1 |
Real-time Video Encoder On Tmsc6000 PlatformErdogan, Baran 01 November 2004 (has links) (PDF)
Technology is integrated into daily life more than before as it evolves through
communication area. In the past, it started with audio devices that help us to
communicate while far between two ends of communication line. Nowadays
visual communication comes in front considering the communication technology.
This became possible with the improvement in the compression techniques of
visual data and increasing speed, optimized architecture of the new family
processors. These type processors are named as Digital Signal Processors
(DSP&rsquo / s). Texas Instruments TMS320C6000 Digital Signal Processor family offers
one of the fastest DSP core in the market. TMS320C64x sub-family processors
are newly developed under the TMS320C6000 family to overcome disadvantages
of its predecessor family TMS320C62x. TMS320C64x family has optimized
architecture for packed data processing, improved data paths and functional units,improved memory architecture and increased speed. These capabilities make this
family of processors good candidate for real-time video processing applications.
Advantages of this core are used for implementing newly established H.264
Recommendation. Highly optimizing C Compiler of TMS320C64x enabled fast
running implementation of encoder blocks that bring heavy computational load to
encoder. Such as fast implementation of Motion Estimation, Transform, Entropy
Coding became possible. Simplified Densely Centered Uniform-P Search
algorithm is used for fast estimation of motion vectors. Time taking parts
enhanced to improve the performance of the encoder.
|
2 |
Transform Coefficient Thresholding and Lagrangian Optimization for H.264 Video Coding / Transformkoefficient-tröskling och Lagrangeoptimering för H.264 VideokodningCarlsson, Pontus January 2004 (has links)
<p>H.264, also known as MPEG-4 Part 10: Advanced Video Coding, is the latest MPEG standard for video coding. It provides approximately 50% bit rate savings for equivalent perceptual quality compared to any previous standard. In the same fashion as previous MPEG standards, only the bitstream syntax and the decoder are specified. Hence, coding performance is not only determined by the standard itself but also by the implementation of the encoder. In this report we propose two methods for improving the coding performance while remaining fully compliant to the standard. </p><p>After transformation and quantization, the transform coefficients are usually entropy coded and embedded in the bitstream. However, some of them might be beneficial to discard if the number of saved bits are sufficiently large. This is usually referred to as coefficient thresholding and is investigated in the scope of H.264 in this report. </p><p>Lagrangian optimization for video compression has proven to yield substantial improvements in perceived quality and the H.264 Reference Software has been designed around this concept. When performing Lagrangian optimization, lambda is a crucial parameter that determines the tradeoff between rate and distortion. We propose a new method to select lambda and the quantization parameter for non-reference frames in H.264. </p><p>The two methods are shown to achieve significant improvements. When combined, they reduce the bitrate around 12%, while preserving the video quality in terms of average PSNR. </p><p>To aid development of H.264, a software tool has been created to visualize the coding process and present statistics. This tool is capable of displaying information such as bit distribution, motion vectors, predicted pictures and motion compensated block sizes.</p>
|
3 |
Transform Coefficient Thresholding and Lagrangian Optimization for H.264 Video Coding / Transformkoefficient-tröskling och Lagrangeoptimering för H.264 VideokodningCarlsson, Pontus January 2004 (has links)
H.264, also known as MPEG-4 Part 10: Advanced Video Coding, is the latest MPEG standard for video coding. It provides approximately 50% bit rate savings for equivalent perceptual quality compared to any previous standard. In the same fashion as previous MPEG standards, only the bitstream syntax and the decoder are specified. Hence, coding performance is not only determined by the standard itself but also by the implementation of the encoder. In this report we propose two methods for improving the coding performance while remaining fully compliant to the standard. After transformation and quantization, the transform coefficients are usually entropy coded and embedded in the bitstream. However, some of them might be beneficial to discard if the number of saved bits are sufficiently large. This is usually referred to as coefficient thresholding and is investigated in the scope of H.264 in this report. Lagrangian optimization for video compression has proven to yield substantial improvements in perceived quality and the H.264 Reference Software has been designed around this concept. When performing Lagrangian optimization, lambda is a crucial parameter that determines the tradeoff between rate and distortion. We propose a new method to select lambda and the quantization parameter for non-reference frames in H.264. The two methods are shown to achieve significant improvements. When combined, they reduce the bitrate around 12%, while preserving the video quality in terms of average PSNR. To aid development of H.264, a software tool has been created to visualize the coding process and present statistics. This tool is capable of displaying information such as bit distribution, motion vectors, predicted pictures and motion compensated block sizes.
|
Page generated in 0.0149 seconds