Abstract: Systems, apparatus, and methods are provided to enhance transmitting and receiving video data streams with feedback information over a lossy and/or congested network. The systems, apparatus, and methods may optimize retransmission for lost packets or lost data frames. Optimizations are also provided to select reference frames in a data stream so that block errors are contained when RPS is used to encode data frames. Optimization in decoding may include reconstructing high-resolution data frames from low-resolution data frames.

Abstract: Communications signal transcoder. A solution is provided to transcode a signal from a first signal type to a second signal type to ensure proper interfacing between devices that may operate using different signal types. For example, within a communication system, a first signal type (having a first modulation type, e.g., 8 PSK) may be received. The transcoder then ensures that this signal, after it has undergone any initial processing (such as tuning, down-converting, decoding, and so on), is encoded into a second signal type (having a second modulation type, e.g., QPSK) such that it can interface properly with a device for which the received signal is intended. This transcoder functionality may be implemented within discrete components, or it may alternatively be integrated within a functional block of an integrated circuit. This functionality may be implemented in a variety of communication systems including satellite, cable television, Internet, and others.

Abstract: Methods, devices, and systems for coding and decoding audio are disclosed. Digital samples of an audio signal are transformed from the time domain to the frequency domain. The resulting transform coefficients are coded with a fast lattice vector quantizer. The quantizer has a high rate quantizer and a low rate quantizer. The high rate quantizer includes a scheme to truncate the lattice. The low rate quantizer includes a table based searching method. The low rate quantizer may also include a table based indexing scheme. The high rate quantizer may further include Huffman coding for the quantization indices of transform coefficients to improve the quantizing/coding efficiency.

Abstract: Embodiments of methods and apparatus for providing channel feedback information based at least in part on predicted future channel states is disclosed and described. In various embodiments, future channel states may be predicted based at least in part on received channel sounding signals, and amounts of delay in time in transmission and receipt between a subscriber station and a base station. Other embodiments may be described and claimed.

Abstract: Systems and methods are described for automatically controlling the resolution of video content that is streaming over a data connection. Video content frames are generated that each have a predetermined frame resolution and comprise video data encoded at an encoding resolution. The video content frames are transmitted over a network, and one or more conditions of the network are sensed. The encoding resolution of the video data is selectively adjusted in each video content frame in response to the one or more sensed network conditions.

Abstract: A quantization matrix used in inverse quantization is generated. A received bitstream includes a coded truncated quantization matrix. The coded truncated quantization matrix has first coded bits and second coded bits. The first coded bits include bits obtained by coding a transmitting part of quantization elements and the second coded bits includes bits obtained by coding an end code. The coded truncated quantization matrix is decoded until the second coded bits corresponding to the end code are read out, to obtain the transmitting part of quantization elements. At least one additional quantization element is obtained. A complete quantization matrix is generated, using the transmitting part of quantization elements and at least one additional quantization element, by ordering the transmitting part of quantization elements and at least one additional quantization element in a zig-zag scan.

Abstract: A Method And Apparatus For Control of Rate-Distortion Tradeoff by Mode Selection in Video Encoders is Disclosed. The system of the present invention first selects a distortion value D near a desired distortion value. Next, the system determines a quantizer value Q using the selected distortion value D. The system then calculates a Lagrange multiplier lambda using the quantizer value Q. Using the selected Lagrange multiplier lambda and quantizer value Q, the system begins encoding pixelblocks. If the system detects a potential buffer overflow, then the system will increase the Lagrange multiplier lambda. If the Lagrange multiplier lambda exceeds a maximum lambda threshold then the system will increase the quantizer value Q. If the system detects a potential buffer underflow, then the system will decrease the Lagrange multiplier lambda. If the Lagrange multiplier lambda falls below a minimum lambda threshold then the system will decrease the quantizer value Q.

Abstract: A network access unit of a communications network includes: a source data receiver module to receive first source data representing video content and second source data; a network control module to receive link condition data and configuration data, calculate priority data based on the link condition data and the configuration data, use the priority data to generate a master schedule indicating a first coding and modulation scheme for a first layer of the first source data and a second coding and modulation scheme for a second layer of the first source data, wherein at least one of the coding and modulation schemes for a next sequence is fixed relative to a present sequence; a pre-coder module to pre-code the first source data using pre-coding schemes to generate sets of representation data; and an ACM module to associate the sets of representation data with the coding and modulation schemes.

