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1
/*
2
 * nut muxer
3
 * Copyright (c) 2004-2007 Michael Niedermayer
4
 *
5
 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
21

    
22
#include "libavutil/intreadwrite.h"
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#include "libavutil/tree.h"
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#include "libavcodec/mpegaudiodata.h"
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#include "nut.h"
26

    
27
static int find_expected_header(AVCodecContext *c, int size, int key_frame, uint8_t out[64]){
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    int sample_rate= c->sample_rate;
29

    
30
    if(size>4096)
31
        return 0;
32

    
33
    AV_WB24(out, 1);
34

    
35
    if(c->codec_id == CODEC_ID_MPEG4){
36
        if(key_frame){
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            return 3;
38
        }else{
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            out[3]= 0xB6;
40
            return 4;
41
        }
42
    }else if(c->codec_id == CODEC_ID_MPEG1VIDEO || c->codec_id == CODEC_ID_MPEG2VIDEO){
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        return 3;
44
    }else if(c->codec_id == CODEC_ID_H264){
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        return 3;
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    }else if(c->codec_id == CODEC_ID_MP3 || c->codec_id == CODEC_ID_MP2){
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        int lsf, mpeg25, sample_rate_index, bitrate_index, frame_size;
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        int layer= c->codec_id == CODEC_ID_MP3 ? 3 : 2;
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        unsigned int header= 0xFFF00000;
50

    
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        lsf     = sample_rate < (24000+32000)/2;
52
        mpeg25  = sample_rate < (12000+16000)/2;
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        sample_rate <<= lsf + mpeg25;
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        if     (sample_rate < (32000 + 44100)/2) sample_rate_index=2;
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        else if(sample_rate < (44100 + 48000)/2) sample_rate_index=0;
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        else                                     sample_rate_index=1;
57

    
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        sample_rate= ff_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25);
59

    
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        for(bitrate_index=2; bitrate_index<30; bitrate_index++){
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            frame_size = ff_mpa_bitrate_tab[lsf][layer-1][bitrate_index>>1];
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            frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1);
63

    
64
            if(frame_size == size)
65
                break;
66
        }
67

    
68
        header |= (!lsf)<<19;
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        header |= (4-layer)<<17;
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        header |= 1<<16; //no crc
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        AV_WB32(out, header);
72
        if(size <= 0)
73
            return 2; //we guess there is no crc, if there is one the user clearly does not care about overhead
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        if(bitrate_index == 30)
75
            return -1; //something is wrong ...
76

    
77
        header |= (bitrate_index>>1)<<12;
78
        header |= sample_rate_index<<10;
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        header |= (bitrate_index&1)<<9;
80

    
81
        return 2; //FIXME actually put the needed ones in build_elision_headers()
82
        return 3; //we guess that the private bit is not set
83
//FIXME the above assumptions should be checked, if these turn out false too often something should be done
84
    }
85
    return 0;
86
}
87

    
88
static int find_header_idx(AVFormatContext *s, AVCodecContext *c, int size, int frame_type){
89
    NUTContext *nut = s->priv_data;
90
    uint8_t out[64];
91
    int i;
92
    int len= find_expected_header(c, size, frame_type, out);
93

    
94
//av_log(NULL, AV_LOG_ERROR, "expected_h len=%d size=%d codec_id=%d\n", len, size, c->codec_id);
95

    
96
    for(i=1; i<nut->header_count; i++){
97
        if(   len == nut->header_len[i]
98
           && !memcmp(out, nut->header[i], len)){
99
//    av_log(NULL, AV_LOG_ERROR, "found %d\n", i);
100
            return i;
101
        }
102
    }
103
//    av_log(NULL, AV_LOG_ERROR, "nothing found\n");
104
    return 0;
105
}
106

    
107
static void build_elision_headers(AVFormatContext *s){
108
    NUTContext *nut = s->priv_data;
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    int i;
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    //FIXME this is lame
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    //FIXME write a 2pass mode to find the maximal headers
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    static const uint8_t headers[][5]={
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        {3, 0x00, 0x00, 0x01},
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        {4, 0x00, 0x00, 0x01, 0xB6},
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        {2, 0xFF, 0xFA}, //mp3+crc
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        {2, 0xFF, 0xFB}, //mp3
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        {2, 0xFF, 0xFC}, //mp2+crc
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        {2, 0xFF, 0xFD}, //mp2
119
    };
120

