media/libopus/celt/entenc.h@6474c204b198 (annotated)
media/libopus/celt/entenc.h
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* Copyright (c) 2001-2011 Timothy B. Terriberry |
| michael@0 | 2 | Copyright (c) 2008-2009 Xiph.Org Foundation */ |
| michael@0 | 3 | /* |
| michael@0 | 4 | Redistribution and use in source and binary forms, with or without |
| michael@0 | 5 | modification, are permitted provided that the following conditions |
| michael@0 | 6 | are met: |
| michael@0 | 7 | |
| michael@0 | 8 | - Redistributions of source code must retain the above copyright |
| michael@0 | 9 | notice, this list of conditions and the following disclaimer. |
| michael@0 | 10 | |
| michael@0 | 11 | - Redistributions in binary form must reproduce the above copyright |
| michael@0 | 12 | notice, this list of conditions and the following disclaimer in the |
| michael@0 | 13 | documentation and/or other materials provided with the distribution. |
| michael@0 | 14 | |
| michael@0 | 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| michael@0 | 16 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| michael@0 | 17 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| michael@0 | 18 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER |
| michael@0 | 19 | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| michael@0 | 20 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| michael@0 | 21 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| michael@0 | 22 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| michael@0 | 23 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| michael@0 | 24 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| michael@0 | 25 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| michael@0 | 26 | */ |
| michael@0 | 27 | |
| michael@0 | 28 | #if !defined(_entenc_H) |
| michael@0 | 29 | # define _entenc_H (1) |
| michael@0 | 30 | # include <stddef.h> |
| michael@0 | 31 | # include "entcode.h" |
| michael@0 | 32 | |
| michael@0 | 33 | /*Initializes the encoder. |
| michael@0 | 34 | _buf: The buffer to store output bytes in. |
| michael@0 | 35 | _size: The size of the buffer, in chars.*/ |
| michael@0 | 36 | void ec_enc_init(ec_enc *_this,unsigned char *_buf,opus_uint32 _size); |
| michael@0 | 37 | /*Encodes a symbol given its frequency information. |
| michael@0 | 38 | The frequency information must be discernable by the decoder, assuming it |
| michael@0 | 39 | has read only the previous symbols from the stream. |
| michael@0 | 40 | It is allowable to change the frequency information, or even the entire |
| michael@0 | 41 | source alphabet, so long as the decoder can tell from the context of the |
| michael@0 | 42 | previously encoded information that it is supposed to do so as well. |
| michael@0 | 43 | _fl: The cumulative frequency of all symbols that come before the one to be |
| michael@0 | 44 | encoded. |
| michael@0 | 45 | _fh: The cumulative frequency of all symbols up to and including the one to |
| michael@0 | 46 | be encoded. |
| michael@0 | 47 | Together with _fl, this defines the range [_fl,_fh) in which the |
| michael@0 | 48 | decoded value will fall. |
| michael@0 | 49 | _ft: The sum of the frequencies of all the symbols*/ |
| michael@0 | 50 | void ec_encode(ec_enc *_this,unsigned _fl,unsigned _fh,unsigned _ft); |
| michael@0 | 51 | |
| michael@0 | 52 | /*Equivalent to ec_encode() with _ft==1<<_bits.*/ |
| michael@0 | 53 | void ec_encode_bin(ec_enc *_this,unsigned _fl,unsigned _fh,unsigned _bits); |
| michael@0 | 54 | |
| michael@0 | 55 | /* Encode a bit that has a 1/(1<<_logp) probability of being a one */ |
| michael@0 | 56 | void ec_enc_bit_logp(ec_enc *_this,int _val,unsigned _logp); |
