Pre-compression HD from analog component outputs? at DVinfo.net

Paul Mogg · February 9th, 2004, 01:50 AM

I've read people posting on another forum that the HD1OU puts out pre-compression HD from the analog component outputs.
Can anyone confirm if this is true or not please?, it would be great, but it seems a bit too good to be true to me. Anyone out there know for sure?

Thanks

David Newman · February 9th, 2004, 11:42 AM

It very likely to be pre-compression, but the signal out of the analog component connector while shooting is only 480p, even in the 720p mode. I don't know why, but it puts a damper on some neat ideas.

Paul Mogg · February 9th, 2004, 12:24 PM

Thanks David, that's what I thought, not much good if it's only 480p, even if it is pre-compression. I don't know why they're getting so excited about capturing it via a Kona card if it's only 480p unless you're only working with SD, oh well.

Paul St. Denis · February 9th, 2004, 01:12 PM

Steve Mullen's original review from the camera says that you can output 720p from component

"A YPbPr cable supplies analog component output for all recording formats. You can choose to output 480i/480p/720p"
Video Systems,_Feb 1, 2003

Where have you seen that it will not output 720p when recording?

David Newman · February 9th, 2004, 01:24 PM

<<<-- Originally posted by Paul St. Denis : Steve Mullen's original review from the camera says that you can output 720p from component

"A YPbPr cable supplies analog component output for all recording formats. You can choose to output 480i/480p/720p"
Video Systems,_Feb 1, 2003

Were have you seen that it will not output 720p when recording? -->>>

I know both from experience and from JVC staff. The menu is only available via playback, and then yes in playback you get 720p, but not while capturing. There is no way to get uncompressed 720p from this camera. However the need for an uncompressed feed from the camera is not as great in the DV world. In DV 4:1:1 happens at the compression stage, there is more color information pre-compression. In the JVC camera the 4:2:0 is inherent in the CCD architecture, therefore you are not lossing color resolution. MPEG2 compression artifacts are of course are present, but are they not significant and anything unwanted can be cleaned up in post.

Paul St. Denis · February 9th, 2004, 02:20 PM

Thanks David,
A few things are still confusing to me though.
I have a YPbPr menu item while recording which gives me the option of outputing 720p.
When I change the output to 420i in the monitor I get pillar boxing on a 16:9 monitor, but not for 720p (not for 420p either), shouldn't the output be 4:3 for 420p? The image does not appear to be stretched.

David Newman · February 9th, 2004, 02:40 PM

Yes the menu exists in record mode, but it simply doesn't function as one would hope.

February 9th, 2004, 01:50 AM	#1
Paul Mogg Major Player Join Date: Apr 2003 Location: San Francisco CA Posts: 386	Pre-compression HD from analog component outputs? I've read people posting on another forum that the HD1OU puts out pre-compression HD from the analog component outputs. Can anyone confirm if this is true or not please?, it would be great, but it seems a bit too good to be true to me. Anyone out there know for sure? Thanks __________________ Paul

February 9th, 2004, 11:42 AM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	It very likely to be pre-compression, but the signal out of the analog component connector while shooting is only 480p, even in the 720p mode. I don't know why, but it puts a damper on some neat ideas. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

February 9th, 2004, 12:24 PM	#3
Paul Mogg Major Player Join Date: Apr 2003 Location: San Francisco CA Posts: 386	Thanks David, that's what I thought, not much good if it's only 480p, even if it is pre-compression. I don't know why they're getting so excited about capturing it via a Kona card if it's only 480p unless you're only working with SD, oh well. __________________ Paul

February 9th, 2004, 01:24 PM	#5
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	<<<-- Originally posted by Paul St. Denis : Steve Mullen's original review from the camera says that you can output 720p from component "A YPbPr cable supplies analog component output for all recording formats. You can choose to output 480i/480p/720p" Video Systems,_Feb 1, 2003 Were have you seen that it will not output 720p when recording? -->>> I know both from experience and from JVC staff. The menu is only available via playback, and then yes in playback you get 720p, but not while capturing. There is no way to get uncompressed 720p from this camera. However the need for an uncompressed feed from the camera is not as great in the DV world. In DV 4:1:1 happens at the compression stage, there is more color information pre-compression. In the JVC camera the 4:2:0 is inherent in the CCD architecture, therefore you are not lossing color resolution. MPEG2 compression artifacts are of course are present, but are they not significant and anything unwanted can be cleaned up in post. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

February 9th, 2004, 02:40 PM	#7
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Yes the menu exists in record mode, but it simply doesn't function as one would hope. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

February 9th, 2004, 01:12 PM	#4
Paul St. Denis Regular Crew Join Date: Nov 2003 Location: Stony Brook NY Posts: 169	Steve Mullen's original review from the camera says that you can output 720p from component "A YPbPr cable supplies analog component output for all recording formats. You can choose to output 480i/480p/720p" Video Systems,_Feb 1, 2003 Where have you seen that it will not output 720p when recording?

February 9th, 2004, 02:20 PM	#6
Paul St. Denis Regular Crew Join Date: Nov 2003 Location: Stony Brook NY Posts: 169	Thanks David, A few things are still confusing to me though. I have a YPbPr menu item while recording which gives me the option of outputing 720p. When I change the output to 420i in the monitor I get pillar boxing on a 16:9 monitor, but not for 720p (not for 420p either), shouldn't the output be 4:3 for 420p? The image does not appear to be stretched.