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ffmpeg / libavformat / ffmdec.c @ 7080cbe2

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1
/*
2
 * FFM (ffserver live feed) demuxer
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 * Copyright (c) 2001 Fabrice Bellard.
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 *
5
 * This file is part of FFmpeg.
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 *
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
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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,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * 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 "avformat.h"
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#include "ffm.h"
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#ifdef CONFIG_FFSERVER
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#include <unistd.h>
26

    
27
offset_t ffm_read_write_index(int fd)
28
{
29
    uint8_t buf[8];
30

    
31
    lseek(fd, 8, SEEK_SET);
32
    read(fd, buf, 8);
33
    return AV_RB64(buf);
34
}
35

    
36
void ffm_write_write_index(int fd, offset_t pos)
37
{
38
    uint8_t buf[8];
39
    int i;
40

    
41
    for(i=0;i<8;i++)
42
        buf[i] = (pos >> (56 - i * 8)) & 0xff;
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    lseek(fd, 8, SEEK_SET);
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    write(fd, buf, 8);
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}
46

    
47
void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
48
{
49
    FFMContext *ffm = s->priv_data;
50
    ffm->write_index = pos;
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    ffm->file_size = file_size;
52
}
53
#endif // CONFIG_FFSERVER
54

    
55
static int ffm_is_avail_data(AVFormatContext *s, int size)
56
{
57
    FFMContext *ffm = s->priv_data;
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    offset_t pos, avail_size;
59
    int len;
60

    
61
    len = ffm->packet_end - ffm->packet_ptr;
62
    if (size <= len)
63
        return 1;
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    pos = url_ftell(s->pb);
65
    if (pos == ffm->write_index) {
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        /* exactly at the end of stream */
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        return 0;
68
    } else if (pos < ffm->write_index) {
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        avail_size = ffm->write_index - pos;
70
    } else {
71
        avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
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    }
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    avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
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    if (size <= avail_size)
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        return 1;
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    else
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        return 0;
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}
79

    
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/* first is true if we read the frame header */
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static int ffm_read_data(AVFormatContext *s,
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                         uint8_t *buf, int size, int header)
83
{
84
    FFMContext *ffm = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    int len, fill_size, size1, frame_offset;
87

    
88
    size1 = size;
89
    while (size > 0) {
90
    redo:
91
        len = ffm->packet_end - ffm->packet_ptr;
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        if (len < 0)
93
            return -1;
94
        if (len > size)
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            len = size;
96
        if (len == 0) {
97
            if (url_ftell(pb) == ffm->file_size)
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                url_fseek(pb, ffm->packet_size, SEEK_SET);
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    retry_read:
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            get_be16(pb); /* PACKET_ID */
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            fill_size = get_be16(pb);
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            ffm->pts = get_be64(pb);
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            ffm->first_frame_in_packet = 1;
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            frame_offset = get_be16(pb);
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            get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
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            ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
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            if (ffm->packet_end < ffm->packet || frame_offset < 0)
108
                return -1;
109
            /* if first packet or resynchronization packet, we must
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               handle it specifically */
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            if (ffm->first_packet || (frame_offset & 0x8000)) {
112
                if (!frame_offset) {
113
                    /* This packet has no frame headers in it */
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                    if (url_ftell(pb) >= ffm->packet_size * 3) {
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                        url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
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                        goto retry_read;
117
                    }
118
                    /* This is bad, we cannot find a valid frame header */
119
                    return 0;
120
                }
121
                ffm->first_packet = 0;
122
                if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
123
                    return -1;
124
                ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
125
                if (!header)
126
                    break;
127
            } else {
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                ffm->packet_ptr = ffm->packet;
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            }
130
            goto redo;
131
        }
132
        memcpy(buf, ffm->packet_ptr, len);
133
        buf += len;
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        ffm->packet_ptr += len;
135
        size -= len;
136
        header = 0;
137
    }
138
    return size1 - size;
139
}
140

    
141
//#define DEBUG_SEEK
142

    
143
/* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
144
   by the write position inside this function */
145
static void ffm_seek1(AVFormatContext *s, offset_t pos1)
146
{
147
    FFMContext *ffm = s->priv_data;
148
    ByteIOContext *pb = s->pb;
149
    offset_t pos;
150

    
151
    pos = pos1 + ffm->write_index;
152
    if (pos >= ffm->file_size)
153
        pos -= (ffm->file_size - FFM_PACKET_SIZE);
154
#ifdef DEBUG_SEEK
155
    av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
156
#endif
157
    url_fseek(pb, pos, SEEK_SET);
158
}
159

    
160
static int64_t get_pts(AVFormatContext *s, offset_t pos)
161
{
162
    ByteIOContext *pb = s->pb;
163
    int64_t pts;
164

