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ffmpeg / libavformat / flvdec.c @ 63613fe6

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1
/*
2
 * FLV demuxer
3
 * Copyright (c) 2003 The FFmpeg Project
4
 *
5
 * This demuxer will generate a 1 byte extradata for VP6F content.
6
 * It is composed of:
7
 *  - upper 4bits: difference between encoded width and visible width
8
 *  - lower 4bits: difference between encoded height and visible height
9
 *
10
 * This file is part of FFmpeg.
11
 *
12
 * FFmpeg is free software; you can redistribute it and/or
13
 * modify it under the terms of the GNU Lesser General Public
14
 * License as published by the Free Software Foundation; either
15
 * version 2.1 of the License, or (at your option) any later version.
16
 *
17
 * FFmpeg is distributed in the hope that it will be useful,
18
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20
 * Lesser General Public License for more details.
21
 *
22
 * You should have received a copy of the GNU Lesser General Public
23
 * License along with FFmpeg; if not, write to the Free Software
24
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25
 */
26

    
27
#include "libavutil/avstring.h"
28
#include "libavcodec/bytestream.h"
29
#include "libavcodec/mpeg4audio.h"
30
#include "avformat.h"
31
#include "flv.h"
32

    
33
typedef struct {
34
    int wrong_dts; ///< wrong dts due to negative cts
35
} FLVContext;
36

    
37
static int flv_probe(AVProbeData *p)
38
{
39
    const uint8_t *d;
40

    
41
    d = p->buf;
42
    if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0) {
43
        return AVPROBE_SCORE_MAX;
44
    }
45
    return 0;
46
}
47

    
48
/**
49
 * Builds a Speex header.
50
 * This is not needed for the libavcodec libspeex decoder, but is needed for
51
 * stream copy and for decoders which require a header.
52
 */
53
static void flv_build_speex_header(uint8_t *extradata)
54
{
55
    memset(extradata, 0, 80);
56
    bytestream_put_buffer(&extradata, "Speex   ", 8);   // speex_string
57
    bytestream_put_buffer(&extradata, "1.2rc1",   6);   // speex_version
58
    extradata += 14;                                    // speex_version padding
59
    bytestream_put_le32(&extradata,     1);             // speex_version_id
60
    bytestream_put_le32(&extradata,    80);             // header_size
61
    bytestream_put_le32(&extradata, 16000);             // rate
62
    bytestream_put_le32(&extradata,     1);             // mode
63
    bytestream_put_le32(&extradata,     4);             // mode_bitstream_version
64
    bytestream_put_le32(&extradata,     1);             // nb_channels
65
    bytestream_put_le32(&extradata,    -1);             // bitrate
66
    bytestream_put_le32(&extradata,   320);             // frame_size
67
                                                        // vbr = 0
68
                                                        // frames_per_packet = 0
69
                                                        // extra_headers = 0
70
                                                        // reserved1 = 0
71
                                                        // reserved2 = 0
72
}
73

    
74
static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, int flv_codecid) {
75
    AVCodecContext *acodec = astream->codec;
76
    switch(flv_codecid) {
77
        //no distinction between S16 and S8 PCM codec flags
78
        case FLV_CODECID_PCM:
79
            acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_S8 :
80
#if HAVE_BIGENDIAN
81
                                CODEC_ID_PCM_S16BE;
82
#else
83
                                CODEC_ID_PCM_S16LE;
84
#endif
85
            break;
86
        case FLV_CODECID_PCM_LE:
87
            acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_S8 : CODEC_ID_PCM_S16LE; break;
88
        case FLV_CODECID_AAC  : acodec->codec_id = CODEC_ID_AAC;                                    break;
89
        case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF;                              break;
90
        case FLV_CODECID_SPEEX:
91
            acodec->codec_id = CODEC_ID_SPEEX;
92
            acodec->sample_rate = 16000;
93
            acodec->extradata = av_mallocz(80 + FF_INPUT_BUFFER_PADDING_SIZE);
94
            if (acodec->extradata) {
95
                acodec->extradata_size = 80;
96
                flv_build_speex_header(acodec->extradata);
97
            } else {
98
                av_log(s, AV_LOG_WARNING, "Unable to create Speex extradata\n");
99
            }
100
            break;
101
        case FLV_CODECID_MP3  : acodec->codec_id = CODEC_ID_MP3      ; astream->need_parsing = AVSTREAM_PARSE_FULL; break;
102
        case FLV_CODECID_NELLYMOSER_8KHZ_MONO:
103
            acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate
104
        case FLV_CODECID_NELLYMOSER:
105
            acodec->codec_id = CODEC_ID_NELLYMOSER;
106
            break;
107
        default:
108
            av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
109
            acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET;
110
    }
111
}
112

