Compressing DV without losing quality?

[Nikos]

I know DV is uncompressed. But I have some Sport Highlights that I imported via Firewire/DV. It is uncompressed. The source is really from a VHS (VHs to D8 to Cpu), so the quality is not that good to begin with.

But I want to compress the files WITHOUT losing any noticable quality. Again it is sport highlights, so it is a little sensitive to compression.

How should I go about compressing it without losing much visible quality?

Any help would be greatly appreciated. And sorry if this is int he wrong forum, I am not sure where to post the question.

Thanks

[jimmalenko]

I know DV is uncompressed.

No. DV (25Mbps) is compressed at about 5:1 - see http://www.dvcollections.com/support_dvcompress.html

But I want to compress the files WITHOUT losing any noticable quality. Again it is sport highlights, so it is a little sensitive to compression.

How should I go about compressing it without losing much visible quality?

Is it bad quality because there's a lot of noise ?
Are you getting macroblocking / artifacting when you compress ?
Are you prepared to use filters to clean it up as best as possible ?


I use this guide for editing / applying noise reduction, and open the script directly in TMPGEnc. You can then use CQ mode (which theoretically is the best overall quality) , but with the disclaimer that the resulting filesize is almost impossible to predict.

[edDV]

VHS is a low quality source.
If it looks OK in DV format, lightly compress it to DVD.

That is if DVD is your goal.

What is your goal?
Is a 40 cent DVD per hour beyond your budget?

Are you trying to email this to someone?

[Nikos]

No it is just a collection of highlights of a Sporting Game. The quality is VHS, that is why I said it is just OK quality.

What compression scheme should I use, where I can save physical HD space, but still not see much of a loss in quality is my question?

[edDV]

No it is just a collection of highlights of a Sporting Game. The quality is VHS, that is why I said it is just OK quality.

What compression scheme should I use, where I can save physical HD space, but still not see much of a loss in quality is my question?

Got it.

25 Mbps DV (720x480/567) holds up well at 7-9 Mbps DVD MPeg2.
CBR may be best if there is mostly action. You could experiment with VBR.

If you don't like the quality, take it up to 12-15 Mbps but this will be too high for a DVD player.

If you wanted to go higher compression you could experiment with 352x480/576 at around 5-6Mbps. In theory VHS horizontal resolution will max below 352 pixels (~240 perceived lines).

[Nikos]

What program can I use to make these comversions?

[edDV]

What program can I use to make these comversions?

An MPeg2 encoder.

You may have one in an editing or DVD authoring application.

[thecoalman]

If it's just for computer playback you can try Windows Media Encoder. It will compress them more than mpeg2 and still maintsain the quality, the only trouble is that it's not a viable alternative if you wish to create DVD's from these files.