Abstract: A method for communicating video data on a wireless channel in a packet-switched network includes the steps of operating at a wireless terminal a compression in packets on the video data during a video coding operation, detecting wireless channel conditions and adapting control parameters of the video coding operation to the detected wireless channel conditions. The compression operation is a robust header compression operation and the step of adapting control parameters of said video coding operation is performed depending on information about the wireless channel conditions detected on a feedback channel made available in a decompression step associated with the compression operation.

Abstract: Communications signal transcoder. A solution is provided to transcode a signal from a first signal type to a second signal type to ensure proper interfacing between devices that may operate using different signal types. For example, within a communication system, a first signal type (having a first modulation type, e.g., 8 PSK) may be received. The transcoder then ensures that this signal, after it has undergone any initial processing (such as tuning, down-converting, decoding, and so on), is encoded into a second signal type (having a second modulation type, e.g., QPSK) such that it can interface properly with a device for which the received signal is intended. This transcoder functionality may be implemented within discrete components, or it may alternatively be integrated within a functional block of an integrated circuit. This functionality may be implemented in a variety of communication systems including satellite, cable television, Internet, and others.

Abstract: A computer-implemented system and method are described for performing video compression. For example, a method according to one embodiment comprises: encoding a plurality of video frames or portions thereof according to a first encoding format; transmitting the plurality of encoded video frames or portions to a client device; receiving feedback information from the client device, the feedback information usable to determine whether data contained in the video frames or portions has not been successfully received and/or decoded; in response to detecting that a video frame or portion thereof has not been successfully received and/or decoded, encoding a video frame or portion thereof according to a second encoding format; and transmitting the video frames or portions thereof to the client device.

Abstract: A computer-implemented system and method for performing video compression are described.

Abstract: A computer-implemented system and method are described for performing video compression.

Abstract: A computer-implemented system and method for performing video compression are described.

Abstract: A system and method for dynamically encoding multimedia streams is provided. A user-end device is allowed to generate a network status message and transmit it to a data server, and the data server dynamically adjusts encoding parameters based on the network status message, encodes multimedia data using the adjusted encoding parameters, and sends the encoded multimedia data to the user-end device. This system and method solves problems where the picture quality and playback smoothness are affected by packets loss or error at the user end due to inability to adapt to constantly changing network conditions as in the prior art.

Abstract: A scaleable macro block rate control method particularly well-suited for MPEG video. There is provided a method to easily derive a quantization parameter (QP) value using information such as bit usage, previous QP values and SAD values from the past encoded and future frames. The method utilizes quantization estimation techniques based on statistical relationships between different intensity measures, such as distortion intensity, absolute difference intensity and mean of absolute difference intensity. The method is well-suited to applications utilizing MPEG video such as MPEG-1, MPEG-2, MPEG-4, JVT/H.264 standards and so forth.

Abstract: 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.

Abstract: Method and apparatus for encoding video is described. In one example, average of motion vectors for each of a plurality of blocks is maintained over a threshold number of inter-coded frames in the video. The running average of motion vectors for each of the plurality of blocks is compared to a threshold value. Each of the plurality of blocks the running average of which does not satisfy the threshold value is encoded using a first quantization parameter. Each of the plurality of blocks the running average of which satisfies the threshold value is encoded using a second quantization parameter. The second quantization parameter results in a coarser quantization of transformed coefficients than the first quantization parameter.

Abstract: A digital video coding system is provided that is capable of reducing the load of a CPU (Central Processing Unit) that controls a video coding system for implementing a digital video data compression/decompression standard such as MPEG-1, 2, 4, H.261 or H.263. In a conventional video coding system, the circuit configuration and control method of a variable length encoder are becoming increasingly complex with the development of a video compression/decompression standard. In a conventional system structure, a complex control operation must be carried out, such that there is a problem in that the load of the CPU controlling the video coding system increases. Thus, the video coding technology is provided to reduce the load of the CPU necessary for controlling a VLC (Variable Length Coding) unit.

