libavcodec/utils.c

   1 /*
   2  * utils for libavcodec
   3  * Copyright (c) 2001 Fabrice Bellard.
   4  * Copyright (c) 2003 Michel Bardiaux for the av_log API
   5  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 /**
  23  * @file utils.c
  24  * utils.
  25  */
  26
  27 #include "avcodec.h"
  28 #include "dsputil.h"
  29 #include "mpegvideo.h"
  30 #include "integer.h"
  31 #include <stdarg.h>
  32 #include <limits.h>
  33
  34 const uint8_t ff_sqrt_tab[128]={
  35         0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5,
  36         5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
  37         8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
  38         9, 9, 9, 9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11
  39 };
  40
  41 const uint8_t ff_log2_tab[256]={
  42         0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
  43         5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
  44         6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
  45         6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
  46         7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
  47         7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
  48         7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
  49         7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
  50 };
  51
  52 void avcodec_default_free_buffers(AVCodecContext *s);
  53
  54 void *av_mallocz(unsigned int size)
  55 {
  56     void *ptr;
  57
  58     ptr = av_malloc(size);
  59     if (!ptr)
  60         return NULL;
  61     memset(ptr, 0, size);
  62     return ptr;
  63 }
  64
  65 char *av_strdup(const char *s)
  66 {
  67     char *ptr;
  68     int len;
  69     len = strlen(s) + 1;
  70     ptr = av_malloc(len);
  71     if (!ptr)
  72         return NULL;
  73     memcpy(ptr, s, len);
  74     return ptr;
  75 }
  76
  77 /**
  78  * realloc which does nothing if the block is large enough
  79  */
  80 void *av_fast_realloc(void *ptr, unsigned int *size, unsigned int min_size)
  81 {
  82     if(min_size < *size)
  83         return ptr;
  84
  85     *size= FFMAX(17*min_size/16 + 32, min_size);
  86
  87     return av_realloc(ptr, *size);
  88 }
  89
  90
  91 static unsigned int last_static = 0;
  92 static unsigned int allocated_static = 0;
  93 static void** array_static = NULL;
  94
  95 /**
  96  * allocation of static arrays - do not use for normal allocation.
  97  */
  98 void *av_mallocz_static(unsigned int size)
  99 {
 100     void *ptr = av_mallocz(size);
 101
 102     if(ptr){
 103         array_static =av_fast_realloc(array_static, &allocated_static, sizeof(void*)*(last_static+1));
 104         if(!array_static)
 105             return NULL;
 106         array_static[last_static++] = ptr;
 107     }
 108
 109     return ptr;
 110 }
 111
 112 /**
 113  * same as above, but does realloc
 114  */
 115
 116 void *av_realloc_static(void *ptr, unsigned int size)
 117 {
 118     int i;
 119     if(!ptr)
 120       return av_mallocz_static(size);
 121     /* Look for the old ptr */
 122     for(i = 0; i < last_static; i++) {
 123         if(array_static[i] == ptr) {
 124             array_static[i] = av_realloc(array_static[i], size);
 125             return array_static[i];
 126         }
 127     }
 128     return NULL;
 129
 130 }
 131
 132 /**
 133  * free all static arrays and reset pointers to 0.
 134  */
 135 void av_free_static(void)
 136 {
 137     while(last_static){
 138         av_freep(&array_static[--last_static]);
 139     }
 140     av_freep(&array_static);
 141 }
 142
 143 /**
 144  * Frees memory and sets the pointer to NULL.
