System and method for creating trick play video streams from a compressed normal play video bitstream

A system for generating trickplay streams from a compressed normal play bitstream, comprising:

• a storage media storing a compressed normal play bitstream, wherein said compressed normal play bitstream includes a plurality of intracoded frames and a plurality of interceded frames;
• a filter for extracting said intracoded frames from said compressed normal play bitstream;
• a storage memory for storing said extracted intracoded frames;
• a verifier/fixer for assembling said stored intracoded frames to form an assembled bitstream;
• a decoder which decodes said assembled bitstream to produce a plurality of uncompressed frames;
• and
• an encoder which encodes said plurality of uncompressed frames to produce a compressed trick play bitstream, wherein said compressed trick play bitstream includes only a subset of frames of said normal play bitstream.

A method for generating trickplay streams from an MPEG compressed normal play bitstream, comprising:

• receiving a compressed normal play bitstream, wherein said compressed normal play bitstream includes a plurality of Intra frames, a plurality of Predicted frames, and a plurality of Bi-directionally predicted frames;
• extracting said Intra frames from said compressed normal play bitstream, wherein said extracting includes storing said Intra frames in a storage memory;
• assembling said Intra frames to form an assembled bitstream after said extracting;
• decoding said assembled bitstream to produce a plurality of uncompressed frames;
• and
• encoding said plurality of uncompressed frames after said decoding to produce a compressed trick play bitstream, wherein said compressed trick play bitstream includes only a subset of frames of said normal play bitstream.

A computer-implemented method for generating trickplay streams from a compressed normal play bitstream, comprising:

• receiving a compressed normal play bitstream, wherein said compressed normal play bitstream includes a plurality of intracoded frames and a plurality of intercoded frames;
• extracting said intracoded frames from said compressed normal play bitstream, wherein said extracting includes storing said intracoded frames in a storage memory;
• assembling said intracoded frames to form an assembled bitstream after said extracting;
• and
• storing said assembled bitstream;
• wherein said compressed normal play bitstream includes a plurality of sequence headers which comprise information for at least a plurality of said intracoded frames;
• wherein said extracting comprises extracting said sequence headers from said compressed normal play bitstream, wherein said extracting includes storing said sequence headers in a storage memory;
• and wherein said assembling comprises assembling said sequence headers and said intracoded frames to form said assembled bitstream.

A computer-implemented method for generating trickplay streams from a compressed normal play bitstream, comprising:

• receiving a compressed normal play bitstream, wherein said compressed normal play bitstream includes a plurality of intracoded frames and a plurality of interceded frames;
• extracting said intracoded frames from said compressed normal play bitstream, wherein said extracting includes storing said intracoded frames in a storage memory;
• assembling said intracoded frames to form an assembled bitstream after said extracting;
• and
• storing said assembled bitstream;
• wherein said compressed normal play bitstream includes a plurality of matrices which correspond to said intracoded frames;
• the method further comprising:
• locating said matrices in said compressed normal play bitstream;
• wherein said assembling said intracoded frames to form said assembled bitstream includes including said matrices in said assembled bitstream.

A computer-implemented method for generating trickplay streams from a compressed normal play bitstream, comprising:

• receiving a compressed normal play bitstream, wherein said compressed normal play bitstream includes a plurality of intracoded frames and a plurality of intercoded frames;
• extracting said intracoded frames from said compressed normal play bitstream, wherein said extracting includes storing said intracoded frames in a storage memory;
• assembling said intracoded frames to form an assembled bitstream after said extracting;
• and
• storing said assembled bitstream;
• decoding said assembled bitstream to produce a plurality of uncompressed frames after said storing said assembled bitstream;
• encoding said plurality of uncompressed frames after said decoding to produce a compressed trick play bitstream wherein said compressed trick play bitstream includes only a subset of frames of said normal play bitstream;
• and
• storing said compressed trick play bitstream.

A computer-readable storage media for operating in a computer system, the computer system including a central processing unit and memory, wherein the computer-readable storage media includes a substrate having a physical configuration representing data, the storage media comprising:

• an extraction program comprised on the storage media for extracting intracoded frames from a compressed normal play bitstream, wherein said extraction program stores said intracoded frames in a storage memory;
• an assembling program for assembling said intracoded frames to form an assembled bitstream;
• a decoding program for decoding said assembled bitstream to produce a plurality of uncompressed frames;
• and
• an encoding program for encoding said plurality of uncompressed frames after operation of said decoding program to produce a compressed trick play bitstream, wherein said compressed trick play bitstream includes only a subset of frames of said normal play bitstream.

A computer implemented method for generating a reverse trick play stream from a compressed normal play video stream, comprising:

• receiving a compressed normal play video stream, wherein said compressed normal play video stream includes video data;
• storing a marker onto a memory stack;
• searching for a start code in the video stream, wherein said searching comprises searching from the end to the beginning of the compressed normal play video stream;
• finding a start code in the video stream in response to said searching;
• storing coordinates of a user data block onto the memory stack if said finding finds a start code of a user data block;
• storing coordinates of an extension block onto the memory stack if said finding finds a start code for an extension block;
• popping coordinates from the memory stack until the marker is detected if said finding finds a start code of a B or P frame picture header block, wherein the marker remains on the stack;
• storing coordinates of an I-frame picture header block onto the memory stack if said finding finds a start code for an I-frame picture header;
• popping coordinates currently on the memory stack until the marker is detected after said storing coordinates of the I-frame picture header block on the memory stack, if said finding finds a start code for an I-frame picture header;
• writing data from the compressed normal play video stream indicated by said coordinates removed from the memory stack to an output reverse trick play stream as said coordinates are popped from the memory stack in said popping if said finding finds a start code for an I-frame picture header;
• searching for a first sequence header start code if said finding finds a start code for an I-frame picture header;
• and
• repeating said searching for a start code in the video stream and subsequent steps for a plurality of times to generate said reverse trick play stream.