Instant replay of digital video optimized using non MPEG frame tags

• US 6,295,094 B1
• Filed: 09/11/1997
• Issued: 09/25/2001
• Est. Priority Date: 09/11/1997
• Status: Expired due to Term

• Current Assignee: Funai Electric Co., Ltd.
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Cuccia, David W.
• Primary Examiner(s): Eisenhopf, Reinhard J.
• Assistant Examiner(s): Lo, Linus H.
• Application Number:
  US08/927,830
• Time in Patent Office: 1,475 Days
• Field of Search: H04/N.544, 348/559, 348/560, 348/564, 348/565, 348/566, 348/567, 348/568, 386/85, 386/109, 386/112, 386/125
• US Class Current: 348/559
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/8455 involving pointers to the content, e.g. pointers to the I-frames of the video stream
• CPC Class Codes: H04N 5/4448 for frame-grabbing

Abstract

A method and device for providing instant replay in an MPEG video decoder. The method and device provides non-MPEG frame tags for correlation of the frames in the decompressed domain to the frames in the compressed domain.

Claims

1. A video decoder for providing instant replay, comprising:

a memory for storing compressed video information;

a write controller for receiving the compressed video information and for writing it to the memory;

a marker for marking portions of the received compressed video with tags corresponding to the location in the memory of where the portions of the compressed video information are stored;

a decompressor for

i) receiving the compressed video information and the tags from the memory,

ii) decompressing the compressed video information, and

iii) storing the tags;

a display processor for

i) receiving the tags and the decompressed video information,

ii) displaying the decompressed video information, and

iii) storing the tag of a recently displayed decompressed frame; and

a read controller for, upon request for instant replay, receiving the tag of a recently displayed decompressed frame and for accessing the locations in the memory corresponding to a sequence of previously displayed compressed frames for redisplay by the display processor.

2. The video decoder in accordance with claim 1, wherein the tags are pointer values which point to the addresses in the memory of the beginning of the frames of compressed video information.

3. The video decoder in accordance with claim 2, wherein the compressed video information includes anchor frames and non-anchor frames and the tags indicate the anchor frames.

4. The video decoder in accordance with claim 1, further including i) a pointer store for storing pointer values which indicate the addresses in the memory of where the beginning of the frames of compressed video information are stored;

and ii) a mapper which maps the most recently displayed decompressed frame tag to the pointer value of the address in the memory where the most recently displayed frame is stored.

5. The video decoder in accordance with claim 4, wherein the compressed video information includes anchor frames and non-anchor frames and the pointer values indicate the anchor frames.

6. The video decoder in accordance with claim 4, wherein the compressed video includes anchor frames and non-anchor frames and the read controller includes means for selecting an address in the memory which holds an anchor frame and for providing the anchor frame as the first frame of the sequence of frames to be redisplayed.

7. A video decoder for providing instant replay, comprising:

a rate buffer for storing compressed video information for decode and display in real time;

an instant replay memory for storing the compressed video information for instant replay;

a write controller for receiving the compressed video information and for writing the compressed video information into the rate buffer and the instant replay memory;

a marker for marking frames of the compressed video information stored in the rate buffer with tags, and for marking the same frames stored in the instant replay memory with corresponding tags;

a decompressor for decompressing the compressed video information received from the rate buffer;

a display processor for displaying the decompressed video information and for storing the tag of a recently displayed frame of decompressed video information; and

an instant replay memory reader for receiving the tag of the most recently displayed frame of decompressed video information and for reading from the instant replay memory the most recently displayed compressed frame, and for providing the most recently displayed compressed frame to the decompressor and display processor for redisplay.

8. A method of providing instant replay, comprising the steps of:

writing compressed video information to a memory;

storing the compressed video information in the memory;

marking portions of the compressed video information with different tags which correspond to locations in the memory of where the portions of the compressed video information are stored;

decompressing the compressed video information;

storing the tags of the decompressed video information in the decompressor;

displaying the decompressed video information;

storing the tag of a recently displayed decompressed frame;

receiving a request for instant replay;

correlating the tag of the recently displayed decompressed frame to the location in memory of the corresponding compressed frame of video information; and

retrieving the most recently displayed compressed frame and a sequence of previously displayed frames for redisplay.

9. The method in accordance with claim 8, wherein the step of retrieving the sequence retrieves a sequence of frames which correspond to a preselected duration of instant replay.

10. The method in accordance with claim 8, wherein the compressed video information includes anchor frames and non-anchor frames and wherein the step of correlating further includes the step of locating the nearest previously displayed anchor frame to the first frame to be redisplayed and beginning redisplay with this nearest previously displayed anchor frame.

11. The method in accordance with claim 10, wherein each tag indicates the location in memory of the anchor frame of the first frame of the sequence to be redisplayed and the step of retrieving begins by retrieving this anchor frame.

12. The method in accordance with claim 10, wherein the step of correlating includes the step of mapping the tag of the most recently displayed frame to a pointer value, which pointer value indicates a first anchor frame to be redisplayed.

13. The method in accordance with claim 10, wherein the step of decompressing decompresses the video information in accordance with MPEG 2.