Capture in AVI format and the Bit rates

adeel · Post by **adeel** » Mon May 21, 2007 7:07 am

Hi,

These 2 questions may have been asked before but i couldn't find anything in the search so apologies in advance

1) I use a USB capture device to capture video in ULEAD visual studio v8 in DVD format which is fine. But then i have do some minor editing and then create a Disc file before creating a final DVD. I've read before that after each reencoding the quality is lost a little. To avoid this i then tried to capture in AVI format. The settings i selected for AVI was "No Compress" which was great for quality but then the file size for 1 minute of captured vidoe was approx. 1.2GB!!! This is just unacceptable. I know with DV its 13GB per hour which seem peanuts compared to this. I have more than enough hard disk space (160gb) but with this file size 160gb is not a lot.

I then tried capturing in AVI with famous Huffyuv v2.1.1. I left the settings as default for Huffyuv. Things started off ok but then it slows down and eventually the sound dissapears after a minute or so of capturing.

Can anyone tell me what is the best settings to use when capturing AVI with Huffyuv 2.1.1 or if there is an alternative to capture in AVI but without the huge file size?

2) I've read some forum that as long as the original capture is done at high quality and bit rate (e.g 8000) then increasing the bit rate of the final DVD will only inrease the file size and won't affect the quality. Is this the case??

I capture in DVD format with 8000kpbs then after making some editing, i want to create disc file with 3000kbps (to fit around 2.5hrs of video on one DVD). If the above is true then this would work perfectly.

By the way, i capture vidoe in DVD format then edit it, then create disc file then create final DVD since i have a USB capture device.

PC Specs:
Intel Core 2 duo E4300
1GB DDR 2 RAM
160GB SATA HDD
USB 2.0 Capture device with sound

PS: i upgraded my PC since my last post

Thanks in advance for your help.
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Post by **jparnold** » Mon May 21, 2007 7:16 am

As far as I know, USB is not fast enough to capture in DV format, You should use Firewire connection when capturing in DV format as the throughput is much faster.

adeel · Post by **adeel** » Wed May 23, 2007 4:33 am

Hi John,

Thanks for your reply.

Actually i am able to capture in AVI but its not the DV AVI format. I understand that with USB i am not ablet to capture in DV format. In fact when i select DV it reverts back to either AVI or DVD. This AVI option allows me either select uncompressed capture or compressed using one of the codecs like Huffyuv. With Huffyuv i get no sound and slow capture after about 1 mintue.

Any ideas on my 2nd question about bit rates? Anyone?

Regards
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Ken Veal · Post by **Ken Veal** » Fri May 25, 2007 12:40 am

Hi
Have a look at the following + see if anything there helps
BIT RATES

Calculator http://dvd-hq.info/Calculator.html

http://www.videohelp.com/calc.htm
Compression issues
http://phpbb.ulead.com.tw/ENviewtopic.php?t=12118
regards Ken

adeel · Post by **adeel** » Mon May 28, 2007 4:50 am

Thanks Ken. These sites are quite helpful.
I tested the captured bit rate vs the final dvd bit rate. I have to say that it does matter. I captured a 1hr video with 8000kbps. Then output to DVD with 3000kbps. The difference was obviuos. There were lots of square pixels appearing when there was movement and it wasn't sharp at all compared to original capture.

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heinz-oz · Post by **heinz-oz** » Mon May 28, 2007 5:15 am

You don't tell us what your camcorder type is. If it is MiniDV and has a firewire port, you should capture to DV-AVI. AVI is only a container format and can contain anything from uncompressed DV (over 60 GB per hour) to highly compressed video like DivX, Xvid, mpeg4 etc. These highly compressed formats are a pain to edit and quality loss is immense. USB is not fast enough in sustained data rate with uncompressed or DV-AVI, that's why you should capture via firewire. DV-AVI does not have any settings to worry about since you merely transfer the data from your camera to the PC. There is no compression involved. This has already been done, relatively lossless, by your camcorder. Rendering this format to DVD compliant mpeg2, after your editing is done, yields excellent quality and is the only way I will work with digital video.

GeorgeW · Post by **GeorgeW** » Mon May 28, 2007 4:29 pm

adeel wrote: 2) I've read some forum that as long as the original capture is done at high quality and bit rate (e.g 8000) then increasing the bit rate of the final DVD will only inrease the file size and won't affect the quality. Is this the case??

I capture in DVD format with 8000kpbs then after making some editing, i want to create disc file with 3000kbps (to fit around 2.5hrs of video on one DVD). If the above is true then this would work perfectly.

Going from 8000kbps to 3000kbps will decrease quality of your video. What USB capture device do you have, and what is your source video (VHS or some other analog video)?