 145  * @param arg pointer to the pointer which should be freed
 146  */
 147 void av_freep(void *arg)
 148 {
 149     void **ptr= (void**)arg;
 150     av_free(*ptr);
 151     *ptr = NULL;
 152 }
 153
 154 /* encoder management */
 155 AVCodec *first_avcodec = NULL;
 156
 157 void register_avcodec(AVCodec *format)
 158 {
 159     AVCodec **p;
 160     p = &first_avcodec;
 161     while (*p != NULL) p = &(*p)->next;
 162     *p = format;
 163     format->next = NULL;
 164 }
 165
 166 void avcodec_set_dimensions(AVCodecContext *s, int width, int height){
 167     s->coded_width = width;
 168     s->coded_height= height;
 169     s->width = -((-width )>>s->lowres);
 170     s->height= -((-height)>>s->lowres);
 171 }
 172
 173 typedef struct InternalBuffer{
 174     int last_pic_num;
 175     uint8_t *base[4];
 176     uint8_t *data[4];
 177     int linesize[4];
 178 }InternalBuffer;
 179
 180 #define INTERNAL_BUFFER_SIZE 32
 181
 182 #define ALIGN(x, a) (((x)+(a)-1)&~((a)-1))
 183
 184 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height){
 185     int w_align= 1;
 186     int h_align= 1;
 187
 188     switch(s->pix_fmt){
 189     case PIX_FMT_YUV420P:
 190     case PIX_FMT_YUV422:
 191     case PIX_FMT_UYVY422:
 192     case PIX_FMT_YUV422P:
 193     case PIX_FMT_YUV444P:
 194     case PIX_FMT_GRAY8:
 195     case PIX_FMT_YUVJ420P:
 196     case PIX_FMT_YUVJ422P:
 197     case PIX_FMT_YUVJ444P:
 198         w_align= 16; //FIXME check for non mpeg style codecs and use less alignment
 199         h_align= 16;
 200         break;
 201     case PIX_FMT_YUV411P:
 202     case PIX_FMT_UYVY411:
 203         w_align=32;
 204         h_align=8;
 205         break;
 206     case PIX_FMT_YUV410P:
 207         if(s->codec_id == CODEC_ID_SVQ1){
 208             w_align=64;
 209             h_align=64;
 210         }
 211     case PIX_FMT_RGB555:
 212         if(s->codec_id == CODEC_ID_RPZA){
 213             w_align=4;
 214             h_align=4;
 215         }
 216     case PIX_FMT_PAL8:
 217         if(s->codec_id == CODEC_ID_SMC){
 218             w_align=4;
 219             h_align=4;
 220         }
 221         break;
 222     case PIX_FMT_BGR24:
 223         if((s->codec_id == CODEC_ID_MSZH) || (s->codec_id == CODEC_ID_ZLIB)){
 224             w_align=4;
 225             h_align=4;
 226         }
 227         break;
 228     default:
 229         w_align= 1;
 230         h_align= 1;
 231         break;
 232     }
 233
 234     *width = ALIGN(*width , w_align);
 235     *height= ALIGN(*height, h_align);
 236 }
 237
 238 int avcodec_check_dimensions(void *av_log_ctx, unsigned int w, unsigned int h){
 239     if((int)w>0 && (int)h>0 && (w+128)*(uint64_t)(h+128) < INT_MAX/4)
 240         return 0;
 241
 242     av_log(av_log_ctx, AV_LOG_ERROR, "picture size invalid (%ux%u)\n", w, h);
 243     return -1;
 244 }
 245
 246 int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic){
 247     int i;
 248     int w= s->width;
 249     int h= s->height;
 250     InternalBuffer *buf;
 251     int *picture_number;
 252
 253     assert(pic->data[0]==NULL);
 254     assert(INTERNAL_BUFFER_SIZE > s->internal_buffer_count);
 255
 256     if(avcodec_check_dimensions(s,w,h))
 257         return -1;
 258
 259     if(s->internal_buffer==NULL){
 260         s->internal_buffer= av_mallocz(INTERNAL_BUFFER_SIZE*sizeof(InternalBuffer));
 261     }
 262 #if 0
 263     s->internal_buffer= av_fast_realloc(
 264         s->internal_buffer,
 265         &s->internal_buffer_size,
 266         sizeof(InternalBuffer)*FFMAX(99,  s->internal_buffer_count+1)/*FIXME*/
 267         );
 268 #endif
 269
