DV loss

[skipc10]

What is the difference between type 1 and 2 DV and if given the choice, what should one choose?

Also, is DV a lossless compression and do different implementations have different quality levels, or is it pretty much standard now?

Thanks.

[EricB]

http://www.microsoft.com/hwdev/tech/stream/vidcap/dvavi.asp

The short version is that both Types have audio interleaved with video. Type 2 adds an additional audio track which is not interleaved making it more backwards compatible.

In practical terms, programs like Adobe Premiere expect Type 2 files and will report incorrect frame sizes and require rendering if you try to use Type 1. Ulead uses Type 1. So you should capture in the format that your editing program needs.

DV is not lossless. It is lightly compressed so there is some "loss" from the original source (ie. a 720 x480 frame for NTSC). However, once converted to DV, you now have a digital file which you can pass back and forth from editors, to the camera, etc with no difference in the file. So it is lossless in that sense. When you edit, only the frames that are changed get re-compressed.

[EricB]

.... there are not different versions with different quality levels. It is a file transfer from camera to computer. The computer does no compression work (already done by camera, or DV bridge) so frame dropping is a thing of the past.