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ffmpeg / libavformat / flvdec.c @ d2062ff6

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1 d4f5d74a Garrick Meeker
/*
2 7fbde343 Aurelien Jacobs
 * FLV demuxer
3 d4f5d74a Garrick Meeker
 * Copyright (c) 2003 The FFmpeg Project.
4
 *
5 7b94177e Diego Biurrun
 * 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
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 *
10 b78e7197 Diego Biurrun
 * This file is part of FFmpeg.
11
 *
12
 * FFmpeg is free software; you can redistribute it and/or
13 d4f5d74a Garrick Meeker
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
15 b78e7197 Diego Biurrun
 * version 2.1 of the License, or (at your option) any later version.
16 d4f5d74a Garrick Meeker
 *
17 b78e7197 Diego Biurrun
 * FFmpeg is distributed in the hope that it will be useful,
18 d4f5d74a Garrick Meeker
 * 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 b78e7197 Diego Biurrun
 * License along with FFmpeg; if not, write to the Free Software
24 5509bffa Diego Biurrun
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 d4f5d74a Garrick Meeker
 */
26
#include "avformat.h"
27 6cac3a3b Allan Hsu
#include "flv.h"
28 d4f5d74a Garrick Meeker
29
static int flv_probe(AVProbeData *p)
30
{
31
    const uint8_t *d;
32
33
    d = p->buf;
34 74248229 Michael Niedermayer
    if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0) {
35
        return AVPROBE_SCORE_MAX;
36 d4f5d74a Garrick Meeker
    }
37
    return 0;
38
}
39
40 428cc588 Allan Hsu
static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, int flv_codecid) {
41
    AVCodecContext *acodec = astream->codec;
42
    switch(flv_codecid) {
43
        //no distinction between S16 and S8 PCM codec flags
44
        case FLV_CODECID_PCM_BE:
45
            acodec->codec_id = acodec->bits_per_sample == 8 ? CODEC_ID_PCM_S8 : CODEC_ID_PCM_S16BE; break;
46
        case FLV_CODECID_PCM_LE:
47
            acodec->codec_id = acodec->bits_per_sample == 8 ? CODEC_ID_PCM_S8 : CODEC_ID_PCM_S16LE; break;
48
        case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF;                              break;
49 57004ff1 Aurelien Jacobs
        case FLV_CODECID_MP3  : acodec->codec_id = CODEC_ID_MP3      ; astream->need_parsing = AVSTREAM_PARSE_FULL; break;
50 428cc588 Allan Hsu
        case FLV_CODECID_NELLYMOSER_8HZ_MONO:
51
            acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate
52
        case FLV_CODECID_NELLYMOSER:
53
        default:
54
            av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
55
            acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET;
56
    }
57
}
58
59
static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) {
60
    AVCodecContext *vcodec = vstream->codec;
61
    switch(flv_codecid) {
62
        case FLV_CODECID_H263  : vcodec->codec_id = CODEC_ID_FLV1   ; break;
63
        case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break;
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        case FLV_CODECID_VP6   : vcodec->codec_id = CODEC_ID_VP6F   ;
65
            if(vcodec->extradata_size != 1) {
66
                vcodec->extradata_size = 1;
67
                vcodec->extradata = av_malloc(1);
68
            }
69
            vcodec->extradata[0] = get_byte(&s->pb);
70
            return 1; // 1 byte body size adjustment for flv_read_packet()
71
        default:
72
            av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid);
73
            vcodec->codec_tag = flv_codecid;
74
    }
75
76
    return 0;
77
}
78
79 896bcd2e Michael Niedermayer
static int amf_get_string(ByteIOContext *ioc, char *buffer, int buffsize) {
80 759dd138 Michael Niedermayer
    int length = get_be16(ioc);
81 896bcd2e Michael Niedermayer
    if(length >= buffsize) {
82
        url_fskip(ioc, length);
83 759dd138 Michael Niedermayer
        return -1;
84 896bcd2e Michael Niedermayer
    }
85
86
    get_buffer(ioc, buffer, length);
87
88
    buffer[length] = '\0';
89
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    return length;
91
}
92
93 428cc588 Allan Hsu
static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, unsigned int max_pos, int depth) {
94
    AVCodecContext *acodec, *vcodec;
95
    ByteIOContext *ioc;
96
    AMFDataType amf_type;
97
    char str_val[256];
98
    double num_val;
99
100
    num_val = 0;
101
    ioc = &s->pb;
102
103
    amf_type = get_byte(ioc);
104
105
    switch(amf_type) {
106
        case AMF_DATA_TYPE_NUMBER:
107
            num_val = av_int2dbl(get_be64(ioc)); break;
108
        case AMF_DATA_TYPE_BOOL:
109
            num_val = get_byte(ioc); break;
110
        case AMF_DATA_TYPE_STRING:
111
            if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
112
                return -1;
113
            break;
114
        case AMF_DATA_TYPE_OBJECT: {
115
            unsigned int keylen;
116
117
            while(url_ftell(ioc) < max_pos - 2 && (keylen = get_be16(ioc))) {
118
                url_fskip(ioc, keylen); //skip key string
119
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
120
                    return -1; //if we couldn't skip, bomb out.
