| 摘要 |
A method and apparatus that provides dynamic frame rate control for compressed digital video sequences to facilitate applying VCR-like controls to the compressed digital video sequences. More specifically, for each compressed video file produced by an encoder (102), there is an associated auxiliary file, e.g., with the same prefixes as the compressed file but with a "VCR" suffix, that would contain information about the intracoded frames (I-frames) of the compressed bitstream. This auxiliary file is created at the time that the original raw video sequence is being encoded (compressed), and contains information about the position of I-frames within the compressed bitstream. These I-frames, which can be independently decoded by a decoder (504/604), serve as reference points for decoding and displaying other predicted frames. Thus, to perform random frame access, for example, the decoder (504/604) can find the position of the nearest I-frame preceding the frame of interest by accessing the auxiliary file. The system can then decode the I-frame without displaying that decoded frame and then decode and display the frame of interest. This technique can randomly access any frame in a compressed sequence to implement fast forward and fast reverse functions.
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