DYNAMIC VIDEO DATA COMPRESSION

• US 20120170667A1
• Filed: 12/30/2010
• Published: 07/05/2012
• Est. Priority Date: 12/30/2010
• Status: Active Grant

• Current Assignee: VIXS Systems Incorporated (Pixelworks Incorporated)
• Original Assignee: VIXS Systems Incorporated (Pixelworks Incorporated)
• Inventors: Girardeau, James Ward Jr., Gupta, Rajat
• Granted Patent: US 8,781,000 B2
• Time in Patent Office: Days
• US Class Current: 375/240.25
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/436 using parallelised computational arrangements
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards

Abstract

A method includes decompressing first compressed video data to provide uncompressed video data in a first order. The method includes compressing the uncompressed video data to provide second compressed video data in a second order. The decompressing and compressing are based on first and second compression rates, respectively. The first order may be based on fundamental blocks of a frame of video data and the second order is based on lines of the frame of video data. The compressing may include alternating compression of partial portions of a first line of uncompressed video data with compression of partial portions of at least a second line of uncompressed video data to thereby generate a first line of compressed video data corresponding to the first line of uncompressed video data and at least a second line of compressed video data corresponding to the second line of uncompressed video data.

Claims

1. A method comprising:

decompressing first compressed video data to provide uncompressed video data in a first order, the decompressing being based on a first compression rate; and

compressing the uncompressed video data to provide second compressed video data in a second order, the compressing being based on a second compression rate.

2. The method, as recited in claim 1, wherein the compressing comprises:

compressing a first line of uncompressed video data to generate a first line of the second compressed video data, the compressing comprising;

compressing a first portion of the first line of uncompressed video data to generate a first state of a compressor; and

compressing a second portion of the first line of uncompressed video data based on the first state of the compressor; and

compressing a portion of at least one other line of uncompressed video data in between the compressing of the first portion of the first line of uncompressed video data and the compressing of the second portion of the first line of uncompressed video data.

3. The method, as recited in claim 2, wherein the compressing the first line of uncompressed video data further comprises:

saving the first state of the compressor before compressing the portion of the at least one other line of uncompressed video data; and

restoring the first state of the compressor before compressing the second portion of the first line of uncompressed video data.

4. The method, as recited in claim 1, wherein the compressing comprises:

alternating compression of partial portions of a first line of uncompressed video data with compression of partial portions of at least a second line of uncompressed video data to thereby generate a first line of compressed video data corresponding to the first line of uncompressed video data and at least a second line of compressed video data corresponding to the second line of uncompressed video data.

5. The method, as recited in claim 1, wherein the first order is a non-linear order and the second order is a linear order.

6. The method, as recited in claim 1, wherein the first order is based on fundamental blocks of a frame of video data and the second order is based on lines of the frame of video data.

7. The method, as recited in claim 1, wherein the first compression rate is at least an order of magnitude greater than the second compression rate.

8. The method, as recited in claim 1, wherein the first compressed video data is compressed compliant with a Moving Picture Experts Group (MPEG) video compression standard and the second compressed video data is compressed using a compression technique having a latency that is orders of magnitude less than the latency of MPEG video compression.

9. The method, as recited in claim 1, further comprising:

writing a sequence of multiple lines of second compressed video data to corresponding contiguously addressed locations in memory.

10. The method, as recited in claim 9, further comprising:

providing to a memory controller the sequence of multiple lines of second compressed video data to be stored in the corresponding contiguously addressed locations in memory.

11. The method, as recited in claim 1, further comprising:

decompressing the second compressed video data based on the second compression rate to thereby generate uncompressed video data; and

providing the uncompressed video data to a video processor.

12. An apparatus comprising:

a buffer;

a first video data decompressor operative to decompress first compressed video data based on a first compression rate and to write uncompressed video data to the buffer in a first order; and

a video data compressor operative to read the uncompressed video data from the buffer and to provide second compressed video data in a second order.

13. The apparatus, as recited in claim 12, wherein the video data compressor is operative to alternate compression of partial portions of a first line of uncompressed video data with compression of partial portions of at least a second line of uncompressed video data to thereby generate a first line of compressed video data corresponding to the first line of uncompressed video data and at least a second line of compressed video data corresponding to the second line of uncompressed video data.

14. The apparatus, as recited in claim 13, wherein the video data compressor is operative to save state information of the video data compressor after compressing a first portion of the first line of uncompressed video data and operative to restore the state information to the video data compressor before compressing a second portion of the first line of the uncompressed video data.

15. The apparatus, as recited in claim 12, wherein the first order is a non-linear order and the second order is a linear order.

16. The apparatus, as recited in claim 12, wherein the first order is based on fundamental blocks of a frame of video data and the second order is based on lines of the frame of video data.

17. The apparatus, as recited in claim 12, wherein the first compression rate is at least an order of magnitude greater than the second compression rate.

18. The apparatus, as recited in claim 12, wherein the video data compressor comprises a plurality of encoders operative in parallel.

19. The apparatus, as recited in claim 12, wherein the first compressed video data is compressed compliant with a Moving Picture Experts Group (MPEG) video compression standard.

20. The apparatus, as recited in claim 12, further comprising:

a memory controller operative to receive the second compressed video data from the video data compressor and to write the second compressed video data to memory.

21. The apparatus, as recited in claim 12, further comprising:

a memory comprising an expansion portion, the memory being operative to store lines of video data larger than corresponding uncompressed lines of video data.

22. The apparatus, as recited in claim 12, further comprising:

a second video data decompressor operative to decompress the second compressed video data based on the second compression rate.

23. The apparatus, as recited in claim 12, further comprising:

a memory range storage element operative to store an indication of a memory range associated with second compressed video data.

24. An apparatus comprising:

means for decompressing first compressed video data to provide uncompressed video data in a first order, the decompressing being based on a first compression rate; and

means for compressing the uncompressed video data to provide second compressed video data in a second order, the compressing being based on a second compression rate.

25. The apparatus, as recited in claim 24, wherein the first order is based on fundamental blocks of a frame of video data and the second order is based on lines of the frame of video data.