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post #1 of 11 Old 12-15-2018, 12:30 PM - Thread Starter
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Are 60i sports broadcasts "pulled up" 30p or straight 60i? Straight 60i

I hope the topic title makes sense, and that this is the right forum. Basically I'm wondering if 1080/60i sports broadcasts are sent as 30p in 60i container (frames 1t/1b/2t/2b...), so they can be deinterlaced with 2:2 pulldown, or straight 60i (1t/2b/3t/4b...). I tried searching the web but couldn't find any conclusive answers. Would there be a way to determine this through pc software? Thanks in advance for any insight.
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post #2 of 11 Old 12-15-2018, 12:45 PM - Thread Starter
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Apologies: i found my answer-- dont know what i did wrong in my earlier avsforum searches, but obviously i wasnt using the right terms. The answer from the thread below is that the info is sent as native 60i, not 30p split into two separate frames.

http://01966633.com/forum/25-hd...i-signals.html
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post #3 of 11 Old 12-15-2018, 03:16 PM
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Originally Posted by dkfan9 View Post
Apologies: i found my answer-- dont know what i did wrong in my earlier avsforum searches, but obviously i wasnt using the right terms. The answer from the thread below is that the info is sent as native 60i, not 30p split into two separate frames.

http://01966633.com/forum/25-hd...i-signals.html
Yes - 60i sport (and 50i in 50Hz regions) is captured as 60 (or 50) separate images per second, just as is the case with 60p (and 50p). The difference is that only half the lines (i.e. every other alternate line) of each captured image are sent in an interlaced field, with the next field containing the alternate lines of the next image.

With 60p (or 50p) every line is sent for every image - so there is no loss of vertical resolution on moving content compared to 60i (or 50i).
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post #4 of 11 Old 12-16-2018, 06:08 PM - Thread Starter
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Originally Posted by sneals2000 View Post
Yes - 60i sport (and 50i in 50Hz regions) is captured as 60 (or 50) separate images per second, just as is the case with 60p (and 50p). The difference is that only half the lines (i.e. every other alternate line) of each captured image are sent in an interlaced field, with the next field containing the alternate lines of the next image.

With 60p (or 50p) every line is sent for every image - so there is no loss of vertical resolution on moving content compared to 60i (or 50i).
Thank you for the concise explanation

Now it's time to take some slo mo video and compare deinterlacing and motion smoothing algorithms between my TVs.
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post #5 of 11 Old 12-16-2018, 08:10 PM
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Originally Posted by dkfan9 View Post
I hope the topic title makes sense, and that this is the right forum. Basically I'm wondering if 1080/60i sports broadcasts are sent as 30p in 60i container (frames 1t/1b/2t/2b...), so they can be deinterlaced with 2:2 pulldown, or straight 60i (1t/2b/3t/4b...). I tried searching the web but couldn't find any conclusive answers. Would there be a way to determine this through pc software? Thanks in advance for any insight.
Your use of 60i is basically wrong. Usually the number refers to FRAMES/sec, not FIELDS/sec. Therefore your query is about 30i, i.e., 30 FRAMES/sec interlaced. For a moment there I thought you were asking about 60 frames/sec video.

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post #6 of 11 Old 12-18-2018, 02:13 PM - Thread Starter
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Originally Posted by mrvideo View Post
Your use of 60i is basically wrong. Usually the number refers to FRAMES/sec, not FIELDS/sec. Therefore your query is about 30i, i.e., 30 FRAMES/sec interlaced. For a moment there I thought you were asking about 60 frames/sec video.
Ah i did not realize that--but also it makes sense given reading about the NTSC standard as 29.97i, i just didn't find 2+2

Thanks for the info

Actually, a quick clarifying question: this means that 2 interlaced fields are called one frame even when they show different moments in time (eg each field separated by 1/60 of a second), correct?

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post #7 of 11 Old 12-18-2018, 07:24 PM
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Actually, a quick clarifying question: this means that 2 interlaced fields are called one frame even when they show different moments in time (eg each field separated by 1/60 of a second), correct?
Correct. Keep in mind the the 1/59.94th of a second fully applies to "live" video. 23.976 video (usually scripted shows) that are 2:3 telecined to 29.97 will have three frames that are from the same period in "time." Google 2:3 (or 3:2) pulldown to learn more about that.

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post #8 of 11 Old 12-18-2018, 07:32 PM
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Originally Posted by sneals2000 View Post
Yes - 60i sport (and 50i in 50Hz regions) is captured as 60 (or 50) separate images per second, just as is the case with 60p (and 50p).
Actually, these days (especially with U.S. football), the video is captured at higher progressive video rates. That is what allows for the really smooth slo-mo without interlaced "jaggies." When broadcast "live," x-number of frames are dropped and I suspect that half the "lines" from one frame are used for one field and half the "lines" from the next kept frame are used for the next field. That is my guess. I don't watch football, so I have not looked at the images closely. Isn't technology wonderful, even though I do not partake in it (not a sports watcher).