    
121
    nut->header_count= 7;
122
    for(i=1; i<nut->header_count; i++){
123
        nut->header_len[i]=  headers[i-1][0];
124
        nut->header    [i]= &headers[i-1][1];
125
    }
126
}
127

    
128
static void build_frame_code(AVFormatContext *s){
129
    NUTContext *nut = s->priv_data;
130
    int key_frame, index, pred, stream_id;
131
    int start=1;
132
    int end= 254;
133
    int keyframe_0_esc= s->nb_streams > 2;
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    int pred_table[10];
135
    FrameCode *ft;
136

    
137
    ft= &nut->frame_code[start];
138
    ft->flags= FLAG_CODED;
139
    ft->size_mul=1;
140
    ft->pts_delta=1;
141
    start++;
142

    
143
    if(keyframe_0_esc){
144
        /* keyframe = 0 escape */
145
        FrameCode *ft= &nut->frame_code[start];
146
        ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
147
        ft->size_mul=1;
148
        start++;
149
    }
150

    
151
    for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
152
        int start2= start + (end-start)*stream_id / s->nb_streams;
153
        int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
154
        AVCodecContext *codec = s->streams[stream_id]->codec;
155
        int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
156
        int intra_only= /*codec->intra_only || */is_audio;
157
        int pred_count;
158

    
159
        for(key_frame=0; key_frame<2; key_frame++){
160
            if(intra_only && keyframe_0_esc && key_frame==0)
161
                continue;
162

    
163
            {
164
                FrameCode *ft= &nut->frame_code[start2];
165
                ft->flags= FLAG_KEY*key_frame;
166
                ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
167
                ft->stream_id= stream_id;
168
                ft->size_mul=1;
169
                if(is_audio)
170
                    ft->header_idx= find_header_idx(s, codec, -1, key_frame);
171
                start2++;
172
            }
173
        }
174

    
175
        key_frame= intra_only;
176
#if 1
177
        if(is_audio){
178
            int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
179
            int pts;
180
            for(pts=0; pts<2; pts++){
181
                for(pred=0; pred<2; pred++){
182
                    FrameCode *ft= &nut->frame_code[start2];
183
                    ft->flags= FLAG_KEY*key_frame;
184
                    ft->stream_id= stream_id;
185
                    ft->size_mul=frame_bytes + 2;
186
                    ft->size_lsb=frame_bytes + pred;
187
                    ft->pts_delta=pts;
188
                    ft->header_idx= find_header_idx(s, codec, frame_bytes + pred, key_frame);
189
                    start2++;
190
                }
191
            }
192
        }else{
193
            FrameCode *ft= &nut->frame_code[start2];
194
            ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
195
            ft->stream_id= stream_id;
196
            ft->size_mul=1;
197
            ft->pts_delta=1;
198
            start2++;
199
        }
200
#endif
201

    
202
        if(codec->has_b_frames){
203
            pred_count=5;
204
            pred_table[0]=-2;
205
            pred_table[1]=-1;
206
            pred_table[2]=1;
207
            pred_table[3]=3;
208
            pred_table[4]=4;
209
        }else if(codec->codec_id == CODEC_ID_VORBIS){
210
            pred_count=3;
211
            pred_table[0]=2;
212
            pred_table[1]=9;
213
            pred_table[2]=16;
214
        }else{
215
            pred_count=1;
216
            pred_table[0]=1;
217
        }
218

    
219
        for(pred=0; pred<pred_count; pred++){
220
            int start3= start2 + (end2-start2)*pred / pred_count;
221
            int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
222

    
223
            for(index=start3; index<end3; index++){
224
                FrameCode *ft= &nut->frame_code[index];
225
                ft->flags= FLAG_KEY*key_frame;
226
                ft->flags|= FLAG_SIZE_MSB;
227
                ft->stream_id= stream_id;
228
//FIXME use single byte size and pred from last
229
                ft->size_mul= end3-start3;
230
                ft->size_lsb= index - start3;
231
                ft->pts_delta= pred_table[pred];
232
                if(is_audio)
233
                    ft->header_idx= find_header_idx(s, codec, -1, key_frame);
234
            }
235
        }
236
    }
237
    memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
238
    nut->frame_code[  0].flags=
239
    nut->frame_code[255].flags=
240
    nut->frame_code['N'].flags= FLAG_INVALID;
241
}
242

    
243
/**
244
 * Gets the length in bytes which is needed to store val as v.
245
 */
246
static int get_length(uint64_t val){
247
    int i=1;
248

