H261_IBLOCK_REFRESH

This attribute sets the desired period in milliseconds before the compressor should update a given H261 macroblock with an intra-encoded block. H261 requires that each macroblock be encoded as an intra-encoded block every 132 frames. If compressing at 10 fps, this implies that a given block may not be intra-encoded for up to 13 seconds. On a lossy network, a loss of a frame results visually in distorted blocks in the decompressed image. Waiting for up to 13 seconds for these bad blocks to refresh is probably not acceptable. The purpose of this attribute is to speed up the refresh of macroblocks during lossy transmission of H261 streams over networks.

Access: set/get Type: int Default: 1500 (msec)