Libav 0.7.1
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00001 /* 00002 * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at> 00003 * 00004 * This file is part of Libav. 00005 * 00006 * Libav is free software; you can redistribute it and/or 00007 * modify it under the terms of the GNU Lesser General Public 00008 * License as published by the Free Software Foundation; either 00009 * version 2.1 of the License, or (at your option) any later version. 00010 * 00011 * Libav is distributed in the hope that it will be useful, 00012 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00014 * Lesser General Public License for more details. 00015 * 00016 * You should have received a copy of the GNU Lesser General Public 00017 * License along with Libav; if not, write to the Free Software 00018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00019 */ 00020 00026 #ifndef AVCODEC_PUT_BITS_H 00027 #define AVCODEC_PUT_BITS_H 00028 00029 #include <stdint.h> 00030 #include <stdlib.h> 00031 #include <assert.h> 00032 #include "libavutil/bswap.h" 00033 #include "libavutil/common.h" 00034 #include "libavutil/intreadwrite.h" 00035 #include "libavutil/log.h" 00036 #include "mathops.h" 00037 #include "config.h" 00038 00039 //#define ALT_BITSTREAM_WRITER 00040 //#define ALIGNED_BITSTREAM_WRITER 00041 00042 /* buf and buf_end must be present and used by every alternative writer. */ 00043 typedef struct PutBitContext { 00044 #ifdef ALT_BITSTREAM_WRITER 00045 uint8_t *buf, *buf_end; 00046 int index; 00047 #else 00048 uint32_t bit_buf; 00049 int bit_left; 00050 uint8_t *buf, *buf_ptr, *buf_end; 00051 #endif 00052 int size_in_bits; 00053 } PutBitContext; 00054 00061 static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size) 00062 { 00063 if(buffer_size < 0) { 00064 buffer_size = 0; 00065 buffer = NULL; 00066 } 00067 00068 s->size_in_bits= 8*buffer_size; 00069 s->buf = buffer; 00070 s->buf_end = s->buf + buffer_size; 00071 #ifdef ALT_BITSTREAM_WRITER 00072 s->index=0; 00073 ((uint32_t*)(s->buf))[0]=0; 00074 // memset(buffer, 0, buffer_size); 00075 #else 00076 s->buf_ptr = s->buf; 00077 s->bit_left=32; 00078 s->bit_buf=0; 00079 #endif 00080 } 00081 00085 static inline int put_bits_count(PutBitContext *s) 00086 { 00087 #ifdef ALT_BITSTREAM_WRITER 00088 return s->index; 00089 #else 00090 return (s->buf_ptr - s->buf) * 8 + 32 - s->bit_left; 00091 #endif 00092 } 00093 00097 static inline void flush_put_bits(PutBitContext *s) 00098 { 00099 #ifdef ALT_BITSTREAM_WRITER 00100 align_put_bits(s); 00101 #else 00102 #ifndef BITSTREAM_WRITER_LE 00103 s->bit_buf<<= s->bit_left; 00104 #endif 00105 while (s->bit_left < 32) { 00106 /* XXX: should test end of buffer */ 00107 #ifdef BITSTREAM_WRITER_LE 00108 *s->buf_ptr++=s->bit_buf; 00109 s->bit_buf>>=8; 00110 #else 00111 *s->buf_ptr++=s->bit_buf >> 24; 00112 s->bit_buf<<=8; 00113 #endif 00114 s->bit_left+=8; 00115 } 00116 s->bit_left=32; 00117 s->bit_buf=0; 00118 #endif 00119 } 00120 00121 #if defined(ALT_BITSTREAM_WRITER) || defined(BITSTREAM_WRITER_LE) 00122 #define align_put_bits align_put_bits_unsupported_here 00123 #define ff_put_string ff_put_string_unsupported_here 00124 #define ff_copy_bits ff_copy_bits_unsupported_here 00125 #else 00126 00129 void align_put_bits(PutBitContext *s); 00130 00136 void ff_put_string(PutBitContext *pb, const char *string, int terminate_string); 00137 00143 void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length); 00144 #endif 00145 00150 static inline void put_bits(PutBitContext *s, int n, unsigned int value) 00151 #ifndef ALT_BITSTREAM_WRITER 00152 { 00153 unsigned int bit_buf; 00154 int bit_left; 00155 00156 // printf("put_bits=%d %x\n", n, value); 00157 assert(n <= 31 && value < (1U << n)); 00158 00159 bit_buf = s->bit_buf; 00160 bit_left = s->bit_left; 00161 00162 // printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf); 00163 /* XXX: optimize */ 00164 #ifdef BITSTREAM_WRITER_LE 00165 bit_buf |= value << (32 - bit_left); 00166 if (n >= bit_left) { 00167 #if !HAVE_FAST_UNALIGNED 00168 if (3 & (intptr_t) s->buf_ptr) { 00169 