    
249
    while(val>>=7)
250
        i++;
251

    
252
    return i;
253
}
254

    
255
static void put_v(ByteIOContext *bc, uint64_t val){
256
    int i= get_length(val);
257

    
258
    while(--i>0)
259
        put_byte(bc, 128 | (val>>(7*i)));
260

    
261
    put_byte(bc, val&127);
262
}
263

    
264
static void put_tt(NUTContext *nut, StreamContext *nus, ByteIOContext *bc, uint64_t val){
265
    val *= nut->time_base_count;
266
    val += nus->time_base - nut->time_base;
267
    put_v(bc, val);
268
}
269

    
270
/**
271
 * Stores a string as vb.
272
 */
273
static void put_str(ByteIOContext *bc, const char *string){
274
    int len= strlen(string);
275

    
276
    put_v(bc, len);
277
    put_buffer(bc, string, len);
278
}
279

    
280
static void put_s(ByteIOContext *bc, int64_t val){
281
    put_v(bc, 2*FFABS(val) - (val>0));
282
}
283

    
284
#ifdef TRACE
285
static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
286
    av_log(NULL, AV_LOG_DEBUG, "put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
287

    
288
    put_v(bc, v);
289
}
290

    
291
static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
292
    av_log(NULL, AV_LOG_DEBUG, "put_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
293

    
294
    put_s(bc, v);
295
}
296
#define put_v(bc, v)  put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
297
#define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
298
#endif
299

    
300
//FIXME remove calculate_checksum
301
static void put_packet(NUTContext *nut, ByteIOContext *bc, ByteIOContext *dyn_bc, int calculate_checksum, uint64_t startcode){
302
    uint8_t *dyn_buf=NULL;
303
    int dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
304
    int forw_ptr= dyn_size + 4*calculate_checksum;
305

    
306
    if(forw_ptr > 4096)
307
        init_checksum(bc, ff_crc04C11DB7_update, 0);
308
    put_be64(bc, startcode);
309
    put_v(bc, forw_ptr);
310
    if(forw_ptr > 4096)
311
        put_le32(bc, get_checksum(bc));
312

    
313
    if(calculate_checksum)
314
        init_checksum(bc, ff_crc04C11DB7_update, 0);
315
    put_buffer(bc, dyn_buf, dyn_size);
316
    if(calculate_checksum)
317
        put_le32(bc, get_checksum(bc));
318

    
319
    av_free(dyn_buf);
320
}
321

    
322
static void write_mainheader(NUTContext *nut, ByteIOContext *bc){
323
    int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields, tmp_head_idx;
324
    int64_t tmp_match;
325

    
326
    put_v(bc, 3); /* version */
327
    put_v(bc, nut->avf->nb_streams);
328
    put_v(bc, nut->max_distance);
329
    put_v(bc, nut->time_base_count);
330

    
331
    for(i=0; i<nut->time_base_count; i++){
332
        put_v(bc, nut->time_base[i].num);
333
        put_v(bc, nut->time_base[i].den);
334
    }
335

    
336
    tmp_pts=0;
337
    tmp_mul=1;
338
    tmp_stream=0;
339
    tmp_match= 1-(1LL<<62);
340
    tmp_head_idx= 0;
341
    for(i=0; i<256;){
342
        tmp_fields=0;
343
        tmp_size=0;
344
//        tmp_res=0;
345
        if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
346
        if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
347
        if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
348
        if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
349
//        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
350
        if(tmp_head_idx!=nut->frame_code[i].header_idx)tmp_fields=8;
351

    
352
        tmp_pts   = nut->frame_code[i].pts_delta;
353
        tmp_flags = nut->frame_code[i].flags;
354
        tmp_stream= nut->frame_code[i].stream_id;
355
        tmp_mul   = nut->frame_code[i].size_mul;
356
        tmp_size  = nut->frame_code[i].size_lsb;
357
//        tmp_res   = nut->frame_code[i].res;
358
        tmp_head_idx= nut->frame_code[i].header_idx;
359

    
360
        for(j=0; i<256; j++,i++){
361
            if(i == 'N'){
362
                j--;
363
                continue;
364
            }
365
            if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
366
            if(nut->frame_code[i].flags     != tmp_flags ) break;
367
            if(nut->frame_code[i].stream_id != tmp_stream) break;
368
            if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
369
            if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
370
//            if(nut->frame_code[i].res       != tmp_res   ) break;
371
            if(nut->frame_code[i].header_idx!= tmp_head_idx) break;
372
        }
373
        if(j != tmp_mul - tmp_size) tmp_fields=6;
374