 270     buf= &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
 271     picture_number= &(((InternalBuffer*)s->internal_buffer)[INTERNAL_BUFFER_SIZE-1]).last_pic_num; //FIXME ugly hack
 272     (*picture_number)++;
 273
 274     if(buf->base[0]){
 275         pic->age= *picture_number - buf->last_pic_num;
 276         buf->last_pic_num= *picture_number;
 277     }else{
 278         int h_chroma_shift, v_chroma_shift;
 279         int pixel_size;
 280
 281         avcodec_get_chroma_sub_sample(s->pix_fmt, &h_chroma_shift, &v_chroma_shift);
 282
 283         switch(s->pix_fmt){
 284         case PIX_FMT_RGB555:
 285         case PIX_FMT_RGB565:
 286         case PIX_FMT_YUV422:
 287         case PIX_FMT_UYVY422:
 288             pixel_size=2;
 289             break;
 290         case PIX_FMT_RGB24:
 291         case PIX_FMT_BGR24:
 292             pixel_size=3;
 293             break;
 294         case PIX_FMT_RGBA32:
 295             pixel_size=4;
 296             break;
 297         default:
 298             pixel_size=1;
 299         }
 300
 301         avcodec_align_dimensions(s, &w, &h);
 302
 303         if(!(s->flags&CODEC_FLAG_EMU_EDGE)){
 304             w+= EDGE_WIDTH*2;
 305             h+= EDGE_WIDTH*2;
 306         }
 307
 308         buf->last_pic_num= -256*256*256*64;
 309
 310         for(i=0; i<3; i++){
 311             const int h_shift= i==0 ? 0 : h_chroma_shift;
 312             const int v_shift= i==0 ? 0 : v_chroma_shift;
 313
 314             //FIXME next ensures that linesize= 2^x uvlinesize, thats needed because some MC code assumes it
 315             buf->linesize[i]= ALIGN(pixel_size*w>>h_shift, STRIDE_ALIGN<<(h_chroma_shift-h_shift));
 316
 317             buf->base[i]= av_mallocz((buf->linesize[i]*h>>v_shift)+16); //FIXME 16
 318             if(buf->base[i]==NULL) return -1;
 319             memset(buf->base[i], 128, buf->linesize[i]*h>>v_shift);
 320
 321             if(s->flags&CODEC_FLAG_EMU_EDGE)
 322                 buf->data[i] = buf->base[i];
 323             else
 324                 buf->data[i] = buf->base[i] + ALIGN((buf->linesize[i]*EDGE_WIDTH>>v_shift) + (EDGE_WIDTH>>h_shift), STRIDE_ALIGN);
 325         }
 326         pic->age= 256*256*256*64;
 327     }
 328     pic->type= FF_BUFFER_TYPE_INTERNAL;
 329
 330     for(i=0; i<4; i++){
 331         pic->base[i]= buf->base[i];
 332         pic->data[i]= buf->data[i];
 333         pic->linesize[i]= buf->linesize[i];
 334     }
 335     s->internal_buffer_count++;
 336
 337     return 0;
 338 }
 339
 340 void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
 341     int i;
 342     InternalBuffer *buf, *last, temp;
 343
 344     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
 345     assert(s->internal_buffer_count);
 346
 347     buf = NULL; /* avoids warning */
 348     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
 349         buf= &((InternalBuffer*)s->internal_buffer)[i];
 350         if(buf->data[0] == pic->data[0])
 351             break;
 352     }
 353     assert(i < s->internal_buffer_count);
 354     s->internal_buffer_count--;
 355     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
 356
 357     temp= *buf;
 358     *buf= *last;
 359     *last= temp;
 360
 361     for(i=0; i<3; i++){
 362         pic->data[i]=NULL;
 363 //        pic->base[i]=NULL;
 364     }
 365 //printf("R%X\n", pic->opaque);
 366 }
 367
 368 int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic){
 369     AVFrame temp_pic;
 370     int i;
 371
 372     /* If no picture return a new buffer */
 373     if(pic->data[0] == NULL) {
 374         /* We will copy from buffer, so must be readable */
