Video encoding apparatus that adjusts code amount by skipping encoding of image data
First Claim
1. A video encoding apparatus that encodes a sequence of image data while predicting an accumulation amount of a receiver buffer in a decoding apparatus, each image data forming one frame or one field, the video encoding apparatus comprising:
- comparing means for comparing, prior to encoding of each image data, a predictive accumulation amount with a predetermined threshold, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer by the time when data obtained by encoding the image data is decoded; and
skipping means for (a) canceling the encoding of the image data and (b) using a proxy code as data that is fetched from the receiver buffer at the decoding time, if the amount of data is below the predetermined threshold, the proxy code indicating to display image data that is identical to previously decoded image data.
1 Assignment
0 Petitions
Accused Products
Abstract
A comparing/judging unit 125 of a video encoding apparatus compares, prior to encoding each image data, the predictive amount of codes accumulated in a receiver buffer of a decoding apparatus with a threshold that is set for a picture type of a picture to be obtained by encoding the image data. The comparing/judging unit 125 judges, when the predictive amount in the receiver buffer is below the threshold, that encoding the image data is to be skipped, and makes the DCT unit 113 cancel the encoding process. The comparing/judging unit 125 then outputs an all-skip picture in which all macroblocks except a first macroblock and a last macroblock in each slice layer are skipped macroblocks from a SKIP picture storage memory 126.
-
Citations
23 Claims
-
1. A video encoding apparatus that encodes a sequence of image data while predicting an accumulation amount of a receiver buffer in a decoding apparatus, each image data forming one frame or one field, the video encoding apparatus comprising:
-
comparing means for comparing, prior to encoding of each image data, a predictive accumulation amount with a predetermined threshold, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer by the time when data obtained by encoding the image data is decoded; and
skipping means for (a) canceling the encoding of the image data and (b) using a proxy code as data that is fetched from the receiver buffer at the decoding time, if the amount of data is below the predetermined threshold, the proxy code indicating to display image data that is identical to previously decoded image data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A video encoding apparatus that encodes a sequence of image data while predicting an accumulation amount of a receiver buffer in a decoding apparatus, each image data forming one frame or one field, the video encoding apparatus comprising:
-
threshold setting means for setting, after encoding each image data, a threshold according to a picture type of the encoded image data in a case where M≧
2, M representing an appearance cycle of an I-picture or a P-picture, as the following,a threshold Ti in a case where the image data is encoded to be an I-picture is set as Ti=Di, where Di is a predictive code amount of the I-picture, a threshold Tp in a case where the image data is encoded to be a P-picture is set as Tp=Dp, where Dp is a predictive code amount of the P-picture, a threshold Tb(i) in a case where the image data is encoded to be a B-picture immediately preceding an I-picture in an encoding order is set as Tb(i)=Dp+(Ei−
R) when (Ei−
R)≧
0, and Tb(i)=Dp when (Ei−
R)<
0, where Db is a predictive code amount of the B-picture, Ei is a predictive code amount of the I-picture, and R is a transmission bit amount during each decoding time interval, anda threshold Tb(p) in a case where the image data is encoded to be a B-picture immediately preceding a P-picture in the encoding order is set as Tb(p)=Dp+(Ep−
R) when (Ep−
R)≧
0, and Tb(p)=Dp when (Ep−
R)<
0, where Db is a predictive code amount of the B-picture, Ep is a predictive code amount of the P-picture, and R is a transmission bit amount during each decoding time interval;
comparing means for comparing, after encoding the image data, a predictive accumulation amount with the threshold, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer by the time when data obtained by encoding the image data is decoded; and
skipping means for using a proxy code as data that is fetched from the receiver buffer at the decoding time, if the amount of data is below the threshold, the proxy code indicating to display image data that is identical to previously decoded image data.
