MPEG-4 video object type

Overview

Containing profile atom: Track (video), movie
part-ID: 0x20202020 (universal feature)
feature-code: 'm4vo'
feature-value: Unsigned int(32) where the least significant 8 bits hold the video_object_type_indication found in the VideoObjectLayer (Described in ISO/IEC 14496-2, subclause 6.2.3). The VideoObjectLayer is found in the MPEG-4 Elementary Stream Descriptor Atom within the 'esds' sample description atom of the video sample description for the QuickTime video codec of type 'mp4v'.

Feature Values

The value is a video object type constant that indicates a set of video tools. The list of video object type constants is defined in specification ISO/IEC 14496-2, subclause 6.3.3. The least significant 8 bits hold the value. The most significant 24 bits should be set to 0.

Example: The Simple Object Type video object is indicated by the value 1.

Writer Responsibilities

A writer of the MPEG-4 Video Object Type feature should record the 8 bits corresponding to the video_object_type_indication found in the VideoObjectLayer within the ES_descriptor’s video DecoderSpecificConfig. The most significant 24 bits of the value should be set to 0. This feature should be written only for MPEG-4 video of video object type 1 (Video ID). If the MPEG-4 video does not use Video ID (1) for visual_object_type, the esds will have no VideoObjectLayer and consequently no video_object_type_indication. In this case, no MPEG-4 Video Object Type feature should be written.

Feature Value Algorithm

The MPEG-4 video object type is the least significant 8 bits of the video_object_type_indication found in the VideoObjectLayer. See ISO/IEC 14496-2, subclause 6.2.3. The VideoObjectLayer is found in the MPEG-4 Elementary Stream Descriptor Atom within the 'esds' sample description atom of the video sample description for the QuickTime video codec of type 'mp4v'.

Reader Responsibilities

A reader of this feature code should compare the recorded value with the set of MPEG-4 video tools supported by the reader.