Image courtesy of Sony

Sony’s latest compression algorithms are more efficient than ever. This image shows a comparison of frames uncompressed and compressed—MPEG- 2 long-GOP at 50 Mbps (left two images) vs. AVC-I compression at 100 Mbps (right two images)—after five generations.

real-time performance has to be guaranteed.) Panasonic says AVC-Intra requires only about twice the processing power of a long-GOP MPEG system, but is much less complex to process than AVCHD (long-GOP H.264/AVC), though both can be easily edited on today’s NLE platforms.

Comparing the Quality

“AVC-Intra at 50 Mbps doesn’t even come close, in terms of picture quality, to MPEG- 2 at 50,” contends Ott, citing results shown at a number of demos around the country to prove Sony’s case.

“I think you have to go up to 140 Mbps to get the same quality as MPEG- 2 at 25 Mbps,” Ott says. From a field editing standpoint, he adds, there’s another clear advantage to MPEG-2: “AVC-Intra is not laptop-ready [due to processing requirements]. It’s going to take several years to get to where MPEG- 2 is today.”

According to Ott, AVC-Intra at 70–75 Mbps will match MPEG- 2 long-GOP at 25 Mbps (all other elements being equal, such as

1440x1080 and 4:2:0 color structure). For AVC-I to exceed the quality of MPEG- 2 long-GOP at 50 Mbps (1920 x 1080 and 4:2: 2 color structure), Ott says, more than 100 Mbps would be needed, especially for demanding picture material and multigeneration work.

Panasonic, which conducted comparison demonstrations throughout 2007 and earlier this year at several trade conferences and exhibitions, counters that AVC-Intra 50 takes advantage of the new H.264 compression tools to offer high picture quality comparable to DVCPRO HD with double the storage efficiency (64 minutes on one 32 GB P2 card). And for 1920 x 1080 24p recordings in AVC-Intra 100, one 32 GB P2 card can hold up to 40 minutes of almost D- 5 quality content.

There are laptop editing software packages available from Apple, Avid, Grass Valley and others that do support AVC-Intra material, but the bit rate is lower than 50 Mbps and the resulting picture quality is lacking. Ott says he expects clients will have issues with the quality, especially as a project goes through multiple iterations during editing and transmission.

AVC-Intra, like almost all Intraframe professional HD compression schemes used for acquisition and post-production (such as DVCPRO HD, D- 5, HDCAM and HDCAM SR), facilitates more precise editing and images are generally sharper, as there is zero interaction with content in the adjacent video frames, says Steve Mahrer, director of engineering at Panasonic Broadcast’s Business Development Group. This results in dramatically higher image quality, more deterministic performance and easier implementation in hardware.

“AVC-Intra was designed to give professionals the highest level of image quality,” Mahrer says. “The use of low-bit-rate MPEG- 2 long-