121
            }
122
            if(get_byte(ioc) != AMF_END_OF_OBJECT)
123
                return -1;
124
        }
125
            break;
126
        case AMF_DATA_TYPE_NULL:
127
        case AMF_DATA_TYPE_UNDEFINED:
128
        case AMF_DATA_TYPE_UNSUPPORTED:
129
            break; //these take up no additional space
130
        case AMF_DATA_TYPE_MIXEDARRAY:
131
            url_fskip(ioc, 4); //skip 32-bit max array index
132
            while(url_ftell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
133
                //this is the only case in which we would want a nested parse to not skip over the object
134
                if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
135
                    return -1;
136
            }
137
            if(get_byte(ioc) != AMF_END_OF_OBJECT)
138
                return -1;
139
            break;
140
        case AMF_DATA_TYPE_ARRAY: {
141
            unsigned int arraylen, i;
142
143
            arraylen = get_be32(ioc);
144
            for(i = 0; i < arraylen && url_ftell(ioc) < max_pos - 1; i++) {
145
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
146
                    return -1; //if we couldn't skip, bomb out.
147
            }
148
        }
149
            break;
150
        case AMF_DATA_TYPE_DATE:
151
            url_fskip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
152
            break;
153
        default: //unsupported type, we couldn't skip
154
            return -1;
155
    }
156
157
    if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
158
        acodec = astream ? astream->codec : NULL;
159
        vcodec = vstream ? vstream->codec : NULL;
160
161
        if(amf_type == AMF_DATA_TYPE_BOOL) {
162
            if(!strcmp(key, "stereo") && acodec) acodec->channels = num_val > 0 ? 2 : 1;
163
        } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
164
            if(!strcmp(key, "duration")) s->duration = num_val * AV_TIME_BASE;
165 683ab79c Michael Niedermayer
//            else if(!strcmp(key, "width")  && vcodec && num_val > 0) vcodec->width  = num_val;
166
//            else if(!strcmp(key, "height") && vcodec && num_val > 0) vcodec->height = num_val;
167 428cc588 Allan Hsu
            else if(!strcmp(key, "audiocodecid") && acodec) flv_set_audio_codec(s, astream, (int)num_val << FLV_AUDIO_CODECID_OFFSET);
168
            else if(!strcmp(key, "videocodecid") && vcodec) flv_set_video_codec(s, vstream, (int)num_val);
169
            else if(!strcmp(key, "audiosamplesize") && acodec && num_val >= 0) {
170
                acodec->bits_per_sample = num_val;
171
                //we may have to rewrite a previously read codecid because FLV only marks PCM endianness.
172
                if(num_val == 8 && (acodec->codec_id == CODEC_ID_PCM_S16BE || acodec->codec_id == CODEC_ID_PCM_S16LE))
173
                    acodec->codec_id = CODEC_ID_PCM_S8;
174
            }
175
            else if(!strcmp(key, "audiosamplerate") && acodec && num_val >= 0) {
176
                //some tools, like FLVTool2, write consistently approximate metadata sample rates
177
                switch((int)num_val) {
178
                    case 44000: acodec->sample_rate = 44100  ; break;
179
                    case 22000: acodec->sample_rate = 22050  ; break;
180
                    case 11000: acodec->sample_rate = 11025  ; break;
181
                    case 5000 : acodec->sample_rate = 5512   ; break;
182
                    default   : acodec->sample_rate = num_val;
183
                }
184
            }
185
        }
186
    }
187
188
    return 0;
189
}
190
191
static int flv_read_metabody(AVFormatContext *s, unsigned int next_pos) {
192
    AMFDataType type;
193
    AVStream *stream, *astream, *vstream;
194
    ByteIOContext *ioc;
195
    int i, keylen;
196
    char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
197
198
    astream = NULL;
199
    vstream = NULL;
200
    keylen = 0;
201
    ioc = &s->pb;
202
203
    //first object needs to be "onMetaData" string
204
    type = get_byte(ioc);
205
    if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
