Abstract: A method and apparatus for variable accuracy inter-picture timing specification for digital video encoding is disclosed. Specifically, the present invention discloses a system that allows the relative timing of nearby video pictures to be encoded in a very efficient manner. In one embodiment, the display time difference between a current video picture and a nearby video picture is determined. The display time difference is then encoded into a digital representation of the video picture. In a preferred embodiment, the nearby video picture is the most recently transmitted stored picture. For coding efficiency, the display time difference may be encoded using a variable length coding system or arithmetic coding. In an alternate embodiment, the display time difference is encoded as a power of two to reduce the number of bits transmitted.

Abstract: A method is provided for decoding a bit stream representing an image that has been encoded The method includes the steps of: performing an entropy decoding of the bit stream to form a plurality of transform coefficients and a plurality of motion vectors; performing an inverse transformation on the plurality of transform coefficients to form a plurality of error blocks; determining a plurality of predicted blocks based on bidirectional motion estimation that employs the motion vectors, wherein the bidirectional motion estimation includes a direct prediction mode and a second prediction mode; and, adding the plurality of error blocks to the plurality of predicted blocks to form the image. The second prediction mode may include forward, backward, and interpolated prediction modes.

Abstract: The invention provides devices and methods that process images. The invention processes a received signal representing information of texture and information of an image, which has the texture removed from at least one region. The image information is encoded to obtain encoded information of the image. An output signal is generated representing the texture information and the encoded image information. In another embodiment, the invention synthesizes texture based on the received texture information, decodes received image information, which is encoded, to obtain a decoded image, and then maps the synthesized texture onto the decoded image.

Abstract: A video coding system that codes video objects as scalable video object layers. Data of each video object may be segregated into one or more layers. A base layer contains sufficient information to decode a basic representation of the video object. Enhancement layers contain supplementary data regarding the video object that, if decoded, enhance the basic representation obtained from the base layer. The present invention thus provides a coding scheme suitable for use with decoders of varying processing power. A simple decoder may decode only the base layer of video objects to obtain the basic representation. However, more powerful decoders may decode the base layer data of video objects and additional enhancement layer data to obtain improved decoded output. The coding scheme supports enhancement of both the spatial resolution and the temporal resolution of video objects.

Abstract: A method is provided for decoding a bit stream representing an image that has been encoded The method includes the steps of: performing an entropy decoding of the bit stream to form a plurality of transform coefficents and a plurality of motion vectors; performing an inverse transformation on the plurality of transform coefficients to form a plurality of error blocks; determining a plurality of predicted blocks based on bidirectional motion estimation that employs the motion vectors, wherein the bidirectional motion estimation includes a direct prediction mode and a second prediction mode; and, adding the plurality of error blocks to the plurality of predicted blocks to form the image. The second prediction mode may include forward, backward, and interpolated prediction modes.

Abstract: A video coding system that codes video objects as scalable video object layers. Data of each video object may be segregated into one or more layers. A base layer contains sufficient information to decode a basic representation of the video object. Enhancement layers contain supplementary data regarding the video object that, if decoded, enhance the basic representation obtained from the base layer. The present invention thus provides a coding scheme suitable for use with decoders of varying processing power. A single decoder may decode only the base layer of video objects to obtain the basic representation. However, more powerful decoders may decode the base layer data of video objects and additional enhancement layer data to obtain improved decoded output. The coding scheme supports enhancement of both the spatial resolution and the temporal resolution of video objects.

Abstract: A rate control system is disclosed for video coding applications. The rate controller assigns a quantization parameter for video data in a picture in response to complexity indicators indicative of spatial complexity, motion complexity and/or bits per pel of the picture. A virtual buffer based quantizer parameter is proposed based on a virtual buffer fullness analysis and a target rate estimate, which is derived from the complexity indicators. A second quantizer parameter is proposed from a linear regression analysis of quantizer parameters used to code previously coded pictures of similar type (e.g., I pictures, P pictures or B pictures). A coding policy decision unit defines a final quantizer parameter from a comparison of the two proposed quantizer parameters.

Abstract: A method and apparatus for displaying received data, analyze the quality of the displayed data formulating a media-parameter suggestion for the encoder to alter the characteristics of data to be sent to the receiver, and sending from the receiver, the formulated suggestion.

Abstract: A method is provided for decoding a bit stream representing an image that has been encoded. The method includes the steps of: performing an entropy decoding of the bit stream to form a plurality of transform coefficients and a plurality of motion vectors; performing an inverse transformation on the plurality of transform coefficients to form a plurality of error blocks; determining a plurality of predicted blocks based on bidirectional motion estimation that employs the motion vectors, wherein the bidirectional motion estimation includes a direct prediction mode and a second prediction mode; and, adding the plurality of error blocks to the plurality of predicted blocks to form the image. The second prediction mode may include forward, backward, and interpolated prediction modes.

Abstract: A method and apparatus for performing motion estimation in a digital video system is disclosed. Specifically, the present invention discloses a system that quickly calculates estimated motion vectors in a very efficient manner. In one embodiment, a first multiplicand is determined by multiplying a first display time difference between a first video picture and a second video picture by a power of two scale value. This step scales up a numerator for a ratio. Next, the system determines a scaled ratio by dividing that scaled numerator by a second first display time difference between said second video picture and a third video picture. The scaled ratio is then stored calculating motion vector estimations. By storing the scaled ratio, all the estimated motion vectors can be calculated quickly with good precision since the scaled ratio saves significant bits and reducing the scale is performed by simple shifts.