 375         pic->buffer_hints |= FF_BUFFER_HINTS_READABLE;
 376         return s->get_buffer(s, pic);
 377     }
 378
 379     /* If internal buffer type return the same buffer */
 380     if(pic->type == FF_BUFFER_TYPE_INTERNAL)
 381         return 0;
 382
 383     /*
 384      * Not internal type and reget_buffer not overridden, emulate cr buffer
 385      */
 386     temp_pic = *pic;
 387     for(i = 0; i < 4; i++)
 388         pic->data[i] = pic->base[i] = NULL;
 389     pic->opaque = NULL;
 390     /* Allocate new frame */
 391     if (s->get_buffer(s, pic))
 392         return -1;
 393     /* Copy image data from old buffer to new buffer */
 394     img_copy((AVPicture*)pic, (AVPicture*)&temp_pic, s->pix_fmt, s->width,
 395              s->height);
 396     s->release_buffer(s, &temp_pic); // Release old frame
 397     return 0;
 398 }
 399
 400 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void **arg, int *ret, int count){
 401     int i;
 402
 403     for(i=0; i<count; i++){
 404         int r= func(c, arg[i]);
 405         if(ret) ret[i]= r;
 406     }
 407     return 0;
 408 }
 409
 410 enum PixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum PixelFormat * fmt){
 411     return fmt[0];
 412 }
 413
 414 static const char* context_to_name(void* ptr) {
 415     AVCodecContext *avc= ptr;
 416
 417     if(avc && avc->codec && avc->codec->name)
 418         return avc->codec->name;
 419     else
 420         return "NULL";
 421 }
 422
 423 static AVClass av_codec_context_class = { "AVCodecContext", context_to_name };
 424
 425 void avcodec_get_context_defaults(AVCodecContext *s){
 426     memset(s, 0, sizeof(AVCodecContext));
 427
 428     s->av_class= &av_codec_context_class;
 429     s->bit_rate= 800*1000;
 430     s->bit_rate_tolerance= s->bit_rate*10;
 431     s->qmin= 2;
 432     s->qmax= 31;
 433     s->mb_qmin= 2;
 434     s->mb_qmax= 31;
 435     s->rc_eq= "tex^qComp";
 436     s->qcompress= 0.5;
 437     s->max_qdiff= 3;
 438     s->b_quant_factor=1.25;
 439     s->b_quant_offset=1.25;
 440     s->i_quant_factor=-0.8;
 441     s->i_quant_offset=0.0;
 442     s->error_concealment= 3;
 443     s->error_resilience= 1;
 444     s->workaround_bugs= FF_BUG_AUTODETECT;
 445     s->frame_rate_base= 1;
 446     s->frame_rate = 25;
 447     s->gop_size= 50;
 448     s->me_method= ME_EPZS;
 449     s->get_buffer= avcodec_default_get_buffer;
 450     s->release_buffer= avcodec_default_release_buffer;
 451     s->get_format= avcodec_default_get_format;
 452     s->execute= avcodec_default_execute;
 453     s->thread_count=1;
 454     s->me_subpel_quality=8;
 455     s->lmin= FF_QP2LAMBDA * s->qmin;
 456     s->lmax= FF_QP2LAMBDA * s->qmax;
 457     s->sample_aspect_ratio= (AVRational){0,1};
 458     s->ildct_cmp= FF_CMP_VSAD;
 459     s->profile= FF_PROFILE_UNKNOWN;
 460     s->level= FF_LEVEL_UNKNOWN;
 461
 462     s->intra_quant_bias= FF_DEFAULT_QUANT_BIAS;
 463     s->inter_quant_bias= FF_DEFAULT_QUANT_BIAS;
 464     s->palctrl = NULL;
 465     s->reget_buffer= avcodec_default_reget_buffer;
 466 }
 467
 468 /**
 469  * allocates a AVCodecContext and set it to defaults.
 470  * this can be deallocated by simply calling free()
 471  */
 472 AVCodecContext *avcodec_alloc_context(void){
 473     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
 474
 475     if(avctx==NULL) return NULL;
 476
 477     avcodec_get_context_defaults(avctx);
 478
 479     return avctx;
 480 }
 481
 482 void avcodec_get_frame_defaults(AVFrame *pic){
 483     memset(pic, 0, sizeof(AVFrame));
 484
 485     pic->pts= AV_NOPTS_VALUE;
 486 }
 487
 488 /**
 489  * allocates a AVPFrame and set it to defaults.