Abstract: A method and system of lossless adaptive Golomb/Rice (G/R) encoding of integer data using a novel backward-adaptive technique having novel adaptation rules. The adaptive G/R encoder and decoder (codec) and method uses adaptation rules that adjust the G/R parameter after each codeword is generated. These adaptation rules include defining an adaptation value and adjusting the G/R parameter based on the adaptation value. If the adaptation value equals zero, then the G/R parameter is decreased by an integer constant. If the adaptation value equals one, then the G/R parameter is left unchanged. If the adaptation value is greater than one, then the G/R parameter is increased by the adaptation value. In addition, the adaptive G/R encoder and method include fractional adaptation, which defines a scaled G/R parameter in terms of the G/R parameter and updates and adapts the scaled G/R parameter to slow down the rate of adaptation.

Abstract: A video server adaptively selects an appropriate video encoding standard and an appropriate video encoding rate for encoding video content to be downloaded to one or more video client devices over a communication network. The video server adaptively selects the video encoding standard and the video encoding rate based upon factors such as the data transmission rate of the communication network, the processing speed of the video client device, or the type of the video content to be downloaded. Once the video encoding standard and the video encoding rate are selected, video content can be transcoded prior to downloading to one or more video client devices. During the download, the video content may be adaptively transrated, such as in response to a change in the data transmission rate of the communication network.

Abstract: In order to enhance the picture quality of a detected area, the present invention provides a video coding apparatus. In the apparatus, a reliability indicative of the degree of coincidence of an area detected by an important area detecting section with a real important area is calculated, and a coding parameter calculating section calculates a coding parameter to be set to the detected area according to the reliability, thereby controlling the picture quality of the detected area. Consequently, a whole image has a coding bit amount which does not break the restrictions of a transmission bit rate, and a larger coding bit amount is assigned to the important area so that a picture quality thereof can be improved and a visibility can be enhanced. In addition, the picture quality is more enhanced if a probability that the detected area might be an important area is higher.

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: An advanced noise estimation method is provided. The noise estimation method includes calculating motion compensation information of the input picture at a first resolution, calculating the motion compensation information of the input picture at a second resolution, and based on the motion compensation information at the first resolution and the motion compensation information at the second resolution, estimating the noise of the input picture.

Abstract: A forward error correction encoder encodes input data words into code words that comprise a parity matrix. In one aspect, the encoder is optimized based on the properties of the parity matrix in order to reduce routing overhead size.

Abstract: With respect to change of a bit rate at the time of transmitting encoded data TS, a system delay is fixed and the output size of data frame_bit [j] every predetermined data unit is successively calculated, thereby making it possible to continuously obtain data from the buffer 103 of a decoding side without breaks irrespective of change of the bit rate.

Abstract: A network-based video encoding and decoding system encodes and decodes remotely displayed user application data on a centralized desktop computer. Remotely displayed user application data are screen captures of a browsing application run by the centralized desktop computer on user's behalf. The encoding system optimizes its encoding performance using back channel information which includes real time network capacity information and decoder feedback. The encoding system consults a back channel information manager to dynamically adjust encoding parameters. Based on the real time network capacity information received, the encoding system adjusts its capturing sampling rate. Based on encoding errors identified by the decoding system, the encoding system selectively re-send previously encoded frames/blocks, or send intra frames on demand to allow the decoding system to correct encoding errors.

Abstract: A motion-picture-experts group (MPEG) decoder performs AC prediction to decode first-column or first-row coefficients that are coded as differences from corresponding coefficients in a prior block or an above block. Rather than perform AC prediction between the variable-length decoder (VLD) and the inverse-quantizer (IQ), AC prediction is performed after the IQ. Post-IQ AC prediction allows the VLD and IQ to be constructed as a unified stage, improving decoding speed or efficiency as a single hardware stage can be used for the combined VLD/IQ. Rather than store prior-block quantized DCT coefficients, a coefficient store stores post-IQ DCT coefficients and quantization parameters. A Q-subtractor operates on the IQ output using the current quantization parameter, while another Q-subtractor operates on the stored coefficients and stored quantization parameter. The Q-subtractor subtracts a signed, odd-rounded quantization parameter from a coefficient.

