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1
/*
2
 * utils for libavcodec
3
 * Copyright (c) 2001 Fabrice Bellard.
4
 * Copyright (c) 2003 Michel Bardiaux for the av_log API
5
 *
6
 * This library is free software; you can redistribute it and/or
7
 * modify it under the terms of the GNU Lesser General Public
8
 * License as published by the Free Software Foundation; either
9
 * version 2 of the License, or (at your option) any later version.
10
 *
11
 * This library is distributed in the hope that it will be useful,
12
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14
 * Lesser General Public License for more details.
15
 *
16
 * You should have received a copy of the GNU Lesser General Public
17
 * License along with this library; if not, write to the Free Software
18
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19
 */
20
 
21
/**
22
 * @file utils.c
23
 * utils.
24
 */
25
 
26
#include "avcodec.h"
27
#include "dsputil.h"
28
#include "mpegvideo.h"
29
#include <stdarg.h>
30

    
31
void *av_mallocz(unsigned int size)
32
{
33
    void *ptr;
34
    
35
    ptr = av_malloc(size);
36
    if (!ptr)
37
        return NULL;
38
    memset(ptr, 0, size);
39
    return ptr;
40
}
41

    
42
char *av_strdup(const char *s)
43
{
44
    char *ptr;
45
    int len;
46
    len = strlen(s) + 1;
47
    ptr = av_malloc(len);
48
    if (!ptr)
49
        return NULL;
50
    memcpy(ptr, s, len);
51
    return ptr;
52
}
53

    
54
/**
55
 * realloc which does nothing if the block is large enough
56
 */
57
void *av_fast_realloc(void *ptr, unsigned int *size, unsigned int min_size)
58
{
59
    if(min_size < *size) 
60
        return ptr;
61
    
62
    *size= min_size + 10*1024;
63

    
64
    return av_realloc(ptr, *size);
65
}
66

    
67

    
68
/* allocation of static arrays - do not use for normal allocation */
69
static unsigned int last_static = 0;
70
static char*** array_static = NULL;
71
static const unsigned int grow_static = 64; // ^2
72
void *__av_mallocz_static(void** location, unsigned int size)
73
{
74
    unsigned int l = (last_static + grow_static) & ~(grow_static - 1);
75
    void *ptr = av_mallocz(size);
76
    if (!ptr)
77
        return NULL;
78

    
79
    if (location)
80
    {
81
        if (l > last_static)
82
            array_static = av_realloc(array_static, l);
83
        array_static[last_static++] = (char**) location;
84
        *location = ptr;
85
    }
86
    return ptr;
87
}
88
/* free all static arrays and reset pointers to 0 */
89
void av_free_static(void)
90
{
91
    if (array_static)
92
    {
93
        unsigned i;
94
        for (i = 0; i < last_static; i++)
95
        {
96
            av_free(*array_static[i]);
97
            *array_static[i] = NULL;
98
        }
99
        av_free(array_static);
100
        array_static = 0;
101
    }
102
    last_static = 0;
103
}
104

    
105
/* cannot call it directly because of 'void **' casting is not automatic */
106
void __av_freep(void **ptr)
107
{
108
    av_free(*ptr);
109
    *ptr = NULL;
110
}
111

    
112
/* encoder management */
113
AVCodec *first_avcodec;
114

    
115
void register_avcodec(AVCodec *format)
116
{
117
    AVCodec **p;
118
    p = &first_avcodec;
119
    while (*p != NULL) p = &(*p)->next;
120
    *p = format;
121
    format->next = NULL;
122
}
123

    
124
typedef struct InternalBuffer{
125
    int last_pic_num;
126
    uint8_t *base[4];
127
    uint8_t *data[4];
128
    int linesize[4];
129
}InternalBuffer;
130

    
131
#define INTERNAL_BUFFER_SIZE 32
132

    
133
#define ALIGN(x, a) (((x)+(a)-1)&~((a)-1))
134

    
135
void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height){
136
    int w_align= 1;    
137
    int h_align= 1;    
138
    
