Compressed video and audio transport stream multiplexer

• US 6,310,898 B1
• Filed: 01/27/1998
• Issued: 10/30/2001
• Est. Priority Date: 01/27/1998
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Schwartz, Mayer D.
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): Tran, Maikhanh
• Application Number:
  US09/013,850
• Time in Patent Office: 1,372 Days
• Field of Search: 370/472, 370/473, 370/474, 370/537, 370/538, 370/465, 370/522, 370/389, 348/423, 375/240.26
• US Class Current: 370/537
• CPC Class Codes: H04N 21/236 Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream multiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00

Abstract

A compressed video and audio transport stream multiplexer pre-builds a multiplex pattern in microprocessor local memory using a microprocessor with a DMA controller. The transport stream headers, a null packet, program specific information tables and packetized elementary stream buffers accessed by an assembly buffer that has DMA control blocks, two blocks per transport stream packet. The DMA control blocks are built and loaded into the assembly buffer based upon the number of packets required for the packetized elementary streams and program specific information according to the multiplex pattern. Packetized elementary stream data is received from respective sources and loaded into the packetized elementary stream buffers, and then output according to the DMA control blocks in the assembly buffer to form the transport stream.

Claims

1. A compressed video and audio transport stream multiplexer comprising:

a local memory;

means for pre-building a multiplex pattern in the local memory; and

means for generating an output transport stream in the form of transport stream packets from data packetized elementary streams according to the multiplex pattern.

2. The multiplexer according to claim 1 wherein the pre-building means comprises:

means for allocating an assembly buffer in the local memory for DMA control blocks, each pair of DMA control blocks representing a transport stream packet;

means for generating header and program specific information tables that define the multiplex pattern;

means for determining the number of transport stream packets required for the data packetized elementary streams according to the multiplex pattern; and

means for placing the DMA blocks in the assembly buffer according to the multiplex pattern.

3. A method of compressed video transport stream multiplexing comprising the steps of:

pre-building a multiplex pattern in a local memory; and

generating an output transport stream in the form of transport stream packets from data packetized elementary streams according to the multiplex pattern.

4. The multiplexing method according to claim 3 wherein the pre-building step comprises the steps of:

allocating an assembly buffer in the local memory for DMA control blocks, each pair of DMA control blocks representing a transport stream packet;

generating header and program specific information tables that define the multiplex pattern;

determining the number of transport stream packets required for the data packetized elementary streams according to the multiplex pattern; and

placing the DMA blocks in the assembly buffer according to the multiplex pattern.