Benefits of XAVC Intra over XAVC Long GOP at DVinfo.net

Paul Anderegg · May 18th, 2015, 04:01 PM

Would I see any benefits in shooting 720p60 XAVC-I over XAVC-L. My final product is HDV 720p60 18Mbps. I was thinking the Intra codec would produce less blocking on movement and flames etc, and that less deterioration in the master would mean less reencoding ugliness when it gets compressed as that crappy MPEG2 HDV flavor.

Paul

Jack Zhang · May 18th, 2015, 06:37 PM

The big difference between Intra and Long GOP is for VFX work. Intra compresses every single frame as a frame. Long GOP compresses 1 complete frame every 15 frames, with 14 "prediction" frames based on motion data only.

When you need to track something in 3D space, Intra is pretty much needed.

For ENG, you can stick to Long GOP cause you're not doing anything to the footage later other than storing it as file footage.

As for benefits, it's there, but for ENG purposes, it's not worth it over the space savings of Long-GOP. Intra is more for major productions like primetime stuff on PBS or Discovery.

May 18th, 2015, 04:01 PM	#1
Paul Anderegg Trustee Join Date: Jan 2013 Location: San Diego, Califonia Posts: 1,559	Benefits of XAVC Intra over XAVC Long GOP Would I see any benefits in shooting 720p60 XAVC-I over XAVC-L. My final product is HDV 720p60 18Mbps. I was thinking the Intra codec would produce less blocking on movement and flames etc, and that less deterioration in the master would mean less reencoding ugliness when it gets compressed as that crappy MPEG2 HDV flavor. Paul

May 18th, 2015, 06:37 PM	#2
Jack Zhang Inner Circle Join Date: May 2005 Location: Burnaby, BC, Canada Posts: 3,053	Re: Benefits of XAVC Intra over XAVC Long GOP The big difference between Intra and Long GOP is for VFX work. Intra compresses every single frame as a frame. Long GOP compresses 1 complete frame every 15 frames, with 14 "prediction" frames based on motion data only. When you need to track something in 3D space, Intra is pretty much needed. For ENG, you can stick to Long GOP cause you're not doing anything to the footage later other than storing it as file footage. As for benefits, it's there, but for ENG purposes, it's not worth it over the space savings of Long-GOP. Intra is more for major productions like primetime stuff on PBS or Discovery.