    
113
static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) {
114
    AVCodecContext *vcodec = vstream->codec;
115
    switch(flv_codecid) {
116
        case FLV_CODECID_H263  : vcodec->codec_id = CODEC_ID_FLV1   ; break;
117
        case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break;
118
        case FLV_CODECID_VP6   : vcodec->codec_id = CODEC_ID_VP6F   ;
119
        case FLV_CODECID_VP6A  :
120
            if(flv_codecid == FLV_CODECID_VP6A)
121
                vcodec->codec_id = CODEC_ID_VP6A;
122
            if(vcodec->extradata_size != 1) {
123
                vcodec->extradata_size = 1;
124
                vcodec->extradata = av_malloc(1);
125
            }
126
            vcodec->extradata[0] = get_byte(s->pb);
127
            return 1; // 1 byte body size adjustment for flv_read_packet()
128
        case FLV_CODECID_H264:
129
            vcodec->codec_id = CODEC_ID_H264;
130
            return 3; // not 4, reading packet type will consume one byte
131
        default:
132
            av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid);
133
            vcodec->codec_tag = flv_codecid;
134
    }
135

    
136
    return 0;
137
}
138

    
139
static int amf_get_string(ByteIOContext *ioc, char *buffer, int buffsize) {
140
    int length = get_be16(ioc);
141
    if(length >= buffsize) {
142
        url_fskip(ioc, length);
143
        return -1;
144
    }
145

    
146
    get_buffer(ioc, buffer, length);
147

    
148
    buffer[length] = '\0';
149

    
150
    return length;
151
}
152

    
153
static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) {
154
    AVCodecContext *acodec, *vcodec;
155
    ByteIOContext *ioc;
156
    AMFDataType amf_type;
157
    char str_val[256];
158
    double num_val;
159

    
160
    num_val = 0;
161
    ioc = s->pb;
162

    
163
    amf_type = get_byte(ioc);
164

    
165
    switch(amf_type) {
166
        case AMF_DATA_TYPE_NUMBER:
167
            num_val = av_int2dbl(get_be64(ioc)); break;
168
        case AMF_DATA_TYPE_BOOL:
169
            num_val = get_byte(ioc); break;
170
        case AMF_DATA_TYPE_STRING:
171
            if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
172
                return -1;
173
            break;
174
        case AMF_DATA_TYPE_OBJECT: {
175
            unsigned int keylen;
176

    
177
            while(url_ftell(ioc) < max_pos - 2 && (keylen = get_be16(ioc))) {
178
                url_fskip(ioc, keylen); //skip key string
179
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
180
                    return -1; //if we couldn't skip, bomb out.
181
            }
182
            if(get_byte(ioc) != AMF_END_OF_OBJECT)
183
                return -1;
184
        }
185
            break;
186
        case AMF_DATA_TYPE_NULL:
187
        case AMF_DATA_TYPE_UNDEFINED:
188
        case AMF_DATA_TYPE_UNSUPPORTED:
189
            break; //these take up no additional space
190
        case AMF_DATA_TYPE_MIXEDARRAY:
191
            url_fskip(ioc, 4); //skip 32-bit max array index
192
            while(url_ftell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
193
                //this is the only case in which we would want a nested parse to not skip over the object
194
                if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
195
                    return -1;
196
            }
197
            if(get_byte(ioc) != AMF_END_OF_OBJECT)
198
                return -1;
199
            break;
200
        case AMF_DATA_TYPE_ARRAY: {
201
            unsigned int arraylen, i;
202

    
203
            arraylen = get_be32(ioc);
204
            for(i = 0; i < arraylen && url_ftell(ioc) < max_pos - 1; i++) {
205
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
206
                    return -1; //if we couldn't skip, bomb out.
207
            }
208
        }
209
            break;
210
        case AMF_DATA_TYPE_DATE:
211
            url_fskip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
212
            break;
213
        default: //unsupported type, we couldn't skip
214
            return -1;
215
    }
216

    
217
    if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
218
        acodec = astream ? astream->codec : NULL;
219
        vcodec = vstream ? vstream->codec : NULL;
220

    
221
        if(amf_type == AMF_DATA_TYPE_BOOL) {
222
            av_strlcpy(str_val, num_val > 0 ? "true" : "false", sizeof(str_val));
223
            av_metadata_set(&s->metadata, key, str_val);
224
        } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
225
            snprintf(str_val, sizeof(str_val), "%.f", num_val);
226
            av_metadata_set(&s->metadata, key, str_val);
227
            if(!strcmp(key, "duration")) s->duration = num_val * AV_TIME_BASE;
228
            else if(!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0))
229
                vcodec->bit_rate = num_val * 1024.0;
230
        } else if (amf_type == AMF_DATA_TYPE_STRING)
231
          av_metadata_set(&s->metadata, key, str_val);
232
    }
233

