63 results about "Average bitrate" patented technology

The invention is directed to the provision of a moving image data playback method, and more particularly, an MPEG data playback method that can randomly access MPEG data stored at a VBR. The playback method comprises: storing in a table an average bit rate computed from time information at the beginning and end of stored moving image data; detecting and storing the time information and position information of randomly accessible picture groups one at the beginning of the moving image data and the other at the end thereof, and computing a picture group unit time from the number of frames between adjacent picture groups and storing the result in the table; computing a point to be accessed, based on the average bit rate and other information stored in the table; and starting playback from the computed point to be accessed, and storing in the table the time information and position information of the picture groups detected during the playback and the average bit rate between each picture group computed from the detected time information and position information.

An encode control strategy is provided for variable bit rate encoding of a sequence of video frames in a single pass. The control strategy includes determining whether a video frame has a complexity level statistically outside a defined range from a complexity level of at least one preceding frame of the sequence of video frames, and if so, determining a new average bit rate target for the video frame. The new average bit rate for the video frame is determined employing at least one of spatial complexity and temporal complexity of the video frame. The new average bit rate target for the video frame is used to set frame level bit rate control parameter(s), and the video frame is encoded using the set frame level bit rate control parameter(s).

A multimedia program type of a received multimedia data is determined. Based on the determined multimedia program type, a peak bit rate limit and / or an average bit rate limit are determined. In instances where a transrated version of the multimedia data is to be stored, a remaining storage capacity of a storage device is determined and the peak bit rate limit and / or the average bit rate limit can be adjusted based on the remaining storage capacity. The multimedia data then is transrated to generate transrated multimedia data that has a peak bit rate that does not exceed the selected peak bit rate limit and / or having an average bit rate that does not exceed the selected average bit rate limit. The transrating of the multimedia additionally can include the application of rule sets based on content characteristics. After transrating, the multimedia data can be transmitted via a network to a destination multimedia device, stored locally for subsequent use, or a combination thereof.

The invention relates to the technical field of adaptive streaming media code rate, in particular to a wireless DASH streaming media code rate smoothing adaptive transmission method, comprising the steps of counting download rate data of N slices before, predicting bandwidth trend and bandwidth value of a wireless network; according to the predicted bandwidth trend, bandwidth value and buffer occupancy, the slice scheduling model adaptively selecting the optimal bit rate. The method of the invention considers a plurality of parameters, accurately judges the change trend of the bandwidth of thewireless network, and at the same time, smoothes the short-term fluctuation of the bandwidth. The method of the invention provides a higher average code rate in the video playing process while maintaining less code rate switching times, and provides a good video experience quality of the wireless terminal for the viewer.

The present invention relates to methods and devices for encoding and decoding digital audio signals, e.g. a speech signal. An audio coder and a decoder are provided wherein a modeller adds a first distribution model obtained from model parameters of past segments of the digital audio signal and a fixed distribution model, each of the models being multiplied by a weighting coefficient, for obtaining a combined distribution model. The weighting coefficients are selected to minimize a code length of a current segment of the digital audio signal. As the combined distribution model is a sum of several distribution models, wherein at least some of the models is based on the model parameters, flexibility is introduced in the signal model used to encode the digital audio signal. Thus, an audio coder and decoder providing a low bit rate in average, low bit rate variations and low error propagation are provided.

A method and apparatus for the variable rate coding of a speech signal. An input speech signal is classified and an appropriate coding mode is selected based on this classification. For each classification, the coding mode that achieves the lowest bit rate with an acceptable quality of speech reproduction is selected. Low average bit rates are achieved by only employing high fidelity modes (i.e., high bit rate, broadly applicable to different types of speech) during portions of the speech where this fidelity is required for acceptable output. Lower bit rate modes are used during portions of speech where these modes produce acceptable output. Input speech signal is classified into active and inactive regions. Active regions are further classified into voiced, unvoiced, and transient regions. Various coding modes are applied to active speech, depending upon the required level of fidelity. Coding modes may be utilized according to the strengths and weaknesses of each particular mode. The apparatus dynamically switches between these modes as the properties of the speech signal vary with time. And where appropriate, regions of speech are modeled as pseudo-random noise, resulting in a significantly lower bit rate. This coding is used in a dynamic fashion whenever unvoiced speech or background noise is detected.

