摘要:
A seamless bitstream switching schema is presented. The schema takes advantage of both the high coding efficiency of non-scalable bitstreams and the flexibility of scalable bitstreams. Small bandwidth fluctuations are accommodated by the scalability of the bitstreams, while large bandwidth fluctuations are tolerated by switching among scalable bitstreams. This seamless bitstream switching schema is significantly improves the efficiency of scalable video coding over a broad range of bit rates.
摘要:
A motion-compensated video encoding scheme employs progressive fine-granularity layered coding to encode macroblocks of video data into frames having multiple layers, including a base layer of comparatively low quality video and multiple enhancement layers of increasingly higher quality video. Some of the enhancement layers in a current frame are predicted from different quality layers in reference frames. The video encoding scheme estimates drifting errors during the encoding and chooses a coding mode for each macroblock in the enhancement layer to maximize high coding efficiency while minimizing drifting errors.
摘要:
A scalable layered video coding scheme that encodes video data frames into multiple layers, including a base layer of comparatively low quality video and multiple enhancement layers of increasingly higher quality video, adds error resilience to the enhancement layer. Unique resynchronization marks are inserted into the enhancement layer bitstream in headers associated with each video packet, headers associated with each bit plane, and headers associated with each video-of-plane (VOP) segment. Following transmission of the enhancement layer bitstream, the decoder tries to detect errors in the packets. Upon detection, the decoder seeks forward in the bitstream for the next known resynchronization mark. Once this mark is found, the decoder is able to begin decoding the next video packet. With the addition of many resynchronization marks within each frame, the decoder can recover very quickly and with minimal data loss in the event of a packet loss or channel error in the received enhancement layer bitstream. The video coding scheme also facilitates redundant encoding of header information from the higher-level VOP header down into lower level bit plane headers and video packet headers. Header extension codes are added to the bit plane and video packet headers to identify whether the redundant data is included.
摘要:
A scalable layered video coding scheme that encodes video data frames into multiple layers, including a base layer of comparatively low quality video and multiple enhancement layers of increasingly higher quality video, adds error resilience to the enhancement layer. Unique resynchronization marks are inserted into the enhancement layer bitstream in headers associated with each video packet, headers associated with each bit plane, and headers associated with each video-of-plane (VOP) segment. Following transmission of the enhancement layer bitstream, the decoder tries to detect errors in the packets. Upon detection, the decoder seeks forward in the bitstream for the next known resynchronization mark. Once this mark is found, the decoder is able to begin decoding the next video packet. With the addition of many resynchronization marks within each frame, the decoder can recover very quickly and with minimal data loss in the event of a packet loss or channel error in the received enhancement layer bitstream. The video coding scheme also facilitates redundant encoding of header information from the higher-level VOP header down into lower level bit plane headers and video packet headers. Header extension codes are added to the bit plane and video packet headers to identify whether the redundant data is included.
摘要:
A scalable layered video coding scheme that encodes video data frames into multiple layers, including a base layer of comparatively low quality video and multiple enhancement layers of increasingly higher quality video, adds error resilience to the enhancement layer. Unique resynchronization marks are inserted into the enhancement layer bitstream in headers associated with each video packet, headers associated with each bit plane, and headers associated with each video-of-plane (VOP) segment. Following transmission of the enhancement layer bitstream, the decoder tries to detect errors in the packets. Upon detection, the decoder seeks forward in the bitstream for the next known resynchronization mark. Once this mark is found, the decoder is able to begin decoding the next video packet. With the addition of many resynchronization marks within each frame, the decoder can recover very quickly and with minimal data loss in the event of a packet loss or channel error in the received enhancement layer bitstream. The video coding scheme also facilitates redundant encoding of header information from the higher-level VOP header down into lower level bit plane headers and video packet headers. Header extension codes are added to the bit plane and video packet headers to identify whether the redundant data is included.
摘要:
A method comprising receiving media data in a compressed, digital domain, analyzing motion vectors associated with the received media content while in the compressed digital domain and identifying one or more objects in the received media data based, at least in part, on the motion vector analysis.
摘要:
A method and apparatus for selecting a quantizer scale for each frame to optimize the coding rate is disclosed. A quantizer scale is selected for each frame such that the target bit rate for the frame is achieved while maintaining a uniform visual quality over an entire sequence of frames.
摘要:
A video encoding system and method utilizes a three-dimensional (3-D) wavelet transform and entropy coding that utilize motion information in a way to reduce the sensitivity to motion. In one implementation, the coding process initially estimates motion trajectories of pixels in a video object from frame to frame in a video sequence to account for motion of the video object throughout the frames. After motion estimation, a wavelet transform is applied to produce coefficients within different sub-bands. The wavelet coefficients are coded independently for each sub-band to permit easy separation at a decoder, making resolution scalability and temporal scalability natural and easy. In particular, the coefficients are assigned various contexts based on the significance of neighboring samples in previous, current, and next frame, thereby taking advantage of any motion information between frames.
摘要:
A scalable layered video coding scheme that encodes video data frames into multiple layers, including a base layer of comparatively low quality video and multiple enhancement layers of increasingly higher quality video, adds error resilience to the enhancement layer. Unique resynchronization marks are inserted into the enhancement layer bitstream in headers associated with each video packet, headers associated with each bit plane, and headers associated with each video-of-plane (VOP) segment. Following transmission of the enhancement layer bitstream, the decoder tries to detect errors in the packets. Upon detection, the decoder seeks forward in the bitstream for the next known resynchronization mark. Once this mark is found, the decoder is able to begin decoding the next video packet. With the addition of many resynchronization marks within each frame, the decoder can recover very quickly and with minimal data loss in the event of a packet loss or channel error in the received enhancement layer bitstream. The video coding scheme also facilitates redundant encoding of header information from the higher-level VOP header down into lower level bit plane headers and video packet headers. Header extension codes are added to the bit plane and video packet headers to identify whether the redundant data is included.
摘要:
A video encoding system and method utilizes a three-dimensional (3-D) wavelet transform and entropy coding that utilize motion information in a way to reduce the sensitivity to motion. In one implementation, the coding process initially estimates motion trajectories of pixels in a video object from frame to frame in a video sequence to account for motion of the video object throughout the frames. After motion estimation, a 3-D wavelet transform is applied in two parts. First, a temporal 1-D wavelet transform is applied to the corresponding pixels along the motion trajectories in a time direction. The temporal wavelet transform produces decomposed frames of temporal wavelet transforms, where the spatial correlation within each frame is well preserved. Second, a spatial 2-D wavelet transform is applied to all frames containing the temporal wavelet coefficients. The wavelet transforms produce coefficients within different sub-bands. The process then codes wavelet coefficients. In particular, the coefficients are assigned various contexts based on the significance of neighboring samples in previous, current, and next frame, thereby taking advantage of any motion information between frames. The wavelet coefficients are coded independently for each sub-band to permit easy separation at a decoder, making resolution scalability and temporal scalability natural and easy. During the coding, bits are allocated among sub-bands according to a technique that optimizes rate-distortion characteristics.