Statistics
| Branch: | Revision:

ffmpeg / libavformat / nutenc.c @ 831ec935

History | View | Annotate | Download (25.5 KB)

1
/*
2
 * nut muxer
3
 * Copyright (c) 2004-2007 Michael Niedermayer
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg 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 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
#include "libavutil/tree.h"
23
#include "libavcodec/mpegaudiodata.h"
24
#include "nut.h"
25

    
26
static int find_expected_header(AVCodecContext *c, int size, int key_frame, uint8_t out[64]){
27
    int sample_rate= c->sample_rate;
28

    
29
    if(size>4096)
30
        return 0;
31

    
32
    AV_WB24(out, 1);
33

    
34
    if(c->codec_id == CODEC_ID_MPEG4){
35
        if(key_frame){
36
            return 3;
37
        }else{
38
            out[3]= 0xB6;
39
            return 4;
40
        }
41
    }else if(c->codec_id == CODEC_ID_MPEG1VIDEO || c->codec_id == CODEC_ID_MPEG2VIDEO){
42
        return 3;
43
    }else if(c->codec_id == CODEC_ID_H264){
44
        return 3;
45
    }else if(c->codec_id == CODEC_ID_MP3 || c->codec_id == CODEC_ID_MP2){
46
        int lsf, mpeg25, sample_rate_index, bitrate_index, frame_size;
47
        int layer= c->codec_id == CODEC_ID_MP3 ? 3 : 2;
48
        unsigned int header= 0xFFF00000;
49

    
50
        lsf     = sample_rate < (24000+32000)/2;
51
        mpeg25  = sample_rate < (12000+16000)/2;
52
        sample_rate <<= lsf + mpeg25;
53
        if     (sample_rate < (32000 + 44100)/2) sample_rate_index=2;
54
        else if(sample_rate < (44100 + 48000)/2) sample_rate_index=0;
55
        else                                     sample_rate_index=1;
56

    
57
        sample_rate= ff_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25);
58

    
59
        for(bitrate_index=2; bitrate_index<30; bitrate_index++){
60
            frame_size = ff_mpa_bitrate_tab[lsf][layer-1][bitrate_index>>1];
61
            frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1);
62

    
63
            if(frame_size == size)
64
                break;
65
        }
66

    
67
        header |= (!lsf)<<19;
68
        header |= (4-layer)<<17;
69
        header |= 1<<16; //no crc
70
        AV_WB32(out, header);
71
        if(size <= 0)
72
            return 2; //we guess there is no crc, if there is one the user clearly does not care about overhead
73
        if(bitrate_index == 30)
74
            return -1; //something is wrong ...
75

    
76
        header |= (bitrate_index>>1)<<12;
77
        header |= sample_rate_index<<10;
78
        header |= (bitrate_index&1)<<9;
79

    
80
        return 2; //FIXME actually put the needed ones in build_elision_headers()
81
        return 3; //we guess that the private bit is not set
82
//FIXME the above assumptions should be checked, if these turn out false too often something should be done
83
    }
84
    return 0;
85
}
86

    
87
static int find_header_idx(AVFormatContext *s, AVCodecContext *c, int size, int frame_type){
88
    NUTContext *nut = s->priv_data;
89
    uint8_t out[64];
90
    int i;
91
    int len= find_expected_header(c, size, frame_type, out);
92

    
93
//av_log(NULL, AV_LOG_ERROR, "expected_h len=%d size=%d codec_id=%d\n", len, size, c->codec_id);
94

    
95
    for(i=1; i<nut->header_count; i++){
96
        if(   len == nut->header_len[i]
97
           && !memcmp(out, nut->header[i], len)){
98
//    av_log(NULL, AV_LOG_ERROR, "found %d\n", i);
99
            return i;
100
        }
101
    }
102
//    av_log(NULL, AV_LOG_ERROR, "nothing found\n");
103
    return 0;
104
}
105