    
375
        put_v(bc, tmp_flags);
376
        put_v(bc, tmp_fields);
377
        if(tmp_fields>0) put_s(bc, tmp_pts);
378
        if(tmp_fields>1) put_v(bc, tmp_mul);
379
        if(tmp_fields>2) put_v(bc, tmp_stream);
380
        if(tmp_fields>3) put_v(bc, tmp_size);
381
        if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
382
        if(tmp_fields>5) put_v(bc, j);
383
        if(tmp_fields>6) put_v(bc, tmp_match);
384
        if(tmp_fields>7) put_v(bc, tmp_head_idx);
385
    }
386
    put_v(bc, nut->header_count-1);
387
    for(i=1; i<nut->header_count; i++){
388
        put_v(bc, nut->header_len[i]);
389
        put_buffer(bc, nut->header[i], nut->header_len[i]);
390
    }
391
}
392

    
393
static int write_streamheader(NUTContext *nut, ByteIOContext *bc, AVStream *st, int i){
394
    AVCodecContext *codec = st->codec;
395
    put_v(bc, i);
396
    switch(codec->codec_type){
397
    case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
398
    case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
399
    case CODEC_TYPE_SUBTITLE: put_v(bc, 2); break;
400
    default              : put_v(bc, 3); break;
401
    }
402
    put_v(bc, 4);
403
    if (codec->codec_tag){
404
        put_le32(bc, codec->codec_tag);
405
    }else
406
        return -1;
407

    
408
    put_v(bc, nut->stream[i].time_base - nut->time_base);
409
    put_v(bc, nut->stream[i].msb_pts_shift);
410
    put_v(bc, nut->stream[i].max_pts_distance);
411
    put_v(bc, codec->has_b_frames);
412
    put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
413

    
414
    put_v(bc, codec->extradata_size);
415
    put_buffer(bc, codec->extradata, codec->extradata_size);
416

    
417
    switch(codec->codec_type){
418
    case CODEC_TYPE_AUDIO:
419
        put_v(bc, codec->sample_rate);
420
        put_v(bc, 1);
421
        put_v(bc, codec->channels);
422
        break;
423
    case CODEC_TYPE_VIDEO:
424
        put_v(bc, codec->width);
425
        put_v(bc, codec->height);
426

    
427
        if(st->sample_aspect_ratio.num<=0 || st->sample_aspect_ratio.den<=0){
428
            put_v(bc, 0);
429
            put_v(bc, 0);
430
        }else{
431
            put_v(bc, st->sample_aspect_ratio.num);
432
            put_v(bc, st->sample_aspect_ratio.den);
433
        }
434
        put_v(bc, 0); /* csp type -- unknown */
435
        break;
436
    default:
437
        break;
438
    }
439
    return 0;
440
}
441

    
442
static int add_info(ByteIOContext *bc, const char *type, const char *value){
443
    put_str(bc, type);
444
    put_s(bc, -1);
445
    put_str(bc, value);
446
    return 1;
447
}
448

    
449
static int write_globalinfo(NUTContext *nut, ByteIOContext *bc){
450
    AVFormatContext *s= nut->avf;
451
    ByteIOContext *dyn_bc;
452
    uint8_t *dyn_buf=NULL;
453
    int count=0, dyn_size;
454
    int ret = url_open_dyn_buf(&dyn_bc);
455
    if(ret < 0)
456
        return ret;
457

    
458
    if(s->title    [0]) count+= add_info(dyn_bc, "Title"    , s->title);
459
    if(s->author   [0]) count+= add_info(dyn_bc, "Author"   , s->author);
460
    if(s->copyright[0]) count+= add_info(dyn_bc, "Copyright", s->copyright);
461
    if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
462
                        count+= add_info(dyn_bc, "Encoder"  , LIBAVFORMAT_IDENT);
463

    
464
    put_v(bc, 0); //stream_if_plus1
465
    put_v(bc, 0); //chapter_id
466
    put_v(bc, 0); //timestamp_start
467
    put_v(bc, 0); //length
468

    
469
    put_v(bc, count);
470

    
471
    dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
472
    put_buffer(bc, dyn_buf, dyn_size);
473
    av_free(dyn_buf);
474
    return 0;
475
}
476

