Video Coding

a video and coding technology, applied in the field of video coding, can solve the problems of bitstream handling, circular buffers won't work, and the h.264 implementation of 16-bit devices is not suitable for video coding

Inactive Publication Date: 2008-12-25
TEXAS INSTR INC
View PDF2 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This approach enhances bitstream handling efficiency by reducing the complexity of emulation prevention and maintaining performance on 16-bit devices, with significant cycle savings on both encoder and decoder sides, ensuring effective bitstream processing without the need for additional memory access adjustments.

Problems solved by technology

However, the two-buffer method leads to problems for H.264 implementation on 16-bit devices, such as the DM270 manufactured by Texas Instruments, especially on the decoder side.
This creates problems for bitstream handling because of circular bitstream buffer usage, BURST aligned SDRAM access requirements.
However, the active circular buffer size has to be a multiple of 16 bits (because a 16-bit DSP cannot access memory in bytes).
Otherwise, the circular buffer won't work.
The decoder has the choice to not load the additional byte so as to keep the next SDRAM access start address BURST-aligned, but this will disable the bitstream buffer to work in a circular manner and greatly decrease the decoder performance.
Indeed, any odd number of stuffing bytes in the given size of bitstream will lead to these problems.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Video Coding
  • Video Coding
  • Video Coding

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

1. Overview

[0036]The preferred embodiment methods of prevention of start code emulation incorporate the emulation prevention into bitstream handling routines for both the encoder and decoder.

[0037]The bitstream handling routines refer to the following four functions:

put_bits(buf_ptr, bit_ptr,append “length”-bit “codeword” to thedatabuf, length, codeword)bitstream, and update the bitstreamposition by “length” bits.get_bits(buf_ptr, bit_ptr,extract the value (as binary integer) ofdatabuf, length)“length” bits from the bitstream, and updatethe bitstream position by “length” bits.next_bits(buf_ptr,extract the value of “length” bits frombit_ptr, databuf, length)the bitstream without updating thebitstream position.flush_bits(buf_ptr,move the bitstream position by “length”bit_ptr, databuf, length)bits

where (buf_ptr, bit_ptr) is the bitstream position (see FIG. 5), and databuf is the bitstream buffer.

[0038]The function put_bits( ) is used by the encoder, whereas get_bits( ), next_bits( ), a...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A low-complexity method for prevention of H.264 start code emulation by bit-handling routines with additional functionality. The low-complexity is achieved by employing a start code pre-determination scheme, which saves bitstream handling complexity by about 50% and 30% on the encoder and decoder sides, respectively. The start code emulation prevention has been embedded into the low-level bitstream handling routines. By doing so it avoids the use of the second bitstream buffer, maintains the decoder ability of using a circular bitstream buffer, and satisfies the BURST-aligned SDRAM access requirement.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority from application Ser. No. 10 / 888,702, filed Jul. 9, 2004, which is herein incorporated by reference.BACKGROUND OF THE INVENTION[0002]The present invention relates to video coding, and more particularly to H.264 and related coding methods.[0003]Currently, H.264 is the most advanced video compression standard and is being jointly developed by MPEG and ITU-T. It offers much higher coding efficiency compared to the existing video standards such as MPEG1, MPEG2, and MPEG4. It is widely expected that H.264 will be adopted in applications such as video conferencing, streaming video, HD-DVD, and digital video broadcasting.[0004]In H.264 the video element bitstream is defined in the form of network abstraction layer (NAL) units. A NAL unit is a syntax structure containing an indication of the type of data to follow and bytes containing that data in the form of a raw byte stream payload (RBSP) interspersed as necess...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityApplications(United States)
IPC IPC(8): H04N11/02H03M7/00H04N7/15H04N7/26
CPCH04N7/15H04N19/70H04N19/102H04N19/184H04N19/423
InventorZHOU, MINHUA
OwnerTEXAS INSTR INC