139
    switch(s->pix_fmt){
140
    case PIX_FMT_YUV420P:
141
    case PIX_FMT_YUV422:
142
    case PIX_FMT_YUV422P:
143
    case PIX_FMT_YUV444P:
144
    case PIX_FMT_GRAY8:
145
    case PIX_FMT_YUVJ420P:
146
    case PIX_FMT_YUVJ422P:
147
    case PIX_FMT_YUVJ444P:
148
        w_align= 16; //FIXME check for non mpeg style codecs and use less alignment
149
        h_align= 16;
150
        break;
151
    case PIX_FMT_YUV411P:
152
        w_align=32;
153
        h_align=8;
154
        break;
155
    case PIX_FMT_YUV410P:
156
        if(s->codec_id == CODEC_ID_SVQ1){
157
            w_align=64;
158
            h_align=64;
159
        }
160
        break;
161
    default:
162
        w_align= 1;
163
        h_align= 1;
164
        break;
165
    }
166

    
167
    *width = ALIGN(*width , w_align);
168
    *height= ALIGN(*height, h_align);
169
}
170

    
171
int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic){
172
    int i;
173
    int w= s->width;
174
    int h= s->height;
175
    InternalBuffer *buf;
176
    int *picture_number;
177
    
178
    assert(pic->data[0]==NULL);
179
    assert(INTERNAL_BUFFER_SIZE > s->internal_buffer_count);
180

    
181
    if(s->internal_buffer==NULL){
182
        s->internal_buffer= av_mallocz(INTERNAL_BUFFER_SIZE*sizeof(InternalBuffer));
183
    }
184
#if 0
185
    s->internal_buffer= av_fast_realloc(
186
        s->internal_buffer, 
187
        &s->internal_buffer_size, 
188
        sizeof(InternalBuffer)*FFMAX(99,  s->internal_buffer_count+1)/*FIXME*/
189
        );
190
#endif
191
     
192
    buf= &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
193
    picture_number= &(((InternalBuffer*)s->internal_buffer)[INTERNAL_BUFFER_SIZE-1]).last_pic_num; //FIXME ugly hack
194
    (*picture_number)++;
195
    
196
    if(buf->base[0]){
197
        pic->age= *picture_number - buf->last_pic_num;
198
        buf->last_pic_num= *picture_number;
199
    }else{
200
        int h_chroma_shift, v_chroma_shift;
201
        int s_align, pixel_size;
202
        
203
        avcodec_get_chroma_sub_sample(s->pix_fmt, &h_chroma_shift, &v_chroma_shift);
204
        
205
        switch(s->pix_fmt){
206
        case PIX_FMT_RGB555:
207
        case PIX_FMT_RGB565:
208
        case PIX_FMT_YUV422:
209
            pixel_size=2;
210
            break;
211
        case PIX_FMT_RGB24:
212
        case PIX_FMT_BGR24:
213
            pixel_size=3;
214
            break;
215
        case PIX_FMT_RGBA32:
216
            pixel_size=4;
217
            break;
218
        default:
219
            pixel_size=1;
220
        }
221

    
222
        avcodec_align_dimensions(s, &w, &h);
223
#if defined(ARCH_POWERPC) || defined(HAVE_MMI) //FIXME some cleaner check
224
        s_align= 16;
225
#else
226
        s_align= 8;
227
#endif
228
            
229
        if(!(s->flags&CODEC_FLAG_EMU_EDGE)){
230
            w+= EDGE_WIDTH*2;
231
            h+= EDGE_WIDTH*2;
232
        }
233
        
234
        buf->last_pic_num= -256*256*256*64;
235

    
236
        for(i=0; i<3; i++){
237
            const int h_shift= i==0 ? 0 : h_chroma_shift;
238
            const int v_shift= i==0 ? 0 : v_chroma_shift;
239

