Is DV codec capture from DV camcorder losless or not ?

[donpedro]

I saw some posts about capturing and codec issue. It will alleays end up with saying that with "every" codec (compressioon/capturing method) you loose quality. Now... I am confused about all this. I alwayss tought that with DV camcorders you don't loose quality at all. So here is example.

1. Shooting video with DV Camcorder = DV codec compression tak place and data are stored compressed on tape.

2. Capturing data from DV Camcoder through FireWire (IEEE-1394) to PC. This should be lossles data trasfer. Only possible issues are if PC can't catch up with data.

3. Editing with software without adding titles or transitions. Simple cutting and joining. Should be lossless since no reencoding is needed.

4. Creating AVI file with same DV codec as it was captured. Losless since it will just join original parts of AVI file.

5. Transfering back to DV Camcorder FireWire (IEEE-1394) to PC. This should be lossles data trasfer. Only possible issues are if PC can't provide continues stream of data.

So am I missing something ? Are my assumptions wrong ?

[Craig Tucker]

No that all seems correct to me.

The DV codec itself isn't lossless, in your first point you mention DV codec compression for storing video on tape this is the lossy part.

When you record using your DV camcorder it is compressed using the DV codec, transfering it to your PC incurs no further loss or compression. So this transfering process can be considered lossless.

[donpedro]

Thanks Craig for confirming my assumptions.

And just for fun :

The DV codec itself isn't lossless, in your first point you mention DV codec compression for storing video on tape this is the lossy part.

Well... any kind of video storage isn't losless. My eyes can see more then 720 lines . Not sure about frequency...

[EricB]

The codecs considered "lossless" do a direct transfer of the whole frame. File sizes tend to be huge, and the system must be optimized to prevent dropping frames.

The beauty of DV is that it produces a manageable file size with light compression that only needs re-encoding in sections that get titles, transistions, or other special effects.