Encoder-side decisions for sample adaptive offset filtering

One or more tangible computer-readable media storing computer-executable instructions for causing a computing device, when programmed thereby, to perform operations comprising:

• for a series of pictures or picture portions being encoded, periodically applying a second stage of filtering of a multi-stage filtering process;
• for each picture or picture portion in the series, specifying one or more syntax elements for controlling the second stage of filtering, the one or more syntax elements including a syntax element that signals the periodic application of the second stage of filtering;
• encoding the series of picture portions, thereby producing a bitstream, the bitstream including the specified one or more syntax elements for controlling application of the second stage of filtering;
• and
• outputting the bitstream.

A computer system comprising:

• a video encoder, implemented using one or more processors and memory, configured to perform operations, the operations comprising:
• for a series of pictures or picture portions being encoded, periodically applying a second stage of filtering of a multi-stage filtering process;
• for each picture or picture portion in the series, specifying one or more syntax elements for controlling the second stage of filtering, the one or more syntax elements including a syntax element that signals the periodic application of the second stage of filtering;
• and
• encoding the series of picture portions, thereby producing a bitstream, the bitstream including the specified one or more syntax elements for controlling application of the second stage of filtering;
• and
• a buffer configured to store the bitstream for output.