Patent ID: 6111917
Filing Date: 2000-08-29
Classification: H04N

Abstract:
A video transmission system comprising:in the video sending side:an encoding section for encoding an input picture by an inter-picture coding method of compressing data using inter-picture differences, and outputting encoded video data;a signal receiving section for receiving a signal from the video receiving side, the signal indicating presence or absence of an error relating to the encoded video data received at the video receiving side and a picture number of the encoded video data;a memory section having buffers for maintaining the encoded video data output from the encoding section as reference pictures used for the encoding based on the inter-picture coding method;a reference picture determining section for selecting a reference picture used in the encoding section among pictures stored in the memory section if at least one picture is stored in the memory section, based on information indicated by the signal received by the signal receiving section;a reference picture communicating section for communicating a picture number of the reference picture used in the encoding section to the video receiving side; anda picture number communicating section for communicating a picture number of the encoded video data output from the encoding section; andin the video receiving side:an encoded data receiving section for receiving the encoded video data output from the encoding section of the video sending side, and detecting and outputting presence or absence of an error relating to the video data;a picture number receiving section for receiving the picture number of the encoded video data communicated from the picture number communicating section of the video sending side;a signal sending section for sending the video sending side a signal which indicates the picture number of the encoded video data received by the picture number receiving section and the presence or absence of an error with respect to the relevant video data which was detected by the encoded data receiving section;a decoding section for decoding the encoded video data received by the encoded data receiving section and outputting decoded video data;a memory section having buffers for maintaining the decoded video data output from the decoding section as reference pictures used for the decoding;a reference picture number receiving section for receiving the picture number of the reference picture used at the time of encoding, communicated from the reference picture communicating section of the video sending side; anda reference picture determining section for selecting a reference picture used in the decoding section among pictures stored in the memory section if at least one picture is stored in the memory section, according to the picture number of the reference picture received by the reference picture number receiving section; the system further comprising:memory changing means for performing control of data storage of the encoded video data output from the encoding section into the memory section based on information indicated by the signal received by the signal receiving section of the video sending side, the control including determination whether new data are stored, determination of an area for storing data in the memory section, and deletion of data stored in the memory section.