Abstract: A method and apparatus for rate control for a constant-bit-rate finite-buffer-size video encoder is described. Rate control is provided by adjusting the size of non-intra frames based on the size of intra frames. A sliding window approach is implemented to avoid excessive adjustment of non-intra frames located near the end of a group of pictures. A measurement of “power” based on a sum of absolute values of pixel values is used. The “power” measurement is used to adjust a global complexity value, which is used to adjust the sizes of frames. The global complexity value responds to scene changes. An embodiment of the invention calculates and uses L1 distances and pixel block complexities to provide rate control. An embodiment of the invention implements a number of bit predictor block. Predictions may be performed at a group-of-pictures level, at a picture level, and at a pixel block level. An embodiment of the invention resets a global complexity parameter when a scene change occurs.

Abstract: The present invention provides methods and apparatus for improving video quality in statistical multiplexing. For each encoding channel in a statistical multiplexer, a respective bit rate need parameter is calculated for encoding of a current frame in that encoding channel. A video buffering verifier level (VBV_Fullness) available to each encoding channel is also calculated. It is then determined whether the VBV_Fullness available to each encoding channel is sufficient for encoding the current frame of that encoding channel based on an initial complexity estimate for that current frame. In the event that the VBV_Fullness is determined to be sufficient, the current frame is encoded using the need parameter. In the event that the VBV_Fullness is determined to be insufficient, the need parameter is scaled by an adaptive panic multiplier and the current frame is encoded using the scaled need parameter.

Abstract: Disclosed is a video transcoding apparatus converting a specific bit rate of an MPEG (moving pictures experts group) bit stream into a different rate thereof for transportation. The present invention includes a video pre-processing unit having a predetermined matrix structure and down-sampling a macro block decoded by the video decoder by transforming the macro block into a corresponding picture structure to the compressed video bit stream, a transcoding parameter control unit detecting information about a picture from a previous bit stream variable-length-decoded by the video decoder and setting up an encoding mode for a transcoding in accordance with the detected information, etc. Therefore, the present invention does not need the motion estimation unit of encoder and reduce the complexity of the bit allocation unit. When changing HD-rated MPEG sequence over 10 Mbps into NTSC-rated MPEG sequence below 6 Mbps, the present invention reduces calculation time and complexity of hardware.

Abstract: A run-level domain transcoder receives a stream of compressed frames carried in a bit stream. The run-level domain transcoder decodes the bit stream into run-level pairs and selectively processes the compressed frames so as to, among other things, reduce the number of bits necessary to represent the compressed frames.

Abstract: Video image data is commonly encoded using a video encoder operating under the control of a bit-rate controller where a plurality of encoding passes are performed so as to improve quality in each video frame. According to an embodiment of the present invention, a systematic review of the steps and sub-steps of the encoding passes is performed so as to identify those sub-steps which are necessary and those that are unnecessary to the execution of the encoding passes. Then, those steps identified as being necessary are executed during the encoding passes. Doing so reduces the amount of processor computation that is needed to perform a given number of encoding passes allowing the passes to be performed quicker or at a greater rate, thus improving quality.

Abstract: An apparatus and method thereof to encode a moving image include a discrete cosine transform (DCT) unit performing a DCT process on input video data, a quantizer, and a motion estimation (ME) unit calculating a motion vector and a SAD per macro block. A DCT computational complexity calculator calculates a computational complexity of the ME unit, estimates a difference between the ME computational complexity and a target ME computational complexity, and updates a target DCT computational complexity based on the estimated difference. A DCT skipping unit sets a threshold value to determine whether to skip performing the DCT process on the input video data, based on the target DCT computational complexity updated by the DCT computational complexity calculator, compares the SAD per macro block, and the quantization parameter with the threshold value, and determines whether to allow the DCT unit to perform the DCT process on the input video data.

