A video data recoding method suitable for recording computer sessions. Each video image frame is divided into multiple blocks. A server processes the video frames and transmits only changed blocks for each frame to a video log server. The video log server stores the changed blocks with block indices in a data file. The video log server also maintains a virtual frame table which stores, for each block of the frame, the data location within the data file where the most recent occurrence of that block is stored. The virtual frame table is continuously updated as changed blocks are stored in the data file. The video log server further stores a snapshot file containing snapshots of the virtual frame table at predetermined time points, along with time stamps and a next changed frame location. The data file and the snapshot file are used to reproduce the video images.