    
477
static int write_streaminfo(NUTContext *nut, ByteIOContext *bc, int stream_id){
478
    AVFormatContext *s= nut->avf;
479
    AVStream* st = s->streams[stream_id];
480
    ByteIOContext *dyn_bc;
481
    uint8_t *dyn_buf=NULL;
482
    int count=0, dyn_size, i;
483
    int ret = url_open_dyn_buf(&dyn_bc);
484
    if(ret < 0)
485
        return ret;
486

    
487
    for (i=0; ff_nut_dispositions[i].flag; ++i) {
488
        if (st->disposition & ff_nut_dispositions[i].flag)
489
            count += add_info(dyn_bc, "Disposition", ff_nut_dispositions[i].str);
490
    }
491
    dyn_size = url_close_dyn_buf(dyn_bc, &dyn_buf);
492

    
493
    if (count) {
494
        put_v(bc, stream_id + 1); //stream_id_plus1
495
        put_v(bc, 0); //chapter_id
496
        put_v(bc, 0); //timestamp_start
497
        put_v(bc, 0); //length
498

    
499
        put_v(bc, count);
500

    
501
        put_buffer(bc, dyn_buf, dyn_size);
502
    }
503

    
504
    av_free(dyn_buf);
505
    return count;
506
}
507

    
508
static int write_headers(NUTContext *nut, ByteIOContext *bc){
509
    ByteIOContext *dyn_bc;
510
    int i, ret;
511

    
512
    ret = url_open_dyn_buf(&dyn_bc);
513
    if(ret < 0)
514
        return ret;
515
    write_mainheader(nut, dyn_bc);
516
    put_packet(nut, bc, dyn_bc, 1, MAIN_STARTCODE);
517

    
518
    for (i=0; i < nut->avf->nb_streams; i++){
519
        ret = url_open_dyn_buf(&dyn_bc);
520
        if(ret < 0)
521
            return ret;
522
        write_streamheader(nut, dyn_bc, nut->avf->streams[i], 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(pkt->pts < 0)
654
        return -1;
655

    
656
    if(1LL<<(20+3*nut->header_count) <= url_ftell(bc))
657
        write_headers(nut, bc);
658

    
659
    if(key_frame && !(nus->last_flags & FLAG_KEY))
660
        store_sp= 1;
661

    
662
    if(pkt->size + 30/*FIXME check*/ + url_ftell(bc) >= nut->last_syncpoint_pos + nut->max_distance)
663
        store_sp= 1;
664

    
665
//FIXME: Ensure store_sp is 1 in the first place.
666

    
667
    if(store_sp){
668
        Syncpoint *sp, dummy= {.pos= INT64_MAX};
669

    
670
        ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
671
        for(i=0; i<s->nb_streams; i++){
672
            AVStream *st= s->streams[i];
673
            int64_t dts_tb = av_rescale_rnd(pkt->dts,
674
                nus->time_base->num * (int64_t)nut->stream[i].time_base->den,
675
                nus->time_base->den * (int64_t)nut->stream[i].time_base->num,
676
                AV_ROUND_DOWN);
677
            int index= av_index_search_timestamp(st, dts_tb, AVSEEK_FLAG_BACKWARD);
678
            if(index>=0) dummy.pos= FFMIN(dummy.pos, st->index_entries[index].pos);
679
        }
680
        if(dummy.pos == INT64_MAX)
681
            dummy.pos= 0;
682
        sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
683

    
684
        nut->last_syncpoint_pos= url_ftell(bc);
685
        ret = url_open_dyn_buf(&dyn_bc);
686
        if(ret < 0)
687
            return ret;
688
        put_tt(nut, nus, dyn_bc, pkt->dts);
689
        put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos)>>4 : 0);
690
        put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
691

    
692
        ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0/*unused*/, pkt->dts);
693
    }
694
    assert(nus->last_pts != AV_NOPTS_VALUE);
695

    
696
    coded_pts = pkt->pts & ((1<<nus->msb_pts_shift)-1);
697
    if(ff_lsb2full(nus, coded_pts) != pkt->pts)
698
        coded_pts= pkt->pts + (1<<nus->msb_pts_shift);
699

    
700
    best_header_idx= find_best_header_idx(nut, pkt);
701

    
702
    best_length=INT_MAX;
703
    frame_code= -1;
704
    for(i=0; i<256; i++){
705
        int length= 0;
706
        FrameCode *fc= &nut->frame_code[i];
707
        int flags= fc->flags;
708

