gen loss in dv to dv? at DVinfo.net

Ali Jafri · August 1st, 2008, 09:32 AM

Hi! This might be the most basic of questions but it would be nice if I get an answer once and for all. Do I lose a generation if I render the edited DV AVI clips on my timeline to make a single DV AVI file? How many times can I do this before I start seeing any distortion or artifacts? Naturally I won't be adding any effects or such and will always be staying in the exact format that the original footage is in.

Dwain Elliott · August 1st, 2008, 01:39 PM

In theory, there should be no generational loss going from DV to DV.

In analog, you are transferring actual visual information from tape to tape. The "D" in DV is for digital, which means you are transferring the description of the visual information in 0's and 1's. Since the digital/numeric description is always the same, the signals should be identical.

John Miller · August 1st, 2008, 03:15 PM

As long as the video is in the form of files on your computer, there won't be any loss (although any metadata such as recording time, date etc are usually replaced with null information).

If you send the video to and fro from the PC to a DV deck/camcorder, eventually you will get losses though it will take quite a few iterations. The recording of DV to tape is not as perfect as you may be led to believe. The DV specification permits a certain level of error and quite a lot of the information written to tape is for error correction and concealment. Correction allows perfect restoration of damaged information - a lot of this on the tape is for audio. Concealment provides a way to hide damaged information - the video part has a simple but effective concealment scheme. Even a first generation DV-to-DV copy will not be bit perfect but you will be unlikely to tell where the differences are without a rigorous bit-for-bit comparison. This applies to tape. For other storage media, copying is bit-for-bit perfect.

August 1st, 2008, 09:32 AM	#1
Ali Jafri Major Player Join Date: May 2008 Location: Karachi, Pakistan Posts: 210	gen loss in dv to dv? Hi! This might be the most basic of questions but it would be nice if I get an answer once and for all. Do I lose a generation if I render the edited DV AVI clips on my timeline to make a single DV AVI file? How many times can I do this before I start seeing any distortion or artifacts? Naturally I won't be adding any effects or such and will always be staying in the exact format that the original footage is in. __________________ Windows 7 Ultimate 64-bit // i7 2600K // 16GB RAM // ASUS P8P67 Board // NVIDIA GTX 470 Sony Vegas Pro 13 // Adobe Premiere Pro CC 2014 // http://vimeo.com/alijafri

August 1st, 2008, 01:39 PM	#2
Dwain Elliott New Boot Join Date: May 2004 Location: Dallas, TX Posts: 23	No generational loss in DV In theory, there should be no generational loss going from DV to DV. In analog, you are transferring actual visual information from tape to tape. The "D" in DV is for digital, which means you are transferring the description of the visual information in 0's and 1's. Since the digital/numeric description is always the same, the signals should be identical.

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August 1st, 2008, 03:15 PM	#3
John Miller Major Player Join Date: Oct 2005 Location: Hillsborough, NC, USA Posts: 968	As long as the video is in the form of files on your computer, there won't be any loss (although any metadata such as recording time, date etc are usually replaced with null information). If you send the video to and fro from the PC to a DV deck/camcorder, eventually you will get losses though it will take quite a few iterations. The recording of DV to tape is not as perfect as you may be led to believe. The DV specification permits a certain level of error and quite a lot of the information written to tape is for error correction and concealment. Correction allows perfect restoration of damaged information - a lot of this on the tape is for audio. Concealment provides a way to hide damaged information - the video part has a simple but effective concealment scheme. Even a first generation DV-to-DV copy will not be bit perfect but you will be unlikely to tell where the differences are without a rigorous bit-for-bit comparison. This applies to tape. For other storage media, copying is bit-for-bit perfect.