DVD Recorder Extended Play format?

[scorpio47]

When a DVD recorder records to a disc in extended play format, how does it do this? Is it still in mpeg2 format, just at a lower bitrate? or is it lowered into mpeg1 format? In either case, does anyone know the associated bitrates?

[guns1inger]

It will probably be half-D1 and a lowered bitrate. The manual may tell you the bitrate, otherwise record something then watch the bitrate on playback. Actual methods vary from player to player, so it's hard to be exact.

[Krispy Kritter]

From a few of the posts that I have seen here...on a few of the recorders, the bitrate never changes between speed settings.

But as guns1inger pointed out, the best way to find out is to experiment.

[thecoalman]

the bitrate never changes between speed settings.

It has to change, the bitrate is the amount of data being used per second. As the bitrate changes the amount of disc space required changes. You can't have more or less disc space for without changing the bitrate.

[Krispy Kritter]

That's what I thought. But he posted here asking why his DVD recordings in SP or LP were both recording at a bitrate of 8000. If I can find the post, I'll link to it.

[thecoalman]

That's what I thought. But he posted here asking why his DVD recordings in SP or LP were both recording at a bitrate of 8000. If I can find the post, I'll link to it.

It may be it's using a variable bitrate with the max being 8000 for both but with a lower minimum and average bitrate for the extended play.

[pjcrown]

The 4 hour mode is typically 2.5 Mbits/sec at 1/2 D1 (360x480 NTSC) which is also the SVCD spec.

[lordsmurf]

Some call 4-hour "EP" and some call 6-hour "EP"
Depending on the unit, 4-hour may be okay.
The 6-hour will always look like crap.

[Jester700]

The 4 hour mode is typically 2.5 Mbits/sec at 1/2 D1 (360x480 NTSC) which is also the SVCD spec.

Actually, iirc ntsc svcd is 480x480 (2/3 D1). This isn't a very high bitrate for that resolution, and my tries at these tended to show artifacts.

[nathanaa]

What is "half D1" exactly? I've seen it mentioned before, but I don't know what it is.

It sounds like it lowers the quality of the video file? To make it smaller?

[guns1inger]

nathanaa - read here https://www.videohelp.com/dvd

[Cornucopia]

D1 is 704x480NTSC(576PAL)fullscan, or 720x480/576 overscan
1/2 D1 is half the fullscan horiz. rez or 352x480/576

both of these use MPEG2 in DVD's

DVD's can also make use of what might be called 1/4 D1, but is more properly called SIF (or CIF): 352x240 part of MPEG1

Scott

[thecoalman]

.

It sounds like it lowers the quality of the video file? To make it smaller?

As mentioed it's lower resolution with less detail but if your using lower bitrates is preferable because it will eliminate macroblocking that starts to occur around 4000 kbps when using 720x480.

720x480 @3000 kbps


352x240 @3000 kbps (not half D1 but lower)