Abstract: A Method And Apparatus For Control of Rate-Distortion Tradeoff by Mode Selection in Video Encoders is Disclosed. The system of the present invention first selects a distortion value D near a desired distortion value. Next, the system determines a quantizer value Q using the selected distortion value D. The system then calculates a Lagrange multiplier lambda using the quantizer value Q. Using the selected Lagrange multiplier lambda and quantizer value Q, the system begins encoding pixelblocks. If the system detects a potential buffer overflow, then the system will increase the Lagrange multiplier lambda. If the Lagrange multiplier lambda exceeds a maximum lambda threshold then the system will increase the quantizer value Q. If the system detects a potential buffer underflow, then the system will decrease the Lagrange multiplier lambda. If the Lagrange multiplier lambda falls below a minimum lambda threshold then the system will decrease the quantizer value Q.

Abstract: A digital video encoder is presented adapted for dynamically switching between sets of quantizer matrix tables without pausing encoding of a stream of video data. Two or more sets of quantizer matrix tables are held at the encoder's quantization unit and compressed store interface for dynamically switching between sets of quant matrix tables at a picture boundary of the sequence of video data, i.e., without stopping encoding of the sequence of video data. Further, while one set of matrix tables is being employed to quantize the stream of video data, the encoder can be updating or modifying another set of quantization matrix tables, again without stopping encoding of the sequence of video data.

Abstract: An information stream organized as a sequence of blocks is encoded according to a graceful degradation principle. The stream poses temporal non-uniform data processing requirements. In particular, with respect to a received block one or more blockwise defined control parameters and an associated blockwise processing load are detected (44). Under control (46) of a processing load for one or more previous blocks, one or more later blocks before processing thereof get an adjustment (48) of one or more of the control parameters. This lowers an expected load for the later block in case of an excessive load, and vice versa when detecting a sub-standard load.

Abstract: To provide a coding device which does not generate a video packet having only a stuffing but can insert a minimum stuffing to prevent an underflow of a buffer in the case in which a video packet has a length limit. A minimum code volume (Tmin) is set for each VOP and a break of a video packet and an insertion of a stuffing are determined such that a code volume (Sc) of the VOP is not smaller than the minimum code volume (Tmin).

Abstract: The present invention enables to effectively coding a predetermined time length of a video signal with a variable bit rate at real time (one-path) into a total coding bit amount of a constant data capacity. A coding difficulty calculator 13 determines a coding difficulty of an input signal for each unit time. An allocation bit amount calculator 14 interrelates an allocation sign amount with a coding difficulty for each unit time standardized in advance using an ordinary input signal of the type to which the input signal belongs, so as to obtain a reference value of the allocation sign amount for each unit time interrelated with the coding difficulty supplied from the coding difficulty calculator 13. This reference value of the allocation sign amount is modified by a controller 15 into an actual allocation sign amount, according to which the input signal is coded by a moving picture image coding apparatus 18, so as to create a coded data.

Abstract: A method and structure for performing a sequence of integer divides without propagation of truncation error. During encoding and decoding of video signals, a buffer is dynamically filled with binary bits of encoded video data at a variable rate, and the data is subsequently removed from the buffer at a constant rate. Calculating the number of bits removed from the buffer as each video frame is processed requires integer divides with consequent truncation of the quotient. An accumulator is utilized for each integer divide to cumulatively store remainders generated by successive integer divides. If the accumulator accumulates to a value (A) that is no less than the divisor (D) of the associated integer divide, then the quotient is effectively increased by 1, and A is decremented by D, which compensates for the prior truncations and avoids a buffer overflow violation that may otherwise occur.

Abstract: A method and apparatus for temporally allocating bits between frames in a coding system such that temporal fluctuations are smoothed out. Namely, a picture quality is monitored on a frame by frame basis. An average distortion measure is derived from previous picture frames and that average is compared to the distortion measure of a current frame, where the result is used to effect bit budget allocation for each frame in an input image sequence.

Abstract: A process of bit rate control includes asymmetrical reactions to changes in the signal density of the digital video signals. In the process, two different averaging periods are employed to meet a long term bit rate target and to achieve a short term quick reaction. When encoding a motion picture, the bit rate control is relaxed during high motion scenes to allow high peaks of bit rate at those points. The coding process reacts slowly to transitions from low to high motion sequences to preserve the best overall video quality, and reacts quickly to transitions from high to low motion sequences to enhance the image quality.

