C-cube Microsystems, Inc.

Other

C-cube Semiconductor Ii Inc.

Aaron Wells

K Metin Uz

Elliot N Linzer

Didier J LeGall

An apparatus and method for compressing multiple resolution versions of a video signal are disclosed. A first resolution version of a video signal is applied to an input of a first video compressor and to an input of a video scaler. The first video compressor encodes the first resolution version of the video signal to generate a first compressed video bit stream. The video scaler generates a reduced resolution version of the video signal from the first resolution version. The reduced resolution version is supplied to a second video compressor and to the first video compressor. The first video compressor utilizes the reduced resolution version of the video signal in performing a hierarchical motion estimation (ME) search as part of the encoding process for the first resolution version. The second video compressor encodes the reduced resolution version to generate a second compressed bit stream. The second video compressor receives motion vectors or other results of the hierarchical ME search performed in the first video compressor, and uses these results to facilitate the encoding of the reduced resolution version. The apparatus and method may be used in a non-linear video editor, a video server or other video processing system. The video scaler and first and second video compressors may share memory, a transform unit and other processing hardware such that system cost and complexity are reduced.

Multiple resolution video compression

A statistical multiplexing apparatus and method for generating and combining a plurality of encoded video bit streams. A storage device contains pre-stored a priori statistics indicative of the encoding complexity of the video signals from which the encoded video bit streams will be generated. The pre-stored a priori statistics may include inter-pixel differences in the same picture or between multiple pictures or pre-encoding a priori statistics generated during a preliminary encoding of the video signals. Examples of pre-encoding a priori statistics include the number of bits per picture at a given quantization level, an average quantization level, picture types, scene change locations and repeat field for one or more of the video bit streams. The video signals are applied to encoders which compress the signals in accordance with bit allocation decisions generated by a statistics computer. The statistics computer uses only pre-encoding a priori statistics from the storage device to generate bit allocation decisions. Alternatively, the statistics computer may use any type of a priori statistics in conjunction with a posteriori statistics received from the encoders in allocating bits. The resulting compressed video bit streams are applied to a multiplexer and combined into a single multiplexed bit stream for transmission on a single channel. The statistics computer thus has access to additional information regarding the encoding complexity of the video bit streams to be encoded and combined, and can therefore generate more accurate bit allocations and better maintain consistent video quality across multiple encoded bit streams.

Statistical multiplexed video encoding using pre-encoding a priori statistics and a priori and a posteriori statistics

Compressed video transcoding apparatus and methods are disclosed. One embodiment eliminates the need for reorder buffers by utilizing an encode order video decoder which decodes a first compressed video bit stream to provide a sequence of frames in an encode order suitable for direct encoding without further reordering. An encode order video encoder receives the sequence of frames in encode order and directly encodes the frames without further reordering to provide a second compressed video bit stream. Another embodiment utilizes a frame reorder device to reorder compressed frames of a first compressed video bit stream into an encode order such that a subsequent encoding operation after decoding the first compressed video bit stream can be performed without further reordering of the frames. The reordered compressed frames are decoded and applied in the encode order to an encoder which encodes the frames to provide a second compressed video bit stream. Another embodiment includes a decoder which decodes a first compressed video bit stream to provide a sequence of decoded frames. The sequence of decoded frames is applied to an encoder along with auxiliary information regarding the first compressed video bit stream. The encoder utilizes the auxiliary information to simplify encoding of the decoded frame sequence. The auxiliary information may include motion vectors, quantization scale, number of bits used, motion compensation mode and repeat field indications for the first compressed video bit stream.

Compressed video transcoder

Statistical multiplexed video encoding using pre-encoding a priori

A rate control algorithm for an MPEG-2 compliant encoder has embodiments useful for constant bit rate and variable bit rate encoding. In particular, the present invention relates to variable bit rate encoding.

Variable bit rate encoding

A rate control algorithm for an MPEG-2 compliant encoder is described. The rate control algorithm has embodiments useful for constant bit rate and variable bit rate encoding. In particular, the invention relates to scene change detection.

Scene change detection using quantization scale factor rate control

A rate control algorithm for an MPEG-2 compliant encoder wherein the rate control algorithm has embodiments useful for constant bit rate and variable bit rate encoding. In particular, the present invention relates to statistical multiplexing.

Statistical multiplexing system which encodes a sequence of video images

The invention provides methods and apparatus for filtering an input video frame sequence to be encoded. An odd-tap filter is used to generate a first interpolated pixel from a group of pixels in an even field of the video sequence. An even-tap filter is used to generate a second interpolated pixel from a group of pixels in an odd field of the video sequence. The use of the even-tap filter for the group of pixels in the odd field ensures that the interpolated pixels generated for both the odd and even fields are located at substantially the same vertical location. This significantly reduces an undesirable vertical signal component which would otherwise be generated when the first and second interpolated pixels are subtracted as part of a field comparison operation. The resulting improvement in field comparison accuracy provides advantages in a variety of video preprocessing applications such as deinterlacing, inverse telecine processing, adaptive field/frame filtering and video framing.

Adaptive filter for video processing applications

A rate control algorithm for an MPEG-2 compliant encoder is described. The rate control algorithm has embodiments useful for constant bit rate and variable bit rate encoding. In particular, the present invention relates to statistical multiplexing.

Method for performing rate control in a video encoder which provides a

A rate control algorithm for an MPEG-2 compliant encoder is described. The rate control algorithm has embodiments useful for constant bit rate and variable bit rate encoding. In particular, the invention relates to rate control with panic mode.

Rate control with panic mode

A rate control algorithm for an MPEG-2 compliant encoder is described. The rate control algorithm has embodiments useful for constant bit rate and variable bit rate encoding. In particular, the present invention relates to the overall rate control implementation.

Method of encoding video using master and slave encoders wherein bit

A method and system for performing inverse telecine processing requires a minimum amount of memory capacity. Specifically, the inverse telecine processing technique requires only first and second dual field buffers. The first dual field buffer has a first even buffer (1E) and a first odd buffer (1O). The second dual field buffer has a second even buffer (2E) and a second odd buffer (2O). The input video sequence to be processed comprises a sequence of video fields of alternating even and odd parity. The even fields of the input sequence are written into the even buffers of the two dual field buffers on an alternating basis and the odd fields of the input sequence are written into the odd buffers of the dual field buffers on an alternating basis. This order is changed (i.e., toggled) when a repeat field is detected. The repeat field is dropped by writing over it with the next field of the same parity in the input sequence.

MPEG-2 inverse telecine circuit

A rate control algorithm for an MPEG-2 compliant encoder. The rate control has embodiments useful for constant bit rate and variable bit rate encoding of video frames. The present invention relates to statistical multiplexing, virtual buffers and virtual buffer verifiers.

Growing community of inventors

New Rochelle, NY, United States of America

Aaron Wells