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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.c | |
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.c')
-rw-r--r-- | contrib/ffmpeg/libavcodec/rangecoder.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/rangecoder.c b/contrib/ffmpeg/libavcodec/rangecoder.c new file mode 100644 index 000000000..1f35d0852 --- /dev/null +++ b/contrib/ffmpeg/libavcodec/rangecoder.c @@ -0,0 +1,181 @@ +/* + * 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.c + * Range coder. + * based upon + * "Range encoding: an algorithm for removing redundancy from a digitised + * message. + * G. N. N. Martin Presented in March 1979 to the Video & + * Data Recording Conference, + * IBM UK Scientific Center held in Southampton July 24-27 1979." + * + */ + +#include <string.h> + +#include "avcodec.h" +#include "common.h" +#include "rangecoder.h" + + +void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size){ + c->bytestream_start= + c->bytestream= buf; + c->bytestream_end= buf + buf_size; + + c->low= 0; + c->range= 0xFF00; + c->outstanding_count= 0; + c->outstanding_byte= -1; +} + +void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size){ + /* cast to avoid compiler warning */ + ff_init_range_encoder(c, (uint8_t *) buf, buf_size); + + c->low =(*c->bytestream++)<<8; + c->low+= *c->bytestream++; +} + +void ff_build_rac_states(RangeCoder *c, int factor, int max_p){ + const int64_t one= 1LL<<32; + int64_t p; + int last_p8, p8, i; + + memset(c->zero_state, 0, sizeof(c->zero_state)); + memset(c-> one_state, 0, sizeof(c-> one_state)); + +#if 0 + for(i=1; i<256; i++){ + if(c->one_state[i]) + continue; + + p= (i*one + 128) >> 8; + last_p8= i; + for(;;){ + p+= ((one-p)*factor + one/2) >> 32; + p8= (256*p + one/2) >> 32; //FIXME try without the one + if(p8 <= last_p8) p8= last_p8+1; + if(p8 > max_p) p8= max_p; + if(p8 < last_p8) + break; + c->one_state[last_p8]= p8; + if(p8 == last_p8) + break; + last_p8= p8; + } + } +#endif +#if 1 + last_p8= 0; + p= one/2; + for(i=0; i<128; i++){ + p8= (256*p + one/2) >> 32; //FIXME try without the one + if(p8 <= last_p8) p8= last_p8+1; + if(last_p8 && last_p8<256 && p8<=max_p) + c->one_state[last_p8]= p8; + + p+= ((one-p)*factor + one/2) >> 32; + last_p8= p8; + } +#endif + for(i=256-max_p; i<=max_p; i++){ + if(c->one_state[i]) + continue; + + p= (i*one + 128) >> 8; + p+= ((one-p)*factor + one/2) >> 32; + p8= (256*p + one/2) >> 32; //FIXME try without the one + if(p8 <= i) p8= i+1; + if(p8 > max_p) p8= max_p; + c->one_state[ i]= p8; + } + + for(i=1; i<255; i++) + c->zero_state[i]= 256-c->one_state[256-i]; +#if 0 + for(i=0; i<256; i++) + av_log(NULL, AV_LOG_DEBUG, "%3d %3d\n", i, c->one_state[i]); +#endif +} + +/** + * + * @return the number of bytes written + */ +int ff_rac_terminate(RangeCoder *c){ + c->range=0xFF; + c->low +=0xFF; + renorm_encoder(c); + c->range=0xFF; + renorm_encoder(c); + + assert(c->low == 0); + assert(c->range >= 0x100); + + return c->bytestream - c->bytestream_start; +} + +#if 0 //selftest +#define SIZE 10240 +int main(){ + RangeCoder c; + uint8_t b[9*SIZE]; + uint8_t r[9*SIZE]; + int i; + uint8_t state[10]= {0}; + + ff_init_range_encoder(&c, b, SIZE); + ff_build_rac_states(&c, 0.05*(1LL<<32), 128+64+32+16); + + memset(state, 128, sizeof(state)); + + for(i=0; i<SIZE; i++){ + r[i]= random()%7; + } + + + for(i=0; i<SIZE; i++){ +START_TIMER + put_rac(&c, state, r[i]&1); +STOP_TIMER("put_rac") + } + + ff_put_rac_terminate(&c); + + ff_init_range_decoder(&c, b, SIZE); + + memset(state, 128, sizeof(state)); + + for(i=0; i<SIZE; i++){ +START_TIMER + if( (r[i]&1) != get_rac(&c, state) ) + av_log(NULL, AV_LOG_DEBUG, "rac failure at %d\n", i); +STOP_TIMER("get_rac") + } + + return 0; +} + +#endif |