    
106
static void build_elision_headers(AVFormatContext *s){
107
    NUTContext *nut = s->priv_data;
108
    int i;
109
    //FIXME this is lame
110
    //FIXME write a 2pass mode to find the maximal headers
111
    const static uint8_t headers[][5]={
112
        {3, 0x00, 0x00, 0x01},
113
        {4, 0x00, 0x00, 0x01, 0xB6},
114
        {2, 0xFF, 0xFA}, //mp3+crc
115
        {2, 0xFF, 0xFB}, //mp3
116
        {2, 0xFF, 0xFC}, //mp2+crc
117
        {2, 0xFF, 0xFD}, //mp2
118
    };
119

    
120
    nut->header_count= 7;
121
    for(i=1; i<nut->header_count; i++){
122
        nut->header_len[i]=  headers[i-1][0];
123
        nut->header    [i]= &headers[i-1][1];
124
    }
125
}
126

    
127
static void build_frame_code(AVFormatContext *s){
128
    NUTContext *nut = s->priv_data;
129
    int key_frame, index, pred, stream_id;
130
    int start=1;
131
    int end= 254;
132
    int keyframe_0_esc= s->nb_streams > 2;
133
    int pred_table[10];
134
    FrameCode *ft;
135

    
136
    ft= &nut->frame_code[start];
137
    ft->flags= FLAG_CODED;
138
    ft->size_mul=1;
139
    ft->pts_delta=1;
140
    start++;
141

    
142
    if(keyframe_0_esc){
143
        /* keyframe = 0 escape */
144
        FrameCode *ft= &nut->frame_code[start];
145
        ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
146
        ft->size_mul=1;
147
        start++;
148
    }
149

    
150
    for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
151
        int start2= start + (end-start)*stream_id / s->nb_streams;
152
        int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
153
        AVCodecContext *codec = s->streams[stream_id]->codec;
154
        int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
155
        int intra_only= /*codec->intra_only || */is_audio;
156
        int pred_count;
157

    
158
        for(key_frame=0; key_frame<2; key_frame++){
159
            if(intra_only && keyframe_0_esc && key_frame==0)
160
                continue;
161

    
162
            {
163
                FrameCode *ft= &nut->frame_code[start2];
164
                ft->flags= FLAG_KEY*key_frame;
165
                ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
166
                ft->stream_id= stream_id;
167
                ft->size_mul=1;
168
                if(is_audio)
169
                    ft->header_idx= find_header_idx(s, codec, -1, key_frame);
170
                start2++;
171
            }
172
        }
173

    
174
        key_frame= intra_only;
175
#if 1
176
        if(is_audio){
177
            int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
178
            int pts;
179
            for(pts=0; pts<2; pts++){
180
                for(pred=0; pred<2; pred++){
181
                    FrameCode *ft= &nut->frame_code[start2];
182
                    ft->flags= FLAG_KEY*key_frame;
183
                    ft->stream_id= stream_id;
184
                    ft->size_mul=frame_bytes + 2;
185
                    ft->size_lsb=frame_bytes + pred;
186
                    ft->pts_delta=pts;
187
                    ft->header_idx= find_header_idx(s, codec, frame_bytes + pred, key_frame);
188
                    start2++;
189
                }
190
            }
191
        }else{
192
            FrameCode *ft= &nut->frame_code[start2];
193
            ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
194
            ft->stream_id= stream_id;
195
            ft->size_mul=1;
196
            ft->pts_delta=1;
197
            start2++;
198
        }
199
#endif
200

    
201
        if(codec->has_b_frames){
202
            pred_count=5;
203
            pred_table[0]=-2;
204
            pred_table[1]=-1;
205
            pred_table[2]=1;
206
            pred_table[3]=3;
207
            pred_table[4]=4;
208
        }else if(codec->codec_id == CODEC_ID_VORBIS){
209
            pred_count=3;
210
            pred_table[0]=2;
211
            pred_table[1]=9;
212
            pred_table[2]=16;
213
        }else{
214
            pred_count=1;
215
            pred_table[0]=1;
216
        }
217