-
-
13. A video encoding apparatus that encodes a sequence of image data in a frame structure, each image data forming one frame, comprising:
-
comparing means for comparing, prior to encoding of each image data, one of (a) a predictive accumulation amount of a receiver buffer in a decoding apparatus and (b) an accumulation amount of an output buffer, with a predetermined standard value, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer;
skipping means for (a) canceling the encoding of the image data in the frame structure and (b) substituting a proxy code indicating to display two fields that each are identical to one of a top field and a bottom field of previously decoded image data, for data that is obtained by encoding a top field and a bottom field of the image data, if the amount of data is below the predetermined standard value. - View Dependent Claims (14, 15, 16, 17)
-
-
18. A video encoding apparatus that encodes a sequence image data while predicting an accumulation amount of a receiver buffer in a decoding apparatus, each image data forming one frame or one field, the video encoding apparatus comprising:
-
comparing means for comparing, prior to encoding of each image data, a predictive accumulation amount with a threshold, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer by the time when data obtained by encoding the image data is decoded, the threshold being set for a picture type of a picture that is obtained by encoding the image data; and
controlling means for (a) canceling the encoding of the image data and (b) using a proxy code as data that is fetched from the receiver buffer at the decoding time, if the amount of data is below the threshold and the picture type is a B-picture, the proxy code indicating to display image data that is identical to previously decoded image data.
-
-
19. A video encoding apparatus that encodes a sequence of image data while predicting an accumulation amount of a receiver buffer in a decoding apparatus, each image data forming one frame or one field, the video encoding apparatus comprising:
-
comparing means for comparing, prior to encoding of each image data, a predictive accumulation amount with a threshold, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer by the time when data obtained by encoding the image data is decoded, the threshold being set for a picture type of a picture that is obtained by encoding the image data; and
controlling means for (a) canceling the encoding of the image data and (b) using a proxy code as data that is fetched from the receiver buffer at the decoding time, if the amount of data is below the threshold and the picture type is a B-picture or a P-picture, the proxy code indicating to display image data that is identical to previously decoded image data.
-
-
20. A video encoding method for encoding a sequence of image data while predicting an accumulation amount of a receiver buffer in a decoding apparatus, each image data forming one frame or one field, the video encoding method comprising:
-
comparing step for comparing, prior to encoding of each image data, a predictive accumulation amount with a predetermined threshold, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer by the time when data obtained by encoding the image data is decoded; and
skipping step for (a) canceling the encoding of the image data and (b) using a proxy code as data that is fetched from the receiver buffer at the decoding time, if the amount of data is below the predetermined threshold, the proxy code indicating to display image data that is identical to previously decoded image data.
-
-
21. A video encoding method for encoding a sequence of image data in a frame structure, each image data forming one frame, comprising:
-
comparing step for comparing, prior to encoding of each image data, one of (a) a predictive accumulation amount of a receiver buffer in a decoding apparatus and (b) an accumulation amount of an output buffer, with a predetermined standard value, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer;
skipping step for (a) canceling the encoding of the image data in the frame structure and (b) substituting a proxy code indicating to display two fields that each are identical to one of a top field and a bottom field of previously decoded image data, for data that is obtained by encoding a top field and a bottom field of the image data, if the amount of data is below the predetermined standard value.
-
-
22. A video encoding program for encoding a sequence of image data while predicting an accumulation amount of a receiver buffer in a decoding apparatus, each image data forming one frame or one field, the video encoding program comprising:
-
comparing step for comparing, prior to encoding of each image data, a predictive accumulation amount with a predetermined threshold, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer by the time when data obtained by encoding the image data is decoded; and
skipping step for (a) canceling the encoding of the image data and (b) using a proxy code as data that is fetched from the receiver buffer at the decoding time, if the amount of data is below the predetermined threshold, the proxy code indicating to display image data that is identical to previously decoded image data.
-
-
23. A video encoding program for encoding a sequence of image data in a frame structure, each image data forming one frame, comprising:
-
comparing step for comparing, prior to encoding of each image data, one of (a) a predictive accumulation amount of a receiver buffer in a decoding apparatus and (b) an accumulation amount of an output buffer, with a predetermined standard value, the predictive accumulation amount being an amount of data predicted to be accumulated in the receiver buffer;
skipping step for (a) canceling the encoding of the image data in the frame structure and (b) substituting a proxy code indicating to display two fields that each are identical to one of a top field and a bottom field of previously decoded image data, for data that is obtained by encoding a top field and a bottom field of the image data, if the amount of data is below the predetermined standard value.
-
Specification