Are films presented at 1080i always at the wrong speed?

[Bruce Morrison]

This is something I ought to know, but I just need someone to confirm it. If a feature film is presented on a BD at 1080i rather than 1080p, does it necessarily follow that it is also at 50Hz and therefore running at the wrong speed (i.e. similar to a PAL DVD)? Or is is still possible for it to run at 24 fps?

I seem to recall that, if material is mastered at 50Hz, then it must be encoded on a BD as interlaced rather than progressive, since the BD spec does not support 1080p25. However, I'm not sure whether the converse statement is true.

Thanks in anticipation!

[CH108]

Hi there,

If the source is supposed to be 23.976 fps then encodes that run at 1080i at 50hz will be at the wrong speed and have the horrible PAL speedup effect that we have to put up with in our UK DVD's and the added travesty of the scan lines caused by interlacing.

If it's 1080i at 60hz however it would be identical to NTSC speed (the right speed) but you still have the scan lines.

Hope this helps

[4K2K]

If it's a European TV programme it's nearly always supposed to be 50i otherwise it's most likely running at the wrong speed.

A few films are made a 25p/50i too I think very few probably.

So things like Planet Earth at 1080p will be running in slow motion. Also American releases of European programmes that are encoded at 1080p are also running in slow motion (more than 4% too slow).

Technically most films run in slow motion on Blu-ray since they are mostly encoded at 23.976 fps instead of the 24.0 fps they are mostly shot at.

So the answer is "no" films presented in 50i are not always the wrong speed. But often are.

I seem to recall that, if material is mastered at 50Hz, then it must be encoded on a BD as interlaced rather than progressive, since the BD spec does not support 1080p25

If the material was mastered at 50Hz (50i) wouldn't you want it to be encoded at 50i and not 1080p25, unless it was all shot 25Hz and edited as 25Hz (no 50Hz credits/fades etc.).

[Bruce Morrison]

Originally Posted by CH108

If it's 1080i at 60hz however it would be identical to NTSC speed (the right speed) but you still have the scan lines.

Hi, thanks for the quick response. Are you aware of any BDs of feature films that are encoded at 1080i60 rather than 1080i50? (As far as I know, most BDs of feature films that are 1080i are also 50Hz.)

I'm specifically wondering about the UK BD of 'Crash', released by Fox-Pathé, which is apparently 1080i. I'm wondering whether that is encoded at 50Hz.

[4K2K]

If it's 1080i at 60hz however it would be identical to NTSC speed (the right speed) but you still have the scan lines.

Shouldn't the player/TV de-interlace it so you didn't have visible scan lines/combing artefacts (if you are watching a progressive TV)? Wouldn't a 60i version probably just be more filtered than a 24p version?

Are you aware of any BDs of feature films that are encoded at 1080i60 rather than 1080i50?

I can think of one - the original US release of Terminator 3
https://www.blu-ray.com/movies/Termi...ray/83/#Review

Originally Posted by Bruce Morrison

I'm specifically wondering about the UK BD of 'Crash', released by Fox-Pathé, which is apparently 1080i. I'm wondering whether that is encoded at 50Hz.

I don't know but the Australian version is encoded at 1080/50i according to the web.

[CH108]

Originally Posted by 4K2K

Shouldn't the player/TV de-interlace it so you didn't have visible scan lines/combing artefacts (if you are watching a progressive TV)? Wouldn't a 60i version probably just be more filtered than a 24p version?

I thought it would've done but when I got a faulty 1080i/50 copy of In Bruges(Icon) from Australian there were many scenes showing the scan lines.

[CH108]

Originally Posted by Bruce Morrison

Hi, thanks for the quick response. Are you aware of any BDs of feature films that are encoded at 1080i60 rather than 1080i50? (As far as I know, most BDs of feature films that are 1080i are also 50Hz.)

I'm specifically wondering about the UK BD of 'Crash', released by Fox-Pathé, which is apparently 1080i. I'm wondering whether that is encoded at 50Hz.

Your welcome.

Are you sure that Crash in the UK is 1080i or is that what the packaging says?

I had a similar problem when buying eastern promises which is also a Fox/Pathé title that said it was 1080i on the cover but was in fact 1080p.

As for 1080i/60 titles:
Short Circuit from Image Entertainment
Warner's Terminator 3 that the other user mentioned
Either Life or Planet Earth from Warner got a 1080i/60 transfer.

[svenge]

The Hong Kong and Taiwan BD releases of Ponyo have 1080i/60 video as well.

[Bruce Morrison]

Originally Posted by CH108

Your welcome.

Are you sure that Crash in the UK is 1080i or is that what the packaging says?

I had a similar problem when buying eastern promises which is also a Fox/Pathé title that said it was 1080i on the cover but was in fact 1080p.

As for 1080i/60 titles:
Short Circuit from Image Entertainment
Warner's Terminator 3 that the other user mentioned
Either Life or Planet Earth from Warner got a 1080i/60 transfer.

Hi, thanks for the response. I'm just going by what the packaging says, so in view of the Eastern Promises example, maybe I'll try the UK 'Crash' edition. It certainly has some advantages over the US release, provided it is in fact 1080p.

[steve_dave]

Originally Posted by Bruce Morrison

Are you aware of any BDs of feature films that are encoded at 1080i60 rather than 1080i50? (As far as I know, most BDs of feature films that are 1080i are also 50Hz.)

As stated before there is 1080/50hz and 1080/60hz. Countries like the UK and Australia where PAL is color standard for standard definition material will use 1080/50hz. Countries which use NTSC as the color standard for standard definiton material will use 1080/60hz.

99.9% of all 1080i BD releases in the UK, France, and Australia are 1080/50hz.

All 1080i BD releases in the US and Canada are 1080/60hz as this would be the only signal compatible with all televisions in North America.

Originally Posted by Bruce Morrison

I'm specifically wondering about the UK BD of 'Crash', released by Fox-Pathé, which is apparently 1080i. I'm wondering whether that is encoded at 50Hz.

Crash (2004) UK Blu-ray Disc is 1080/50hz.

DVD Active Review

[amper]

I dont know what yall are talking bout. I got an older, 1080i tv, so i set the player to play at 1080i instead of 1080p. never had anything slowdown or show lines.

[4K2K]

Originally Posted by amper

I dont know what yall are talking bout. I got an older, 1080i tv, so i set the player to play at 1080i instead of 1080p. never had anything slowdown or show lines.

I think you're talking about outputting a 1080p24 Blu-ray at 1080/60i (or a 1080p23.976 Blu-ray output at 59.94i ).

Doing that won't cause it to slow down. If it's an LCD/Plasma and it de-interlaces correctly it shouldn't show lines either I think. Though if it can't display it at a multiple of 24 or 23.976 fps you'll get 3:2 pull-down judder.

It's when 25 fps content gets converted to 1080p23.976 that it will be slowed down by over 4% (think the 1080p versions of Planet Earth or most other European TV series released on Blu-ray at 1080p). Maybe things like "28 Days Later" too (since it was mostly shot with a PAL camcorder).

Films converted from 24 fps to 23.976 (the majority of Blu-ray releases) will be slowed down by 0.1%.

Films shot at 24 fps and released on Blu-ray at 1080/50i will usually be sped up by 4%.