I-Frame indicator?? at DVinfo.net

Brian T. Young · July 13th, 2012, 04:38 PM

Greetings -
New NanoFlash owner here, so forgive if this is stupid.

I am looking to use the NF in a couple of ways: to replicate P2 AVC-Intra recording by putting the NF on a PDW-F800 and record in I-frame - and to replicate XDCAM 422 Long-GOP when using it on an HPX2700 Varicam and recording in Long-GOP. In basic words, to make an xdcam a p2 cam and vice versa.

My question is - in performing test recordings on the F-800 with the NF set to I-frame/100mb/1080/30p, and then playing back in both QuickTime Player 7 and FCP 7, I always see (under "format): Apple XDCAM HD422 50 Mb/s CBR when analyzing the clip.

is my mac/fcp/QT doing something to this upon playback??

thank you!
Brian

Jack Zhang · July 13th, 2012, 05:25 PM

First off: MPEG-2 I-frame is less efficient than AVC-Intra so it requires more bitrate to be relatively equal. 220+Mbps I-frame MPEG-2 should be relatively equal to or superior to AVC-Intra at 100Mbps.

It is normal for QT to read 50Mbps as the codec. Your actual data rate shows in Movie Inspector as MB/s.

Brian T. Young · July 13th, 2012, 05:35 PM

Jack,

Understood on I-frame/Intra efficiencies - thank you.

Strange for QT to incorrectly show the codec, isn't it?

Thanks again,
b

Billy Steinberg · July 15th, 2012, 09:20 PM

The Apple XDCAM HD422 Quicktime codec can play any bitrate the nano can record, but the Quicktime codec can only encode to 50Mb. It's "title" includes the 50Mb part.

July 13th, 2012, 04:38 PM	#1
Brian T. Young Regular Crew Join Date: Nov 2003 Location: Los Angeles, CA Posts: 137	I-Frame indicator?? Greetings - New NanoFlash owner here, so forgive if this is stupid. I am looking to use the NF in a couple of ways: to replicate P2 AVC-Intra recording by putting the NF on a PDW-F800 and record in I-frame - and to replicate XDCAM 422 Long-GOP when using it on an HPX2700 Varicam and recording in Long-GOP. In basic words, to make an xdcam a p2 cam and vice versa. My question is - in performing test recordings on the F-800 with the NF set to I-frame/100mb/1080/30p, and then playing back in both QuickTime Player 7 and FCP 7, I always see (under "format): Apple XDCAM HD422 50 Mb/s CBR when analyzing the clip. is my mac/fcp/QT doing something to this upon playback?? thank you! Brian __________________ Brian Young - Los Angeles - www.FlacaProductions.com F800, F5, FS7, A7s

July 13th, 2012, 05:25 PM	#2
Jack Zhang Inner Circle Join Date: May 2005 Location: Burnaby, BC, Canada Posts: 3,053	Re: I-Frame indicator?? First off: MPEG-2 I-frame is less efficient than AVC-Intra so it requires more bitrate to be relatively equal. 220+Mbps I-frame MPEG-2 should be relatively equal to or superior to AVC-Intra at 100Mbps. It is normal for QT to read 50Mbps as the codec. Your actual data rate shows in Movie Inspector as MB/s.

July 13th, 2012, 05:35 PM	#3
Brian T. Young Regular Crew Join Date: Nov 2003 Location: Los Angeles, CA Posts: 137	Re: I-Frame indicator?? Jack, Understood on I-frame/Intra efficiencies - thank you. Strange for QT to incorrectly show the codec, isn't it? Thanks again, b __________________ Brian Young - Los Angeles - www.FlacaProductions.com F800, F5, FS7, A7s

July 15th, 2012, 09:20 PM	#4
Billy Steinberg Regular Crew Join Date: Nov 2008 Location: NYC Posts: 122	Re: I-Frame indicator?? The Apple XDCAM HD422 Quicktime codec can play any bitrate the nano can record, but the Quicktime codec can only encode to 50Mb. It's "title" includes the 50Mb part.