 490  * this can be deallocated by simply calling free()
 491  */
 492 AVFrame *avcodec_alloc_frame(void){
 493     AVFrame *pic= av_malloc(sizeof(AVFrame));
 494
 495     if(pic==NULL) return NULL;
 496
 497     avcodec_get_frame_defaults(pic);
 498
 499     return pic;
 500 }
 501
 502 int avcodec_open(AVCodecContext *avctx, AVCodec *codec)
 503 {
 504     int ret;
 505
 506     if(avctx->codec)
 507         return -1;
 508
 509     avctx->codec = codec;
 510     avctx->codec_id = codec->id;
 511     avctx->frame_number = 0;
 512     if (codec->priv_data_size > 0) {
 513         avctx->priv_data = av_mallocz(codec->priv_data_size);
 514         if (!avctx->priv_data)
 515             return -ENOMEM;
 516     } else {
 517         avctx->priv_data = NULL;
 518     }
 519
 520     if(avctx->coded_width && avctx->coded_height)
 521         avcodec_set_dimensions(avctx, avctx->coded_width, avctx->coded_height);
 522     else if(avctx->width && avctx->height)
 523         avcodec_set_dimensions(avctx, avctx->width, avctx->height);
 524
 525     if((avctx->coded_width||avctx->coded_height) && avcodec_check_dimensions(avctx,avctx->coded_width,avctx->coded_height)){
 526         av_freep(&avctx->priv_data);
 527         return -1;
 528     }
 529
 530     ret = avctx->codec->init(avctx);
 531     if (ret < 0) {
 532         av_freep(&avctx->priv_data);
 533         return ret;
 534     }
 535     return 0;
 536 }
 537
 538 int avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf, int buf_size,
 539                          const short *samples)
 540 {
 541     if(buf_size < FF_MIN_BUFFER_SIZE && 0){
 542         av_log(avctx, AV_LOG_ERROR, "buffer smaller then minimum size\n");
 543         return -1;
 544     }
 545     if((avctx->codec->capabilities & CODEC_CAP_DELAY) || samples){
 546         int ret = avctx->codec->encode(avctx, buf, buf_size, (void *)samples);
 547         avctx->frame_number++;
 548         return ret;
 549     }else
 550         return 0;
 551 }
 552
 553 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
 554                          const AVFrame *pict)
 555 {
 556     if(buf_size < FF_MIN_BUFFER_SIZE){
 557         av_log(avctx, AV_LOG_ERROR, "buffer smaller then minimum size\n");
 558         return -1;
 559     }
 560     if(avcodec_check_dimensions(avctx,avctx->width,avctx->height))
 561         return -1;
 562     if((avctx->codec->capabilities & CODEC_CAP_DELAY) || pict){
 563         int ret = avctx->codec->encode(avctx, buf, buf_size, (void *)pict);
 564         avctx->frame_number++;
 565         emms_c(); //needed to avoid a emms_c() call before every return;
 566
 567         return ret;
 568     }else
 569         return 0;
 570 }
 571
 572 /**
 573  * decode a frame.
 574  * @param buf bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE larger then the actual read bytes
 575  * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
 576  * @param buf_size the size of the buffer in bytes
 577  * @param got_picture_ptr zero if no frame could be decompressed, Otherwise, it is non zero
 578  * @return -1 if error, otherwise return the number of
 579  * bytes used.
 580  */
 581 int avcodec_decode_video(AVCodecContext *avctx, AVFrame *picture,
 582                          int *got_picture_ptr,
 583                          uint8_t *buf, int buf_size)
 584 {
 585     int ret;
 586
 587     *got_picture_ptr= 0;
 588     if((avctx->coded_width||avctx->coded_height) && avcodec_check_dimensions(avctx,avctx->coded_width,avctx->coded_height))
 589         return -1;
 590     ret = avctx->codec->decode(avctx, picture, got_picture_ptr,
 591                                buf, buf_size);
 592
 593     emms_c(); //needed to avoid a emms_c() call before every return;
 594
 595     if (*got_picture_ptr)
 596         avctx->frame_number++;
 597     return ret;
