Both picture and sound...

Generally quite similar.

Both...

Picturewise, it comes down to how well the DVD was encoded. DVD can look better, SD FTA can look better. For sound, the DVD will almost always win. Most SD FTA only has stereo audio (MPEG layer 2 or AC3, both potentially being a dolby mix) while most DVDs have 448k 5.1, and possibly better (DTS).

In real-world use I find DVD to be better (not by much though).

A few statistics:

Typical bitrate of SD: 6-7.5Mbps
Bitrate of DVD: variable up to 10Mbps
Bitrate of home burned DVD*: a little over 5Mbps

Aspect ratio of SD: 16:9 (4:3 is supported by the specification but is not used in Australia.)
Aspect ratio of DVD: 4:3 or 16:9

Scan mode of SD: interlaced (Progressive is probably supported. It isn't used.)
Scan mode of SD: interlaced or progressive

*By home burned I mean using the default settings of a set top DVD recorder - 2hrs per disc.

DVD has a little more freedom for parameter adjustments. In the right hands that freedom will result in better quality. On the flipside, not all DVDs are made by the "right hands" and can easily be outdone by DTV.

Do you have a lisp or something?

thufferin thuckotash!

JSmith :ph34r:


Both SD and DVD can be upconverted to a progessive signal, or a higher resolution interlaced signal (1080i), so it certainly is used and available. The bitrate is the defining factor here and original material's form.

JSmith :ph34r:

Hi Power Surge,

We all know the generic answer to most tech. questions ... It depends! And it certainly applies here. Forget the video bitrates and other technicalities. SD was designed to supply as good a picture quality and sound capability (bar DTS) as DVD and it comes very close. If you were to take a 'good DVD' (well recorded source material, properly encoded at a reasonable bit-rate on good DVD media) and compare it to the same source material properly processed (again at a reasonable bit-rate) and transmitted through DVB-T to a decent SD box and viewed on the same display then you'd be hard pressed to see a difference. The main reason being that a 'good DVD' is very hard to find (taking the specialised 'Superbit' DVDs out of the equation, although even them do not get to the claimed 10Mbps - if someone come across one please let me know the title as I have been on the look-out for a good DVD with a high sustained bit-rate above 9Mbps for a long time!).

Please note that some SD boxes offer a AC3/52 capability for 5.1 Dolby Digital multichannel sound (eg. from Channel 10 here in Brisbane). My SD TEAC BV300 has it.

But more to the point, you will find, visually, a lot of difference in video quality even within the same service (TV network) depending on source material. Also, I have found that in general, the video quality is much higher on the ABC network than on other services. This may be due to various factors, but I would not be surprised if they are transmitting higher bit-rate encoded material than the others - they also broadcast a lot of UK based material which is PAL encoded source material (ie. approx. 600 lines @ 50Hz) which is inherently higher resolution than the typical NTSC material from the US (approx. 500 lines @ 60Hz) - the number of additional lines does make a difference.

The net result is that for all intents and purposes you could say that SD DVB-T and DVD are the same ... given the various factors mentioned above.

InTune

Yeah but progressive video stored/transmitted as interlaced still has lower chroma quality due to the 4:2:0 subsampling.