    
709
        if(flags & FLAG_INVALID)
710
            continue;
711
        needed_flags= get_needed_flags(nut, nus, fc, pkt);
712

    
713
        if(flags & FLAG_CODED){
714
            length++;
715
            flags = needed_flags;
716
        }
717

    
718
        if((flags & needed_flags) != needed_flags)
719
            continue;
720

    
721
        if((flags ^ needed_flags) & FLAG_KEY)
722
            continue;
723

    
724
        if(flags & FLAG_STREAM_ID)
725
            length+= get_length(pkt->stream_index);
726

    
727
        if(pkt->size % fc->size_mul != fc->size_lsb)
728
            continue;
729
        if(flags & FLAG_SIZE_MSB)
730
            length += get_length(pkt->size / fc->size_mul);
731

    
732
        if(flags & FLAG_CHECKSUM)
733
            length+=4;
734

    
735
        if(flags & FLAG_CODED_PTS)
736
            length += get_length(coded_pts);
737

    
738
        if(   (flags & FLAG_CODED)
739
           && nut->header_len[best_header_idx] > nut->header_len[fc->header_idx]+1){
740
            flags |= FLAG_HEADER_IDX;
741
        }
742

    
743
        if(flags & FLAG_HEADER_IDX){
744
            length += 1 - nut->header_len[best_header_idx];
745
        }else{
746
            length -= nut->header_len[fc->header_idx];
747
        }
748

    
749
        length*=4;
750
        length+= !(flags & FLAG_CODED_PTS);
751
        length+= !(flags & FLAG_CHECKSUM);
752

    
753
        if(length < best_length){
754
            best_length= length;
755
            frame_code=i;
756
        }
757
    }
758
    assert(frame_code != -1);
759
    fc= &nut->frame_code[frame_code];
760
    flags= fc->flags;
761
    needed_flags= get_needed_flags(nut, nus, fc, pkt);
762
    header_idx= fc->header_idx;
763

    
764
    init_checksum(bc, ff_crc04C11DB7_update, 0);
765
    put_byte(bc, frame_code);
766
    if(flags & FLAG_CODED){
767
        put_v(bc, (flags^needed_flags) & ~(FLAG_CODED));
768
        flags = needed_flags;
769
    }
770
    if(flags & FLAG_STREAM_ID)  put_v(bc, pkt->stream_index);
771
    if(flags & FLAG_CODED_PTS)  put_v(bc, coded_pts);
772
    if(flags & FLAG_SIZE_MSB)   put_v(bc, pkt->size / fc->size_mul);
773
    if(flags & FLAG_HEADER_IDX) put_v(bc, header_idx= best_header_idx);
774

    
775
    if(flags & FLAG_CHECKSUM)   put_le32(bc, get_checksum(bc));
776
    else                        get_checksum(bc);
777

    
778
    put_buffer(bc, pkt->data + nut->header_len[header_idx], pkt->size - nut->header_len[header_idx]);
779
    nus->last_flags= flags;
780
    nus->last_pts= pkt->pts;
781

    
782
    //FIXME just store one per syncpoint
783
    if(flags & FLAG_KEY)
784
        av_add_index_entry(
785
            s->streams[pkt->stream_index],
786
            nut->last_syncpoint_pos,
787
            pkt->pts,
788
            0,
789
            0,
790
            AVINDEX_KEYFRAME);
791

    
792
    return 0;
793
}
794

    
795
static int write_trailer(AVFormatContext *s){
796
    NUTContext *nut= s->priv_data;
797
    ByteIOContext *bc= s->pb;
798

    
799
    while(nut->header_count<3)
800
        write_headers(nut, bc);
801
    put_flush_packet(bc);
802

    
803
    return 0;
804
}
805

    
806
AVOutputFormat nut_muxer = {
807
    "nut",
808
    NULL_IF_CONFIG_SMALL("NUT format"),
809
    "video/x-nut",
810
    "nut",
811
    sizeof(NUTContext),
812
#if   CONFIG_LIBVORBIS
813
    CODEC_ID_VORBIS,
814
#elif CONFIG_LIBMP3LAME
815
    CODEC_ID_MP3,
816
#else
817
    CODEC_ID_MP2,
818
#endif
819
    CODEC_ID_MPEG4,
820
    write_header,
821
    write_packet,
822
    write_trailer,
823
    .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
824
    .codec_tag= (const AVCodecTag* const []){codec_bmp_tags, codec_wav_tags, ff_nut_subtitle_tags, 0},
825
};