    
218
        for(pred=0; pred<pred_count; pred++){
219
            int start3= start2 + (end2-start2)*pred / pred_count;
220
            int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
221

    
222
            for(index=start3; index<end3; index++){
223
                FrameCode *ft= &nut->frame_code[index];
224
                ft->flags= FLAG_KEY*key_frame;
225
                ft->flags|= FLAG_SIZE_MSB;
226
                ft->stream_id= stream_id;
227
//FIXME use single byte size and pred from last
228
                ft->size_mul= end3-start3;
229
                ft->size_lsb= index - start3;
230
                ft->pts_delta= pred_table[pred];
231
                if(is_audio)
232
                    ft->header_idx= find_header_idx(s, codec, -1, key_frame);
233
            }
234
        }
235
    }
236
    memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
237
    nut->frame_code[  0].flags=
238
    nut->frame_code[255].flags=
239
    nut->frame_code['N'].flags= FLAG_INVALID;
240
}
241

    
242
/**
243
 * Gets the length in bytes which is needed to store val as v.
244
 */
245
static int get_length(uint64_t val){
246
    int i=1;
247

    
248
    while(val>>=7)
249
        i++;
250

    
251
    return i;
252
}
253

    
254
static void put_v(ByteIOContext *bc, uint64_t val){
255
    int i= get_length(val);
256

    
257
    while(--i>0)
258
        put_byte(bc, 128 | (val>>(7*i)));
259

    
260
    put_byte(bc, val&127);
261
}
262

    
263
static void put_t(NUTContext *nut, StreamContext *nus, ByteIOContext *bc, uint64_t val){
264
    val *= nut->time_base_count;
265
    val += nus->time_base - nut->time_base;
266
    put_v(bc, val);
267
}
268

    
269
/**
270
 * Stores a string as vb.
271
 */
272
static void put_str(ByteIOContext *bc, const char *string){
273
    int len= strlen(string);
274

    
275
    put_v(bc, len);
276
    put_buffer(bc, string, len);
277
}
278

    
279
static void put_s(ByteIOContext *bc, int64_t val){
280
    put_v(bc, 2*FFABS(val) - (val>0));
281
}
282

    
283
#ifdef TRACE
284
static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
285
    av_log(NULL, AV_LOG_DEBUG, "put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
286

    
287
    put_v(bc, v);
288
}
289

    
290
static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
291
    av_log(NULL, AV_LOG_DEBUG, "put_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
292

    
293
    put_s(bc, v);
294
}
295
#define put_v(bc, v)  put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
296
#define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
297
#endif
298

    
299
//FIXME remove calculate_checksum
300
static void put_packet(NUTContext *nut, ByteIOContext *bc, ByteIOContext *dyn_bc, int calculate_checksum, uint64_t startcode){
301
    uint8_t *dyn_buf=NULL;
302
    int dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
303
    int forw_ptr= dyn_size + 4*calculate_checksum;
304

    
305
    if(forw_ptr > 4096)
306
        init_checksum(bc, ff_crc04C11DB7_update, 0);
307
    put_be64(bc, startcode);
308
    put_v(bc, forw_ptr);
309
    if(forw_ptr > 4096)
310
        put_le32(bc, get_checksum(bc));
311

    
312
    if(calculate_checksum)
313
        init_checksum(bc, ff_crc04C11DB7_update, 0);
314
    put_buffer(bc, dyn_buf, dyn_size);
315
    if(calculate_checksum)
316
        put_le32(bc, get_checksum(bc));
317

    
318
    av_free(dyn_buf);
319
}
320

    
321
static void write_mainheader(NUTContext *nut, ByteIOContext *bc){
322
    int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields, tmp_head_idx;
323
    int64_t tmp_match;
324

    
325
    put_v(bc, 3); /* version */
326
    put_v(bc, nut->avf->nb_streams);
327
    put_v(bc, nut->max_distance);
328
    put_v(bc, nut->time_base_count);
329

    
330
    for(i=0; i<nut->time_base_count; i++){
331
        put_v(bc, nut->time_base[i].num);
332
        put_v(bc, nut->time_base[i].den);
333
    }
334

