To add more info to my initial post:
I think also the encoder is an important factor for the resulting video quality. However I’ve read that con/prosumers won’t have a chance to come close to the professional DVD Video quality made in studios, both due to their advanced and multiple encoding process and next due to their high quality source footage.
My digital starting point is PAL DV 720x576, 25 f/s, 4:3 aspect ratio. This is already encoded using 4:2:0 color sampling and such be suited for transcoding to MPEG-2 SD Video. DVD video of max 9.8 Mbps bitrate does apply the MP@ML profile, which however has a defined upper bitrate of 15 Mbps.
As known, DV25 uses a fixed bitrate of 25 Mbps at 1:5 compression, which results in a data rate of 3.6 MB/s. In comparison DVD Video has a data rate of about 1 MB/s, which is almost 1:20 or four times the compression of DV25.
In reality, my DV is also converted from analog Hi8 footages. Although a highend A/D converter and TBC were used, already at this lesser DV compression, some quality degradations as artifacts and noise (grain) are visible when upscaled on a 1920 x1080 LCD. I don’t know why the colors in general become darker using DV playback, in comparision with the analog Hi8 source, even I did adjust colors and brightness using a color corrector/processor during monitoring the A/D conversion. But this can be adjusted easily during post editing I expect.
The most noticeable is maybe a somewhat stuttering video and not smooth moving objects or from camcorder pan or tilt.
I think transcoding DV to DVD Video using MPEG-2, maybe more effective but yet harder and more lossy compression, beside the upscaling to 1080i HDTV during BD playback, probably will uncover even more of these artifacts.
BD-ROM HD movies require 54 Mbps bitrate (1.5x), while current BD players support 2x (72 Mbps) data and a few newer 4x data rate. BD’s Video bit rate is however 40 Mbps, which is four time DVD video’s bitrate
Therefore my simple thought was to utilize BD’s extended video bit rate (band width), beside a rich storage capacity, to get a higher quality SD Video than possible with DVD Video in practice.
Maybe this isn’t possible, maybe the above mentioned MP@ML 15 Mbps isn’t playback supported, and maybe another codec than MPEG-2 can be better?