AV_WL32(s->buf_ptr, bit_buf); 00170 } else 00171 #endif 00172 *(uint32_t *)s->buf_ptr = av_le2ne32(bit_buf); 00173 s->buf_ptr+=4; 00174 bit_buf = (bit_left==32)?0:value >> bit_left; 00175 bit_left+=32; 00176 } 00177 bit_left-=n; 00178 #else 00179 if (n < bit_left) { 00180 bit_buf = (bit_buf<<n) | value; 00181 bit_left-=n; 00182 } else { 00183 bit_buf<<=bit_left; 00184 bit_buf |= value >> (n - bit_left); 00185 #if !HAVE_FAST_UNALIGNED 00186 if (3 & (intptr_t) s->buf_ptr) { 00187 AV_WB32(s->buf_ptr, bit_buf); 00188 } else 00189 #endif 00190 *(uint32_t *)s->buf_ptr = av_be2ne32(bit_buf); 00191 //printf("bitbuf = %08x\n", bit_buf); 00192 s->buf_ptr+=4; 00193 bit_left+=32 - n; 00194 bit_buf = value; 00195 } 00196 #endif 00197 00198 s->bit_buf = bit_buf; 00199 s->bit_left = bit_left; 00200 } 00201 #else /* ALT_BITSTREAM_WRITER defined */ 00202 { 00203 # ifdef ALIGNED_BITSTREAM_WRITER 00204 # if ARCH_X86 00205 __asm__ volatile( 00206 "movl %0, %%ecx \n\t" 00207 "xorl %%eax, %%eax \n\t" 00208 "shrdl %%cl, %1, %%eax \n\t" 00209 "shrl %%cl, %1 \n\t" 00210 "movl %0, %%ecx \n\t" 00211 "shrl $3, %%ecx \n\t" 00212 "andl $0xFFFFFFFC, %%ecx \n\t" 00213 "bswapl %1 \n\t" 00214 "orl %1, (%2, %%ecx) \n\t" 00215 "bswapl %%eax \n\t" 00216 "addl %3, %0 \n\t" 00217 "movl %%eax, 4(%2, %%ecx) \n\t" 00218 : "=&r" (s->index), "=&r" (value) 00219 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n)) 00220 : "%eax", "%ecx" 00221 ); 00222 # else 00223 int index= s->index; 00224 uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5); 00225 00226 value<<= 32-n; 00227 00228 ptr[0] |= av_be2ne32(value>>(index&31)); 00229 ptr[1] = av_be2ne32(value<<(32-(index&31))); 00230 //if(n>24) printf("%d %d\n", n, value); 00231 index+= n; 00232 s->index= index; 00233 # endif 00234 # else //ALIGNED_BITSTREAM_WRITER 00235 # if ARCH_X86 00236 __asm__ volatile( 00237 "movl $7, %%ecx \n\t" 00238 "andl %0, %%ecx \n\t" 00239 "addl %3, %%ecx \n\t" 00240 "negl %%ecx \n\t" 00241 "shll %%cl, %1 \n\t" 00242 "bswapl %1 \n\t" 00243 "movl %0, %%ecx \n\t" 00244 "shrl $3, %%ecx \n\t" 00245 "orl %1, (%%ecx, %2) \n\t" 00246 "addl %3, %0 \n\t" 00247 "movl $0, 4(%%ecx, %2) \n\t" 00248 : "=&r" (s->index), "=&r" (value) 00249 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value) 00250 : "%ecx" 00251 ); 00252 # else 00253 int index= s->index; 00254 uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3)); 00255 00256 ptr[0] |= av_be2ne32(value<<(32-n-(index&7) )); 00257 ptr[1] = 0; 00258 //if(n>24) printf("%d %d\n", n, value); 00259 index+= n; 00260 s->index= index; 00261 # endif 00262 # endif //!ALIGNED_BITSTREAM_WRITER 00263 } 00264 #endif 00265 00266 static inline void put_sbits(PutBitContext *pb, int n, int32_t value) 00267 { 00268 assert(n >= 0 && n <= 31); 00269 00270 put_bits(pb, n, value & ((1<<n)-1)); 00271 } 00272 00276 static void av_unused put_bits32(PutBitContext *s, uint32_t value) 00277 { 00278 int lo = value & 0xffff; 00279 int hi = value >> 16; 00280 #ifdef BITSTREAM_WRITER_LE 00281 put_bits(s, 16, lo); 00282 put_bits(s, 16, hi); 00283 #else 00284 put_bits(s, 16, hi); 00285 put_bits(s, 16, lo); 00286 #endif 00287 } 00288 00293 static inline uint8_t* put_bits_ptr(PutBitContext *s) 00294 { 00295 #ifdef ALT_BITSTREAM_WRITER 00296 return s->buf + (s->index>>3); 00297 #else 00298 return s->buf_ptr; 00299 #endif 00300 } 00301 00306 static inline void skip_put_bytes(PutBitContext *s, int n) 00307 { 00308 assert((put_bits_count(s)&7)==0); 00309 #ifdef ALT_BITSTREAM_WRITER 00310 FIXME may need some cleaning of the buffer 00311 s->index += n<<3; 00312 #else 00313 assert(s->bit_left==32); 00314 s->buf_ptr += n; 00315 #endif 00316 } 00317 00323 static inline void skip_put_bits(PutBitContext *s, int n) 00324 { 00325 #ifdef ALT_BITSTREAM_WRITER 00326 s->index += n; 00327 #else 00328 s->bit_left -= n; 00329 s->buf_ptr-= 4*(s->bit_left>>5); 00330 s->bit_left &= 31; 00331 #endif 00332 } 00333 00339 static inline void set_put_bits_buffer_size(PutBitContext *s, int size) 00340 { 00341 s->buf_end= s->buf + size; 00342 } 00343 00344 #endif /* AVCODEC_PUT_BITS_H */