PPMZ2 is a high compression markov predictive coder. It was originally developed by Charles Bloom http://www.cbloom.com as a testbed for experiments in entropy coding. The infrastructure has been upgraded to make it more accessible and to ease development. Feel free to peruse the source code, download the source and give it a try. We'd love to hear feedback on any parts of the code. Any feedback or thoughts on how to improve the code is useful. It's especially useful to hear whether you found the code accessible or obtuse as making the code easy for people to pick up is important for the success of open source projects. We're also interested to hear thoughts on the latest and greatest in development, or compression so please don't hesitate to send us a note.
The PPMZ2 source code is released under the MIT public license. The license can be changed in the future by joint agreement of the project maintainers.
Copyright (c) 2009 Charles Bloom, Ian Cadieu
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
It's pretty early in the product roadmap, but we have some interesting things planned. A large part of the initial changes are focused on making the platform easier to use. For example, creating a managed API, removing reliance on CrbLib in favor of standard libraries, automated testing, better abstractions etc.
- Managed API Done
- Automated Test Harness Done
- Unit Tests Done
- Massive Refactorings Done
- C++ Rewrite Done
- x64 Compatibility Done
- Expose more options Done
- Expand Unit Testing Done
- Speed optimizations
- Fix memory leak
Once the above is set we'll focus on performance aspects from both a compression and speed perspective.
We'd love to have more people contribute to the project. We can use all the help we can get from simple feedback to, help with documentation, testing, and contributions. Please contact "Ian at Cadieu.us" if you're interested in contributing. If there's enough interest we'll set up a mailing list to help people keep abreast of what's going on.