    
234
    return 0;
235
}
236

    
237
static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
238
    AMFDataType type;
239
    AVStream *stream, *astream, *vstream;
240
    ByteIOContext *ioc;
241
    int i;
242
    char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
243

    
244
    astream = NULL;
245
    vstream = NULL;
246
    ioc = s->pb;
247

    
248
    //first object needs to be "onMetaData" string
249
    type = get_byte(ioc);
250
    if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
251
        return -1;
252

    
253
    //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
254
    for(i = 0; i < s->nb_streams; i++) {
255
        stream = s->streams[i];
256
        if     (stream->codec->codec_type == CODEC_TYPE_AUDIO) astream = stream;
257
        else if(stream->codec->codec_type == CODEC_TYPE_VIDEO) vstream = stream;
258
    }
259

    
260
    //parse the second object (we want a mixed array)
261
    if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
262
        return -1;
263

    
264
    return 0;
265
}
266

    
267
static AVStream *create_stream(AVFormatContext *s, int is_audio){
268
    AVStream *st = av_new_stream(s, is_audio);
269
    if (!st)
270
        return NULL;
271
    st->codec->codec_type = is_audio ? CODEC_TYPE_AUDIO : CODEC_TYPE_VIDEO;
272
    av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
273
    return st;
274
}
275

    
276
static int flv_read_header(AVFormatContext *s,
277
                           AVFormatParameters *ap)
278
{
279
    int offset, flags;
280

    
281
    url_fskip(s->pb, 4);
282
    flags = get_byte(s->pb);
283
    /* old flvtool cleared this field */
284
    /* FIXME: better fix needed */
285
    if (!flags) {
286
        flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
287
        av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
288
    }
289

    
290
    if((flags & (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
291
             != (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
292
        s->ctx_flags |= AVFMTCTX_NOHEADER;
293

    
294
    if(flags & FLV_HEADER_FLAG_HASVIDEO){
295
        if(!create_stream(s, 0))
296
            return AVERROR(ENOMEM);
297
    }
298
    if(flags & FLV_HEADER_FLAG_HASAUDIO){
299
        if(!create_stream(s, 1))
300
            return AVERROR(ENOMEM);
301
    }
302

    
303
    offset = get_be32(s->pb);
304
    url_fseek(s->pb, offset, SEEK_SET);
305

    
306
    s->start_time = 0;
307

    
308
    return 0;
309
}
310

    
311
static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
312
{
313
    av_free(st->codec->extradata);
314
    st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
315
    if (!st->codec->extradata)
316
        return AVERROR(ENOMEM);
317
    st->codec->extradata_size = size;
318
    get_buffer(s->pb, st->codec->extradata, st->codec->extradata_size);
319
    return 0;
320
}
321

    
322
static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
323
{
324
    FLVContext *flv = s->priv_data;
325
    int ret, i, type, size, flags, is_audio;
326
    int64_t next, pos;
327
    int64_t dts, pts = AV_NOPTS_VALUE;
328
    AVStream *st = NULL;
329

    
330
 for(;;){
331
    pos = url_ftell(s->pb);
332
    url_fskip(s->pb, 4); /* size of previous packet */
333
    type = get_byte(s->pb);
334
    size = get_be24(s->pb);
335
    dts = get_be24(s->pb);
336
    dts |= get_byte(s->pb) << 24;
337
//    av_log(s, AV_LOG_DEBUG, "type:%d, size:%d, dts:%d\n", type, size, dts);
338
    if (url_feof(s->pb))
339
        return AVERROR_EOF;
340
    url_fskip(s->pb, 3); /* stream id, always 0 */
341
    flags = 0;
342

    
343
    if(size == 0)
344
        continue;
345

    
346
    next= size + url_ftell(s->pb);
347

    
348
    if (type == FLV_TAG_TYPE_AUDIO) {
349
        is_audio=1;
350
        flags = get_byte(s->pb);
351
        size--;
352
    } else if (type == FLV_TAG_TYPE_VIDEO) {
353
        is_audio=0;
354
        flags = get_byte(s->pb);
355
        size--;
356
        if ((flags & 0xf0) == 0x50) /* video info / command frame */
357
            goto skip;
358
    } else {
359
        if (type == FLV_TAG_TYPE_META && size > 13+1+4)
360
            flv_read_metabody(s, next);
361
        else /* skip packet */
362
            av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
363
    skip:
364
        url_fseek(s->pb, next, SEEK_SET);
365
        continue;
366
    }
367

