Embodiments feature families of rate allocation and rate control methods that utilize advanced processing of past and future frame/field picture statistics and are designed to operate with one or more coding passes. At least two method families include: a family of methods for a rate allocation with picture look-ahead; and a family of methods for average bit rate (ABR) control methods. At least two other methods for each method family are described. For the first family of methods, some methods may involve intra rate control. For the second family of methods, some methods may involve high complexity ABR control and/or low complexity ABR control. These and other embodiments can involve any of the following: spatial coding parameter adaptation, coding prediction, complexity processing, complexity estimation, complexity filtering, bit rate considerations, quality considerations, coding parameter allocation, and/or hierarchical prediction structures, among others.

Video compression and transmission techniques

An indexed file layout, comprising index information, is defined for segmented streaming of multimedia content. The index information can comprise program description information and streaming segment index information. In addition, the layout can comprise files containing streaming segments of the program, where the streaming segments are each encoded at one or more bitrates independently of other streaming segments of the program. The layout supports client switching between different bitrates at segment boundaries. Optimized client-side rate control of streaming content can be provided by defining a plurality of states, selecting available paths based on constraint conditions, and selecting a best path through the states (e.g., based on a distortion measure). In one client-side rate control solution states correspond to a specific bitrate of a specific streaming segment, and in another client-side rate control solution states correspond to a measure of client buffer fullness.

Optimized client side rate control and indexed file layout for streaming media

The present disclosure relates to playback of video/audio streaming media data. The media stream is available from the network at multiple bit rates. When a seek operation is performed, a playback device requests a lower bit rate media stream in order to quickly fill a playback buffer so that playback can commence more readily. After a seek start-up period is complete, the playback device can return to downloading the media stream associated with higher bit rates in order to increase the quality of the playback.

Media streaming with enhanced seek operation

Techniques and tools for adjusting quality and bit rate of multiple chunks of media delivered over a network are described. For example, each of the multiple chunks is encoded as multiple layers (e.g., a base layer and multiple embedded residual layers) for fine-grained scalability at different rate/quality points. A server stores the encoded data for the layers of chunks as well as curve information that parameterizes rate-distortion curves for the chunks. The server sends the curve information to a client. For the multiple chunks, the client uses the curve information to determine rate-distortion preferences for the respective chunks, then sends feedback indicating the rate-distortion preferences to the server. For each of the multiple chunks, the server, based at least in part upon the feedback, selects one or more scalable layers of the chunk to deliver to the client.

Fine-grained client-side control of scalable media delivery

An encoder uses multi-pass VBR control strategies to provide constant or relatively constant quality for VBR output while guaranteeing (within tolerance) either compressed file size or, equivalently, overall average bitrate. The control strategies include various techniques and tools, which can be used in combination or independently. For example, in a first pass, an audio encoder encodes a sequence of audio data partitioned into variable-size chunks. In a second pass, the encoder encodes the sequence according to control parameters to produce output of relatively constant quality. The encoder sets checkpoints in the second pass to adjust the control parameters and/or subsequent checkpoints. The encoder selectively considers a peak bitrate constraint to limit peak bitrate. The encoder stores auxiliary information from the first pass for use in the second pass, which increases the speed of the second pass. Finally, the encoder compares signatures for the input data to check consistency between passes.

Multi-pass variable bitrate media encoding

A system and method is provided for variable bit rate encoding using a complexity ratio. Quantization parameter is calculated using a complexity ratio, which is equal to a local complexity divided by a global complexity. Complex pictures are allocated a larger bit budget relative to simple pictures. With the larger bit budget the quality of complex pictures can be maintained while reducing the overall size of the encoded video stream.

Video encoding using variable bit rates

A method and system is provided for calculating motion vectors of macroblocks in a digital image of a digital video stream. The method and system reduces the computational overhead of calculating motion vectors computing difference measures using a predetermined pattern of pixels in each macroblock rather than all the pixels of the macroblock. Reduction of computational overhead can be further enhanced first using a subpattern, i.e., a sub-sample of the predetermined pattern on a subset of the macroblocks to determine close matching macroblocks and then using the predetermined pattern to determine the best matching macroblock from within the close matching macroblocks.

Motion estimation using predetermined pixel patterns and subpatterns

A method and system is provided for calculating motion vectors of macroblocks in a digital image of a digital video stream. The method and system reduces the computational overhead of calculating motion vectors by limiting the search for the origin block to a coarse search window and a fine search window within the coarse search window. The difference measure is computed for only a subset of pixel blocks within the coarse search window to reduce the computational overhead. However, to increase accuracy, the difference measure of all the pixel blocks in the fine search window are computed. The pixel block having the smallest difference measure is selected as the origin block.

Motion estimation using multiple search windows

A method and system is provided for calculating motion vectors of macroblocks in a digital image of a digital video stream. The method and system reduces the computational overhead of calculating motion vectors computing difference measures using a multi-phase computational scheme. Specifically, the pixel blocks the previous image are divided into different groups. The closest matching pixel block of each group is determined in a first phase. Then a more accurate difference measure is used to determine the origin block from among the closest matching pixel blocks.

Sho Long Chen

Papers

Video encoding using variable bit rates

Motion estimation using predetermined pixel patterns and subpatterns

Motion estimation using multiple search windows

Multi-phase motion estimation system and method