    
240
            buf->linesize[i]= ALIGN(pixel_size*w>>h_shift, s_align);
241

    
242
            buf->base[i]= av_mallocz((buf->linesize[i]*h>>v_shift)+16); //FIXME 16
243
            if(buf->base[i]==NULL) return -1;
244
            memset(buf->base[i], 128, buf->linesize[i]*h>>v_shift);
245
        
246
            if(s->flags&CODEC_FLAG_EMU_EDGE)
247
                buf->data[i] = buf->base[i];
248
            else
249
                buf->data[i] = buf->base[i] + ALIGN((buf->linesize[i]*EDGE_WIDTH>>v_shift) + (EDGE_WIDTH>>h_shift), s_align);
250
        }
251
        pic->age= 256*256*256*64;
252
    }
253
    pic->type= FF_BUFFER_TYPE_INTERNAL;
254

    
255
    for(i=0; i<4; i++){
256
        pic->base[i]= buf->base[i];
257
        pic->data[i]= buf->data[i];
258
        pic->linesize[i]= buf->linesize[i];
259
    }
260
    s->internal_buffer_count++;
261

    
262
    return 0;
263
}
264

    
265
void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
266
    int i;
267
    InternalBuffer *buf, *last, temp;
268

    
269
    assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
270
    assert(s->internal_buffer_count);
271

    
272
    buf = NULL; /* avoids warning */
273
    for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
274
        buf= &((InternalBuffer*)s->internal_buffer)[i];
275
        if(buf->data[0] == pic->data[0])
276
            break;
277
    }
278
    assert(i < s->internal_buffer_count);
279
    s->internal_buffer_count--;
280
    last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
281

    
282
    temp= *buf;
283
    *buf= *last;
284
    *last= temp;
285

    
286
    for(i=0; i<3; i++){
287
        pic->data[i]=NULL;
288
//        pic->base[i]=NULL;
289
    }
290
//printf("R%X\n", pic->opaque);
291
}
292

    
293
enum PixelFormat avcodec_default_get_format(struct AVCodecContext *s, enum PixelFormat * fmt){
294
    return fmt[0];
295
}
296

    
297
void avcodec_get_context_defaults(AVCodecContext *s){
298
    s->bit_rate= 800*1000;
299
    s->bit_rate_tolerance= s->bit_rate*10;
300
    s->qmin= 2;
301
    s->qmax= 31;
302
    s->mb_qmin= 2;
303
    s->mb_qmax= 31;
304
    s->rc_eq= "tex^qComp";
305
    s->qcompress= 0.5;
306
    s->max_qdiff= 3;
307
    s->b_quant_factor=1.25;
308
    s->b_quant_offset=1.25;
309
    s->i_quant_factor=-0.8;
310
    s->i_quant_offset=0.0;
311
    s->error_concealment= 3;
312
    s->error_resilience= 1;
313
    s->workaround_bugs= FF_BUG_AUTODETECT;
314
    s->frame_rate_base= 1;
315
    s->frame_rate = 25;
316
    s->gop_size= 50;
317
    s->me_method= ME_EPZS;
318
    s->get_buffer= avcodec_default_get_buffer;
319
    s->release_buffer= avcodec_default_release_buffer;
320
    s->get_format= avcodec_default_get_format;
321
    s->me_subpel_quality=8;
322
    s->lmin= FF_QP2LAMBDA * s->qmin;
323
    s->lmax= FF_QP2LAMBDA * s->qmax;
324
    s->sample_aspect_ratio= (AVRational){0,1};
325
    
326
    s->intra_quant_bias= FF_DEFAULT_QUANT_BIAS;
327
    s->inter_quant_bias= FF_DEFAULT_QUANT_BIAS;
328
    s->palctrl = NULL;
329
    s->cr_available = 0;
330
}
331

