BARCELONA, Spain--H.264 is today's leader when it comes to mainstream video encoding technologies, but it will have to share the stage in 2013 with a successor called H.265 that can squeeze a video into nearly half the file size.
H.264, also known as the Advanced Video Codec (AVC), defines how a video can be compressed for reduced storage requirements and--very importantly given the online video explosion--for streaming across networks. H.265, also called High Efficiency Video Codec (HEVC), uses new techniques to compress video even more.
Qualcomm, a San Diego-based chipmaker that's on the international standards group developing H.265, demonstrated a preliminary version of H.265 video on an Android tablet at the Mobile World Congress show here in Barcelona.
The H.265 codec is likely to gain widespread support, but it and H.264 competes with a royalty-free alternative called VP8 that Google has released. Qualcomm competitor Nvidia has built VP8 decoding support into its newer Tegra 3 chips alongside H.264 support.
Qualcomm is bullish about the codec. If a given network capacity can sustain higher-quality video, that means mobile devices are better for entertainment. And because H.265's efficiencies come at the cost of a significantly higher need for processing power, mobile device makers have a new reason to buy the latest chips.
"We expect the standard to be ratified early next year," said Phillippe Decotigne, a Qualcomm product manager, in an interview today.
In the demo, Qualcomm showed a side-by-side comparison of H.264 and H.265 video on an Android tablet powered by a current-generation Qualcomm Snapdragon S4 dual-core processor running at 1.5GHz. The video, showing race cars peeling around a track, played at a bit rate of 610 kilobits per second on H.265 compared to 1,183Kbps for H.264. The size of the video file itself was 3.10MB for H.265 vs 6.01MB for H.264. Each video had 800x480-pixel resolution.
The statistics look impressive, and the tablet decoded the video with relative aplomb, but the H.265 specification needs work in one particular area: encoding.
"Encoding it is very time-intensive. It takes amazingly long," said Homer Dowlat, a senior staff engineering manager at Qualcomm.
That's not a big deal for people just watching video on their devices, but it would pose a challenge to makers of video cameras, mobile phones, or video-editing software that record video--but decoding improvements are expected.
"That's our next thing," Dowlat said.
The demo video, which nearly halved H.264's storage and bandwidth requirements, was better suited to H.265's benefits than average, Decotigne said. "This one is favorable, but it's not an unrealistic scene. It's very natural," he said. On average, H.265 file sizes and bit rates are about 40 to 45 percent smaller than with H.264, he said.
Dedicated hardware on the Snapdragon chip decoded the H.264 video, but software running on the general-purpose CPU decoded H.265 video because Qualcomm can't build chip support until H.265 is finished, Decotigne said.
When it is done, Qualcomm will build H.265 encoding into its chips, Decotigne said, though he wouldn't make any promises about when or in which processor model.