What framerate are PAL SD/HDTV transmissions?

[craigpro]

Just wondering about this.. as PAL is normally 50 (interlaced) frames per second for analogue, and NTSC is 60 (interlaced) frames per second for analogue... but I've noticed that the HDTV TV rips from USA sourced shows are 23.96 frames per second.

So what is the framerate for PAL SDTV and HDTV shows? Anyone know? Is there a difference in framerate between SD and HD transmissions?
(SD= Standard Digital, HD=High Definition)

regards,

Craigpro

[Stereodude]

I think there isn't a set standard for PAL HDTV. So far what I've read seems to indicate PAL HDTV is still 1920x1080, but at 25fps instead of 29.97. Technically there is no standard for 1080p24. People are doing an Inverse Telecine on the 29.97fps video and then discarding the duplicate frame. This gives you 23.976fps.

This only works for shows that have a 3:2 pulldown applied. There are a lot of stupid people out there trying to IVTC true interlaced material.

[craigpro]

Hi SteroeDude,

that's what I was thinking.. the 23.97 FPS should only apply for movies transmitted on HDTV, I'm fairly certain that the majority of TV shows would be shot at either the NTSC 29.97 FPS or PAL 25 FPS, even if they are shot on HD cameras. (Hmm.. unsure now.. just checked up some info on a Panasonic HD video camera, and it's selectable from 60 FPS progressive down to 24 FPS progressive - and that was the PAL version!)

Basically I'm asking as I live in Australia (PAL analogue transmission) and I've got a DVB-T PC card which I was considering XviD'ing some TV transmissions and was wanting to know what framerate I should be converting them to.

A lot of the HDTV TV rips I see from the USA are (converted?) down to 23.97 FPS, which I thought was wrong.

Also whats the bloody difference (is there a 'standard'?) between the HDTV and PDTV rips? HDTV *SHOULD* be self explanatory, but 've seen PDTV rips that are the same widescreen resolution as a HDTV rip, as well as being full screen Pan and Scan (4:3) 'resolution'. What's the story with that?

many thanks in advance for all comments and help.

Craigpro

[Doom9]

since the standard comittees couldn't agree on a HD standard we don't have one in PAL land :/ But regular DVB broadcasts are all 25fps.

[Stereodude]

Originally posted by craigpro
Hi SteroeDude,

that's what I was thinking.. the 23.97 FPS should only apply for movies transmitted on HDTV, I'm fairly certain that the majority of TV shows would be shot at either the NTSC 29.97 FPS or PAL 25 FPS, even if they are shot on HD cameras. (Hmm.. unsure now.. just checked up some info on a Panasonic HD video camera, and it's selectable from 60 FPS progressive down to 24 FPS progressive - and that was the PAL version!)

Basically I'm asking as I live in Australia (PAL analogue transmission) and I've got a DVB-T PC card which I was considering XviD'ing some TV transmissions and was wanting to know what framerate I should be converting them to.

A lot of the HDTV TV rips I see from the USA are (converted?) down to 23.97 FPS, which I thought was wrong.

Also whats the bloody difference (is there a 'standard'?) between the HDTV and PDTV rips? HDTV *SHOULD* be self explanatory, but 've seen PDTV rips that are the same widescreen resolution as a HDTV rip, as well as being full screen Pan and Scan (4:3) 'resolution'. What's the story with that?

many thanks in advance for all comments and help.

Craigpro
Most of CBS's shows can be sucessfully converted to 23.976FPS. I'm not sure how they're shot (often looks like film to me). From my playing with NBC shows (like Leno) they are true interlaced, not IVTC friendly and they have to stay at 29.97fps

In theory a HDTV rip should look better than a SDTV rip and they generally do. CPU usage and filesize go up fast once you get beyond 640x something. So, no one seems to encode beyond that. So a SDrip and the HDrip are going to have the same dimentions. Some of the SD shows are letterboxed now to look 16:9, so people are probably cutting those off before compressing.

Also, there are wankers stream saving SD that has been upsampled by the broadcaster and then calling it a HDTVrip. That's how you get 4:3 HDTVrips. There is no standard for 4:3 HDTV. It has to be 16:9 by it's very definition.

[DrP]

Ideally you shouldn't be changing the frame rate at all. The nice thing about PAL is that its 25FPS. More often than not, filmed 24FPS is simply sped up a slight bit to make it 25FPS. This does cause a shift in audio pitch, but its quite small and not noticeable unless you have the original 24FPS audio track to compare with. We don't have to deal with all the nastiness of telecining as the NTSC viewers do. At times I have seen hideous conversion jobs done though. I've seen a 24FPS show telecined to 29.97 and then down converted to 25FPS. Frames get blended to hell and in general, there's not a lot you can do to repair something like that. Rarely you see a show that has been converted by taking the 24 FPS film and adding in a repeat field to nudge it up to 25FPS while maintaining the duration and audio pitch. Hardly see that these days though.

A lot of TV shows from the US are recorded at 24FPS or 23.97 and simply sped up for PAL viewing. At times you will see shows with apparent interlacing from the US (Touched By An Angel shown on 9 in Australia is an example) or where the odd scene or two appears interlaced. More than likely its just the field ordering in the show is a little broken. decomb's or mpeg2dec's telecide() function will fix that nicely in avisynth, or the DFOC filter for virtualdub giving you nice 25FPS progressive frames with very little trouble.

[MvB]

More often than not, filmed 24FPS is simply sped up a slight bit to make it 25FPS. This does cause a shift in audio pitch, but its quite small and not noticeable unless you have the original 24FPS audio track to compare with.

I hear it and I wasn't and won't accept it. That's why i convert all my PAL Dvds to NTSC

[DrP]

each to his own.

[Stereodude]

Originally posted by MvB
I hear it and I wasn't and won't accept it. That's why i convert all my PAL Dvds to NTSC Why don't you just use a DVD player like nVDVD that will slow down the DVDs slightly?

[minolta]

From my experience, almost all tv shows on CBS (Raymond, JAG, Joan of Arcadia, etc) are shot with film (24 progressive fps). Those who rip the shows first decomb to the original 24fps before encoding (w/o much quality loss). Of course, events like the Superbowl on CBS are still truly-interlaced (1080i, 1920x1080, 60 fields/sec). And shows on other networks (NBS, ABC, FOX, etc) are almost always truly-interlaced.

SDTV and HDTV are both MPEG2 and support interlacing. You can bet that PAL will stick w/ 50Hz and ATSC w/ 60Hz.