    
332
/**
333
 * allocates a AVCodecContext and set it to defaults.
334
 * this can be deallocated by simply calling free() 
335
 */
336
AVCodecContext *avcodec_alloc_context(void){
337
    AVCodecContext *avctx= av_mallocz(sizeof(AVCodecContext));
338
    
339
    if(avctx==NULL) return NULL;
340
    
341
    avcodec_get_context_defaults(avctx);
342
    
343
    return avctx;
344
}
345

    
346
/**
347
 * allocates a AVPFrame and set it to defaults.
348
 * this can be deallocated by simply calling free() 
349
 */
350
AVFrame *avcodec_alloc_frame(void){
351
    AVFrame *pic= av_mallocz(sizeof(AVFrame));
352
    
353
    return pic;
354
}
355

    
356
int avcodec_open(AVCodecContext *avctx, AVCodec *codec)
357
{
358
    int ret;
359

    
360
    if(avctx->codec)
361
        return -1;
362

    
363
    avctx->codec = codec;
364
    avctx->codec_id = codec->id;
365
    avctx->frame_number = 0;
366
    if (codec->priv_data_size > 0) {
367
        avctx->priv_data = av_mallocz(codec->priv_data_size);
368
        if (!avctx->priv_data) 
369
            return -ENOMEM;
370
    } else {
371
        avctx->priv_data = NULL;
372
    }
373
    ret = avctx->codec->init(avctx);
374
    if (ret < 0) {
375
        av_freep(&avctx->priv_data);
376
        return ret;
377
    }
378
    return 0;
379
}
380

    
381
int avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf, int buf_size, 
382
                         const short *samples)
383
{
384
    int ret;
385

    
386
    ret = avctx->codec->encode(avctx, buf, buf_size, (void *)samples);
387
    avctx->frame_number++;
388
    return ret;
389
}
390

    
391
int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size, 
392
                         const AVFrame *pict)
393
{
394
    int ret;
395

    
396
    ret = avctx->codec->encode(avctx, buf, buf_size, (void *)pict);
397
    
398
    emms_c(); //needed to avoid a emms_c() call before every return;
399

    
400
    avctx->frame_number++;
401
    return ret;
402
}
403

    
404
/** 
405
 * decode a frame. 
406
 * @param buf bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE larger then the actual read bytes
407
 * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
408
 * @param buf_size the size of the buffer in bytes
409
 * @param got_picture_ptr zero if no frame could be decompressed, Otherwise, it is non zero
410
 * @return -1 if error, otherwise return the number of
411
 * bytes used. 
412
 */
413
int avcodec_decode_video(AVCodecContext *avctx, AVFrame *picture, 
414
                         int *got_picture_ptr,
415
                         uint8_t *buf, int buf_size)
416
{
417
    int ret;
418
    
419
    ret = avctx->codec->decode(avctx, picture, got_picture_ptr, 
420
                               buf, buf_size);
421

    
422
    emms_c(); //needed to avoid a emms_c() call before every return;
423
    
424
    if (*got_picture_ptr)                           
425
        avctx->frame_number++;
426
    return ret;
427
}
428

    
429
/* decode an audio frame. return -1 if error, otherwise return the
430
   *number of bytes used. If no frame could be decompressed,
431
   *frame_size_ptr is zero. Otherwise, it is the decompressed frame
432
   *size in BYTES. */
433
int avcodec_decode_audio(AVCodecContext *avctx, int16_t *samples, 
434
                         int *frame_size_ptr,
435
                         uint8_t *buf, int buf_size)
436
{
437
    int ret;
438

    
439
    ret = avctx->codec->decode(avctx, samples, frame_size_ptr, 
440
                               buf, buf_size);
441
    avctx->frame_number++;
442
    return ret;
443
}
444

    
445
int avcodec_close(AVCodecContext *avctx)
446
{
447
    if (avctx->codec->close)
448
        avctx->codec->close(avctx);
449
    av_freep(&avctx->priv_data);
450
    avctx->codec = NULL;
451
    return 0;
452
}
453