206
        return -1;
207
208
    //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
209
    for(i = 0; i < s->nb_streams; i++) {
210
        stream = s->streams[i];
211
        if     (stream->codec->codec_type == CODEC_TYPE_AUDIO) astream = stream;
212
        else if(stream->codec->codec_type == CODEC_TYPE_VIDEO) vstream = stream;
213
    }
214
215
    //parse the second object (we want a mixed array)
216
    if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
217
        return -1;
218
219
    return 0;
220
}
221
222 d4f5d74a Garrick Meeker
static int flv_read_header(AVFormatContext *s,
223
                           AVFormatParameters *ap)
224
{
225 15f14fc7 Michael Niedermayer
    int offset, flags;
226 4eb0c665 Michael Niedermayer
    AVStream *st;
227 d4f5d74a Garrick Meeker
228
    url_fskip(&s->pb, 4);
229
    flags = get_byte(&s->pb);
230 031311cb Alex Beregszaszi
    /* old flvtool cleared this field */
231
    /* FIXME: better fix needed */
232
    if (!flags) {
233
        flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
234
        av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
235
    }
236 d4f5d74a Garrick Meeker
237 4eb0c665 Michael Niedermayer
    if(flags & FLV_HEADER_FLAG_HASVIDEO){
238
        st = av_new_stream(s, 0);
239
        if (!st)
240 769e10f0 Panagiotis Issaris
            return AVERROR(ENOMEM);
241 4eb0c665 Michael Niedermayer
        st->codec->codec_type = CODEC_TYPE_VIDEO;
242
        av_set_pts_info(st, 24, 1, 1000); /* 24 bit pts in ms */
243
    }
244
    if(flags & FLV_HEADER_FLAG_HASAUDIO){
245
        st = av_new_stream(s, 1);
246
        if (!st)
247 769e10f0 Panagiotis Issaris
            return AVERROR(ENOMEM);
248 4eb0c665 Michael Niedermayer
        st->codec->codec_type = CODEC_TYPE_AUDIO;
249
        av_set_pts_info(st, 24, 1, 1000); /* 24 bit pts in ms */
250
    }
251
252 d4f5d74a Garrick Meeker
    offset = get_be32(&s->pb);
253
    url_fseek(&s->pb, offset, SEEK_SET);
254
255 aeb20f7f Nazo
    s->start_time = 0;
256
257 d4f5d74a Garrick Meeker
    return 0;
258
}
259
260
static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
261
{
262 aeb20f7f Nazo
    int ret, i, type, size, pts, flags, is_audio, next, pos;
263 923bd441 Alex Beregszaszi
    AVStream *st = NULL;
264 115329f1 Diego Biurrun
265 068f2a22 Michael Niedermayer
 for(;;){
266 aeb20f7f Nazo
    pos = url_ftell(&s->pb);
267 d4f5d74a Garrick Meeker
    url_fskip(&s->pb, 4); /* size of previous packet */
268
    type = get_byte(&s->pb);
269
    size = get_be24(&s->pb);
270
    pts = get_be24(&s->pb);
271 92a26775 Michael Niedermayer
//    av_log(s, AV_LOG_DEBUG, "type:%d, size:%d, pts:%d\n", type, size, pts);
272 d4f5d74a Garrick Meeker
    if (url_feof(&s->pb))
273 6f3e0b21 Panagiotis Issaris
        return AVERROR(EIO);
274 d4f5d74a Garrick Meeker
    url_fskip(&s->pb, 4); /* reserved */
275
    flags = 0;
276 115329f1 Diego Biurrun
277 068f2a22 Michael Niedermayer
    if(size == 0)
278
        continue;
279 115329f1 Diego Biurrun
280 dd9f5916 Michael Niedermayer
    next= size + url_ftell(&s->pb);
281
282 6cac3a3b Allan Hsu
    if (type == FLV_TAG_TYPE_AUDIO) {
283 068f2a22 Michael Niedermayer
        is_audio=1;
284 d4f5d74a Garrick Meeker
        flags = get_byte(&s->pb);
285 6cac3a3b Allan Hsu
    } else if (type == FLV_TAG_TYPE_VIDEO) {
286 068f2a22 Michael Niedermayer
        is_audio=0;
287 d4f5d74a Garrick Meeker
        flags = get_byte(&s->pb);
288
    } else {
289 428cc588 Allan Hsu
        if (type == FLV_TAG_TYPE_META && size > 13+1+4)
290
            flv_read_metabody(s, next);
291
        else /* skip packet */
292
            av_log(s, AV_LOG_ERROR, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
293 dd9f5916 Michael Niedermayer
        url_fseek(&s->pb, next, SEEK_SET);
294 068f2a22 Michael Niedermayer
        continue;
295 d4f5d74a Garrick Meeker
    }
296
297
    /* now find stream */
298
    for(i=0;i<s->nb_streams;i++) {
299
        st = s->streams[i];
300 068f2a22 Michael Niedermayer
        if (st->id == is_audio)
301
            break;
