1080/30p in 60i container - why?

William Hohauser · January 16th, 2011, 09:49 AM

And the VG10 image sensor captures it's video images in either 30p or 25p (according to Sony specs) so it is unable to capture an image in 60i or 50i. If you are looking to get 50 frames (either progressive or interlaced), a regular video camera will be a better option.

One extra note, for recording subjects where the viewer wants motion detail, sports for example, a higher frame rate is preferred. For recording subjects where you want to impart the impression of speed to the viewer, a lower frame rate is preferred. A car speeding down the road looks faster at 24f than at 60f due to motion blur.

Waldi Krasowski · January 16th, 2011, 11:00 AM

Quote:

Originally Posted by William Hohauser

A car speeding down the road looks faster at 24f than at 60f due to motion blur.

That is very logical, but it is hard to find it just by yourself, unless you are not well experienced. Many thanks for such a great tip!

Steve Mullen · January 16th, 2011, 04:45 PM

Quote:

Originally Posted by Henry Williams

Steve, I hate to disagree but my version of FCP (studio 2) converts to prores 422 on log and transfer and sees the footage as 25p by default. Would FCP be auto deinterlacing on log and transfer?

My ProRes and AIC clips come in as 30p.

I doubt it is auto deinterlacing.

But, I have an idea.

AVCHD has the ability to mark a video FILE as interlace (50i/60i) or progressive (23.976, 24. 25. 29.97, or 30). I'll bet there is no PsF option, so the stream is set to interlace. Which is the virtue of PsF, it simply passes through.

In the NTSC world 60i can be 60i, 60i/23.976p, or 60i/29.97PsF.

Now if there is another flag in the data itself it could also be set to interlace or progressive. So were this flag set to progressive, there would be confusion over which progressive: 60i/23.976p, or 60i/29.97PsF. So the flag is never set to progressive. Therefore the video header simply says 60i and leaves it to the editor to decide how to process the clip.

In the PAL world 50i is 50i. Or, is is 50i/25sF. If the data flag were set progressive, it must be 25PsF. So region 50 camcorders do not operate like region 60 camcorders.

Smart software would know that 50i files should be checked for the second flag. Dumb software would not.

MY MEMORY IS HAZY ON THIS: This could explain why some Canon camcorders don't work with iMovie. Owners set the frame rate to 25p but iM sees the video as interlaced just as it would had they set the frame rate to 50i. Canon blamed Apple and eventually this camcorder was removed from the list of valid camcorders for iMovie.

It also might explain why I read a post somewhere that Sony Vegas recognized the clips as progressive. Somehow I think I remember he was in Region 50. In the USA it comes in as interlaced!

Henry Williams · January 16th, 2011, 04:54 PM

The default sequence settings place the file within a progressive 25p stream but for some weird reason field dominance is set to "odd". I'm assuming that treating the footage as 25p means that field dominance should be set to "none" and this is what I've done to date. I haven't needed to deinterlace the footage on export and don't seem to have lost any res. at any stage in the process.

Are the Canon cam's you refer to the ones that shot 25f? It was a sort of fudged almost, but not quite progressive used by the HV20 and the XH-A1. That was dealt with simply by logging and capturing the footage as 25p. You could though, if you chose, capture the footage as 50i.

Steve Mullen · January 16th, 2011, 05:26 PM

The ODD indicates that FCP is seeing it as 25fps interlaced. So you need to batch change all clips to NONE. Now FCP will treat the video as what it really is.

Henry Williams · January 16th, 2011, 06:19 PM

Sounds right to me. Thanks, Steve.

Steve Mullen · February 12th, 2011, 06:30 PM

Sometimes I feel so stupid. I've always wondered why there is AVCHD Lite when the AVCHD spec supports 720p.

Of course it does, but Bluray only supports 720p50 and 720p60. And, since the idea is to be able make camcorder to BD copies -- the camera MUST record 720p50 and 720p60. And, since the sensor of these cameras can only do 25p/30p -- each frame either must be recorded twice or a REPEAT FRAME flag used.

And, since BD does not support 1080p25 or 1080p30 nor 1080p50 or 1080p60 the ONLY thing Sony could do is make the captures look like 1080i50 or 1080i60. That's why the spec from Japan HQ said INTERLACE.

In Japan BD is the norm so camcorders must be BD compatible!

Frankly, I can't see why everyone doesn't toss DVD. I just bought 2 BD players. The last for $90 and it includes all the streaming services.

And, since my VAIO has a BD burner I use the Sony PMB application to burn copies of SDHC cards. One 8GB plus one 16MB card. Or, one 32GB plus one 16GB card.

Dave Blackhurst · February 14th, 2011, 12:12 AM

I too finally broke down and picked up a couple BD players, with wireless, and streaming, also well under $100 for a "top of the line" Sony wtith 3D even! Sure they were prolly customer returns, but for the price, it was a no-brainer, and definitely looks way better even on aging 720p HDTV's (which look almost new again).