    
335
    tmp_pts=0;
336
    tmp_mul=1;
337
    tmp_stream=0;
338
    tmp_match= 1-(1LL<<62);
339
    tmp_head_idx= 0;
340
    for(i=0; i<256;){
341
        tmp_fields=0;
342
        tmp_size=0;
343
//        tmp_res=0;
344
        if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
345
        if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
346
        if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
347
        if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
348
//        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
349
        if(tmp_head_idx!=nut->frame_code[i].header_idx)tmp_fields=8;
350

    
351
        tmp_pts   = nut->frame_code[i].pts_delta;
352
        tmp_flags = nut->frame_code[i].flags;
353
        tmp_stream= nut->frame_code[i].stream_id;
354
        tmp_mul   = nut->frame_code[i].size_mul;
355
        tmp_size  = nut->frame_code[i].size_lsb;
356
//        tmp_res   = nut->frame_code[i].res;
357
        tmp_head_idx= nut->frame_code[i].header_idx;
358

    
359
        for(j=0; i<256; j++,i++){
360
            if(i == 'N'){
361
                j--;
362
                continue;
363
            }
364
            if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
365
            if(nut->frame_code[i].flags     != tmp_flags ) break;
366
            if(nut->frame_code[i].stream_id != tmp_stream) break;
367
            if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
368
            if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
369
//            if(nut->frame_code[i].res       != tmp_res   ) break;
370
            if(nut->frame_code[i].header_idx!= tmp_head_idx) break;
371
        }
372
        if(j != tmp_mul - tmp_size) tmp_fields=6;
373

    
374
        put_v(bc, tmp_flags);
375
        put_v(bc, tmp_fields);
376
        if(tmp_fields>0) put_s(bc, tmp_pts);
377
        if(tmp_fields>1) put_v(bc, tmp_mul);
378
        if(tmp_fields>2) put_v(bc, tmp_stream);
379
        if(tmp_fields>3) put_v(bc, tmp_size);
380
        if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
381
        if(tmp_fields>5) put_v(bc, j);
382
        if(tmp_fields>6) put_v(bc, tmp_match);
383
        if(tmp_fields>7) put_v(bc, tmp_head_idx);
384
    }
385
    put_v(bc, nut->header_count-1);
386
    for(i=1; i<nut->header_count; i++){
387
        put_v(bc, nut->header_len[i]);
388
        put_buffer(bc, nut->header[i], nut->header_len[i]);
389
    }
390
}
391

    
392
static int write_streamheader(NUTContext *nut, ByteIOContext *bc, AVCodecContext *codec, int i){
393
    put_v(bc, i);
394
    switch(codec->codec_type){
395
    case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
396
    case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
397
    case CODEC_TYPE_SUBTITLE: put_v(bc, 2); break;
398
    default              : put_v(bc, 3); break;
399
    }
400
    put_v(bc, 4);
401
    if (codec->codec_tag){
402
        put_le32(bc, codec->codec_tag);
403
    }else
404
        return -1;
405

    
406
    put_v(bc, nut->stream[i].time_base - nut->time_base);
407
    put_v(bc, nut->stream[i].msb_pts_shift);
408
    put_v(bc, nut->stream[i].max_pts_distance);
409
    put_v(bc, codec->has_b_frames);
410
    put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
411

    
412
    put_v(bc, codec->extradata_size);
413
    put_buffer(bc, codec->extradata, codec->extradata_size);
414

    
415
    switch(codec->codec_type){
416
    case CODEC_TYPE_AUDIO:
417
        put_v(bc, codec->sample_rate);
418
        put_v(bc, 1);
419
        put_v(bc, codec->channels);
420
        break;
421
    case CODEC_TYPE_VIDEO:
422
        put_v(bc, codec->width);
423
        put_v(bc, codec->height);
424

