Also is 1900 bitrate too low/high, what would you usually use?

[teegee420]

Can you describe in better detail what you are dissatified about with your Divx? Kind of hard to troubleshoot without seeing the problem first hand. By the way, your bitrate should be fine. Did you by chance use the Divx Pre-processing Source? That can easily cause noise if your source file didn't contain much to begin with.

[tonyrobbo]

To be honest i think it might be the original capture, i actually used picvideo at 18 setting on this test encode, i will be using 19 next time, kinda hard to tell with the capture being interlaced and the xvid not.

I did not alter the Divx Pre-processing Source settings.

Can you please confirm if i should use high/low/medium motion on this type of capture.

I was also hoping to reduce the bitrate to around 1350 but is that too low for this kind of capture.

Also, have i resized to the correct size or should i leave it at 720x576?

Just one more thing, should i alter the scene threshold setting?

Thanks again!

[teegee420]

Can you please confirm if i should use high/low/medium motion on this type of capture.

In most cases this setting can be left alone. Being that your source has high motion you can probably move the slider towards high motion. Honestly, I don't think you'll see much difference.

I was also hoping to reduce the bitrate to around 1350 but is that too low for this kind of capture.

That should still be a decent bitrate. Just know that less bitrate equals less quality.

Also, have i resized to the correct size or should i leave it at 720x576?

The size shouldn't matter. In fact when you convert to Divx it's usually a good idea to resize down. The compressor doesn't have to work as hard to spread the bitrate over a smaller area. You should use Lanczos resize for downsizing.

Just one more thing, should i alter the scene threshold setting?

I've experimented with this setting and have not found sufficient reason to change it from the default 50% value.

One more thing, I'm not familliar with your "Deinterlace MAP" filter. This is what I use:



I have to press you some more on what you perceive the problem to be. Do you still see interlace combing? Do you see heavy pixelation? Is there some other kind of noise? Try and explain a little more.