What is the quality of new video formats?
Posted by: Madrid on 25 January 2005
Can anyone advise as to the quality of newer formats such as DivX(MPEG-4) compared with DVD?
Does Does DivX compare favourably insofar as video and audio quality/resolution with recordings on DVD (which may already be compressed in EP mode)?
Cheers,
Does Does DivX compare favourably insofar as video and audio quality/resolution with recordings on DVD (which may already be compressed in EP mode)?
Cheers,
Posted on: 02 February 2005 by mattbr
my understanding is that the quality of Mpeg 4 is superior to that of Mpeg2 (DVD) at equal bit rate. From then on, you can extrapolate two things :
a) Mpg4's quality is superior at a lower bit-rate. This enables you to compress 120 minutes of video+sound on cd-sized media and still get something watchable.
b) Mp4's quality allows for better use of space. Which is why you could encode HDTV-res (say, 720 or 1080) on dvd-sized media.
Is HDTV-res media higher quality than DVD ? you bet.
Will you really notice the difference ? you bet.
Will you get more artefacts on a 1080i stream, compressed to a DVD, than if you encoded in lossless or Mpeg-2 on higher-cap media like the forthcomming blu-ray or HD dvd ? Yes, you will.
So it's all a question of compromise. You've got a signal with both more noise (artefacts) and more information (resolution). And once scaling and noise-reduction and all of that come into play, you're dealing with an interesting equation.
a) Mpg4's quality is superior at a lower bit-rate. This enables you to compress 120 minutes of video+sound on cd-sized media and still get something watchable.
b) Mp4's quality allows for better use of space. Which is why you could encode HDTV-res (say, 720 or 1080) on dvd-sized media.
Is HDTV-res media higher quality than DVD ? you bet.
Will you really notice the difference ? you bet.
Will you get more artefacts on a 1080i stream, compressed to a DVD, than if you encoded in lossless or Mpeg-2 on higher-cap media like the forthcomming blu-ray or HD dvd ? Yes, you will.
So it's all a question of compromise. You've got a signal with both more noise (artefacts) and more information (resolution). And once scaling and noise-reduction and all of that come into play, you're dealing with an interesting equation.
Posted on: 02 February 2005 by HiDefBob
"Will you get more artefacts on a 1080i stream, compressed to a DVD, than if you encoded in lossless or Mpeg-2 on higher-cap media like the forthcomming blu-ray or HD dvd ? Yes, you will."
From someone who has been receiving broadcast HiDef for 4 years now, I can tell you that there are definitely more artifacts with 1080i than 480i (SDTV). However with 720p there are next to none ... less resolution, but less artifacts. Hopefully, eventually everything will be 1080p (TSN HD in the USA are already starting to replace their 1080i HD cameras with 1080p cameras). HiDef is still in its infancy ... someone in the industry said a couple of years ago, what you are seeing today is the worst it will ever be.
At the moment the best PQ comes from D-VHS ... far superior to standard or even superbit DVD and even better than broadcast HDTV ... but it is a tape format and tape has its problems, mainly wear.
It will be interesting to see the PQ from the DVD5 with their scaler on a top quality viewing screen capable of 1080p.
From someone who has been receiving broadcast HiDef for 4 years now, I can tell you that there are definitely more artifacts with 1080i than 480i (SDTV). However with 720p there are next to none ... less resolution, but less artifacts. Hopefully, eventually everything will be 1080p (TSN HD in the USA are already starting to replace their 1080i HD cameras with 1080p cameras). HiDef is still in its infancy ... someone in the industry said a couple of years ago, what you are seeing today is the worst it will ever be.
At the moment the best PQ comes from D-VHS ... far superior to standard or even superbit DVD and even better than broadcast HDTV ... but it is a tape format and tape has its problems, mainly wear.
It will be interesting to see the PQ from the DVD5 with their scaler on a top quality viewing screen capable of 1080p.