    
425
        if(codec->sample_aspect_ratio.num<=0 || codec->sample_aspect_ratio.den<=0){
426
            put_v(bc, 0);
427
            put_v(bc, 0);
428
        }else{
429
            put_v(bc, codec->sample_aspect_ratio.num);
430
            put_v(bc, codec->sample_aspect_ratio.den);
431
        }
432
        put_v(bc, 0); /* csp type -- unknown */
433
        break;
434
    default:
435
        break;
436
    }
437
    return 0;
438
}
439

    
440
static int add_info(ByteIOContext *bc, const char *type, const char *value){
441
    put_str(bc, type);
442
    put_s(bc, -1);
443
    put_str(bc, value);
444
    return 1;
445
}
446

    
447
static int write_globalinfo(NUTContext *nut, ByteIOContext *bc){
448
    AVFormatContext *s= nut->avf;
449
    ByteIOContext *dyn_bc;
450
    uint8_t *dyn_buf=NULL;
451
    int count=0, dyn_size;
452
    int ret = url_open_dyn_buf(&dyn_bc);
453
    if(ret < 0)
454
        return ret;
455

    
456
    if(s->title    [0]) count+= add_info(dyn_bc, "Title"    , s->title);
457
    if(s->author   [0]) count+= add_info(dyn_bc, "Author"   , s->author);
458
    if(s->copyright[0]) count+= add_info(dyn_bc, "Copyright", s->copyright);
459
    if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
460
                        count+= add_info(dyn_bc, "Encoder"  , LIBAVFORMAT_IDENT);
461

    
462
    put_v(bc, 0); //stream_if_plus1
463
    put_v(bc, 0); //chapter_id
464
    put_v(bc, 0); //timestamp_start
465
    put_v(bc, 0); //length
466

    
467
    put_v(bc, count);
468

    
469
    dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
470
    put_buffer(bc, dyn_buf, dyn_size);
471
    av_free(dyn_buf);
472
    return 0;
473
}
474

    
475
static int write_streaminfo(NUTContext *nut, ByteIOContext *bc, int stream_id){
476
    AVFormatContext *s= nut->avf;
477
    AVStream* st = s->streams[stream_id];
478
    ByteIOContext *dyn_bc;
479
    uint8_t *dyn_buf=NULL;
480
    int count=0, dyn_size, i;
481
    int ret = url_open_dyn_buf(&dyn_bc);
482
    if(ret < 0)
483
        return ret;
484

    
485
    for (i=0; ff_nut_dispositions[i].flag; ++i) {
486
        if (st->disposition & ff_nut_dispositions[i].flag)
487
            count += add_info(dyn_bc, "Disposition", ff_nut_dispositions[i].str);
488
    }
489
    dyn_size = url_close_dyn_buf(dyn_bc, &dyn_buf);
490

    
491
    if (count) {
492
        put_v(bc, stream_id + 1); //stream_id_plus1
493
        put_v(bc, 0); //chapter_id
494
        put_v(bc, 0); //timestamp_start
495
        put_v(bc, 0); //length
496

    
497
        put_v(bc, count);
498

    
499
        put_buffer(bc, dyn_buf, dyn_size);
500
    }
501

    
502
    av_free(dyn_buf);
503
    return count;
504
}
505

    
506
static int write_headers(NUTContext *nut, ByteIOContext *bc){
507
    ByteIOContext *dyn_bc;
508
    int i, ret;
509

    
510
    ret = url_open_dyn_buf(&dyn_bc);
511
    if(ret < 0)
512
        return ret;
513
    write_mainheader(nut, dyn_bc);
514
    put_packet(nut, bc, dyn_bc, 1, MAIN_STARTCODE);
515

    
516
    for (i=0; i < nut->avf->nb_streams; i++){
517
        AVCodecContext *codec = nut->avf->streams[i]->codec;
518

    
519
        ret = url_open_dyn_buf(&dyn_bc);
520
        if(ret < 0)
521
            return ret;
522
        write_streamheader(nut, dyn_bc, codec, i);
523
        put_packet(nut, bc, dyn_bc, 1, STREAM_STARTCODE);
524
    }
525

