Video Breakthroughs

Version 2.0 of the DASH-AVC/264 guidelines, with support for 1080p video and multichannel audio, is now publicly available on the DASH Industry Forum (IF) website.

The new guidelines includes several promised extensions, including one on HD video that moves the recommended baseline from 720p to 1080p.

720p had initially been chosen, according to the initial guidelines released in May, as a "tradeoff between content availability, support in existing devices and compression efficiency." At that time, the baseline video support used the Progressive High Profile Level 3.1 decoder and supported up to 1280x720p at 30 fps.

"The choice for HD extensions up to 1920x1080p and 30 fps is H.264 (AVC) Progressive 12 High Profile Level 4.0 decoder," the new guidelines state, adding support for 4.0 decoders that was lacking in the previous set of guidelines.

In addition, the guidelines also provide a way to handle standard definition (SD) content.

DASH-IF introduces a leaner, meaner H.264/fMP4 approach, officially called DASH-AVC/264. 

DASH-IF has identified what it calls "interoperability points" that use AAC as the audio codec, AVC as the video codec (also known as H.264 or MPEG-4 Part 10), and fMP4 as the base container format. The latter is better known as the ISO Base Media File Format (ISOBMFF).

The primary interoperability point is designed around high-definition (HD) video up to 720p at the AVC Progressive High Profile.