    
165
    ffm_seek1(s, pos);
166
    url_fskip(pb, 4);
167
    pts = get_be64(pb);
168
#ifdef DEBUG_SEEK
169
    av_log(s, AV_LOG_DEBUG, "pts=%0.6f\n", pts / 1000000.0);
170
#endif
171
    return pts;
172
}
173

    
174
static void adjust_write_index(AVFormatContext *s)
175
{
176
    FFMContext *ffm = s->priv_data;
177
    ByteIOContext *pb = s->pb;
178
    int64_t pts;
179
    //offset_t orig_write_index = ffm->write_index;
180
    offset_t pos_min, pos_max;
181
    int64_t pts_start;
182
    offset_t ptr = url_ftell(pb);
183

    
184

    
185
    pos_min = 0;
186
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
187

    
188
    pts_start = get_pts(s, pos_min);
189

    
190
    pts = get_pts(s, pos_max);
191

    
192
    if (pts - 100000 > pts_start)
193
        goto end;
194

    
195
    ffm->write_index = FFM_PACKET_SIZE;
196

    
197
    pts_start = get_pts(s, pos_min);
198

    
199
    pts = get_pts(s, pos_max);
200

    
201
    if (pts - 100000 <= pts_start) {
202
        while (1) {
203
            offset_t newpos;
204
            int64_t newpts;
205

    
206
            newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
207

    
208
            if (newpos == pos_min)
209
                break;
210

    
211
            newpts = get_pts(s, newpos);
212

    
213
            if (newpts - 100000 <= pts) {
214
                pos_max = newpos;
215
                pts = newpts;
216
            } else {
217
                pos_min = newpos;
218
            }
219
        }
220
        ffm->write_index += pos_max;
221
    }
222

    
223
    //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
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    //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
225

    
226
 end:
227
    url_fseek(pb, ptr, SEEK_SET);
228
}
229

    
230

    
231
static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
232
{
233
    FFMContext *ffm = s->priv_data;
234
    AVStream *st;
235
    ByteIOContext *pb = s->pb;
236
    AVCodecContext *codec;
237
    int i, nb_streams;
238
    uint32_t tag;
239

    
240
    /* header */
241
    tag = get_le32(pb);
242
    if (tag != MKTAG('F', 'F', 'M', '1'))
243
        goto fail;
244
    ffm->packet_size = get_be32(pb);
245
    if (ffm->packet_size != FFM_PACKET_SIZE)
246
        goto fail;
247
    ffm->write_index = get_be64(pb);
248
    /* get also filesize */
249
    if (!url_is_streamed(pb)) {
250
        ffm->file_size = url_fsize(pb);
251
        adjust_write_index(s);
252
    } else {
253
        ffm->file_size = (UINT64_C(1) << 63) - 1;
254
    }
255

    
256
    nb_streams = get_be32(pb);
257
    get_be32(pb); /* total bitrate */
258
    /* read each stream */
259
    for(i=0;i<nb_streams;i++) {
260
        char rc_eq_buf[128];
261

    
262
        st = av_new_stream(s, 0);
263
        if (!st)
264
            goto fail;
265
        s->streams[i] = st;
266