 598 }
 599
 600 /* decode an audio frame. return -1 if error, otherwise return the
 601    *number of bytes used. If no frame could be decompressed,
 602    *frame_size_ptr is zero. Otherwise, it is the decompressed frame
 603    *size in BYTES. */
 604 int avcodec_decode_audio(AVCodecContext *avctx, int16_t *samples,
 605                          int *frame_size_ptr,
 606                          uint8_t *buf, int buf_size)
 607 {
 608     int ret;
 609
 610     *frame_size_ptr= 0;
 611     ret = avctx->codec->decode(avctx, samples, frame_size_ptr,
 612                                buf, buf_size);
 613     avctx->frame_number++;
 614     return ret;
 615 }
 616
 617 int avcodec_close(AVCodecContext *avctx)
 618 {
 619     if (avctx->codec->close)
 620         avctx->codec->close(avctx);
 621     avcodec_default_free_buffers(avctx);
 622     av_freep(&avctx->priv_data);
 623     avctx->codec = NULL;
 624     return 0;
 625 }
 626
 627 AVCodec *avcodec_find_encoder(enum CodecID id)
 628 {
 629     AVCodec *p;
 630     p = first_avcodec;
 631     while (p) {
 632         if (p->encode != NULL && p->id == id)
 633             return p;
 634         p = p->next;
 635     }
 636     return NULL;
 637 }
 638
 639 AVCodec *avcodec_find_encoder_by_name(const char *name)
 640 {
 641     AVCodec *p;
 642     p = first_avcodec;
 643     while (p) {
 644         if (p->encode != NULL && strcmp(name,p->name) == 0)
 645             return p;
 646         p = p->next;
 647     }
 648     return NULL;
 649 }
 650
 651 AVCodec *avcodec_find_decoder(enum CodecID id)
 652 {
 653     AVCodec *p;
 654     p = first_avcodec;
 655     while (p) {
 656         if (p->decode != NULL && p->id == id)
 657             return p;
 658         p = p->next;
 659     }
 660     return NULL;
 661 }
 662
 663 AVCodec *avcodec_find_decoder_by_name(const char *name)
 664 {
 665     AVCodec *p;
 666     p = first_avcodec;
 667     while (p) {
 668         if (p->decode != NULL && strcmp(name,p->name) == 0)
 669             return p;
 670         p = p->next;
 671     }
 672     return NULL;
 673 }
 674
 675 static AVCodec *avcodec_find(enum CodecID id)
 676 {
 677     AVCodec *p;
 678     p = first_avcodec;
 679     while (p) {
 680         if (p->id == id)
 681             return p;
 682         p = p->next;
 683     }
 684     return NULL;
 685 }
 686
 687 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode)
 688 {
 689     const char *codec_name;
 690     AVCodec *p;
 691     char buf1[32];
 692     char channels_str[100];
 693     int bitrate;
 694
 695     if (encode)
 696         p = avcodec_find_encoder(enc->codec_id);
 697     else
 698         p = avcodec_find_decoder(enc->codec_id);
 699
 700     if (p) {
 701         codec_name = p->name;
 702         if (!encode && enc->codec_id == CODEC_ID_MP3) {
 703             if (enc->sub_id == 2)
 704                 codec_name = "mp2";
 705             else if (enc->sub_id == 1)
 706                 codec_name = "mp1";
 707         }
 708     } else if (enc->codec_id == CODEC_ID_MPEG2TS) {
 709         /* fake mpeg2 transport stream codec (currently not
 710            registered) */
 711         codec_name = "mpeg2ts";
 712     } else if (enc->codec_name[0] != '\0') {
 713         codec_name = enc->codec_name;
 714     } else {
 715         /* output avi tags */
 716         if (enc->codec_type == CODEC_TYPE_VIDEO) {
 717             snprintf(buf1, sizeof(buf1), "%c%c%c%c",
 718                      enc->codec_tag & 0xff,
 719                      (enc->codec_tag >> 8) & 0xff,
 720                      (enc->codec_tag >> 16) & 0xff,
 721                      (enc->codec_tag >> 24) & 0xff);
 722         } else {
 723             snprintf(buf1, sizeof(buf1), "0x%04x", enc->codec_tag);
 724         }
 725         codec_name = buf1;
 726     }
 727
