Half D1 resolutions

[easy2Bcheesy]

Just a quickie -

What is the specification in terms of resolution for Half D1 PAL and NTSC?

Ta

[jeffnoone]

Below is something I copied from elsewhere (can't remember to give credit)

AFAIK Half D1 is 352x480 NTSC and 352x576 PAL

Here are the settings that should be accepted w/o conversion:

Audio
WAVE Audio for Windows 48 kHz, 8-, 16-, or 20-bit stereo (.wav)
MPEG-1 Layer 2 Audio 44.1/48 kHz, 8-, 16-, or 20-bit stereo (.mpa, .abs)
Dolby Digital 48 kHz, 8-, 16-, or 20-bit stereo Bit-rate: 96 to 448 kbps (.ac3)

PARAMETER NTSC (525 lines @ 60 Hz) PAL (625 lines @ 50 Hz)

Recommended source picture resolution:
NTSC 720 x 480,704 x 480, 352 x 480, 352 x 240
PAL 720 x 576, 704 x 576, 352 x 576, 352 x 288


Frame rate:
NTSC 29.97 Hz
PAL 25 Hz

[easy2Bcheesy]

Has any one actually encoded some Half D1 footage? I'm presuming that once run on a DVD player, it's expanded horizontally to fill out the screen?

I've just tried a test just on my PC and via my hardware Cinemaster card. I still get a centred, squished image... any ideas on what I may be doing wrong?

[jeffnoone]

Yes, I have experimented a bit with this and outputted 1 movie to DVD

A few comments:

Letting CCE do the "halving" seems to result in an inferior product with pixelation/step effect fairly noticeable on straigth lines running obliquely across the screen
(settings in CCE: DESELECT "DVD Compliant", select "Horizontal Half Resolution")

____

I then decided to try Avisynth, which I only have limited knowledge on. I used DVD2AVI, the .avs script below and CCE2.5

LoadPlugin("C:\winnt\system\MPEG2DEC.DLL")
mpeg2source("D:\yourmovie.d2v")
BilinearResize(352,480)
ResampleAudio(44100)

(settings in CCE: DESELECT "DVD Compliant", DESELECT "Horizontal Half Resolution")

This was considerably better quality wise and ran about 15% faster than a VFAPI job
______

"HorizontalReduceBy2" - I know this command also exists in Avisynh, but had more difficulty getting this to work

_____

DVD Maestro imported no prob
____

For an 80 min movie (1 pass VBR at 60 and a 2ch AC3 soundtrack), this came in about 0.9GB. It fitted very nicely onto a DVD after one of those 3.7GB war epics

Overall quality was surprisigly good for the size, you can readily reveiw the quality by cancelling CCE after about 10 min, and you will have achunk of movie to preview with PowerDVD or whatever

Played fine on a settop box with no squishing

Jeff

[easy2Bcheesy]

Nice info - thanks.

[amirkhan]

[QUOTE]Originally posted by easy2Bcheesy
Has any one actually encoded some Half D1 footage? I'm presuming that once run on a DVD player, it's expanded horizontally to fill out the screen?QUOTE]

It worked perfectly for me with PAL 352x576 on Pioneer DV444.

[Arky]

Good response, Jeffnoone - I like to see answers with a bit of "substance" - they are a good reference.


Arky ;o)

[easy2Bcheesy]

Hmmmmmmmmm I've done many tests now with Half D1 and CCE and it really seems like a waste of time. Let's say I have a 6000 CBR movie. I had it in my mind that I could re-render it as Half D1, but achieve much the same quality level with 3000 CBR. It's rendering half as many pixels therefore it should only need half the bitrate. Not so!

I did a three pass VBR render at full D1 and half D1 and there wasn't much difference in the file size, and the half D1 version seemed to look a hell of a lot worse. I guess that this MPEG2 at work - more concerned with blocks of colour rather than the amount of pixels at work.

[kon77]

I have authered many pal dvd with half D1 resolution.
I capture with a dvc2 hardarwe encoder in half d1 resolution, 6000 vbr.
the results are good - almost no blockiness, but the picture is less sharp then full d1. However the file size is about 2/3 of full D1 file size. this makes it very attractive in terms of getting more fottage in one disk.