In digital multi-program video transmission, several video programs are compressed (e.g., using MPEG-2), multiplexed, and transmitted over a constant bit rate (CBR) channel. joint coding, or statistical multiplexing, ...
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In digital multi-program video transmission, several video programs are compressed (e.g., using MPEG-2), multiplexed, and transmitted over a constant bit rate (CBR) channel. joint coding, or statistical multiplexing, which is now widely used in digital television broadcasting, dynamically allocates the available channel capacity among programs according to picture content. This scheme is much more efficient than independent coding where each channel is allocated a fixed bit rate. In this paper, we present a model which can relate the decoded picture quality to bit rate, for both independent and joint coding. The model takes into account statistical variations of video program complexity, and incorporates experimental data drawn from formal subjective picture quality assessments. We use the model to calculate the coding gain of joint coding relative to independent coding, in terms of bandwidth savings.
The objective of joint rate control is to dynamically distribute the channel capacity among video sequences according to their respective complexities, thus a more uniform picture quality and a more efficient utilizat...
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The objective of joint rate control is to dynamically distribute the channel capacity among video sequences according to their respective complexities, thus a more uniform picture quality and a more efficient utilization of channel capacity are achieved. Most existing approaches are based on MPEG2 coding platform. This paper presents a novel joint rate control scheme for multiple video sequences coding based on H.264 standard. The joint rate control is performed hierarchically from a group of pictures of all sequences down to each picture of every sequence, depending on both the complexity of frames and the buffer occupancy. A novel complexity measure that adapts to the characteristics of H.264 video coding is proposed. An improved joint buffer control strategy, which is extended from that in the single sequence rate control scheme, is applied. Experimental results show that the proposed scheme maintains a good balance in picture quality among the sequences as well as within a sequence.
Recent studies have shown that joint coding is more efficient and effective than independent coding for compression of multiple video programs [3]-[7]. Unlike independent coding, joint coding is able to dynamically di...
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Recent studies have shown that joint coding is more efficient and effective than independent coding for compression of multiple video programs [3]-[7]. Unlike independent coding, joint coding is able to dynamically distribute the channel capacity among video programs according to their respective complexities and hence achieve a more uniform picture quality, This paper examines the bit-allocation issues for joint coding of multiple video programs and provides a bit-allocation strategy that results in a uniform picture quality among programs as well as within a program. To prevent,the encoder/decoder buffers from overflowing and underflowing, further constraints on bit allocation are also discussed.
By dynamically distributing the channel capacity among video programs according to their respective scene complexities, joint coding has been shown to be more efficient than independent coding for compression of multi...
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ISBN:
(纸本)0819424358
By dynamically distributing the channel capacity among video programs according to their respective scene complexities, joint coding has been shown to be more efficient than independent coding for compression of multiple video programs [3]. This paper examines the bit allocation issue for joint coding of multiple video programs and provides a bit allocation strategy that results in uniform picture quality among programs as well as within a program.
Meteor-burst communication channels are characterised by their availability in time bursts, and the decay of the channel gain within the majority of these bursts. An important performance measure of meteor-burst commu...
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Meteor-burst communication channels are characterised by their availability in time bursts, and the decay of the channel gain within the majority of these bursts. An important performance measure of meteor-burst communication systems is the throughput defined as the average number of bits per second, for a fixed probability of error, that can be transmitted through the channel. Error control coding is desired to improve the performance of these systems. joint coding and interleaving is shown to be a simple and effective method of increasing the throughput of meteor-burst communications.
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