Capture VHS to DVD - constant or variable bitrate?

[Blackmore]

Searching in this forum I learnt that capturing for DVD is better using variable bitrate, but in some experiencing, a captured with constant bitrate (8000, I guess) and the result was much better than the variable.

I'm in doubt now,

- was i making any mistakes capturing variable?

- Is there any problem capturing constant?

- Could anyone specifie some good settings for capturing to DVD in 720/480?

I use ulead videostudio 7 and ATI AIW RADEON

Thank you once more, I'm improving alot with this forum.

Blackus

[Capmaster]

A lot of cappers agree that CBR yields a better picture .....it's debatable. But VBR is way more efficient in using disc space. It ramps up the bitrate in action scenes and drops it in static scenes to save space.

Your bitrate will no doubt be driven by your recording length. If it's a short clip and you have lots of space use something like 8000Kb/s avg. and 9500 peak. If it's longer you can get a simple calculator to figure what your max. bitrate can be for a given recording time. You can usually drop it a bit from the max. to 5000 avg. 6000 or 6500 peak. It's a matter of personal preference and you just have to use trial and error to get that "sweet spot".

[Anonymous65]

For VHS capture, there is no need to do 720x480 pixels. 352x480 will give you all the details that is on the VHS tape, and you can cut the bit rate in half with the same compression artifacts. My default setting for VHS captures is 352x480 at 4 Mb/sec CBR. Be careful using VBR on noisy video, it will increase the bit rate to very high rates trying to compress all the noise. So, for VHS, I would use CBR only.

[Blackmore]

Thanks a lot Capmaster, you explain it perfectly in few words.

Skittelsen, in this forum I read many times that the best capture is full d1.
but I'm gonna do some experiences myself with your setting to decide what is the best with my hard and software. Thank you very much.


Blackus

[SatStorm]

Let me try to clearify it to you:

With NTSC on all cases, it is better to capture VHS the higher you can, add filters, resize to 352 x 480 and encode to 1/2 D1 (352 x 576).

With PAL, it depends the hardware you have. if you have a bt8xx(x) based card, it is better the capture VHS the higher you can, add filter, resize to 352 x 576 and encode to 1/2 D1 (352 x 576) (same as NTSC).
But on all other cases (nvidia/ati/matrox/etc cards), this is an overkill. If you capture direct at 352 x 576, add filters and encode to 1/2 D1, you have exactly the same results.

Realtime mpeg 2 software captures, is another story.
Some programs, cap and encode at the framesize you set up, so it is as before.
Others, capture analogue at a specific framesize they autodetect in a card (or you set it up) and then encode realtime to mpeg at the framesize you set up to be the output (example: 352 x 480/576).


On those cases, you have to test and see the results.

General speaking, applications like WinDVR and PowerVCR simply cap and encode to what you set up: For examle, you set up 352 x 576, they cap and encode at 352 x 576. That explains why on the bt8xxx cards, the picture looks blury when you use those applications at those framesizes and why looks good when you cap at 704 x 576/480 for example.

Other applications cap always at a higher framesize and automatic automatic resize and encode to what you have set up for output the best possible way. So, even if you set up for example 352 x 576, they capture analogue higher, let say 720 x 576, resize to 352 x 576 and encode to 352 x 576. Those applications give better picture results, but they are CPU demending.

Also, there are few more proffecional applications, that allows manual adjustment on the input and the output. A great example on this approach, is Mainconcept 1.4.1

[Blackmore]

Thank you SatStorm. I guess I have all the informations needed and I just have to put in practice!!!

[troyvcd1]

Is this a typo?

Satstorm wrote:
With NTSC on all cases, it is better to capture VHS the higher you can, add filters, resize to 352 x 480 and encode to 1/2 D1 (352 x 576).

For ntsc why would you take your resized 352x480 video and encode to 352x576.

[SatStorm]

yes, this is a typo, sorry for this.
I type so many times 352 x 576 that my hand goes automatic when I type something with 352 x ...
Sorry again

[proac]

Satstorm, sorry for asking newbie question. You said 'it is better the capture VHS the higher you can, add filter, resize to 352 x 576 and encode to 1/2 D1 (352 x 576) (same as NTSC)' ,shouldn't you just encode
it straight to 1/2 D1 from whatever resolution you capture without doing the resizing?thanks

[SatStorm]

depands the hardware you have to capture...

With the bt8xxx cards no. Capture the higher you can, resize, encode.
With the other cards yes, it works that way.