| michael@0 | 57 | |
| michael@0 | 58 | /*Encodes a symbol given an "inverse" CDF table. |
| michael@0 | 59 | _s: The index of the symbol to encode. |
| michael@0 | 60 | _icdf: The "inverse" CDF, such that symbol _s falls in the range |
| michael@0 | 61 | [_s>0?ft-_icdf[_s-1]:0,ft-_icdf[_s]), where ft=1<<_ftb. |
| michael@0 | 62 | The values must be monotonically non-increasing, and the last value |
| michael@0 | 63 | must be 0. |
| michael@0 | 64 | _ftb: The number of bits of precision in the cumulative distribution.*/ |
| michael@0 | 65 | void ec_enc_icdf(ec_enc *_this,int _s,const unsigned char *_icdf,unsigned _ftb); |
| michael@0 | 66 | |
| michael@0 | 67 | /*Encodes a raw unsigned integer in the stream. |
| michael@0 | 68 | _fl: The integer to encode. |
| michael@0 | 69 | _ft: The number of integers that can be encoded (one more than the max). |
| michael@0 | 70 | This must be at least one, and no more than 2**32-1.*/ |
| michael@0 | 71 | void ec_enc_uint(ec_enc *_this,opus_uint32 _fl,opus_uint32 _ft); |
| michael@0 | 72 | |
| michael@0 | 73 | /*Encodes a sequence of raw bits in the stream. |
| michael@0 | 74 | _fl: The bits to encode. |
| michael@0 | 75 | _ftb: The number of bits to encode. |
| michael@0 | 76 | This must be between 1 and 25, inclusive.*/ |
| michael@0 | 77 | void ec_enc_bits(ec_enc *_this,opus_uint32 _fl,unsigned _ftb); |
| michael@0 | 78 | |
| michael@0 | 79 | /*Overwrites a few bits at the very start of an existing stream, after they |
| michael@0 | 80 | have already been encoded. |
| michael@0 | 81 | This makes it possible to have a few flags up front, where it is easy for |
| michael@0 | 82 | decoders to access them without parsing the whole stream, even if their |
| michael@0 | 83 | values are not determined until late in the encoding process, without having |
| michael@0 | 84 | to buffer all the intermediate symbols in the encoder. |
| michael@0 | 85 | In order for this to work, at least _nbits bits must have already been |
| michael@0 | 86 | encoded using probabilities that are an exact power of two. |
| michael@0 | 87 | The encoder can verify the number of encoded bits is sufficient, but cannot |
| michael@0 | 88 | check this latter condition. |
| michael@0 | 89 | _val: The bits to encode (in the least _nbits significant bits). |
| michael@0 | 90 | They will be decoded in order from most-significant to least. |
| michael@0 | 91 | _nbits: The number of bits to overwrite. |
| michael@0 | 92 | This must be no more than 8.*/ |
| michael@0 | 93 | void ec_enc_patch_initial_bits(ec_enc *_this,unsigned _val,unsigned _nbits); |
| michael@0 | 94 | |
| michael@0 | 95 | /*Compacts the data to fit in the target size. |
| michael@0 | 96 | This moves up the raw bits at the end of the current buffer so they are at |
| michael@0 | 97 | the end of the new buffer size. |
| michael@0 | 98 | The caller must ensure that the amount of data that's already been written |
| michael@0 | 99 | will fit in the new size. |
| michael@0 | 100 | _size: The number of bytes in the new buffer. |
| michael@0 | 101 | This must be large enough to contain the bits already written, and |
| michael@0 | 102 | must be no larger than the existing size.*/ |
| michael@0 | 103 | void ec_enc_shrink(ec_enc *_this,opus_uint32 _size); |
| michael@0 | 104 | |
| michael@0 | 105 | /*Indicates that there are no more symbols to encode. |
| michael@0 | 106 | All reamining output bytes are flushed to the output buffer. |
| michael@0 | 107 | ec_enc_init() must be called before the encoder can be used again.*/ |
| michael@0 | 108 | void ec_enc_done(ec_enc *_this); |
| michael@0 | 109 | |
| michael@0 | 110 | #endif |