    
526
    ret = url_open_dyn_buf(&dyn_bc);
527
    if(ret < 0)
528
        return ret;
529
    write_globalinfo(nut, dyn_bc);
530
    put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
531

    
532
    for (i = 0; i < nut->avf->nb_streams; i++) {
533
        ret = url_open_dyn_buf(&dyn_bc);
534
        if(ret < 0)
535
            return ret;
536
        ret = write_streaminfo(nut, dyn_bc, i);
537
        if (ret < 0)
538
            return ret;
539
        if (ret > 0)
540
            put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
541
        else {
542
            uint8_t* buf;
543
            url_close_dyn_buf(dyn_bc, &buf);
544
            av_free(buf);
545
        }
546
    }
547

    
548
    nut->last_syncpoint_pos= INT_MIN;
549
    nut->header_count++;
550
    return 0;
551
}
552

    
553
static int write_header(AVFormatContext *s){
554
    NUTContext *nut = s->priv_data;
555
    ByteIOContext *bc = s->pb;
556
    int i, j;
557

    
558
    nut->avf= s;
559

    
560
    nut->stream   = av_mallocz(sizeof(StreamContext)*s->nb_streams);
561
    nut->time_base= av_mallocz(sizeof(AVRational   )*s->nb_streams);
562

    
563
    for(i=0; i<s->nb_streams; i++){
564
        AVStream *st= s->streams[i];
565
        int ssize;
566
        AVRational time_base;
567
        ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
568

    
569
        av_set_pts_info(st, 64, time_base.num, time_base.den);
570

    
571
        for(j=0; j<nut->time_base_count; j++){
572
            if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
573
                break;
574
            }
575
        }
576
        nut->time_base[j]= time_base;
577
        nut->stream[i].time_base= &nut->time_base[j];
578
        if(j==nut->time_base_count)
579
            nut->time_base_count++;
580

    
581
        if(av_q2d(time_base) >= 0.001)
582
            nut->stream[i].msb_pts_shift = 7;
583
        else
584
            nut->stream[i].msb_pts_shift = 14;
585
        nut->stream[i].max_pts_distance= FFMAX(1/av_q2d(time_base), 1);
586
    }
587

    
588
    nut->max_distance = MAX_DISTANCE;
589
    build_elision_headers(s);
590
    build_frame_code(s);
591
    assert(nut->frame_code['N'].flags == FLAG_INVALID);
592

    
593
    put_buffer(bc, ID_STRING, strlen(ID_STRING));
594
    put_byte(bc, 0);
595

    
596
    write_headers(nut, bc);
597

    
598
    put_flush_packet(bc);
599

    
600
    //FIXME index
601

    
602
    return 0;
603
}
604

    
605
static int get_needed_flags(NUTContext *nut, StreamContext *nus, FrameCode *fc, AVPacket *pkt){
606
    int flags= 0;
607

    
608
    if(pkt->flags & PKT_FLAG_KEY                ) flags |= FLAG_KEY;
609
    if(pkt->stream_index != fc->stream_id       ) flags |= FLAG_STREAM_ID;
610
    if(pkt->size / fc->size_mul                 ) flags |= FLAG_SIZE_MSB;
611
    if(pkt->pts - nus->last_pts != fc->pts_delta) flags |= FLAG_CODED_PTS;
612
    if(pkt->size > 2*nut->max_distance          ) flags |= FLAG_CHECKSUM;
613
    if(FFABS(pkt->pts - nus->last_pts)
614
                         > nus->max_pts_distance) flags |= FLAG_CHECKSUM;
615
    if(   pkt->size < nut->header_len[fc->header_idx]
616
       || (pkt->size > 4096 && fc->header_idx)
617
       || memcmp(pkt->data, nut->header[fc->header_idx], nut->header_len[fc->header_idx]))
618
                                                  flags |= FLAG_HEADER_IDX;
619

    
620
    return flags | (fc->flags & FLAG_CODED);
621
}
622

    
623
static int find_best_header_idx(NUTContext *nut, AVPacket *pkt){
624
    int i;
625
    int best_i  = 0;
626
    int best_len= 0;
627

