Moving-picture compression-encoding apparatus

• US 8,660,183 B2
• Filed: 10/20/2008
• Issued: 02/25/2014
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: KDDI Corporation
• Original Assignee: KDDI Corporation
• Inventors: Miyaji, Satoshi, Takishima, Yasuhiro
• Primary Examiner(s): HOLDER, BRADLEY W
• Application Number:
  US12/254,243
• Publication Number:
  US 20090110056A1
• Time in Patent Office: 1,954 Days
• Field of Search: 375/240.16, 375/240, 375/240.01, 375/240.12
• US Class Current: 375/240.16
• CPC Class Codes: H04N 19/103 Selection of coding mode or of prediction mode
• CPC Class Codes: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/147 according to rate distortion criteria rate-distortion as a criterion for motion estimation H04N19/567
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 19/157 Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
• 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 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

Re-encoding information indicating whether or not an input moving picture has been compression-encoded is provided to a mode determining unit. The mode determining unit determines an optimal encoding mode for the input moving picture, out of a plurality of encoding modes. The mode determining operation is controlled by the re-encoding information. According to a mode determination result of the mode determining unit, a prediction error value corresponding to the determined mode is selected by a selection switch, and then, an encoding process is performed. As the re-encoding information, a pre-determined value, a bit rate, and a quantization parameter, etc., could be provided.

Claims

1. A moving-picture compression-encoding apparatus that selectively compression-encodes a moving picture that has not been compression-encoded and a moving picture obtained by decoding a compression-encoded moving picture, comprising:

a mode determining unit, implemented by a hardware processor, that determines which mode, out of a plurality of encoding modes, is used to encode an input moving picture, by using a mode determining coefficient that serves as a threshold for a mode determination;

an encoding unit, implemented by the processor, that performs an encoding process on the input moving picture with the mode determined by the mode determining unit;

an acquiring unit, implemented by the processor, that acquires re-encoding information indicating whether or not the input moving picture has been compression-encoded; and

a changing unit, implemented by the processor, that changes a mode determining operation in the mode determining unit according to the re-encoding information acquired by the acquiring unit;

wherein the changing unit sets up the mode determining operation as a level of influence of information amount used for transmitting a side information containing prediction direction and where a motion vector is a value utilized with the re-encoding information acquired by the acquiring unit indicating that the input moving picture has not been compression-encoded and changing the mode determining operation so that the level becomes smaller than the value according to degree of compression when the re-encoding information is indicating that the input moving picture has been compression-encoded.

2. The moving-picture compression-encoding apparatus according to claim 1, wherein the changing unit changes the mode determining operation by changing a coupling coefficient in rate-distortion optimization control.

3. The moving-picture compression-encoding apparatus according to claim 2, wherein the re-encoding information acquired by the acquiring unit has a value indicating a level of influence of encoding noise incurred as a result of the compression encoding, and the changing unit changes the mode determining operation according to the value.

4. The moving-picture compression-encoding apparatus according to claim 3, wherein the acquiring unit comprises a unit that calculates a bit rate by observing a number of bits per unit time from a bit stream when the input moving picture is encoded, and provides the bit rate calculated thereby as the re-encoding information.

5. The moving-picture compression-encoding apparatus according to claim 3, wherein the acquiring unit comprises a unit that resolves a bit rate by taking out an information field indicating a bit rate from a bit stream when the input moving picture is encoded, and provides the bit rate taken out thereby as the re-encoding information.

6. The moving-picture compression-encoding apparatus according to claim 3, wherein the acquiring unit comprises a unit that estimates an encoding noise amount by observing a quantization parameter per frame from a bit stream when the input moving picture is encoded, and provides the encoding noise amount estimated thereby as the re-encoding information.

7. The moving-picture compression-encoding apparatus according to claim 1, wherein the changing unit changes the mode determining operation by changing an amount of side information in the mode determining unit.

8. The moving-picture compression-encoding apparatus according to claim 7, wherein the re-encoding information acquired by the acquiring unit has a value indicating a level of influence of encoding noise incurred as a result of the compression encoding, and the changing unit changes the mode determining operation according to the value.

9. The moving-picture compression-encoding apparatus according to claim 8, wherein the acquiring unit comprises a unit that calculates a bit rate by observing a number of bits per unit time from a bit stream when the input moving picture is encoded, and provides the bit rate calculated thereby as the re-encoding information.

10. The moving-picture compression-encoding apparatus according to claim 8, wherein the acquiring unit comprises a unit that resolves a bit rate by taking out an information field indicating a bit rate from a bit stream when the input moving picture is encoded, and provides the bit rate taken out thereby as the re-encoding information.

11. The moving-picture compression-encoding apparatus according to claim 8, wherein the acquiring unit comprises a unit that estimates an encoding noise amount by observing a quantization parameter per frame from a bit stream when the input moving picture is encoded, and provides the encoding noise amount estimated thereby as the re-encoding information.

12. The moving-picture compression-encoding apparatus according to claim 1, wherein the re-encoding information acquired by the acquiring unit has a value indicating a level of influence of encoding noise incurred as a result of the compression encoding, and the changing unit changes the mode determining operation according to the value.

13. The moving-picture compression-encoding apparatus according to claim 12, wherein the acquiring unit comprises a unit that calculates a bit rate by observing a number of bits per unit time from a bit stream when the input moving picture is encoded, and provides the bit rate calculated thereby as the re-encoding information.

14. The moving-picture compression-encoding apparatus according to claim 12, wherein the acquiring unit comprises a unit that resolves a bit rate by taking out an information field indicating a bit rate from a bit stream when the input moving picture is encoded, and provides the bit rate taken out thereby as the re-encoding information.

15. The moving-picture compression-encoding apparatus according to claim 12, wherein the acquiring unit comprises a unit that estimates an encoding noise amount by observing a quantization parameter per frame from a bit stream when the input moving picture is encoded, and provides the encoding noise amount estimated thereby as the re-encoding information.

16. A moving-picture compression-encoding method that selectively compression-encodes a moving picture that has not been compression-encoded and a moving picture obtained by decoding a compression-encoded moving picture, comprising:

determining which mode, out of a plurality of encoding modes, is used to encode an input moving picture, by using a mode determining coefficient that serves as a threshold for a mode determination;

encoding the input moving picture with the determined mode;

acquiring re-encoding information indicating whether or not the input moving picture has been compression-encoded; and

changing a mode determining operation in the determining according to the acquired re-encoding information;

wherein

the determining, the encoding, the acquiring and the changing are performed by a processor; and

the changing sets up the mode determining operation as a level of influence of information amount used for transmitting a side information containing prediction direction and where a motion vector is a value utilized with the re-encoding information acquired by the acquiring unit indicating that the input moving picture has not been compression-encoded and changing the mode determining operation so that the level becomes smaller than the value according to degree of compression when the acquired re-encoding information is indicating that the input moving picture has been compression-encoded.

17. The moving picture compression-encoded method according to claim 16, wherein the changing changes the mode determining operation by changing a coupling coefficient in rate-distortion optimization control.

18. The moving-picture compression-encoding method according to claim 16, wherein the changing changes the mode determining operation by changing an amount of side information in the mode-determining-unit.