| Author | Message | ||
     clyde Rating: N/A |
The current standard is Mpeg2 (high profile)? Is this what is being used at all digital cinemas? Or are there competing codecs? How well does WMVHD stand up to encoding content for HDTV? more precisely, at WHAT BITRATE is video for HD encoded at? Regards Clyde | ||
| M.H. Rating: N/A |
For consumers level HDV cameras the bitrate is given by DV tape bitrate. It is about 3.6 MB/s if I am correct. They use mpeg2. Digital profesional HDTV cameras as Cinea Alta saves uncompressed - realy super sophisticated mutlidisk arrays ar neccesary, bitrates are in X00 Mb/s ... They key problem with all compressions more effcient than mpeg2 is non-constant bitrate producing problems with caching and data flow. This makes DivX e.g. for no use for data storage on tape. CD and DVD do not work with non-consatant bitrate very good as well ... From this point of view mpeg2 still have perspective .... | ||
| Scott Warren Rating: N/A |
There are many differences between HD and Digital Cinema. HD (NTSC) is mainly 1280x720 @ 60Fps or 1920x1080 @ 30Fps Digital Cinema is usually (varies alot): 1.5k -- 1536x1152 @ 24Fps 2k -- 2048x1556 @ 24Fps 3k -- 3072x2304 @ 24Fps 4k -- 4096x3112 @ 24Fps This gives an uncompressed YUV4:2:2 bitrate of: HD720p ~660Mbps HD1080i ~745Mbps 1.5k ~509Mbps 2k ~917Mbps 3k ~2038Mbps 4k ~3671Mbps and if you can get compression to work similarly across the bitrate/resolution spectrum, you might say that you can compress 20:1 and still have a version that is "qualitatively transparent to the average person", compared to the original. That leaves you with these bitrates: HD720p ~33Mbps HD1080i ~37Mbps 1.5k ~25Mbps 2k ~45Mbps 3k ~102Mbps 4k ~183Mbps However, even though HD is often compressed, DigCinema files are only occasionally compressed that much. AFA file format (even though much of HD is tape-based)--HD for HDcam, DVCProHD, and HDV are MPEG2 Transport streams, with HD for HD-DVD or BluRay will be either MPEG2 (program stream) all using MP @ HL,MP @ HL1440. Or the new DVD's will use MPEG4 AVC (aka JVT aka H.264) or VC1 (aka Windows Media9 HD) DigCinema varies a great deal, but many are Cineon, and the Dig Cinema initiative seems to want to standardize on Cineon, DPX, JPEG2000 (as MJPEG), Quvis Wavelet, MPEG2, MPEG4, VC1, and Qualcomm's ABSDCT. Irida and other companies also deal with std. QT, AVI, and TIFF/PNG/Targa Image sequences (whole series of individual picture files). There's some good info at www.dcinematoday.com HTH, Scott | ||
| clyde Rating: N/A |
thanks for setting me on the right track Scott, Regards' Clyde | ||
| Anonymous Rating: N/A |
what is the best codec for creating/playing 720x2560 24 fps side-by-side stereo files? divx will only go to 1920 wide is there a codec that will be recognized by nvidia's hardware decoder? | ||
| M.H. Rating: N/A |
Anonymous: For 1280x1440 over/under the answer is DQ3D stereoscopic codec, part of DepthQ Sever HD version. According the compatiblity with nVidia HW decoder - the nVidia HW decored comunicate only with selected mpeg2 or Micorsoft codecs. Generaly this decoder is for no use for stereoscopic purpose becouse image post-processing is impossible. |
