|
|||||||||
|
Thread Tools | Search this Thread |
May 17th, 2006, 06:11 PM | #1 |
Major Player
Join Date: Nov 2005
Location: Silver City, NM
Posts: 385
|
H.264 / VC-1 codec questions
I was hoping someone could tell me if the amount of compression applied by the H.264 or the VC-1 codec is adjustable. My thinking behind this is that when we eventually begin encoding high-def DVDs (either HD or Blu-ray), standard DV at 25 Mbs is well within the 36 Mbs maximum data rate spec for high-def DVDs and would require no compression, just format conversion, to play on these DVDs. On the other hand, DVCPRO-HD from the Panasonic HVX-200 at 100 Mbs would require at least 3:1 compression to fit within the DVD spec. If the amount of compression in the H.264 and VC-1 codecs is fixed, does someone know what those compression ratios are ?
|
May 18th, 2006, 02:16 AM | #2 |
Inner Circle
Join Date: Feb 2004
Location: switzerland
Posts: 2,133
|
VC-1 is in fact wmv9 so same specifications apply (variable bandwith)
H264 like all mpeg compressions is also variable bandwith. almost all codecs i know offers more or less at least a "quality" setting allowing to change the compression used. The only one is DV, since DV is fixed to 25MB/s. For sure, the goal of a high compression codec, like VC-1 or H264 is to produce small files while keeping good quality, so using them with very high bandwith is counter productive since it should not increase a lot the quality, just the file size. |
May 24th, 2006, 02:07 PM | #3 |
Major Player
Join Date: Nov 2005
Location: Silver City, NM
Posts: 385
|
DV on HD-DVD
Thanks for the response, Giroud. I have another question for the group. What is likely to be the best way to encode standard DV onto HD-DVD discs ? Obviously, no extra compression is needed since a 25 Mbs data stream is within the capacity of the disc, so the ideal codec would do as little compression as possible.
|
May 24th, 2006, 07:07 PM | #4 |
New Boot
Join Date: Jun 2005
Location: Nivelles, Belgium
Posts: 22
|
I did many tests about getting DV quality with H.264. At 9mbit the quality was equal and at 3 the quality was still excellent but lost a bit of sharpness.
|
May 24th, 2006, 10:44 PM | #5 | |
Inner Circle
Join Date: Sep 2004
Location: Sacramento, CA
Posts: 2,488
|
Quote:
|
|
| ||||||
|
Thread Tools | Search this Thread |
|