    
368
    /* skip empty data packets */
369
    if (!size)
370
        continue;
371

    
372
    /* now find stream */
373
    for(i=0;i<s->nb_streams;i++) {
374
        st = s->streams[i];
375
        if (st->id == is_audio)
376
            break;
377
    }
378
    if(i == s->nb_streams){
379
        av_log(s, AV_LOG_ERROR, "invalid stream\n");
380
        st= create_stream(s, is_audio);
381
        s->ctx_flags &= ~AVFMTCTX_NOHEADER;
382
    }
383
//    av_log(s, AV_LOG_DEBUG, "%d %X %d \n", is_audio, flags, st->discard);
384
    if(  (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY ||         is_audio))
385
       ||(st->discard >= AVDISCARD_BIDIR  &&  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio))
386
       || st->discard >= AVDISCARD_ALL
387
       ){
388
        url_fseek(s->pb, next, SEEK_SET);
389
        continue;
390
    }
391
    if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
392
        av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME);
393
    break;
394
 }
395

    
396
    // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
397
    if(!url_is_streamed(s->pb) && s->duration==AV_NOPTS_VALUE){
398
        int size;
399
        const int64_t pos= url_ftell(s->pb);
400
        const int64_t fsize= url_fsize(s->pb);
401
        url_fseek(s->pb, fsize-4, SEEK_SET);
402
        size= get_be32(s->pb);
403
        url_fseek(s->pb, fsize-3-size, SEEK_SET);
404
        if(size == get_be24(s->pb) + 11){
405
            s->duration= get_be24(s->pb) * (int64_t)AV_TIME_BASE / 1000;
406
        }
407
        url_fseek(s->pb, pos, SEEK_SET);
408
    }
409

    
410
    if(is_audio){
411
        if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) {
412
            st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
413
            st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
414
            st->codec->bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
415
        }
416
        if(!st->codec->codec_id){
417
            flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK);
418
        }
419
    }else{
420
        size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
421
    }
422

    
423
    if (st->codec->codec_id == CODEC_ID_AAC ||
424
        st->codec->codec_id == CODEC_ID_H264) {
425
        int type = get_byte(s->pb);
426
        size--;
427
        if (st->codec->codec_id == CODEC_ID_H264) {
428
            int32_t cts = (get_be24(s->pb)+0xff800000)^0xff800000; // sign extension
429
            pts = dts + cts;
430
            if (cts < 0) { // dts are wrong
431
                flv->wrong_dts = 1;
432
                av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n");
433
            }
434
            if (flv->wrong_dts)
435
                dts = AV_NOPTS_VALUE;
436
        }
437
        if (type == 0) {
438
            if ((ret = flv_get_extradata(s, st, size)) < 0)
439
                return ret;
440
            if (st->codec->codec_id == CODEC_ID_AAC) {
441
                MPEG4AudioConfig cfg;
442
                ff_mpeg4audio_get_config(&cfg, st->codec->extradata,
443
                                         st->codec->extradata_size);
444
                if (cfg.chan_config > 7)
445
                    return -1;
446
                st->codec->channels = ff_mpeg4audio_channels[cfg.chan_config];
447
                st->codec->sample_rate = cfg.sample_rate;
448
                dprintf(s, "mp4a config channels %d sample rate %d\n",
449
                        st->codec->channels, st->codec->sample_rate);
450
            }
451

    
452
            return AVERROR(EAGAIN);
453
        }
454
    }
455

    
456
    /* skip empty data packets */
457
    if (!size)
458
        return AVERROR(EAGAIN);
459

    
460
    ret= av_get_packet(s->pb, pkt, size);
461
    if (ret < 0) {
462
        return AVERROR(EIO);
463
    }
464
    /* note: we need to modify the packet size here to handle the last
465
       packet */
466
    pkt->size = ret;
467
    pkt->dts = dts;
468
    pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts;
469
    pkt->stream_index = st->index;
470

    
471
    if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY))
472
        pkt->flags |= PKT_FLAG_KEY;
473

    
474
    return ret;
475
}
476

    
477
AVInputFormat flv_demuxer = {
478
    "flv",
479
    NULL_IF_CONFIG_SMALL("FLV format"),
480
    sizeof(FLVContext),
481
    flv_probe,
482
    flv_read_header,
483
    flv_read_packet,
484
    .extensions = "flv",
485
    .value = CODEC_ID_FLV1,
486
};