I263: Difference between revisions
| Line 19: | Line 19: | ||
* '''Marker (1 bit)''' | * '''Marker (1 bit)''' | ||
This bit should be always set to "1" | This bit should be always set to "1" in order to avoid start code emulation. | ||
* '''H.263 ID (1 bit)''' | |||
This bit should be always set to "0" for distinction with H.261. | |||
Revision as of 11:16, 27 February 2006
- FOURCCs: I263
- Company: Intel
General description
This codec is based on early drafts of the H.263 standard specification. It supports the following modes: Unrestricted Motion Vector mode, Advanced Prediction mode, PB frames mode, Improved PB frames mode (old version!) and Deblocking Filter mode.
Picture Layer
Data for each picture consists of a picture header followed by data for Group of Blocks, eventually followed by an end-of-sequence code and stuffing bits.
Picture Header
The Picture Header of the I.263 has the following format:
- Picture Start Code (PSC) (22 bits)
PSC is a word of 22 bits. Its value is 0000 0000 0000 0000 1 00000. All picture start codes shall be byte aligned.
- Temporal Reference (TR) (8 bits)
An 8-bit number which can have 256 possible values. It is formed by incrementing its value in the previously transmitted picture header by one plus the number of non-transmitted pictures (at 29.97 Hz) since the previously transmitted one. The arithmetic is performed with only the eight LSBs. In the optional PB-frames mode, TR only addresses P-pictures; for the temporal reference for B-pictures refer to section 5.1.7.
- Marker (1 bit)
This bit should be always set to "1" in order to avoid start code emulation.
- H.263 ID (1 bit)
This bit should be always set to "0" for distinction with H.261.