Abstract: A method of determining a quantization parameter for video compression. A block characteristic for blocks in a video frame is quantized and then used to obtain a candidate quantization parameter. With the candidate quantization parameter, a number of bits for the blocks in the video frame is summed, producing a candidate bit rate. If the candidate bit rate is greater than a predetermined bit rate threshold, the candidate quantization parameter is set as the quantization parameter.

Abstract: The invention is a system and method for synchronizing the transmission of compressed headers in data packets between a transmitter and a receiver having a preferred wireless application which is an improvement of RFC2508. In a system having a transmitter transmitting a plurality of packets each containing a header to a receiver, a method of synchronizing the transmission of compressed headers between the transmitter and receiver in accordance with the invention includes transmitting a current packet from the transmitter to the receiver containing information that the transmitter is prepared to send subsequently transmitted packets in which the headers therein are to be compressed in comparison to the header contained in the current packet; and transmitting from the receiver to the transmitter an acknowledgment packet that the receiver has received the current packet.

Abstract: With respect to change of a bit rate at the time of transmitting encoded data TS, a system delay is fixed and the output size of data frame_bit [j] every predetermined data unit is successively calculated, thereby making it possible to continuously obtain data from the buffer 103 of a decoding side without breaks irrespective of change of the bit rate.

Abstract: In MPEG2 encoding, the quantiser is controlled to manage the occupancy of a video buffer. A dynamically varying working range is determined by forecasting from recent coding history the number of bits required in coding of future pictures, and deriving upper and lower ends of the working range which correspond respectively with attainment within the forecast period of predetermined maximum and minimum buffer occupancies. The quantiser scale is then controlled through the position of the actual buffer occupancy within that working range.

Abstract: Possible overflow of a video buffer verifier (VBV) buffer employed in MPEG-like video encoders is prevented by controlling bits being drained from a video encoder buffer (eBuff). Specifically, a number of bits in the encoder buffer is determined when a last prior picture (pic n?1) ends, or when it should end. This number of bits (maxBits) is the maximum number of bits to be read from the encoder buffer and written to the remote decoder before a prescribed time T(n). When maxBits has been read from the encoder buffer and written to the decoder, the writing of bits to the remote decoder is stopped until the process is reset. If the prior picture ends early, maxBits is defined as being the number of bits in the encoder buffer at an expected time (Texp) that the picture should have ended less the number of bits written into the encoder buffer between the time the prior picture actually ended and the expected time for it to end, i.e., Texp. If the prior picture is late, i.e.

Abstract: An encoding system capable of preventing the overflow of a buffer and performing the encoding of a VOP within a predetermined time period even where the processing time period necessary for encoding each macroblock is not constant. In order to provide the encoding system, the maximum number of bits Tmax is set for each VOP, and the output of encoding unit and the output of fixed code output unit is switched and outputted so that the number of bits Sc of the VOP may not exceed the Tmax.

Abstract: For use in a video image upconversion unit of the type that uses motion compensation to generate an interpolated field using motion vectors, an improved method of motion compensation is disclosed that calculates a first correlation value from the values of corresponding neighbor pixels of a previous frame and from the values of causal neighbor pixels of a generated field. The first correlation value is compared with a first threshold value. The value of a pixel to be created within the generated field is set to be equal to the value of a corresponding pixel of the previous frame if the first correlation value is less than the first threshold value. The method also calculates a second correlation value from the values of corresponding neighbor pixels of a next field and from the values of causal neighbor pixels of a generated field. The second correlation value is compared with a second threshold value.

Abstract: This invention employs a scheme to allow an input video signal to undergo encoding, e.g., predictive encoding, DCT processing, quantization at fixed quantization step size and variable length encoding to generate first encoded data to determine (calculate) allocated code quantity every frame or every GOP on the basis of data quantity every predetermined time, e.g., every frame or every GOP of the first encoded data and total quantity of usable data to encode the input video signal every predetermined time on the basis of the allocated code quantity to generate second encoded data. Thus, variable rate encoding such that encoding rate changes every predetermined time is realized. As a result, even if pictures (frames) of complicated are successive, there is no possibility that quantization step size is caused to be large with respect to these pictures as in the conventional apparatus. Thus, uniform high picture quality can be obtained through the entirety.