Libav
|
00001 /* 00002 * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at> 00003 * 00004 * This file is part of FFmpeg. 00005 * 00006 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 00038 //#define ALT_BITSTREAM_WRITER 00039 //#define ALIGNED_BITSTREAM_WRITER 00040 00041 /* buf and buf_end must be present and used by every alternative writer. */ 00042 typedef struct PutBitContext { 00043 #ifdef ALT_BITSTREAM_WRITER 00044 uint8_t *buf, *buf_end; 00045 int index; 00046 #else 00047 uint32_t bit_buf; 00048 int bit_left; 00049 uint8_t *buf, *buf_ptr, *buf_end; 00050 #endif 00051 int size_in_bits; 00052 } PutBitContext; 00053 00060 static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size) 00061 { 00062 if(buffer_size < 0) { 00063 buffer_size = 0; 00064 buffer = NULL; 00065 } 00066 00067 s->size_in_bits= 8*buffer_size; 00068 s->buf = buffer; 00069 s->buf_end = s->buf + buffer_size; 00070 #ifdef ALT_BITSTREAM_WRITER 00071 s->index=0; 00072 ((uint32_t*)(s->buf))[0]=0; 00073 // memset(buffer, 0, buffer_size); 00074 #else 00075 s->buf_ptr = s->buf; 00076 s->bit_left=32; 00077 s->bit_buf=0; 00078 #endif 00079 } 00080 00084 static inline int put_bits_count(PutBitContext *s) 00085 { 00086 #ifdef ALT_BITSTREAM_WRITER 00087 return s->index; 00088 #else 00089 return (s->buf_ptr - s->buf) * 8 + 32 - s->bit_left; 00090 #endif 00091 } 00092 00096 static inline void flush_put_bits(PutBitContext *s) 00097 { 00098 #ifdef ALT_BITSTREAM_WRITER 00099 align_put_bits(s); 00100 #else 00101 #ifndef BITSTREAM_WRITER_LE 00102 s->bit_buf<<= s->bit_left; 00103 #endif 00104 while (s->bit_left < 32) { 00105 /* XXX: should test end of buffer */ 00106 #ifdef BITSTREAM_WRITER_LE 00107 *s->buf_ptr++=s->bit_buf; 00108 s->bit_buf>>=8; 00109 #else 00110 *s->buf_ptr++=s->bit_buf >> 24; 00111 s->bit_buf<<=8; 00112 #endif 00113 s->bit_left+=8; 00114 } 00115 s->bit_left=32; 00116 s->bit_buf=0; 00117 #endif 00118 } 00119 00120 #if defined(ALT_BITSTREAM_WRITER) || defined(BITSTREAM_WRITER_LE) 00121 #define align_put_bits align_put_bits_unsupported_here 00122 #define ff_put_string ff_put_string_unsupported_here 00123 #define ff_copy_bits ff_copy_bits_unsupported_here 00124 #else 00125 00128 void align_put_bits(PutBitContext *s); 00129 00135 void ff_put_string(PutBitContext *pb, const char *string, int terminate_string); 00136 00142 void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length); 00143 #endif 00144 00149 static inline void put_bits(PutBitContext *s, int n, unsigned int value) 00150 #ifndef ALT_BITSTREAM_WRITER 00151 { 00152 unsigned int bit_buf; 00153 int bit_left; 00154 00155 // printf("put_bits=%d %x\n", n, value); 00156 assert(n <= 31 && value < (1U << n)); 00157 00158 bit_buf = s->bit_buf; 00159 bit_left = s->bit_left; 00160 00161 // printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf); 00162 /* XXX: optimize */ 00163 #ifdef BITSTREAM_WRITER_LE 00164 bit_buf |= value << (32 - bit_left); 00165 if (n >= bit_left) { 00166 #if !HAVE_FAST_UNALIGNED 00167 if (3 & (intptr_t) s->buf_ptr) { 00168 AV_WL32(s->buf_ptr, bit_buf); 00169 } else 00170 #endif 00171 *(uint32_t *)s->buf_ptr = le2me_32(bit_buf); 00172 s->buf_ptr+=4; 00173 bit_buf = (bit_left==32)?0:value >> bit_left; 00174 bit_left+=32; 00175 } 00176 bit_left-=n; 00177 #else 00178 if (n < bit_left) { 00179 bit_buf = (bit_buf<<n) | value; 00180 bit_left-=n; 00181 } else { 00182 bit_buf<<=bit_left; 00183 bit_buf |= value >> (n - bit_left); 00184 #if !HAVE_FAST_UNALIGNED 00185 if (3 & (intptr_t) s->buf_ptr) { 00186 AV_WB32(s->buf_ptr, bit_buf); 