Codec questions at DVinfo.net

Mark Donnell · August 21st, 2006, 10:24 PM

Not sure where to post this, but let's try here. One of the few weaknesses of the HDV codec (in my opinion) is the creation of artifacts during single frame viewing due to the interframe (GOP) compression format. DVCPRO HD avoids this by using single frame compression, but results in a large file size. As I understand it, the AVC and VC-1 codecs also use multi-frame compression. Will they also generate artifacts during single-frame viewing ? The MPEG codec is a multi-frame GOP-type frame compression codec. The XDCAM HD uses the MPEG-2MP@HL codec which is similarly multi-frame compression-based. Are there any other codecs that do not use multi-frame compression ? How about the Cineform codec ?

Glenn Chan · August 22nd, 2006, 07:56 AM

Cineform (and Cineform RAW) should be intraframe / "not multi-frame compression based".

Quote:

One of the few weaknesses of the HDV codec (in my opinion) is the creation of artifacts during single frame viewing due to the interframe (GOP) compression format.

The artifacts come from DCT compression... the artifacts appear as noise (particularly mosquito noise) and blocking. Adam Wilt's DV FAQ has good pictures of DV artifacts (DV and DVCPRO HD implement DCT compression too). I believe VC1 also implements DCT compression.

Wavelet-based codecs like JPEG2000 and Cineform will exhibit different artifacts. you get smoothing of image detail, ringing on high contrast edges.

David Kennett · August 22nd, 2006, 10:28 AM

Mark,

You didn't say whether your original material was progressive or interlaced. Extracting stills from interlaced video has always been problematic. I have JVC HD10 and there are insignificant artifacts on stills.

August 21st, 2006, 10:24 PM	#1
Mark Donnell Major Player Join Date: Nov 2005 Location: Silver City, NM Posts: 385	Codec questions Not sure where to post this, but let's try here. One of the few weaknesses of the HDV codec (in my opinion) is the creation of artifacts during single frame viewing due to the interframe (GOP) compression format. DVCPRO HD avoids this by using single frame compression, but results in a large file size. As I understand it, the AVC and VC-1 codecs also use multi-frame compression. Will they also generate artifacts during single-frame viewing ? The MPEG codec is a multi-frame GOP-type frame compression codec. The XDCAM HD uses the MPEG-2MP@HL codec which is similarly multi-frame compression-based. Are there any other codecs that do not use multi-frame compression ? How about the Cineform codec ?

August 22nd, 2006, 10:28 AM	#3
David Kennett Major Player Join Date: Jul 2003 Location: North Ridgeville, Ohio Posts: 407	Mark, You didn't say whether your original material was progressive or interlaced. Extracting stills from interlaced video has always been problematic. I have JVC HD10 and there are insignificant artifacts on stills. __________________ Dave