 728     switch(enc->codec_type) {
 729     case CODEC_TYPE_VIDEO:
 730         snprintf(buf, buf_size,
 731                  "Video: %s%s",
 732                  codec_name, enc->mb_decision ? " (hq)" : "");
 733         if (enc->codec_id == CODEC_ID_RAWVIDEO) {
 734             snprintf(buf + strlen(buf), buf_size - strlen(buf),
 735                      ", %s",
 736                      avcodec_get_pix_fmt_name(enc->pix_fmt));
 737         }
 738         if (enc->width) {
 739             snprintf(buf + strlen(buf), buf_size - strlen(buf),
 740                      ", %dx%d, %0.2f fps",
 741                      enc->width, enc->height,
 742                      (float)enc->frame_rate / enc->frame_rate_base);
 743         }
 744         if (encode) {
 745             snprintf(buf + strlen(buf), buf_size - strlen(buf),
 746                      ", q=%d-%d", enc->qmin, enc->qmax);
 747         }
 748         bitrate = enc->bit_rate;
 749         break;
 750     case CODEC_TYPE_AUDIO:
 751         snprintf(buf, buf_size,
 752                  "Audio: %s",
 753                  codec_name);
 754         switch (enc->channels) {
 755             case 1:
 756                 strcpy(channels_str, "mono");
 757                 break;
 758             case 2:
 759                 strcpy(channels_str, "stereo");
 760                 break;
 761             case 6:
 762                 strcpy(channels_str, "5:1");
 763                 break;
 764             default:
 765                 sprintf(channels_str, "%d channels", enc->channels);
 766                 break;
 767         }
 768         if (enc->sample_rate) {
 769             snprintf(buf + strlen(buf), buf_size - strlen(buf),
 770                      ", %d Hz, %s",
 771                      enc->sample_rate,
 772                      channels_str);
 773         }
 774
 775         /* for PCM codecs, compute bitrate directly */
 776         switch(enc->codec_id) {
 777         case CODEC_ID_PCM_S16LE:
 778         case CODEC_ID_PCM_S16BE:
 779         case CODEC_ID_PCM_U16LE:
 780         case CODEC_ID_PCM_U16BE:
 781             bitrate = enc->sample_rate * enc->channels * 16;
 782             break;
 783         case CODEC_ID_PCM_S8:
 784         case CODEC_ID_PCM_U8:
 785         case CODEC_ID_PCM_ALAW:
 786         case CODEC_ID_PCM_MULAW:
 787             bitrate = enc->sample_rate * enc->channels * 8;
 788             break;
 789         default:
 790             bitrate = enc->bit_rate;
 791             break;
 792         }
 793         break;
 794     case CODEC_TYPE_DATA:
 795         snprintf(buf, buf_size, "Data: %s", codec_name);
 796         bitrate = enc->bit_rate;
 797         break;
 798     default:
 799         snprintf(buf, buf_size, "Invalid Codec type %d", enc->codec_type);
 800         return;
 801     }
 802     if (encode) {
 803         if (enc->flags & CODEC_FLAG_PASS1)
 804             snprintf(buf + strlen(buf), buf_size - strlen(buf),
 805                      ", pass 1");
 806         if (enc->flags & CODEC_FLAG_PASS2)
 807             snprintf(buf + strlen(buf), buf_size - strlen(buf),
 808                      ", pass 2");
 809     }
 810     if (bitrate != 0) {
 811         snprintf(buf + strlen(buf), buf_size - strlen(buf),
 812                  ", %d kb/s", bitrate / 1000);
 813     }
 814 }
 815
 816 unsigned avcodec_version( void )
 817 {
 818   return LIBAVCODEC_VERSION_INT;
 819 }
 820
 821 unsigned avcodec_build( void )
 822 {
 823   return LIBAVCODEC_BUILD;
 824 }
 825
 826 /* must be called before any other functions */
 827 void avcodec_init(void)
 828 {
 829     static int inited = 0;
 830
 831     if (inited != 0)
 832         return;
 833     inited = 1;
 834
 835     dsputil_static_init();
 836 }
 837
 838 /**
 839  * Flush buffers, should be called when seeking or when swicthing to a different stream.
