Implemented in the 1990s, the MPEG-2 standard as one of today's most w i d e b used image compressing methods provides the basis for baseband data transmission in D VB technology. However, the requirements of the cuwenf multimedia applications exceed fhe capabilities of MPEG-2 systems. On the other hand, these requirements are the driving forces of the MPEG-4 related developments worldwide. Our aim is to contribute to these activities b-v elaborating procedures that are more effective than the image compressing methods used in MPEG-2 systems, as well as by integrating them into DYB systems. Keywords-MPEG4, DVB-T, MPEGZ-TS, BIFS, wavelet transform 1. DEVELOPMENT Our development activities covered the following major areas: Design and implementation of the internal interfaces of DVB signal transmission subsystems Interfacing the DVB-T baseband channel for MPEG-4 stream transmission and system integration MPEG 4 codec R&D MPEG4 RELATED RESEARCH AND CODEC DEVELOPMENTThe MPEG-4 codec developed by our group and uniquely optimized in some of its properties applies the so-called wavelet transform instead of blockbased compression used in MPEG-2 systems. Wavelet transform is currently one of the most effective methods in image processing. Its advantage to the conventional algorithms (e.g. DCT) is that it simultaneously handles the spatial and frequency domain behavior of the signal. More to the point, it also fits well to the properties of the human vision system (HVS), i.e. the information relevant for the human eye can be extracted by this method and the less important ones can be suppressed. Besides of all the above mentioned, wavelet transform requires less computational timeiresources than the accelerated algorithms of the conventional procedures, what is highly important in image processing: signals cannot be handled in real-time by complicated algorithms, due to the huge amount of information to be processed.The properties of the coefficients resulted by wavelet transform [ l , 2, 31 are severely affected by the base functions of the transform. In the recent decades, several research activities aimed to develop optimal base functions for different applications (Daubechies, Hair, Coiflet, UCLA, etc), We used Daubechies 7/9 filters for transforming the first intra frames, because this provided the best quality and also the P E G 2000 standard uses this base for coding still pictures. The Daubechies 9/3 base was used for coding the differential images, which is also applied by MPEG-4 for coding moving pictures. We used symmetrical extension during the transform, avoiding this way the false edges that would have been resulted by periodic extensions at the picture boundaries. The transform has separately been completed for all the three components (Y, U, V) in case of color pictures. Naturally the size of the U and V components is half of that of the luminance signal in both horizontal and vertical direction.The coefficients resulted by the wavelet transform are quantized and collected. The three components are handled ...