This \vork presents a MPIXi-compatible coding method dcsigned for the production of visual information. Constant Bit Rate transmission is imposed. Sornc buffer control strategies. \vel1 suited for CUR and adapted to thc specific applications arc prescntcd. In distributive applications, thc edition is supposed to bc ofl-line. This is csploitcd by pcrforniing a pre-nnalysis. detecting [or instance thc scene cuts or others Characteristics to be taken into account !\.hen coding. Thc results show that the tradeoff bct\vccn quality and CUR is good. compared with Test Modrls. for the specific application.

This paper analyses the adequacy of the statistical bit rate (SBR) A TM transfer capability for supporting real time video services, where end to end delay is limited. For these type of services, mean data rates are normally low. However, if a reasonable image quality consistency is imposed, the generated traffic becomes bursty. This results in important bandwidth availability requirements. A method is presented for ensuring that the generated traffic can be transmitted over an SBR connection while respecting the service requirements. Comparison with other transfer capabilities shows that SBR is outstanding in terms of application performance and network resources required.

The state of the art in video coding at constant bit rates of up about 1 .5 Mbit/s is represented by the MPEG 1 recommendation. Interest in low bitrate applications is coming from mobile applications, from storage media limitations and from transmission over subscriber copperloops. In this paper the ability ofthe MPEG1 standard to work at low bit rates, extrapolating it out of its design range is studied. A statistical analysis at bit level of the information generated by a compatible MPEG1 scheme is performed. The aim of this study is to obtain statistical results of the bit distribution in order to find out how the scheme spends the bits. This information will give us essential knowledge to decide in which modules it is posible to obtain a bit rate saving. An study of the motion vector search range reduction of a compatible MPEG1 scheme is also done. Simulations have been done by using a simulator written in "C" language. A video tape with the simulations has been produced.