We developed a new class of algorithms for image compression. Its working title is "SIF-conversion".
This class of algorithms can be realized in a number of ways, and the total efficiency of the resulting compression engine depends on the method of realization chosen.
During several years, we worked on different compression engines based on SIF conversion.
The sixth compression core was found to be the best basis for realizing the new codec.
It should be noted that it could be further improved since the developed engine represents a compromise between the compression efficiency obtained and the time spent on the engine development.
Changes in SIF1 Video Codec 1.20
- Motion detection engine was restructured and optimized for multithreaded operation (up to 32 threads). In current code multithreaded optimization is done using a temporal scheme since the core of SIF transform is the last big unit of code that is not working in multithreaded mode.
- Added multithreaded modes of an entropy codec operation (up to 8 threads). Thus, the decoder now have full multithreading support and supports decoding of streams with 80+ mbits bitrate.
- Codec now supports vertical resolution that is not a multiple of 16.
- Implemented different (in terms of speed & quality) motion detection engine presets.
- Added checking for correct input. Now the decoder doesn't crash on corrupt or invalid files.
- Added turbo first pass mode - about two times faster than second in two-pass mode.
- New PsyRD extrapolation engine, used in the motion detection engine, is written. Due to this, another significant improvement in sharpness and detail of compressed image was achieved.
The SIF1 project was launched in the autumn of 2000, with the major goal of finding new approaches for video compression.