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 if (s->bit_left < 32) 00104 s->bit_buf<<= s->bit_left; 00105 #endif 00106 while (s->bit_left < 32) { 00107 /* XXX: should test end of buffer */ 00108 #ifdef BITSTREAM_WRITER_LE 00109 *s->buf_ptr++=s->bit_buf; 00110 s->bit_buf>>=8; 00111 #else 00112 *s->buf_ptr++=s->bit_buf >> 24; 00113 s->bit_buf<<=8; 00114 #endif 00115 s->bit_left+=8; 00116 } 00117 s->bit_left=32; 00118 s->bit_buf=0; 00119 #endif 00120 } 00121 00122 #if defined(ALT_BITSTREAM_WRITER) || defined(BITSTREAM_WRITER_LE) 00123 #define align_put_bits align_put_bits_unsupported_here 00124 #define ff_put_string ff_put_string_unsupported_here 00125 #define ff_copy_bits ff_copy_bits_unsupported_here 00126 #else 00127 00130 void align_put_bits(PutBitContext *s); 00131 00137 void ff_put_string(PutBitContext *pb, const char *string, int terminate_string); 00138 00144 void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length); 00145 #endif 00146 00151 static inline void put_bits(PutBitContext *s, int n, unsigned int value) 00152 #ifndef ALT_BITSTREAM_WRITER 00153 { 00154 unsigned int bit_buf; 00155 int bit_left; 00156 00157 // printf("put_bits=%d %x\n", n, value); 00158 assert(n <= 31 && value < (1U << n)); 00159 00160 bit_buf = s->bit_buf; 00161 bit_left = s->bit_left; 00162 00163 // printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf); 00164 /* XXX: optimize */ 00165 #ifdef BITSTREAM_WRITER_LE 00166 bit_buf |= value << (32 - bit_left); 00167 if (n >= bit_left) { 00168 #if !HAVE_FAST_UNALIGNED 00169 if (3 & (intptr_t) s->buf_ptr) { 00170 AV_WL32(s->buf_ptr, bit_buf); 00171 } else 00172 #endif 00173 *(uint32_t *)s->buf_ptr = av_le2ne32(bit_buf); 00174 s->buf_ptr+=4; 00175 bit_buf = (bit_left==32)?0:value >> bit_left; 00176 bit_left+=32; 00177 } 00178 bit_left-=n; 00179 #else 00180 if (n < bit_left) { 00181 bit_buf = (bit_buf<<n) | value; 00182 bit_left-=n; 00183 } else { 00184 bit_buf<<=bit_left; 00185 bit_buf |= value >> (n - bit_left); 00186 #if !HAVE_FAST_UNALIGNED 00187 if (3 & (intptr_t) s->buf_ptr) { 00188 AV_WB32(s->buf_ptr, bit_buf); 00189 } else 00190 #endif 00191 *(uint32_t *)s->buf_ptr = av_be2ne32(bit_buf); 00192 //printf("bitbuf = %08x\n", bit_buf); 00193 s->buf_ptr+=4; 00194 bit_left+=32 - n; 00195 bit_buf = value; 00196 } 00197 #endif 00198 00199 s->bit_buf = bit_buf; 00200 s->bit_left = bit_left; 00201 } 00202 #else /* ALT_BITSTREAM_WRITER defined */ 00203 { 00204 # ifdef ALIGNED_BITSTREAM_WRITER 00205 # if ARCH_X86 00206 __asm__ volatile( 00207 "movl %0, %%ecx \n\t" 00208 "xorl %%eax, %%eax \n\t" 00209 "shrdl %%cl, %1, %%eax \n\t" 00210 "shrl %%cl, %1 \n\t" 00211 "movl %0, %%ecx \n\t" 00212 "shrl $3, %%ecx \n\t" 00213 "andl $0xFFFFFFFC, %%ecx \n\t" 00214 "bswapl %1 \n\t" 00215 "orl %1, (%2, %%ecx) \n\t" 00216 "bswapl %%eax \n\t" 00217 "addl %3, %0 \n\t" 00218 "movl %%eax, 4(%2, %%ecx) \n\t" 00219 : "=&r" (s->index), "=&r" (value) 00220 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n)) 00221 : "%eax", "%ecx" 00222 ); 00223 # else 00224 int index= s->index; 00225 uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5); 00226 00227 value<<= 32-n; 00228 00229 ptr[0] |= av_be2ne32(value>>(index&31)); 00230 ptr[1] = av_be2ne32(value<<(32-(index&31))); 00231 //if(n>24) printf("%d %d\n", n, value); 00232 index+= n; 00233 s->index= index; 00234 # endif 00235 # else //ALIGNED_BITSTREAM_WRITER 00236 # if ARCH_X86 00237 __asm__ volatile( 00238 "movl $7, %%ecx \n\t" 00239 "andl %0, %%ecx \n\t" 00240 "addl %3, %%ecx \n\t" 00241 "negl %%ecx \n\t" 00242 "shll %%cl, %1 \n\t" 00243 "bswapl %1 \n\t" 00244 "movl %0, %%ecx \n\t" 00245 "shrl $3, %%ecx \n\t" 00246 "orl %1, (%%ecx, %2) \n\t" 00247 "addl %3, %0 \n\t" 00248 "movl $0, 4(%%ecx, %2) \n\t" 00249 : "=&r" (s->index), "=&r" (value) 00250 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value) 00251 : "%ecx" 00252 ); 00253 # else 00254 int index= s->index; 00255 uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3)); 00256 00257 ptr[0] |= av_be2ne32(value<<(32-n-(index&7) )); 00258 ptr[1] = 0; 00259 //if(n>24) printf("%d %d\n", n, value); 00260 index+= n; 00261 s->index= index; 00262 # endif 00263 # endif //!ALIGNED_BITSTREAM_WRITER 00264 } 00265 #endif 00266 00267 static inline void put_sbits(PutBitContext *pb, int n, int32_t value) 00268 { 00269 assert(n >= 0 && n <= 31); 00270 00271 put_bits(pb, n, value & ((1<<n)-1)); 00272 } 00273 00277 static void av_unused put_bits32(PutBitContext *s, uint32_t value) 00278 { 00279 int lo = value & 0xffff; 00280 int hi = value >> 16; 00281 #ifdef BITSTREAM_WRITER_LE 00282 put_bits(s, 16, lo); 00283 put_bits(s, 16, hi); 00284 #else 00285 put_bits(s, 16, hi); 00286 put_bits(s, 16, lo); 00287 #endif 00288 } 00289 00294 static inline uint8_t* put_bits_ptr(PutBitContext *s) 00295 { 00296 #ifdef ALT_BITSTREAM_WRITER 00297 return s->buf + (s->index>>3); 00298 #else 00299 return s->buf_ptr; 00300 #endif 00301 } 00302 00307 static inline void skip_put_bytes(PutBitContext *s, int n) 00308 { 00309 assert((put_bits_count(s)&7)==0); 00310 #ifdef ALT_BITSTREAM_WRITER 00311 FIXME may need some cleaning of the buffer 00312 s->index += n<<3; 00313 #else 00314 assert(s->bit_left==32); 00315 s->buf_ptr += n; 00316 #endif 00317 } 00318 00324 static inline void skip_put_bits(PutBitContext *s, int n) 00325 { 00326 #ifdef ALT_BITSTREAM_WRITER 00327 s->index += n; 00328 #else 00329 s->bit_left -= n; 00330 s->buf_ptr-= 4*(s->bit_left>>5); 00331 s->bit_left &= 31; 00332 #endif 00333 } 00334 00340 static inline void set_put_bits_buffer_size(PutBitContext *s, int size) 00341 { 00342 s->buf_end= s->buf + size; 00343 } 00344 00345 #endif /* AVCODEC_PUT_BITS_H */