    
454
AVCodec *avcodec_find_encoder(enum CodecID id)
455
{
456
    AVCodec *p;
457
    p = first_avcodec;
458
    while (p) {
459
        if (p->encode != NULL && p->id == id)
460
            return p;
461
        p = p->next;
462
    }
463
    return NULL;
464
}
465

    
466
AVCodec *avcodec_find_encoder_by_name(const char *name)
467
{
468
    AVCodec *p;
469
    p = first_avcodec;
470
    while (p) {
471
        if (p->encode != NULL && strcmp(name,p->name) == 0)
472
            return p;
473
        p = p->next;
474
    }
475
    return NULL;
476
}
477

    
478
AVCodec *avcodec_find_decoder(enum CodecID id)
479
{
480
    AVCodec *p;
481
    p = first_avcodec;
482
    while (p) {
483
        if (p->decode != NULL && p->id == id)
484
            return p;
485
        p = p->next;
486
    }
487
    return NULL;
488
}
489

    
490
AVCodec *avcodec_find_decoder_by_name(const char *name)
491
{
492
    AVCodec *p;
493
    p = first_avcodec;
494
    while (p) {
495
        if (p->decode != NULL && strcmp(name,p->name) == 0)
496
            return p;
497
        p = p->next;
498
    }
499
    return NULL;
500
}
501

    
502
AVCodec *avcodec_find(enum CodecID id)
503
{
504
    AVCodec *p;
505
    p = first_avcodec;
506
    while (p) {
507
        if (p->id == id)
508
            return p;
509
        p = p->next;
510
    }
511
    return NULL;
512
}
513

    
514
void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode)
515
{
516
    const char *codec_name;
517
    AVCodec *p;
518
    char buf1[32];
519
    char channels_str[100];
520
    int bitrate;
521

    
522
    if (encode)
523
        p = avcodec_find_encoder(enc->codec_id);
524
    else
525
        p = avcodec_find_decoder(enc->codec_id);
526

    
527
    if (p) {
528
        codec_name = p->name;
529
        if (!encode && enc->codec_id == CODEC_ID_MP3) {
530
            if (enc->sub_id == 2)
531
                codec_name = "mp2";
532
            else if (enc->sub_id == 1)
533
                codec_name = "mp1";
534
        }
535
    } else if (enc->codec_id == CODEC_ID_MPEG2TS) {
536
        /* fake mpeg2 transport stream codec (currently not
537
           registered) */
538
        codec_name = "mpeg2ts";
539
    } else if (enc->codec_name[0] != '\0') {
540
        codec_name = enc->codec_name;
541
    } else {
542
        /* output avi tags */
543
        if (enc->codec_type == CODEC_TYPE_VIDEO) {
544
            snprintf(buf1, sizeof(buf1), "%c%c%c%c", 
545
                     enc->codec_tag & 0xff,
546
                     (enc->codec_tag >> 8) & 0xff,
547
                     (enc->codec_tag >> 16) & 0xff,
548
                     (enc->codec_tag >> 24) & 0xff);
549
        } else {
550
            snprintf(buf1, sizeof(buf1), "0x%04x", enc->codec_tag);
551
        }
552
        codec_name = buf1;
553
    }
554

