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author | Diego 'Flameeyes' Pettenò <flameeyes@gmail.com> | 2006-12-02 01:19:48 +0000 |
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committer | Diego 'Flameeyes' Pettenò <flameeyes@gmail.com> | 2006-12-02 01:19:48 +0000 |
commit | 0ea721f7ce81357bc4ec6eea609cd50482c3d15b (patch) | |
tree | 25a0871cb3c06f9716acf9c204192d548f214048 /contrib/ffmpeg/libavcodec/rangecoder.h | |
parent | d8ec380876e7f697ba609546d61757ab3f2d8715 (diff) | |
download | xine-lib-0ea721f7ce81357bc4ec6eea609cd50482c3d15b.tar.gz xine-lib-0ea721f7ce81357bc4ec6eea609cd50482c3d15b.tar.bz2 |
Start working on a branch where FFmpeg is not copied, patched and carved to be built with automake but instead imported inline and built using its own build system. This is an import of a slightly modified FFmpeg current tree. xine-lib builds, install and run fine with it, but there are of course plenty of things that needs to be fixed before it can even be considered for a 1.2.x series. Work will continue in the next days of course.
CVS patchset: 8397
CVS date: 2006/12/02 01:19:48
Diffstat (limited to 'contrib/ffmpeg/libavcodec/rangecoder.h')
-rw-r--r-- | contrib/ffmpeg/libavcodec/rangecoder.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/rangecoder.h b/contrib/ffmpeg/libavcodec/rangecoder.h new file mode 100644 index 000000000..68bd3b60e --- /dev/null +++ b/contrib/ffmpeg/libavcodec/rangecoder.h @@ -0,0 +1,127 @@ +/* + * Range coder + * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +/** + * @file rangecoder.h + * Range coder. + */ + +typedef struct RangeCoder{ + int low; + int range; + int outstanding_count; + int outstanding_byte; + uint8_t zero_state[256]; + uint8_t one_state[256]; + uint8_t *bytestream_start; + uint8_t *bytestream; + uint8_t *bytestream_end; +}RangeCoder; + +void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size); +void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size); +int ff_rac_terminate(RangeCoder *c); +void ff_build_rac_states(RangeCoder *c, int factor, int max_p); + +static inline void renorm_encoder(RangeCoder *c){ + //FIXME optimize + while(c->range < 0x100){ + if(c->outstanding_byte < 0){ + c->outstanding_byte= c->low>>8; + }else if(c->low <= 0xFF00){ + *c->bytestream++ = c->outstanding_byte; + for(;c->outstanding_count; c->outstanding_count--) + *c->bytestream++ = 0xFF; + c->outstanding_byte= c->low>>8; + }else if(c->low >= 0x10000){ + *c->bytestream++ = c->outstanding_byte + 1; + for(;c->outstanding_count; c->outstanding_count--) + *c->bytestream++ = 0x00; + c->outstanding_byte= (c->low>>8) & 0xFF; + }else{ + c->outstanding_count++; + } + + c->low = (c->low & 0xFF)<<8; + c->range <<= 8; + } +} + +static inline void put_rac(RangeCoder *c, uint8_t * const state, int bit){ + int range1= (c->range * (*state)) >> 8; + + assert(*state); + assert(range1 < c->range); + assert(range1 > 0); + if(!bit){ + c->range -= range1; + *state= c->zero_state[*state]; + }else{ + c->low += c->range - range1; + c->range = range1; + *state= c->one_state[*state]; + } + + renorm_encoder(c); +} + +static inline void refill(RangeCoder *c){ + if(c->range < 0x100){ + c->range <<= 8; + c->low <<= 8; + if(c->bytestream < c->bytestream_end) + c->low+= c->bytestream[0]; + c->bytestream++; + } +} + +static inline int get_rac(RangeCoder *c, uint8_t * const state){ + int range1= (c->range * (*state)) >> 8; + int attribute_unused one_mask; + + c->range -= range1; +#if 1 + if(c->low < c->range){ + *state= c->zero_state[*state]; + refill(c); + return 0; + }else{ + c->low -= c->range; + *state= c->one_state[*state]; + c->range = range1; + refill(c); + return 1; + } +#else + one_mask= (c->range - c->low-1)>>31; + + c->low -= c->range & one_mask; + c->range += (range1 - c->range) & one_mask; + + *state= c->zero_state[(*state) + (256&one_mask)]; + + refill(c); + + return one_mask&1; +#endif +} + |