Help: Capturing 4 Min DV produces 1 min of video

[ColinSouthern]

Hi folks,

Can someone please point out what's going wrong ...

I've got a Sony TRV355E Digital 8 Camcorder - I'm capturing using Roxio DVD Builder (v6) using a dual P3-500 PC and a USB 1.0 port.

Video displays fine on the PC whilst I'm capturing, but after capturing approx 4 min of video I'm left with about 1 min of capture - playing back, everything appears to be speeded up, except that the sound appears to be playing back in real time - so is hopelessly out of synch.

Anyone got any ideas?

Cheers,

Colin

[bugster]

I don't know anything about your camera, or the application you are using to capture, but USB1?

DV has a data rate of around 25Mb/s, USB1.1 has a MAX data rate of 11Mb/s, and this includes a lot of overhead with max achievable throughput (not burts) being nearer 7Mb/s. Can DV be captured in this way? It doesn't look like it. Does the camera not have firewire (iLink in Sony terms).

[ColinSouthern]

Thanks for that.

I had more of a dig around the net, and it looks like the USB 1.0 is indeed the problem.

By co-incidence, I was able to test on a PC with a firewire port - interestingly, all captured OK - but I ended up with a AVI file instead of the MPEG-2 file I was getting when done via USB.

Any ideas as to why the different format, and is there an easy to use utility to convert it to MPEG-2?

Many thanks.

[Craig Tucker]

When doing it via USB you are capturing an analogue signal from the camcorder, bad news as you will not only drop frames but the capture will be of inferior quality.

When you use firewire you are transferring the DV avi file from the camcorder to your hard drive, this is not capturing but more like copying the file across with no quality lost. This should be the only way anyone uses for getting DV of a camcorder.

To convert to mpeg2 for later authoring and burning to DVD use TMPGEnc.

[ColinSouthern]

Craig,

Thanks for the explanation - Is it best to store 'original' footage in AVI or MPEG-2 format?

Is it possible to tell the difference by looking at it?

Cheers,

Colin

[Craig Tucker]

Its best to store it as AVI as it is much easier to edit than mpeg2, and encoding to mpeg2 will incur some quality loss however small. However the transferred avi files are pretty large, approx 13GB per hour so I keep all my footage on the original DV tape (I dont overwrite), that way I can always go back to the original source if need be.

[chazzie]

Isn't DV around 115 mb /Sec ?

[ColinSouthern]

> Isn't DV around 115 mb /Sec ?

I'm the last person in the workd who could answer this with any certainty, but I read somewhere that the 'DV' stream that's fed out of the camera is already compressed 2:1 for broadcast quality cams, and around 5:1 for the 'average' handycam.

[Craig Tucker]

Isn't DV around 115 mb /Sec ?

No, 25 Mbps or 3.125 MBps

b = bits, B = Bytes, 8 bits in a byte.