    
555
    switch(enc->codec_type) {
556
    case CODEC_TYPE_VIDEO:
557
        snprintf(buf, buf_size,
558
                 "Video: %s%s",
559
                 codec_name, enc->mb_decision ? " (hq)" : "");
560
        if (enc->codec_id == CODEC_ID_RAWVIDEO) {
561
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
562
                     ", %s",
563
                     avcodec_get_pix_fmt_name(enc->pix_fmt));
564
        }
565
        if (enc->width) {
566
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
567
                     ", %dx%d, %0.2f fps",
568
                     enc->width, enc->height, 
569
                     (float)enc->frame_rate / enc->frame_rate_base);
570
        }
571
        if (encode) {
572
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
573
                     ", q=%d-%d", enc->qmin, enc->qmax);
574
        }
575
        bitrate = enc->bit_rate;
576
        break;
577
    case CODEC_TYPE_AUDIO:
578
        snprintf(buf, buf_size,
579
                 "Audio: %s",
580
                 codec_name);
581
        switch (enc->channels) {
582
            case 1:
583
                strcpy(channels_str, "mono");
584
                break;
585
            case 2:
586
                strcpy(channels_str, "stereo");
587
                break;
588
            case 6:
589
                strcpy(channels_str, "5:1");
590
                break;
591
            default:
592
                sprintf(channels_str, "%d channels", enc->channels);
593
                break;
594
        }
595
        if (enc->sample_rate) {
596
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
597
                     ", %d Hz, %s",
598
                     enc->sample_rate,
599
                     channels_str);
600
        }
601
        
602
        /* for PCM codecs, compute bitrate directly */
603
        switch(enc->codec_id) {
604
        case CODEC_ID_PCM_S16LE:
605
        case CODEC_ID_PCM_S16BE:
606
        case CODEC_ID_PCM_U16LE:
607
        case CODEC_ID_PCM_U16BE:
608
            bitrate = enc->sample_rate * enc->channels * 16;
609
            break;
610
        case CODEC_ID_PCM_S8:
611
        case CODEC_ID_PCM_U8:
612
        case CODEC_ID_PCM_ALAW:
613
        case CODEC_ID_PCM_MULAW:
614
            bitrate = enc->sample_rate * enc->channels * 8;
615
            break;
616
        default:
617
            bitrate = enc->bit_rate;
618
            break;
619
        }
620
        break;
621
    case CODEC_TYPE_DATA:
622
        snprintf(buf, buf_size, "Data: %s", codec_name);
623
        bitrate = enc->bit_rate;
624
        break;
625
    default:
626
        av_abort();
627
    }
628
    if (encode) {
629
        if (enc->flags & CODEC_FLAG_PASS1)
630
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
631
                     ", pass 1");
632
        if (enc->flags & CODEC_FLAG_PASS2)
633
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
634
                     ", pass 2");
635
    }
636
    if (bitrate != 0) {
637
        snprintf(buf + strlen(buf), buf_size - strlen(buf), 
638
                 ", %d kb/s", bitrate / 1000);
639
    }
640
}
641

    
642
unsigned avcodec_version( void )
643
{
644
  return LIBAVCODEC_VERSION_INT;
645
}
646

    
647
unsigned avcodec_build( void )
648
{
649
  return LIBAVCODEC_BUILD;
650
}
651

    
652
/* must be called before any other functions */
653
void avcodec_init(void)
654
{
655
    static int inited = 0;
656

    
657
    if (inited != 0)
658
        return;
659
    inited = 1;
660

    
661
    dsputil_static_init();
662
}
663

    
664
/**
665
 * Flush buffers, should be called when seeking or when swicthing to a different stream.
666
 */
667
void avcodec_flush_buffers(AVCodecContext *avctx)
668
{
669
    if(avctx->codec->flush)
670
        avctx->codec->flush(avctx);
671
}
672

    
673
void avcodec_default_free_buffers(AVCodecContext *s){
674
    int i, j;
675

    
676
    if(s->internal_buffer==NULL) return;
677
    
678
    for(i=0; i<INTERNAL_BUFFER_SIZE; i++){
679
        InternalBuffer *buf= &((InternalBuffer*)s->internal_buffer)[i];
680
        for(j=0; j<4; j++){
681
            av_freep(&buf->base[j]);
682
            buf->data[j]= NULL;
683
        }
684
    }
685
    av_freep(&s->internal_buffer);
686
    