    
628
    if(pkt->size > 4096)
629
        return 0;
630

    
631
    for(i=1; i<nut->header_count; i++){
632
        if(   pkt->size >= nut->header_len[i]
633
           &&  nut->header_len[i] > best_len
634
           && !memcmp(pkt->data, nut->header[i], nut->header_len[i])){
635
            best_i= i;
636
            best_len= nut->header_len[i];
637
        }
638
    }
639
    return best_i;
640
}
641

    
642
static int write_packet(AVFormatContext *s, AVPacket *pkt){
643
    NUTContext *nut = s->priv_data;
644
    StreamContext *nus= &nut->stream[pkt->stream_index];
645
    ByteIOContext *bc = s->pb, *dyn_bc;
646
    FrameCode *fc;
647
    int64_t coded_pts;
648
    int best_length, frame_code, flags, needed_flags, i, header_idx, best_header_idx;
649
    int key_frame = !!(pkt->flags & PKT_FLAG_KEY);
650
    int store_sp=0;
651
    int ret;
652

    
653
    if(1LL<<(20+3*nut->header_count) <= url_ftell(bc))
654
        write_headers(nut, bc);
655

    
656
    if(key_frame && !(nus->last_flags & FLAG_KEY))
657
        store_sp= 1;
658

    
659
    if(pkt->size + 30/*FIXME check*/ + url_ftell(bc) >= nut->last_syncpoint_pos + nut->max_distance)
660
        store_sp= 1;
661

    
662
//FIXME: Ensure store_sp is 1 in the first place.
663

    
664
    if(store_sp){
665
        syncpoint_t *sp, dummy= {.pos= INT64_MAX};
666

    
667
        ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
668
        for(i=0; i<s->nb_streams; i++){
669
            AVStream *st= s->streams[i];
670
            int64_t dts_tb = av_rescale_rnd(pkt->dts,
671
                nus->time_base->num * (int64_t)nut->stream[i].time_base->den,
672
                nus->time_base->den * (int64_t)nut->stream[i].time_base->num,
673
                AV_ROUND_DOWN);
674
            int index= av_index_search_timestamp(st, dts_tb, AVSEEK_FLAG_BACKWARD);
675
            if(index>=0) dummy.pos= FFMIN(dummy.pos, st->index_entries[index].pos);
676
        }
677
        if(dummy.pos == INT64_MAX)
678
            dummy.pos= 0;
679
        sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
680

    
681
        nut->last_syncpoint_pos= url_ftell(bc);
682
        ret = url_open_dyn_buf(&dyn_bc);
683
        if(ret < 0)
684
            return ret;
685
        put_t(nut, nus, dyn_bc, pkt->dts);
686
        put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos)>>4 : 0);
687
        put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
688

    
689
        ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0/*unused*/, pkt->dts);
690
    }
691
    assert(nus->last_pts != AV_NOPTS_VALUE);
692

    
693
    coded_pts = pkt->pts & ((1<<nus->msb_pts_shift)-1);
694
    if(ff_lsb2full(nus, coded_pts) != pkt->pts)
695
        coded_pts= pkt->pts + (1<<nus->msb_pts_shift);
696

    
697
    best_header_idx= find_best_header_idx(nut, pkt);
698

    
699
    best_length=INT_MAX;
700
    frame_code= -1;
701
    for(i=0; i<256; i++){
702
        int length= 0;
703
        FrameCode *fc= &nut->frame_code[i];
704
        int flags= fc->flags;
705

    
706
        if(flags & FLAG_INVALID)
707
            continue;
708
        needed_flags= get_needed_flags(nut, nus, fc, pkt);
709

    
710
        if(flags & FLAG_CODED){
711
            length++;
712
            flags = needed_flags;
713
        }
714

    
715
        if((flags & needed_flags) != needed_flags)
716
            continue;
717

    
718
        if((flags ^ needed_flags) & FLAG_KEY)
719
            continue;
720

    
721
        if(flags & FLAG_STREAM_ID)
722
            length+= get_length(pkt->stream_index);
723