Abstract: A method and apparatus for displaying received data, analyze the quality of the displayed data formulating a media-parameter suggestion for the encoder to alter the characteristics of data to be sent to the receiver, and sending from the receiver, the formulated suggestion.

Abstract: Systems and methods for reducing bit rates by replacing original texture in a video sequence with synthesized texture. Reducing the bit rate of the video sequence begins by identifying and removing selected texture from frames in a video sequence. The removed texture is analyzed to generate texture parameters. New texture is synthesized using the texture parameters in combination with a set of constraints. Then, the newly synthesized texture is mapped back into the frames of the video sequence from which the original texture was removed. The resulting frames are then encoded. The bit rate of the video sequence with the synthesized texture is less than the bit rate of the video sequence with the original texture. Also, the ability of a decoder to decode the new video sequence is not compromised because no assumptions are made about the texture synthesis capabilities of the decoder.

Abstract: A method and apparatus for variable accuracy inter-picture timing specification for digital video encoding is disclosed. Specifically, the present invention discloses a system that allows the relative timing of nearby video pictures to be encoded in a very efficient manner. In one embodiment, the display time difference between a current video picture and a nearby video picture is determined. The display time difference is then encoded into a digital representation of the video picture. In a preferred embodiment, the nearby video picture is the most recently transmitted stored picture. For coding efficiency, the display time difference may be encoded using a variable length coding system or arithmetic coding. In an alternate embodiment, the display time difference is encoded as a power of two to reduce the number of bits transmitted.

Abstract: A number of novel configurations for MPEG-4 playback, browsing and user interaction are disclosed. MPEG-4 playback systems are not simple extensions of MPEG-2 playback systems, but, due to object based nature of MPEG-4, present new opportunities and challenges in synchronized management of independent coded objects as well as scene composition and presentation. Therefore, these configurations allow significantly new and enhanced multimedia services and systems. In addition, MPEG-4 aims for an advanced functionality, called Adaptive Audio Visual Session (AAVS) or MPEG-J. Adaptive Audio Visual Session (AAVS) (i.e., MPEG-AAVS, MPEG-Java or MPEG-J) requires, in addition to the definition of configurations, a definition of an application programming interface (API) and its organization into Java packages. Also disclosed are concepts leading to definition of such a framework.

Abstract: Scalable video coding and multiplexing compatible with non-scalable decoders is disclosed. In some embodiments, video data is received and encoded in a manner that renders at least a base layer to be compatible with a non-scalable video encoding standard, including by assigning for at least the base layer default values to one or more scalability parameters. In some embodiments, video data is received and encoded to produce an encoded video data that includes a base layer that conforms to a non-scalable video encoding standard and one or more subordinate non-scalable layers, which subordinate non-scalable layers do not by themselves conform to the non-scalable video encoding standard but which can be combined with the base layer to produce a result that does conform to the non-scalable video encoding standard, such that the result can be decoded by a non-scalable decoder.

Abstract: A quantizer and dequantizer for use in a video coding system that applies non linear, piece-wise linear scaling functions to video information signals based on a value of a variable quantization parameter. The quantizer and dequantizer apply different non linear, piece-wise linear scaling functions to a DC luminance signal, a DC chrominance signal and an AC chrominance signal. A code for reporting updates of the value of the quantization parameter is interpreted to require larger changes when the quantization parameter initially is large and smaller changes when the quantization parameter initially is small.

Abstract: Some embodiments provide a method of performing mode selection in a video compression and encoding system. The method encodes with several encoding modes from a set of encoding modes. The method computes a distortion value for each encoding mode from the several encoding modes. The method computes a bit rate value for each encoding mode from the several encoding modes. The method computes a Lagrangian value for each encoding mode from the several encoding modes, using the distortion value, the bit rate value, and a Lagrangian multiplier. The method selects an encoding mode based on the Lagrangian values. In some embodiments, computing the distortion value includes using a function that reduces the effects of outliers. In some embodiments, the Lagrangian multiplier is a slow varying Lagrangian multiplier that varies at a slower rate than a varying reference Lagrangian multiplier for a reference encoding mode. In yet some embodiments, the method clusters the Lagrangian values.

Abstract: A predictive video coder performs gradient prediction based on previous blocks of image data. For a new block of image data, the prediction determines a horizontal gradient and a vertical gradient from a block diagonally above the new block (vertically above a previous horizontally adjacent block). Based on these gradients, the encoder predicts image information based on image information of either the horizontally adjacent block or a block vertically adjacent to the new block. The encoder determines a residual that is transmitted in an output bitstream. The decoder performs the identical gradient prediction and predicts image information without need for overhead information. The decoder computes the actual information based on the predicted information and the residual from the bitstream.

Abstract: A method and apparatus for variable accuracy inter-picture timing specification for digital video encoding is disclosed. Specifically, the present invention discloses a system that allows the relative timing of nearby video pictures to be encoded in a very efficient manner. In one embodiment, the display time difference between a current video picture and a nearby video picture is determined. The display time difference is then encoded into a digital representation of the video picture. In a preferred embodiment, the nearby video picture is the most recently transmitted stored picture. For coding efficiency, the display time difference may be encoded using a variable length coding system or arithmetic coding. In an alternate embodiment, the display time difference is encoded as a power of two to reduce the number of bits transmitted.

Abstract: A coding protocol provides for coding video data that has been organized as video objects. The protocol provides a keyregion to permit coding of a region of data within the video object having common attributes. According to the protocol a keyregion is identified by a keyregion header, which includes a resync marker that uniquely identifies the keyregion header, a keyregion position signal indicating an origin and a size of the keyregion; and data of the common attribute. Data following the keyregion is coded according to the common attribute.