RTP Payload Format for JPEG-compressed Video (RFC2035)
Original Publication Date: 1996-Oct-01
Included in the Prior Art Database: 2019-Feb-16
Internet Society Requests For Comment (RFCs)
L. Berc: AUTHOR [+3]
This memo describes the RTP payload format for JPEG video streams. The packet format is optimized for real-time video streams where codec parameters change rarely from frame to frame. [STANDARDS-TRACK]
Network Working Group L. Berc Request for Comments: 2035 Digital Equipment Corporation Category: Standards Track W. Fenner Xerox PARC R. Frederick Xerox PARC S. McCanne Lawrence Berkeley Laboratory October 1996
RTP Payload Format for JPEG-compressed Video
Status of this Memo
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
This memo describes the RTP payload format for JPEG video streams. The packet format is optimized for real-time video streams where codec parameters change rarely from frame to frame.
This document is a product of the Audio-Video Transport working group within the Internet Engineering Task Force. Comments are solicited and should be addressed to the working group’s mailing list at rem- email@example.com and/or the author(s).
The Joint Photographic Experts Group (JPEG) standard [1,2,3] defines a family of compression algorithms for continuous-tone, still images. This still image compression standard can be applied to video by compressing each frame of video as an independent still image and transmitting them in series. Video coded in this fashion is often called Motion-JPEG.
We first give an overview of JPEG and then describe the specific subset of JPEG that is supported in RTP and the mechanism by which JPEG frames are carried as RTP payloads.
The JPEG standard defines four modes of operation: the sequential DCT mode, the progressive DCT mode, the lossless mode, and the hierarchical mode. Depending on the mode, the image is represented
Berc, et. al. Standards Track [Page 1]
RFC 2035 RTP Payload Format for JPEG Video October 1996
in one or more passes. Each pass (called a frame in the JPEG standard) is further broken down into one or more scans. Within each scan, there are one to four components,which represent the three components of a color signal (e.g., "red, green, and blue", or a luminance signal and two chromanince signals). These components can be encoded as separate scans or interleaved into a single scan.
Each frame and scan is preceded with a header containing optional definitions for compression parameters like quantization tables and Huffman coding tables. The headers and optional parameters are identified with "markers" and comprise a marker segment; each scan appears as an entropy-coded bit stream within two marker segments. Markers are aligned to byte boundaries and (in general) cannot appear in the entropy-coded segment, allowing scan boundaries to be determined without parsing the bit stream.
Compressed data is represented in one of three formats: the interchange format, the abbreviated format, or the table- specification format. The interchange format contains definitions for all the table used in the by th...