Граф коммитов

8 Коммитов

Автор SHA1 Сообщение Дата
Alex Converse 1f57aa38cd Raise the probability resolution for rANS tokens to 10-bits per symbol
Change-Id: I397b5a9371c85d1df401d261143c985623e9def6
2016-04-22 15:48:11 -07:00
Alex Converse 3829cd2f2f Move ZERO_TOKEN into the ANS coef tokenset.
Change-Id: I87943e027437543ab31fa3ae1aa8b2de3a063ae5
2016-04-19 15:29:47 -07:00
Alex Converse efd566ff93 Add pluggable bitreaders.
This will make the code change for a pure ANS experiment manageable.

Change-Id: I9905f3a89f492a4346860463a72fa8c52aac4c8e
2016-03-25 11:02:41 -07:00
Alex Converse 6b9cb8c489 Add some ANS helpers needed to replace the vpx bool coder with pure ANS.
Change-Id: I32b63fca020c410cef16e93379b4e6e281ccbccd
2016-03-22 16:23:23 -07:00
Yaowu Xu 28eb784e46 Fix several MSVC compiler warning/errors
Change-Id: Iccaacee9b7a66b016b5747a3902c236888ad4ba1
2016-03-07 17:00:03 -08:00
Alex Converse 6bbbe31656 ANS: Switch from PDFs to CDFs.
Make the RANS implementation operate on cumulative distribution
functions rather than individual probability distribution functions.
CDFs have shown themselves more flexible to work with.

Reduces decoding memory usage from scaling O(num_distributions *
symbol_resolution) to O(num_distributions).

No bitstream change. This is an purely implementation change.

Change-Id: I4e18d3a0a3d37a36a61487c3d778f9d088b0b374
2016-03-03 09:32:54 +00:00
Alex Converse 0f840cc3eb Compress the final ANS state.
The '110' prefix on a final byte indicates a superframe marker. Coded
data is not allowed to use this pattern on a final byte.

Code |state - l_base| little endian with the following prefix scheme:
Prefix '00': Single byte coded state.
Prefix '01': Two bytes le coded state.
Prefix '10': Three bytes le coded state.

Change-Id: Ibc953b67675b567394b93de39b7cb22cadc47435
2016-01-12 23:11:17 +00:00
Alex Converse 9ffcb469fb Add an implementation of Asymetric Numeral Systems (ANS).
Change-Id: Ie41bc72127e700887566dcc951da9d83a0b94891
2016-01-11 16:26:30 -08:00