A novel rate control algorithm consisting of two major components , i.e. a variable encoding frame rate method and a hybrid DCT/wavelet I-frame coding scheme, is proposed in this work for low bit rate video coding. Most existing rate control algorithms for low bit rate video focus on bit allocation at the macroblock level under a constant frame rate assumption. The proposed rate control algorit...

CBR (Constant Bit Rate) video fluctuates in quality, while its multiplexing behaviour is easy to predict: the links can be loaded to almost 100%. VBR (Variable Bit Rate) video aims at constant quality, but as the bit rate fluctuates over time the links cannot be fully loaded. Because in unconstrained VBR video the bit rate fluctuation might be too large, capped VBR video is proposed as an alter...

Adaptive modulation and coding (AMC) is a method which adapts its transmitting parameters according to the channel state and is used in various modern wireless communications to maximize spectrum efficiency by minimizing the error rate. One of the driving strengths of AMC is the Signal-to-Noise Ratio (SNR) estimation and feedback channel for adaptation. Degrading effects caused due to sudden va...

In the past decade Code Excited Linear Prediction (CELP) has become Ihe dominan~ speech coding algorifhm for bit rafes between 4 kbps and 16kbps. Traditiowlly, CELP type algorithms produce a fixed bit-rafe. However, a fixed bit-rate is nof a requirement anymore for modern telecommunication and computer networks as well as for voice storage applications. The variable bifrate CELP coder presented...

In 1995, 8 kb/s CS-ACELP coder of G.729 is standardized by ITU-T SG15 and it has been reported that the speech quality of G.729 is better than or equal to that of 32 kb/s ADPCM (G.726). However G.729 is the fixed rate speech coder, and it does not consider the property of voice activity in mutual conversation. If we use the voice activity, we can reduce the average bit rate in half without any ...

A variable bit rate source is modeled as a Markov modulated deterministic uid ow (MMDFF) process. Each state in the stationary discrete time Markov chain represents one of a nite number of deterministic messages of xed lengths and variable bit rates. At the user network interface this sequence is served at a constant bit rate with a bu er of xed length. The combined system forms a regenerative ...

Explosive growth in online services has recently renewed the interest for building modular and e cient network server systems. System design complications coupled with excessive expectations from technological progress previously discouraged the development of media servers e ciently supporting video streams with variable bit rates. In this paper, we describe the design of a distributed media s...

Multimedia applications with stringent delay requirements are usually supported by the constant bit rate (CBR) or real-time variable bit rate VBR (rt-VBR) service categories of ATM. This paper shows that ABR service, which was originally designed for data, can also support multimedia applications under certain circumstances. Issues related to the design of proper ABR traac management algorithms...

A new MPEG-4 rate control algorithm is proposed to calculate the quantization parameter for given target bit rate. The rate-distortion method models the AC DCT coefficients as Laplacian random variables. Derived from the MPEG-4 variable-length code/run-length code (VLC/ RLC) table, the new model accurately predicts the rates and the distortions of an intra frame for all range of quantization pa...