Regards,
George

GeorgeW · Post by **GeorgeW** » Mon May 28, 2007 4:37 pm

heinz-oz wrote:USB is not fast enough in sustained data rate with uncompressed or DV-AVI

USB2 is plenty fast enough for sustained data rates needed for DV-AVI -- it's just that the interface doesn't exist across all DV camcorders. However, there are some dv camcorders with an interface to transfer the dv .avi via USB2 -- and they work just as good as firewire (I've seen a couple of applications with positive results).

Regards,
George

GuyL · Post by **GuyL** » Tue May 29, 2007 5:23 pm

What are you capturing from? It sound to me like you are capturing from an analog source through a USB capture device. Can you verify this and the device you are using, please? Also, please update you system information so we know what hardware you are using.

adeel · Post by **adeel** » Wed May 30, 2007 2:01 am

Thanks all for your help. Much appreciated.

The usb capture device i have doesn't have a brand name. It appears as "Syntek" when i plug it in windows. But the quality is really quite good for the captured video. I am capturing from VHS and Panasonic MiniDV camcorder. I mainly be converting VHS to DVDs and that's why i opted for the USB capture.

The only reason i wanted to capture in AVI was to reduce the risk of quality loss when i have to edit the captured video. But not sure why the AVI option captures in such big file size (1 min = 1.2gb) when "No Compression" selected. Maybe its windows AVI format??

But with Huffyuv selected it doesn't go pass 1 minute without sound going off and video slowing down. I read a lot of good comments about Huffyuv but for some reason it doesn't work well under Ulead VS v8.0. COuld it be Ulead?

PC Specs:
Windows XP Pro Spk2
Intel Core 2 duo E4300
1GB DDR 2 RAM
160GB SATA HDD
USB 2.0 Capture device with sound
Panasonic NV-GS27 miniDV camcorder

Thanks
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Post by **Ken Berry** » Wed May 30, 2007 3:26 am

Regarding captures from your mini-DV camera, the ONLY, repeat ONLY way of getting high quality captures is by capturing to DV format (the exact same format used by the camera) over Firewire. And if your computer does not have a firewire card, then buy and install one. They are cheap these days and (relatively) easy to install.

And if you look at your camera's manual, you may find that it also has a pass-through capacity. This would allow you to connect your VCR to the camera, which then acts as a bridge, converting the analogue VHS to digital DV format which you transmit to your computer via Firewire. Not all cameras have this capacity, however. That's why I say you would need to consult your camera manual.

Re your AVI capture: the Syntek device fairly obviously cannot capture in DV format. The AVI format you originally chose is uncompressed AVI which, as you have found, is huge. Approx. 65 GB per hour of video. DV uses the AVI extension, but is smaller, at 13 GB per hour.

I assume the capture device can be set for mpeg-2 capture? Have you tried that and is the quality reasonable?

Sorry, but I can't comment on the Huffyuv aspect as I have never used it.

GuyL · Post by **GuyL** » Wed May 30, 2007 11:51 am

The AVI format is uncompressed that is why it is so huge. All other forms are compressed. DV, MPEG, HuffyUV are all compressed to some degree or other. If you are forced to capture from an Analog source I would recommend using your passthrough on the DV camera as Ken suggested. However, if you do not have that option the huffyuv codec is by far the best. I used it for years but with an ATI All-In-Wonder capture card.

Your system is more than adequate so I don't think your USB device is capable of capturing huffyuv in a sustainable fashion. However, I've never used such a device so I don't know for sure. I know it worked flawlessly on my ati capture card on a much less powerful system at the time. If you can get it to work it will be about 60GB per hour of video.

daniel · Post by **daniel** » Wed May 30, 2007 1:18 pm

GuyL wrote:The AVI format is uncompressed that is why it is so huge. All other forms are compressed.

Pardon me for taking the liberty to rephrase that for sake of completeness:
The DV-AVI format captured from a DV camera is not compressed any more than it was on the tape.

DV IS a compressed format.
First, half of the color information is simply dropped (sampling at 4:2:0 for PAL or 4:1:1 for NTSC).

Then after that we get about 125MBit/s which is further compressed to about 25 MBit/s, or a 5:1 compression factor. This is mainly done by taking into account the inter-fields redundancy in a frame, and other methods closely related to the standard image treatment in JPEG.
Then you add stereo LPCM audio data... This is how they get to the very low size of 63GB/hour...

Then came high definition video...

adeel · Post by **adeel** » Wed May 30, 2007 11:33 pm

Hi Guys,

Thanks for your help and recommendations. I will play around with Huffyuv to see if i can get it to work. I can capture in DVD format but i wanted to retain the original quality as much as i can after minor editing and thats why i was exploring the AVI path. But the AVI path is quite large!! I'll check if my camcorder has the pass through capability. If it does then that would be great.

This forum is great. I am learning more each time i visit here. Again thanks for taking time to help me.

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