A burner is probably next, with them available right around $100, and disks under a buck...

HD will likely finally become a "standard", with BD adoption making inroads with the lower price point. And 1080 is going to become the standard, with 720 fading out, IMO.

I've been rendering/burning BD compatible to DVD for a while, until burners came down, but I'm running out of excuses!

Robert Young · February 14th, 2011, 01:32 PM

In my experience, once you start putting your HD projects out on BD and viewing them on 1080 HDTV, you'll never go back.
It's breathtaking :)

January 16th, 2011, 09:49 AM	#16
William Hohauser Inner Circle Join Date: Dec 2005 Location: New York City Posts: 2,650	And the VG10 image sensor captures it's video images in either 30p or 25p (according to Sony specs) so it is unable to capture an image in 60i or 50i. If you are looking to get 50 frames (either progressive or interlaced), a regular video camera will be a better option. One extra note, for recording subjects where the viewer wants motion detail, sports for example, a higher frame rate is preferred. For recording subjects where you want to impart the impression of speed to the viewer, a lower frame rate is preferred. A car speeding down the road looks faster at 24f than at 60f due to motion blur. __________________ William Hohauser - New York City Producer/Edit/Camera/Animation

January 16th, 2011, 05:26 PM	#20
Steve Mullen HDV Cinema Join Date: Feb 2003 Location: Las Vegas Posts: 4,007	The ODD indicates that FCP is seeing it as 25fps interlaced. So you need to batch change all clips to NONE. Now FCP will treat the video as what it really is. __________________ Switcher's Quick Guide to the Avid Media Composer >>> http://home.mindspring.com/~d-v-c

February 12th, 2011, 06:30 PM	#22
Steve Mullen HDV Cinema Join Date: Feb 2003 Location: Las Vegas Posts: 4,007	Sometimes I feel so stupid. I've always wondered why there is AVCHD Lite when the AVCHD spec supports 720p. Of course it does, but Bluray only supports 720p50 and 720p60. And, since the idea is to be able make camcorder to BD copies -- the camera MUST record 720p50 and 720p60. And, since the sensor of these cameras can only do 25p/30p -- each frame either must be recorded twice or a REPEAT FRAME flag used. And, since BD does not support 1080p25 or 1080p30 nor 1080p50 or 1080p60 the ONLY thing Sony could do is make the captures look like 1080i50 or 1080i60. That's why the spec from Japan HQ said INTERLACE. In Japan BD is the norm so camcorders must be BD compatible! Frankly, I can't see why everyone doesn't toss DVD. I just bought 2 BD players. The last for $90 and it includes all the streaming services. And, since my VAIO has a BD burner I use the Sony PMB application to burn copies of SDHC cards. One 8GB plus one 16MB card. Or, one 32GB plus one 16GB card. __________________ Switcher's Quick Guide to the Avid Media Composer >>> http://home.mindspring.com/~d-v-c

February 14th, 2011, 01:32 PM	#24
Robert Young Trustee Join Date: Mar 2005 Location: Coronado Island Posts: 1,472	In my experience, once you start putting your HD projects out on BD and viewing them on 1080 HDTV, you'll never go back. It's breathtaking :) __________________ Bob

January 16th, 2011, 04:54 PM	#19
Henry Williams Major Player Join Date: May 2010 Location: Lewisham, London, United Kingdom Posts: 408	The default sequence settings place the file within a progressive 25p stream but for some weird reason field dominance is set to "odd". I'm assuming that treating the footage as 25p means that field dominance should be set to "none" and this is what I've done to date. I haven't needed to deinterlace the footage on export and don't seem to have lost any res. at any stage in the process. Are the Canon cam's you refer to the ones that shot 25f? It was a sort of fudged almost, but not quite progressive used by the HV20 and the XH-A1. That was dealt with simply by logging and capturing the footage as 25p. You could though, if you chose, capture the footage as 50i.

January 16th, 2011, 06:19 PM	#21
Henry Williams Major Player Join Date: May 2010 Location: Lewisham, London, United Kingdom Posts: 408	Sounds right to me. Thanks, Steve.

February 14th, 2011, 12:12 AM	#23
Dave Blackhurst Inner Circle Join Date: Feb 2007 Location: Apple Valley CA Posts: 4,874	I too finally broke down and picked up a couple BD players, with wireless, and streaming, also well under $100 for a "top of the line" Sony wtith 3D even! Sure they were prolly customer returns, but for the price, it was a no-brainer, and definitely looks way better even on aging 720p HDTV's (which look almost new again). A burner is probably next, with them available right around $100, and disks under a buck... HD will likely finally become a "standard", with BD adoption making inroads with the lower price point. And 1080 is going to become the standard, with 720 fading out, IMO. I've been rendering/burning BD compatible to DVD for a while, until burners came down, but I'm running out of excuses!