00187 } else 00188 #endif 00189 *(uint32_t *)s->buf_ptr = be2me_32(bit_buf); 00190 //printf("bitbuf = %08x\n", bit_buf); 00191 s->buf_ptr+=4; 00192 bit_left+=32 - n; 00193 bit_buf = value; 00194 } 00195 #endif 00196 00197 s->bit_buf = bit_buf; 00198 s->bit_left = bit_left; 00199 } 00200 #else /* ALT_BITSTREAM_WRITER defined */ 00201 { 00202 # ifdef ALIGNED_BITSTREAM_WRITER 00203 # if ARCH_X86 00204 __asm__ volatile( 00205 "movl %0, %%ecx \n\t" 00206 "xorl %%eax, %%eax \n\t" 00207 "shrdl %%cl, %1, %%eax \n\t" 00208 "shrl %%cl, %1 \n\t" 00209 "movl %0, %%ecx \n\t" 00210 "shrl $3, %%ecx \n\t" 00211 "andl $0xFFFFFFFC, %%ecx \n\t" 00212 "bswapl %1 \n\t" 00213 "orl %1, (%2, %%ecx) \n\t" 00214 "bswapl %%eax \n\t" 00215 "addl %3, %0 \n\t" 00216 "movl %%eax, 4(%2, %%ecx) \n\t" 00217 : "=&r" (s->index), "=&r" (value) 00218 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n)) 00219 : "%eax", "%ecx" 00220 ); 00221 # else 00222 int index= s->index; 00223 uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5); 00224 00225 value<<= 32-n; 00226 00227 ptr[0] |= be2me_32(value>>(index&31)); 00228 ptr[1] = be2me_32(value<<(32-(index&31))); 00229 //if(n>24) printf("%d %d\n", n, value); 00230 index+= n; 00231 s->index= index; 00232 # endif 00233 # else //ALIGNED_BITSTREAM_WRITER 00234 # if ARCH_X86 00235 __asm__ volatile( 00236 "movl $7, %%ecx \n\t" 00237 "andl %0, %%ecx \n\t" 00238 "addl %3, %%ecx \n\t" 00239 "negl %%ecx \n\t" 00240 "shll %%cl, %1 \n\t" 00241 "bswapl %1 \n\t" 00242 "movl %0, %%ecx \n\t" 00243 "shrl $3, %%ecx \n\t" 00244 "orl %1, (%%ecx, %2) \n\t" 00245 "addl %3, %0 \n\t" 00246 "movl $0, 4(%%ecx, %2) \n\t" 00247 : "=&r" (s->index), "=&r" (value) 00248 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value) 00249 : "%ecx" 00250 ); 00251 # else 00252 int index= s->index; 00253 uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3)); 00254 00255 ptr[0] |= be2me_32(value<<(32-n-(index&7) )); 00256 ptr[1] = 0; 00257 //if(n>24) printf("%d %d\n", n, value); 00258 index+= n; 00259 s->index= index; 00260 # endif 00261 # endif //!ALIGNED_BITSTREAM_WRITER 00262 } 00263 #endif 00264 00265 static inline void put_sbits(PutBitContext *pb, int n, int32_t value) 00266 { 00267 assert(n >= 0 && n <= 31); 00268 00269 put_bits(pb, n, value & ((1<<n)-1)); 00270 } 00271 00275 static void av_unused put_bits32(PutBitContext *s, uint32_t value) 00276 { 00277 int lo = value & 0xffff; 00278 int hi = value >> 16; 00279 #ifdef BITSTREAM_WRITER_LE 00280 put_bits(s, 16, lo); 00281 put_bits(s, 16, hi); 00282 #else 00283 put_bits(s, 16, hi); 00284 put_bits(s, 16, lo); 00285 #endif 00286 } 00287 00292 static inline uint8_t* put_bits_ptr(PutBitContext *s) 00293 { 00294 #ifdef ALT_BITSTREAM_WRITER 00295 return s->buf + (s->index>>3); 00296 #else 00297 return s->buf_ptr; 00298 #endif 00299 } 00300 00305 static inline void skip_put_bytes(PutBitContext *s, int n) 00306 { 00307 assert((put_bits_count(s)&7)==0); 00308 #ifdef ALT_BITSTREAM_WRITER 00309 FIXME may need some cleaning of the buffer 00310 s->index += n<<3; 00311 #else 00312 assert(s->bit_left==32); 00313 s->buf_ptr += n; 00314 #endif 00315 } 00316 00322 static inline void skip_put_bits(PutBitContext *s, int n) 00323 { 00324 #ifdef ALT_BITSTREAM_WRITER 00325 s->index += n; 00326 #else 00327 s->bit_left -= n; 00328 s->buf_ptr-= 4*(s->bit_left>>5); 00329 s->bit_left &= 31; 00330 #endif 00331 } 00332 00338 static inline void set_put_bits_buffer_size(PutBitContext *s, int size) 00339 { 00340 s->buf_end= s->buf + size; 00341 } 00342 00343 #endif /* AVCODEC_PUT_BITS_H */