摘要:
Techniques and tools for reducing latency in video decoding for real-time communication applications that emphasize low delay. For example, a tool such as a video decoder selects a low-latency decoding mode. Based on the selected decoding mode, the tool adjusts output timing determination, picture boundary detection, number of pictures in flight and/or jitter buffer utilization. For low-latency decoding, the tool can use a frame count syntax element to set initial output delay for a decoded picture buffer, and the tool can use auxiliary delimiter syntax elements to detect picture boundaries. To further reduce delay in low-latency decoding, the tool can reduce number of pictures in flight for multi-threaded decoding and reduce or remove jitter buffers. The tool receives encoded data, performs decoding according to the selected decoding mode to reconstruct pictures, and outputs the pictures for display.
摘要:
Techniques and tools for reducing latency in video decoding for real-time communication applications that emphasize low delay. For example, a tool such as a video decoder selects a low-latency decoding mode. Based on the selected decoding mode, the tool adjusts output timing determination, picture boundary detection, number of pictures in flight and/or jitter buffer utilization. For low-latency decoding, the tool can use a frame count syntax element to set initial output delay for a decoded picture buffer, and the tool can use auxiliary delimiter syntax elements to detect picture boundaries. To further reduce delay in low-latency decoding, the tool can reduce number of pictures in flight for multi-threaded decoding and reduce or remove jitter buffers. The tool receives encoded data, performs decoding according to the selected decoding mode to reconstruct pictures, and outputs the pictures for display.
摘要:
Methods are disclosed for supporting stereo 3D video in computing devices. A computing device can receive stereo 3D video data employing a YUV color space and chroma subsampling, and can generate anaglyph video data therefrom. The anaglyph video data can be generated by unpacking the stereo 3D video data to left and right views and combining the left and right views into a single view via matrix transformation. The combining uses transform matrices that correspond to a video pipeline configuration. The transform matrix coefficients can depend on characteristics of the video pipeline components. Modified transform matrix coefficients can be used in response to changes in the video pipeline configuration. Video encoded in stereo 3D video data can be selected to be displayed in stereo 3D, anaglyph or monoscopic form, depending on user input and/or characteristics of video pipeline components.
摘要:
Adjustment of hardware acceleration level in a video decoder utilizing hardware acceleration is described. Errors are detected in a bitstream as it is decoded using different levels of error detection based on decoding characteristics. A statistical analysis is performed on the error values as they are detected. In one technique, if the bitstream is categorized as fitting a high error rate state in a bitstream model, then hardware acceleration is dropped. In another technique, error statistics based on run-lengths of good and bad bitstream units are kept, and compared to predetermined thresholds. If the thresholds are exceeded, the hardware acceleration level is dropped. The level is dropped in order to take advantage of superior error handing abilities of software-based decoding over hardware-accelerated decoding.
摘要:
A video bit stream with pictures comprising inter-coded content can be decoded upon receiving a channel start or file seek instruction. Pictures for beginning decoding and display of the bit stream can be selected based at least in part on one or more tuning parameters that set a preference between a latency of beginning to display video and possible defects in the displayed video. In some embodiments, to implement decoding upon a channel start or file seek, one or more types of data are generated for one or more pictures. For example, picture order counts are generated for pictures after a channel start or file seek operation. As another example, a decoder generates a frame number value that triggers re-initialization of a reference picture buffer before decoding after a channel start or file seek operation.
摘要:
Adjustment of hardware acceleration level in a video decoder utilizing hardware acceleration is described. Errors are detected in a bitstream as it is decoded using different levels of error detection based on decoding characteristics. A statistical analysis is performed on the error values as they are detected. In one technique, if the bitstream is categorized as fitting a high error rate state in a bitstream model, then hardware acceleration is dropped. In another technique, error statistics based on run-lengths of good and bad bitstream units are kept, and compared to predetermined thresholds. If the thresholds are exceeded, the hardware acceleration level is dropped. The level is dropped in order to take advantage of superior error handing abilities of software-based decoding over hardware-accelerated decoding.
摘要:
Methods are disclosed for supporting stereo 3D video in computing devices. A computing device can receive stereo 3D video data employing a YUV color space and chroma subsampling, and can generate anaglyph video data therefrom. The anaglyph video data can be generated by unpacking the stereo 3D video data to left and right views and combining the left and right views into a single view via matrix transformation. The combining uses transform matrices that correspond to a video pipeline configuration. The transform matrix coefficients can depend on characteristics of the video pipeline components. Modified transform matrix coefficients can be used in response to changes in the video pipeline configuration. Video encoded in stereo 3D video data can be selected to be displayed in stereo 3D, anaglyph or monoscopic form, depending on user input and/or characteristics of video pipeline components.
摘要:
A video bit stream with pictures comprising inter-coded content can be decoded upon receiving a channel start or file seek instruction. Pictures for beginning decoding and display of the bit stream can be selected based at least in part on one or more tuning parameters that set a preference between a latency of beginning to display video and possible defects in the displayed video. In some embodiments, to implement decoding upon a channel start or file seek, one or more types of data are generated for one or more pictures. For example, picture order counts are generated for pictures after a channel start or file seek operation. As another example, a decoder generates a frame number value that triggers re-initialization of a reference picture buffer before decoding after a channel start or file seek operation.
摘要:
A decoder which can detect errors in MPEG-2 coefficient blocks can identify syntactically-correct blocks which have out-of-bounds coefficients. The decoder computes coefficient bounds based on quantization scalers and quantization matrices and compares these to coefficient blocks during decoding; if a block has out-of-bounds coefficients, concealment is performed on the block. In a decoder implemented all in software, coefficient bounds checking is performed on iDCT coefficients against upper and lower bounds in a spatial domain. In a decoder which performs iDCT in hardware, DCT coefficients are compared to an upper energy bound.
摘要:
A decoder which can detect errors in MPEG-2 coefficient blocks can identify syntactically-correct blocks which have out-of-bounds coefficients. The decoder computes coefficient bounds based on quantization scalers and quantization matrices and compares these to coefficient blocks during decoding; if a block has out-of-bounds coefficients, concealment is performed on the block. In a decoder implemented all in software, coefficient bounds checking is performed on iDCT coefficients against upper and lower bounds in a spatial domain. In a decoder which performs iDCT in hardware, DCT coefficients are compared to an upper energy bound.