The invention belongs to the field of multi-media communication, and in particular relates to a state machine based dynamic adaptive video transmission code rate switching method. The state machine based dynamic adaptive video transmission code rate switching method comprises the steps that: a server side slices a stored video; each video clip has K code rate grades; a client side calculates the average code rate, the mean square deviation and the average bandwidth of N video clips according to the newly downloaded N video clips; the code rate offset rate and the playing cache of the client side when downloading of the kth video clip is completed are obtained; and, due to different ranges of the playing cache and different ranges of the code rate offset rate, code rate switching is carriedout according to a code rate state switching formula. According to the state machine based dynamic adaptive video transmission code rate switching method disclosed by the invention, the contact between the video code rate and the numerical value change of an influence factor is used as a state transition condition; on the premise that the playing cache and the code rate offset rate are a certainthreshold value, the code rate is switched to the code rate grade that the whole performances of the video quality and the playing fluency are relatively best; and thus, better user viewing experienceis realized.

Provided are an image processing apparatus and a computer-readable storage medium capable of adjusting to an optimum bit rate. In a case where an average bit rate is smaller than a target bit rate, a mobile communication terminal sets an encoding parameter for high image quality in an internal register of an encoding parameter manager to increase the bit rate. In a case where the average bit rate is larger than the target bit rate, the mobile communication terminal sets an encoding parameter for low image quality in the internal register of the encoding parameter manager to reduce the bit rate. Therefore, the mobile communication terminal can encode YUV data at an optimum bit rate.

The invention discloses a video frame encoding method and a terminal. The video frame encoding method comprises the steps of: acquiring an ith video frame of an image group, encoding the ith video frame by a first encoding rule, and carrying out statistics on an actual consumption bit number of the encoded ith video frame; based on the actual consumption bit number, an image group initial averagecode rate, a quantization model and a video frame detection rule, detecting a state of the ith video frame, and when the ith video frame is in a scene switching state, determining a first initial quantization parameter, a first maximum quantization parameter and a first minimum quantization parameter of an (i+1)th video frame; acquiring a compensation length, and based on the compensation length and a compensation model, determining a first compensation allocation bit number of a first to-be-compensated video frame; and when the (i+1)th video frame belongs to the first to-be-compensated videoframe, updating the first encoding rule by the first compensation allocation bit number, the first initial quantization parameter, the first maximum quantization parameter and the first minimum quantization parameter, and encoding the (i+1)th video frame.

The bitrate for any practical video streaming system will vary considerably as a function of the difficulty of encoding the sequence in question. This variation is even more apparent when comparing different video clips of different genres for example where sports clips might require a higher average bitrate and fluctuate more due to the high activity of typical scenes, whereas a news report clip might require a much lower bitrate and be relatively static. As such, to deliver video streams at a constant quality to users sharing a contended network, a constant bandwidth method is not efficient to use across all the streams. The bandwidth allocated to each stream must be allowed to dynamically vary in time in accordance with the precise demands of the video being streamed at that time and also be within any network bandwidth constraints. The present invention defines such a method.

An encode control strategy is provided for variable bit rate encoding of a sequence of video frames in a single pass. The control strategy includes determining whether a video frame has a complexity level statistically outside a defined range from a complexity level of at least one preceding frame of the sequence of video frames, and if so, determining a new average bit rate target for the video frame. The new average bit rate for the video frame is determined employing at least one of spatial complexity and temporal complexity of the video frame. The new average bit rate target for the video frame is used to set frame level bit rate control parameter(s), and the video frame is encoded using the set frame level bit rate control parameter(s).