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post #9 of 11 Old 12-19-2018, 04:44 AM
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Originally Posted by mrvideo View Post
Correct. Keep in mind the the 1/59.94th of a second fully applies to "live" video. 23.976 video (usually scripted shows) that are 2:3 telecined to 29.97 will have three frames that are from the same period in "time." Google 2:3 (or 3:2) pulldown to learn more about that.
23.976 progressive frames to 59.94 progressive frames will have 3 frames repeated followed by 2 frames repeated.


23.976 progressive frames to 59.94 interlaced fields is more complex.


1st 29.97 interlaced frame has two fields from 1st 23.976 progressive frame


2nd 29.97 interlaced frame has two fields from 2nd 23.976 progressive frame


3rd 29.97 interlaced frame has one field from 2nd 23.976p frame and one field from 3rd 23.976p frame


4th 29.97 interlaced frame has one field from 3rd 23.976p frame and one field from 4th 23.976p frame


5th 29.97 interlaced frame has two fields from 4th 23.976 progressive frame

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post #10 of 11 Old 12-19-2018, 09:41 AM
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Originally Posted by mrvideo View Post
Actually, these days (especially with U.S. football), the video is captured at higher progressive video rates. That is what allows for the really smooth slo-mo without interlaced "jaggies." When broadcast "live," x-number of frames are dropped and I suspect that half the "lines" from one frame are used for one field and half the "lines" from the next kept frame are used for the next field. That is my guess. I don't watch football, so I have not looked at the images closely. Isn't technology wonderful, even though I do not partake in it (not a sports watcher).
Couple of things :

1. Most broadcast cameras these days are based on 1080p or 2160p (aka 4K) sensors. However when running native interlaced output these cameras generate interlaced video in the camera head. They usually using frame-line offset line-pair grouping - merging 1080p lines 1&2, 3&4, 5&6 captured at 'n' to create one field, and lines 2&3, 4&5, 6&7 captured at 'n+1/59.94s' (or 1/50 for 50Hz) to create the next field, offset by 1 frame line. The line-pair averaging avoids fine vertical detail 'twittering' at frame rate.

2. Yes - cameras can often capture 2 or 3 x 59.94 at 1080i, 1080p or 2160p to generate super slow motion output. HOWEVER - these cameras are seldom used live as usually their live output is one of the three 'frames' captured delivering effectively 1/179.82th second shuttered content (for 3x SuperSlow) which looks horrible. When running in a native interlaced environment the output is effectively still interlaced at 179.82i (aka 180i) - from the camera, and still interlaced. The SuperSlowMo cameras are separate cameras ISO-recorded to EVS for later replay in slow motion. You do sometimes see them cut to - but they are noticeably different because of the triple frame rate capture. (In days gone by they were separate models of cameras, though these days many regular HD cameras will do 2x, and UHD 3x - removing the need to hire separate SuperSlowMo cameras - though you may still need to purchase a software licence for that facility)

Last edited by sneals2000; 12-19-2018 at 09:44 AM.
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post #11 of 11 Old 12-19-2018, 05:00 PM - Thread Starter
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Originally Posted by sneals2000 View Post
Couple of things :

1. Most broadcast cameras these days are based on 1080p or 2160p (aka 4K) sensors. However when running native interlaced output these cameras generate interlaced video in the camera head. They usually using frame-line offset line-pair grouping - merging 1080p lines 1&2, 3&4, 5&6 captured at 'n' to create one field, and lines 2&3, 4&5, 6&7 captured at 'n+1/59.94s' (or 1/50 for 50Hz) to create the next field, offset by 1 frame line. The line-pair averaging avoids fine vertical detail 'twittering' at frame rate.

2. Yes - cameras can often capture 2 or 3 x 59.94 at 1080i, 1080p or 2160p to generate super slow motion output. HOWEVER - these cameras are seldom used live as usually their live output is one of the three 'frames' captured delivering effectively 1/179.82th second shuttered content (for 3x SuperSlow) which looks horrible. When running in a native interlaced environment the output is effectively still interlaced at 179.82i (aka 180i) - from the camera, and still interlaced. The SuperSlowMo cameras are separate cameras ISO-recorded to EVS for later replay in slow motion. You do sometimes see them cut to - but they are noticeably different because of the triple frame rate capture. (In days gone by they were separate models of cameras, though these days many regular HD cameras will do 2x, and UHD 3x - removing the need to hire separate SuperSlowMo cameras - though you may still need to purchase a software licence for that facility)
Thank you for the detailed reply! That's especially interesting on the line pair grouping and reasoning behind it, and the slo mo info is also useful. This is all great info.

I guess that means the second field shows line 1080 in full and leaves line 1 out?
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