Lower video quality from HDV to Bluray disc or HD DVD?

[Ollie6431]

I have wondered for some time about the possible decrease in video quality from captured HDV footage to recorderd footage in Bluray disc or HD DVD but found no information to either confirm or reject this.

My simple thinking goes like this: since HDV is captured in MPG2, a relatively less compressed format, it probably gives the best video (compared to AVCHD or other formats) when the HDV cam is connected directly to an HDTV. However, when the footage is eventually recoded/burned to a high-def disc (Bluray or HD DVD format), the video would be "heavily" compressed by AVC/h.264 in either format. The video quality of HDV would be decreased in the recorded disc. This is analogous to the video quality of miniDV being decreased when the footage is recoded from DV (less compression) to MPG2 (more compression) in DVD format. On top of that, DVD is limited to 480 horizontal resolution.

I wonder if this reasoning is too off the track (?) and would appreciate any input, either theoretical or from experience, to clear up this question.

[edDV]

According to "What is ... above left
http://www.videohelp.com/hd

HD DVD and BluRay DVD both accept MPeg2 but HDV would need an H expansion from 1440x1080i to 1920x1080i or in the case of Blu-Ray transcoded to AVC h.264 or VC-1 as 1440x1080i. Quality loss in the MPeg2 case should be minimal. There is ample bitrate headroom to keep quality high.

DV to DVD requires lowering bit rate from 25Mb/s to less than 9.8Mb/s.

I'd bet money that many future HD/BD players and recorders will allow direct playback of HDV M2T files much as current DVD players play Divx/Xvid. Direct playback of AVCHD may take longer.

[Ollie6431]

Quality loss in the MPeg2 case should be minimal. There is ample bitrate headroom to keep quality high.

DV to DVD requires lowering bit rate from 25Mb/s to less than 9.8Mb/s.

Thanks edDV, this clears up my long-time confusion. It is the BIT RATE! In a way, burning high-def video into Bluray/HD DVD is a step above burning DV into DVD (no wonder home movie DVD is not great!).

I'd bet money that many future HD/BD players and recorders will allow direct playback of HDV M2T files much as current DVD players play Divx/Xvid. Direct playback of AVCHD may take longer.

This would be nice, saving lots of time transcoding.