    
724
        if(pkt->size % fc->size_mul != fc->size_lsb)
725
            continue;
726
        if(flags & FLAG_SIZE_MSB)
727
            length += get_length(pkt->size / fc->size_mul);
728

    
729
        if(flags & FLAG_CHECKSUM)
730
            length+=4;
731

    
732
        if(flags & FLAG_CODED_PTS)
733
            length += get_length(coded_pts);
734

    
735
        if(   (flags & FLAG_CODED)
736
           && nut->header_len[best_header_idx] > nut->header_len[fc->header_idx]+1){
737
            flags |= FLAG_HEADER_IDX;
738
        }
739

    
740
        if(flags & FLAG_HEADER_IDX){
741
            length += 1 - nut->header_len[best_header_idx];
742
        }else{
743
            length -= nut->header_len[fc->header_idx];
744
        }
745

    
746
        length*=4;
747
        length+= !(flags & FLAG_CODED_PTS);
748
        length+= !(flags & FLAG_CHECKSUM);
749

    
750
        if(length < best_length){
751
            best_length= length;
752
            frame_code=i;
753
        }
754
    }
755
    assert(frame_code != -1);
756
    fc= &nut->frame_code[frame_code];
757
    flags= fc->flags;
758
    needed_flags= get_needed_flags(nut, nus, fc, pkt);
759
    header_idx= fc->header_idx;
760

    
761
    init_checksum(bc, ff_crc04C11DB7_update, 0);
762
    put_byte(bc, frame_code);
763
    if(flags & FLAG_CODED){
764
        put_v(bc, (flags^needed_flags) & ~(FLAG_CODED));
765
        flags = needed_flags;
766
    }
767
    if(flags & FLAG_STREAM_ID)  put_v(bc, pkt->stream_index);
768
    if(flags & FLAG_CODED_PTS)  put_v(bc, coded_pts);
769
    if(flags & FLAG_SIZE_MSB)   put_v(bc, pkt->size / fc->size_mul);
770
    if(flags & FLAG_HEADER_IDX) put_v(bc, header_idx= best_header_idx);
771

    
772
    if(flags & FLAG_CHECKSUM)   put_le32(bc, get_checksum(bc));
773
    else                        get_checksum(bc);
774

    
775
    put_buffer(bc, pkt->data + nut->header_len[header_idx], pkt->size - nut->header_len[header_idx]);
776
    nus->last_flags= flags;
777
    nus->last_pts= pkt->pts;
778

    
779
    //FIXME just store one per syncpoint
780
    if(flags & FLAG_KEY)
781
        av_add_index_entry(
782
            s->streams[pkt->stream_index],
783
            nut->last_syncpoint_pos,
784
            pkt->pts,
785
            0,
786
            0,
787
            AVINDEX_KEYFRAME);
788

    
789
    return 0;
790
}
791

    
792
static int write_trailer(AVFormatContext *s){
793
    NUTContext *nut= s->priv_data;
794
    ByteIOContext *bc= s->pb;
795

    
796
    while(nut->header_count<3)
797
        write_headers(nut, bc);
798
    put_flush_packet(bc);
799

    
800
    return 0;
801
}
802

    
803
AVOutputFormat nut_muxer = {
804
    "nut",
805
    NULL_IF_CONFIG_SMALL("NUT format"),
806
    "video/x-nut",
807
    "nut",
808
    sizeof(NUTContext),
809
#ifdef CONFIG_LIBVORBIS
810
    CODEC_ID_VORBIS,
811
#elif defined(CONFIG_LIBMP3LAME)
812
    CODEC_ID_MP3,
813
#else
814
    CODEC_ID_MP2, /* AC3 needs liba52 decoder */
815
#endif
816
    CODEC_ID_MPEG4,
817
    write_header,
818
    write_packet,
819
    write_trailer,
820
    .flags = AVFMT_GLOBALHEADER,
821
    .codec_tag= (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, ff_nut_subtitle_tags, 0},
822
};