687
    s->internal_buffer_count=0;
688
}
689

    
690
char av_get_pict_type_char(int pict_type){
691
    switch(pict_type){
692
    case I_TYPE: return 'I'; 
693
    case P_TYPE: return 'P'; 
694
    case B_TYPE: return 'B'; 
695
    case S_TYPE: return 'S'; 
696
    case SI_TYPE:return 'i'; 
697
    case SP_TYPE:return 'p'; 
698
    default:     return '?';
699
    }
700
}
701

    
702
int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max){
703
    int exact=1, sign=0;
704
    int64_t gcd;
705

    
706
    assert(den != 0);
707

    
708
    if(den < 0){
709
        den= -den;
710
        nom= -nom;
711
    }
712
    
713
    if(nom < 0){
714
        nom= -nom;
715
        sign= 1;
716
    }
717
    
718
    gcd = ff_gcd(nom, den);
719
    nom /= gcd;
720
    den /= gcd;
721
    
722
    if(nom > max || den > max){
723
        AVRational a0={0,1}, a1={1,0};
724
        exact=0;
725

    
726
        for(;;){
727
            int64_t x= nom / den;
728
            int64_t a2n= x*a1.num + a0.num;
729
            int64_t a2d= x*a1.den + a0.den;
730

    
731
            if(a2n > max || a2d > max) break;
732

    
733
            nom %= den;
734
        
735
            a0= a1;
736
            a1= (AVRational){a2n, a2d};
737
            if(nom==0) break;
738
            x= nom; nom=den; den=x;
739
        }
740
        nom= a1.num;
741
        den= a1.den;
742
    }
743
    
744
    assert(ff_gcd(nom, den) == 1);
745
    
746
    if(sign) nom= -nom;
747
    
748
    *dst_nom = nom;
749
    *dst_den = den;
750
    
751
    return exact;
752
}
753

    
754
int64_t av_rescale(int64_t a, int b, int c){
755
    uint64_t h, l;
756
    assert(c > 0);
757
    assert(b >=0);
758
    
759
    if(a<0) return -av_rescale(-a, b, c);
760
    
761
    h= a>>32;
762
    if(h==0) return a*b/c;
763
    
764
    l= a&0xFFFFFFFF;
765
    l *= b;
766
    h *= b;
767

    
768
    l += (h%c)<<32;
769

    
770
    return ((h/c)<<32) + l/c;
771
}
772

    
773
/* av_log API */
774

    
775
#ifdef AV_LOG_TRAP_PRINTF
776
#undef stderr
777
#undef fprintf
778
#endif
779

    
780
static int av_log_level = AV_LOG_DEBUG;
781

    
782
static void av_log_default_callback(AVCodecContext* avctx, int level, const char* fmt, va_list vl)
783
{
784
    static int print_prefix=1;
785

    
786
    if(level>av_log_level)
787
            return;
788
    if(avctx && print_prefix)
789
        fprintf(stderr, "[%s @ %p]", avctx->codec->name, avctx);
790
        
791
    print_prefix= (int)strstr(fmt, "\n");
792
        
793
    vfprintf(stderr, fmt, vl);
794
}
795

    
796
static void (*av_log_callback)(AVCodecContext*, int, const char*, va_list) = av_log_default_callback;
797

    
798
void av_log(AVCodecContext* avctx, int level, const char *fmt, ...)
799
{
800
    va_list vl;
801
    va_start(vl, fmt);
802
    av_vlog(avctx, level, fmt, vl);
803
    va_end(vl);
804
}
805

    
806
void av_vlog(AVCodecContext* avctx, int level, const char *fmt, va_list vl)
807
{
808
    av_log_callback(avctx, level, fmt, vl);
809
}
810

    
811
int av_log_get_level(void)
812
{
813
    return av_log_level;
814
}
815

    
816
void av_log_set_level(int level)
817
{
818
    av_log_level = level;
819
}
820

    
821
void av_log_set_callback(void (*callback)(AVCodecContext*, int, const char*, va_list))
822
{
823
    av_log_callback = callback;
824
}
825