 840  */
 841 void avcodec_flush_buffers(AVCodecContext *avctx)
 842 {
 843     if(avctx->codec->flush)
 844         avctx->codec->flush(avctx);
 845 }
 846
 847 void avcodec_default_free_buffers(AVCodecContext *s){
 848     int i, j;
 849
 850     if(s->internal_buffer==NULL) return;
 851
 852     for(i=0; i<INTERNAL_BUFFER_SIZE; i++){
 853         InternalBuffer *buf= &((InternalBuffer*)s->internal_buffer)[i];
 854         for(j=0; j<4; j++){
 855             av_freep(&buf->base[j]);
 856             buf->data[j]= NULL;
 857         }
 858     }
 859     av_freep(&s->internal_buffer);
 860
 861     s->internal_buffer_count=0;
 862 }
 863
 864 char av_get_pict_type_char(int pict_type){
 865     switch(pict_type){
 866     case I_TYPE: return 'I';
 867     case P_TYPE: return 'P';
 868     case B_TYPE: return 'B';
 869     case S_TYPE: return 'S';
 870     case SI_TYPE:return 'i';
 871     case SP_TYPE:return 'p';
 872     default:     return '?';
 873     }
 874 }
 875
 876 int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max){
 877     AVRational a0={0,1}, a1={1,0};
 878     int sign= (nom<0) ^ (den<0);
 879     int64_t gcd= ff_gcd(ABS(nom), ABS(den));
 880
 881     nom = ABS(nom)/gcd;
 882     den = ABS(den)/gcd;
 883     if(nom<=max && den<=max){
 884         a1= (AVRational){nom, den};
 885         den=0;
 886     }
 887
 888     while(den){
 889         int64_t x       = nom / den;
 890         int64_t next_den= nom - den*x;
 891         int64_t a2n= x*a1.num + a0.num;
 892         int64_t a2d= x*a1.den + a0.den;
 893
 894         if(a2n > max || a2d > max) break;
 895
 896         a0= a1;
 897         a1= (AVRational){a2n, a2d};
 898         nom= den;
 899         den= next_den;
 900     }
 901     assert(ff_gcd(a1.num, a1.den) == 1);
 902
 903     *dst_nom = sign ? -a1.num : a1.num;
 904     *dst_den = a1.den;
 905
 906     return den==0;
 907 }
 908
 909 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
 910     AVInteger ai;
 911     int64_t r=0;
 912     assert(c > 0);
 913     assert(b >=0);
 914     assert(rnd >=0 && rnd<=5 && rnd!=4);
 915
 916     if(a<0 && a != INT64_MIN) return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd>>1)&1));
 917
 918     if(rnd==AV_ROUND_NEAR_INF) r= c/2;
 919     else if(rnd&1)             r= c-1;
 920
 921     if(b<=INT_MAX && c<=INT_MAX){
 922         if(a<=INT_MAX)
 923             return (a * b + r)/c;
 924         else
 925             return a/c*b + (a%c*b + r)/c;
 926     }
 927
 928     ai= av_mul_i(av_int2i(a), av_int2i(b));
 929     ai= av_add_i(ai, av_int2i(r));
 930
 931     return av_i2int(av_div_i(ai, av_int2i(c)));
 932 }
 933
 934 int64_t av_rescale(int64_t a, int64_t b, int64_t c){
 935     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
 936 }
 937
 938 int64_t ff_gcd(int64_t a, int64_t b){
 939     if(b) return ff_gcd(b, a%b);
 940     else  return a;
 941 }
 942
 943 /* av_log API */
 944
 945 static int av_log_level = AV_LOG_DEBUG;
 946
 947 static void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
 948 {
 949     static int print_prefix=1;
 950     AVClass* avc= ptr ? *(AVClass**)ptr : NULL;
 951     if(level>av_log_level)
 952         return;
 953 #undef fprintf
 954     if(print_prefix && avc) {
 955             fprintf(stderr, "[%s @ %p]", avc->item_name(ptr), avc);
 956     }
 957 #define fprintf please_use_av_log
 958
 959     print_prefix= strstr(fmt, "\n") != NULL;
 960
 961     vfprintf(stderr, fmt, vl);
 962 }
 963
 964 static void (*av_log_callback)(void*, int, const char*, va_list) = av_log_default_callback;
 965
 966 void av_log(void* avcl, int level, const char *fmt, ...)
 967 {
 968     va_list vl;
 969     va_start(vl, fmt);
 970     av_vlog(avcl, level, fmt, vl);
 971     va_end(vl);
 972 }
 973
 974 void av_vlog(void* avcl, int level, const char *fmt, va_list vl)
 975 {
 976     av_log_callback(avcl, level, fmt, vl);
 977 }
 978
 979 int av_log_get_level(void)
 980 {
 981     return av_log_level;
 982 }
 983
 984 void av_log_set_level(int level)
 985 {
 986     av_log_level = level;
 987 }
 988
 989 void av_log_set_callback(void (*callback)(void*, int, const char*, va_list))
 990 {
 991     av_log_callback = callback;
 992 }
 993
 994 #if !defined(HAVE_THREADS)
 995 int avcodec_thread_init(AVCodecContext *s, int thread_count){
 996     return -1;
 997 }
 998 #endif