302 d4f5d74a Garrick Meeker
    }
303 068f2a22 Michael Niedermayer
    if(i == s->nb_streams){
304 4eb0c665 Michael Niedermayer
        av_log(NULL, AV_LOG_ERROR, "invalid stream\n");
305
        url_fseek(&s->pb, next, SEEK_SET);
306
        continue;
307 6ed08157 Michael Niedermayer
    }
308 f3356e9c Michael Niedermayer
//    av_log(NULL, AV_LOG_DEBUG, "%d %X %d \n", is_audio, flags, st->discard);
309 6cac3a3b Allan Hsu
    if(  (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY ||         is_audio))
310
       ||(st->discard >= AVDISCARD_BIDIR  &&  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio))
311 f3356e9c Michael Niedermayer
       || st->discard >= AVDISCARD_ALL
312
       ){
313 dd9f5916 Michael Niedermayer
        url_fseek(&s->pb, next, SEEK_SET);
314 b9866ebc Michael Niedermayer
        continue;
315
    }
316 6cac3a3b Allan Hsu
    if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
317 aeb20f7f Nazo
        av_add_index_entry(st, pos, pts, size, 0, AVINDEX_KEYFRAME);
318 068f2a22 Michael Niedermayer
    break;
319
 }
320
321 15f14fc7 Michael Niedermayer
    // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
322
    if(!url_is_streamed(&s->pb) && s->duration==AV_NOPTS_VALUE){
323
        int size;
324
        const int pos= url_ftell(&s->pb);
325
        const int fsize= url_fsize(&s->pb);
326
        url_fseek(&s->pb, fsize-4, SEEK_SET);
327
        size= get_be32(&s->pb);
328
        url_fseek(&s->pb, fsize-3-size, SEEK_SET);
329
        if(size == get_be24(&s->pb) + 11){
330
            s->duration= get_be24(&s->pb) * (int64_t)AV_TIME_BASE / 1000;
331
        }
332
        url_fseek(&s->pb, pos, SEEK_SET);
333
    }
334
335 068f2a22 Michael Niedermayer
    if(is_audio){
336 428cc588 Allan Hsu
        if(!st->codec->sample_rate || !st->codec->bits_per_sample || (!st->codec->codec_id && !st->codec->codec_tag)) {
337 6cac3a3b Allan Hsu
            st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
338
            if((flags & FLV_AUDIO_CODECID_MASK) == FLV_CODECID_NELLYMOSER_8HZ_MONO)
339 01f4895c Michael Niedermayer
                st->codec->sample_rate= 8000;
340 068f2a22 Michael Niedermayer
            else
341 6cac3a3b Allan Hsu
                st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
342
            st->codec->bits_per_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
343 428cc588 Allan Hsu
            flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK);
344 068f2a22 Michael Niedermayer
        }
345
    }else{
346 428cc588 Allan Hsu
        size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
347 bb01a3f0 Michael Niedermayer
    }
348
349 dd9f5916 Michael Niedermayer
    ret= av_get_packet(&s->pb, pkt, size - 1);
350 d4f5d74a Garrick Meeker
    if (ret <= 0) {
351 6f3e0b21 Panagiotis Issaris
        return AVERROR(EIO);
352 d4f5d74a Garrick Meeker
    }
353
    /* note: we need to modify the packet size here to handle the last
354
       packet */
355
    pkt->size = ret;
356
    pkt->pts = pts;
357
    pkt->stream_index = st->index;
358 115329f1 Diego Biurrun
359 6cac3a3b Allan Hsu
    if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY))
360 bb270c08 Diego Biurrun
        pkt->flags |= PKT_FLAG_KEY;
361 115329f1 Diego Biurrun
362 d4f5d74a Garrick Meeker
    return ret;
363
}
364
365
static int flv_read_close(AVFormatContext *s)
366
{
367
    return 0;
368
}
369
370 aeb20f7f Nazo
static int flv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
371
{
372
    AVStream *st = s->streams[stream_index];
373
    int index = av_index_search_timestamp(st, timestamp, flags);
374
    if (index < 0)
375
        return -1;
376
    url_fseek(&s->pb, st->index_entries[index].pos, SEEK_SET);
377
378
    return 0;
379
}
380
381 d2a067d1 Måns Rullgård
AVInputFormat flv_demuxer = {
382 d4f5d74a Garrick Meeker
    "flv",
383
    "flv format",
384
    0,
385
    flv_probe,
386
    flv_read_header,
387
    flv_read_packet,
388
    flv_read_close,
389 aeb20f7f Nazo
    flv_read_seek,
390 d4f5d74a Garrick Meeker
    .extensions = "flv",
391
    .value = CODEC_ID_FLV1,
392
};