Best bitrate / file size compromise when capturing video?

[NTB]

Most of the time, I just leave it on DVD standard play, which uses a variable bitrate with ~6Mbps average and ~8Mbps peak. However, over the next few days I'd like to do quite a bit of recording - capturing from the card's tuner - and I was wondering if there was any way to decrease the overall file size and still keep a similar level of video quality; I intend on burning the caps to DVD when I'm finished.

One thing I am experimenting with is lowering the average bitrate (which I initially thought was the *minimum* bitrate...oops 😱 ) I lowered it to about 4Mbps, and still got fairly good results, at least when looking at them on my 27" TV. Only real problems I saw in the short bit that I watched were color bands in areas where there wer sharp dilineations in color - the edge between a person's face and the background, for example, would occasionally be a bluish color, or green.

So, what settings do you use?

EDIT: trying this again, since the first one seems not to work 🙁

Nate

 

[Megatomic]

This info is useful to me, too. I'm bookmarking your thread NTB. 😀

 

[NTB]

Originally posted by: Megatomic
This info is useful to me, too. I'm bookmarking your thread NTB. 😀

Too bad nothing useful's been posted yet 😛 To the top!

Nate

 

[Matthias99]

I got better results (personally; this is somewhat a matter of taste) with CBR rather than VBR. I also capture at a fairly high bitrate (7500Kbps) most of the time.

However, you're definitely going to start seeing some degradation if you get much below 6-7Mbps (at least with video with a lot of motion in it; sources with little motion will compress much more readily). There's just no way around it with MPEG2. Capturing in MPEG4 or WMV8/9 may help (they're more efficient, and will look better at the same bitrate than MPEG2), but if you want to burn files playable in a standalone DVD player, that's not really helpful.

 

[Megatomic]

So, MPEG4 won't play back in standalone DVD decks?

 

[Matthias99]

Originally posted by: Megatomic
So, MPEG4 won't play back in standalone DVD decks?

A few newer ones can play back MPEG4 files, as well as raw MPEG2 files on a DVD-R (as opposed to a mastered DVD from .vobs). Most older standalone players cannot play anything but properly mastered MPEG2 DVD disks.

 

[NTB]

^
^
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I was afraid of that. Thought I'd ask, though.

Nate

 

[NTB]

Any other suggestions?

 

[DaveSimmons]

I haven't gotten around to installing my PVR-150 to try this, but you might try recording initially at the highest quality format, then re-encoding to a lower bitrate afterward, not in real-time.

Software like DVD-Shrink can often meet an average bitrate target better than real-time encoding can because it can make a pass through the entire recording to decide which parts need more bits and which need less.

 

[NTB]

Originally posted by: DaveSimmons
I haven't gotten around to installing my PVR-150 to try this, but you might try recording initially at the highest quality format, then re-encoding to a lower bitrate afterward, not in real-time.

Software like DVD-Shrink can often meet an average bitrate target better than real-time encoding can because it can make a pass through the entire recording to decide which parts need more bits and which need less.

That would work, but "episodes per DVD" is not what I'm shooting for - I'm trying to catch as much of a marathon as I can, so I'm trying to conserve space from the word go. I guess the easiest solution is simply a bigger HDD 🙂

Nate

 

[NTB]

Now that I think about it, I suppose I could always just capture at 1/2 D1 (352x480) rather than full (720x480). That requires less space. Never tried that before, though; I wonder if the picture would come out too soft?

Nate

 

[halfadder]

Experiment. It all depends on the quality of the incoming video signal and your own personal tastes. Spend a few hours and find the best combination for you.

 

[NTB]

Originally posted by: halfadder
Experiment. It all depends on the quality of the incoming video signal and your own personal tastes. Spend a few hours and find the best combination for you.

That's what I'm doing. Trying the Half-D1 that I was talking about earlier now. I will record a bit, burn to DVD, and see how it looks.

Nate

 

[Matthias99]

Originally posted by: NTB
Now that I think about it, I suppose I could always just capture at 1/2 D1 (352x480) rather than full (720x480). That requires less space. Never tried that before, though; I wonder if the picture would come out too soft?

Nate

You might try 640x480 rather than 352x480 if you still want good quality. The NTSC 480i input signal only has ~500 horizontal pixels anyway... 720x480 capture is a bit of a waste. 😛

You could also cap to MPEG4 or WMV, then transcode to MPEG2 later to burn to DVD. Depending on what you use to do the re-encoding, this may or may not look like crap.

But, again, quality differences are highly subjective. I'd try a few different things out and see what works best.

 

[NTB]

Originally posted by: Matthias99

Originally posted by: NTB
Now that I think about it, I suppose I could always just capture at 1/2 D1 (352x480) rather than full (720x480). That requires less space. Never tried that before, though; I wonder if the picture would come out too soft?

Nate

You might try 640x480 rather than 352x480 if you still want good quality. The NTSC 480i input signal only has ~500 horizontal pixels anyway... 720x480 capture is a bit of a waste. 😛

You could also cap to MPEG4 or WMV, then transcode to MPEG2 later to burn to DVD. Depending on what you use to do the re-encoding, this may or may not look like crap.

But, again, quality differences are highly subjective. I'd try a few different things out and see what works best.

Can't do that - not in WinTV at least. My only options are 720x480, 480x480, and 352x480. I would try it at the middle res, but I believe that only works for SVCDs, and is not part of the DVD spec. SVCDs don't work in my DVD player, so I doubt that a DVD burnt like that would, either.