0739138-A2 is referenced by 44 patents and cites 6 patents.

A method and apparatus for matching compressed video signals to a communications channel. The compressed bitstream is partially decompressed and the bitstream is regenerated with a reduced bit rate to match the channel capacity. Specifically, control information is decoded and entropy decoding is performed on the entropy coded, quantized frequency domain data. Then, the quantized frequency domain data is re-quantized and re-entropy coded so that the resulting compressed bitstream does not exceed the channel capacity bit rate. However, this entire rate conversion process is performed without converting the frequency domain data out of the frequency domain (and back again) as is done by prior art techniques. That is, the frequency domain data is not inverse transformed (out of the frequency domain) in the process of re-quantization.; In this manner, a compressed and stored video signal can be matched to the constraints of a given communications channel with substantially less computational cost than is required by the techniques of the prior art.

Title
Method and apparatus for matching compressed video signals to a communications channel
Application Number
EP19960302499 19960410
Publication Number
0739138 (A2)
Application Date
April 10, 1996
Publication Date
October 23, 1996
Inventor
Safranek Robert James
US
Kalmanek Charles Robert Jr
US
Assignee
At & T
US
IPC
H04N 07/26
H04N 07/52
H04N 07/50
H04N 07/26
H04N 07/24
H04N 01/41
H03M 07/40
H03M 07/30
H04N 07/30
H04N 07/58
H04N 07/50
H04N 07/26
H04N 07/24
H04N 01/41
H03M 07/40
H03M 07/30
H04N 07/30
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