DVB capture and ITU.R BT-601

[MrDarcy]

After reading the Sticky about "Aspect Ratio & friends" and all the links contained there, I think to have some little understanding of Pixel Aspect Ratio issues.

But how can I know if a DVB-S (digital satellite) stream needs the ITU.R BT-601 checked or not ?

I capture in digital format via SCSI from my Nokia MM 9600 using DVB2000recorder software. Depending on the channel, I get 480x576, 544x576 or 720x576 formats.

I have no problems with DVD2AVI -> GKnot -> Divx PRO 5.0.2, but after reading all the discussion about BT-601 I started to wonder if I should leave it checked or not. According to my (old) eyes, the answer is yes, but I'd like to know if someone else is using the same configuration.

Thanks to GKnot authors for this great tool and regards to everybody.

[TheWEF]

if you enter the pixel aspect ratio manually or using the "select" button, the ITU checkbox has no effect.

pressing select you can choose the correct (ITU conform) pixel aspect ratio for many resolutions, including 480x576 and 720x576.

a resolution i never heard of is 544x576 and i don't know of an ITU conform PAR for that. i suggest you try 1.448 (manually enter next to "other").

wef.

[Herske]

That resolution is perfectly legal for DVB. "544" is upsampled by the decoder to the right horizontal resolution, according to AR. (4:3, 16:9, 2.35:1 ->for DVB)

[MrDarcy]

Originally posted by TheWEF
if you enter the pixel aspect ratio manually or using the "select" button, the ITU checkbox has no effect.



Thank you Wef,
I've seen that with a manual value the ITU checkbox has no effect, but the problem is *what* value should I enter manually.

In your Select list you assume that the resolution is ITU conform, but are we sure that all DVB-S channels are ITU conform too ? I mean, each of them uses different hw/sw equipment for encoding, so at a certain resolution I won't be surprised if different pixel aspect ratio were used.


a resolution i never heard of is 544x576 and i don't know of an ITU conform PAR for that. i suggest you try 1.448 (manually enter next to "other").


You're right. Yesterday, after some tests I found the better setting for a 544x576 resolution was the PAL anamorphic (16:9) pixel aspect ratio, that is 1.459, but I wasn't satisfied and I wrote this message. Now I'll do some more test using your suggestion..

Bye!