    
267
        av_set_pts_info(st, 64, 1, 1000000);
268

    
269
        codec = st->codec;
270
        /* generic info */
271
        codec->codec_id = get_be32(pb);
272
        codec->codec_type = get_byte(pb); /* codec_type */
273
        codec->bit_rate = get_be32(pb);
274
        st->quality = get_be32(pb);
275
        codec->flags = get_be32(pb);
276
        codec->flags2 = get_be32(pb);
277
        codec->debug = get_be32(pb);
278
        /* specific info */
279
        switch(codec->codec_type) {
280
        case CODEC_TYPE_VIDEO:
281
            codec->time_base.num = get_be32(pb);
282
            codec->time_base.den = get_be32(pb);
283
            codec->width = get_be16(pb);
284
            codec->height = get_be16(pb);
285
            codec->gop_size = get_be16(pb);
286
            codec->pix_fmt = get_be32(pb);
287
            codec->qmin = get_byte(pb);
288
            codec->qmax = get_byte(pb);
289
            codec->max_qdiff = get_byte(pb);
290
            codec->qcompress = get_be16(pb) / 10000.0;
291
            codec->qblur = get_be16(pb) / 10000.0;
292
            codec->bit_rate_tolerance = get_be32(pb);
293
            codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
294
            codec->rc_max_rate = get_be32(pb);
295
            codec->rc_min_rate = get_be32(pb);
296
            codec->rc_buffer_size = get_be32(pb);
297
            codec->i_quant_factor = av_int2dbl(get_be64(pb));
298
            codec->b_quant_factor = av_int2dbl(get_be64(pb));
299
            codec->i_quant_offset = av_int2dbl(get_be64(pb));
300
            codec->b_quant_offset = av_int2dbl(get_be64(pb));
301
            codec->dct_algo = get_be32(pb);
302
            codec->strict_std_compliance = get_be32(pb);
303
            codec->max_b_frames = get_be32(pb);
304
            codec->luma_elim_threshold = get_be32(pb);
305
            codec->chroma_elim_threshold = get_be32(pb);
306
            codec->mpeg_quant = get_be32(pb);
307
            codec->intra_dc_precision = get_be32(pb);
308
            codec->me_method = get_be32(pb);
309
            codec->mb_decision = get_be32(pb);
310
            codec->nsse_weight = get_be32(pb);
311
            codec->frame_skip_cmp = get_be32(pb);
312
            codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
313
            codec->codec_tag = get_be32(pb);
314
            break;
315
        case CODEC_TYPE_AUDIO:
316
            codec->sample_rate = get_be32(pb);
317
            codec->channels = get_le16(pb);
318
            codec->frame_size = get_le16(pb);
319
            break;
320
        default:
321
            goto fail;
322
        }
323
        if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
324
            codec->extradata_size = get_be32(pb);
325
            codec->extradata = av_malloc(codec->extradata_size);
326
            if (!codec->extradata)
327
                return AVERROR(ENOMEM);
328
            get_buffer(pb, codec->extradata, codec->extradata_size);
329
        }
330
    }
331

    
332
    /* get until end of block reached */
333
    while ((url_ftell(pb) % ffm->packet_size) != 0)
334
        get_byte(pb);
335

    
336
    /* init packet demux */
337
    ffm->packet_ptr = ffm->packet;
338
    ffm->packet_end = ffm->packet;
339
    ffm->frame_offset = 0;
340
    ffm->pts = 0;
341
    ffm->read_state = READ_HEADER;
342
    ffm->first_packet = 1;
343
    return 0;
344
 fail:
345
    for(i=0;i<s->nb_streams;i++) {
346
        st = s->streams[i];
347
        if (st) {
348
            av_freep(&st->priv_data);
349
            av_free(st);
350
        }
351
    }
352
    return -1;
353
}
354

    
355
/* return < 0 if eof */
356
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
357
{
358
    int size;
359
    FFMContext *ffm = s->priv_data;
360
    int duration;
361

    
362
    switch(ffm->read_state) {
363
    case READ_HEADER:
364
        if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
365
            return AVERROR(EAGAIN);
366
        }
367
        dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
368
               url_ftell(s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
369
        if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
370
            FRAME_HEADER_SIZE)
371
            return AVERROR(EAGAIN);
372
#if 0
373
        av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
374
#endif
375
        ffm->read_state = READ_DATA;
376
        /* fall thru */
377
    case READ_DATA:
378
        size = AV_RB24(ffm->header + 2);
379
        if (!ffm_is_avail_data(s, size)) {
380
            return AVERROR(EAGAIN);
381
        }
382

    
383
        duration = AV_RB24(ffm->header + 5);
384

    
385
        av_new_packet(pkt, size);
386
        pkt->stream_index = ffm->header[0];
387
        if ((unsigned)pkt->stream_index >= s->nb_streams) {
388
            av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
389
            av_free_packet(pkt);
390
            ffm->read_state = READ_HEADER;
391
            return AVERROR(EAGAIN);
392
        }
393
        pkt->pos = url_ftell(s->pb);
394
        if (ffm->header[1] & FLAG_KEY_FRAME)
395
            pkt->flags |= PKT_FLAG_KEY;
396

    
397
        ffm->read_state = READ_HEADER;
398
        if (ffm_read_data(s, pkt->data, size, 0) != size) {
399
            /* bad case: desynchronized packet. we cancel all the packet loading */
400
            av_free_packet(pkt);
401
            return AVERROR(EAGAIN);
402
        }
403
        if (ffm->first_frame_in_packet)
404
        {
405
            pkt->pts = ffm->pts;
406
            ffm->first_frame_in_packet = 0;
407
        }
408
        pkt->duration = duration;
409
        break;
410
    }
411
    return 0;
412
}
413

    
414
/* seek to a given time in the file. The file read pointer is
415
   positioned at or before pts. XXX: the following code is quite
416
   approximative */
417
static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
418
{
419
    FFMContext *ffm = s->priv_data;
420
    offset_t pos_min, pos_max, pos;
421
    int64_t pts_min, pts_max, pts;
422
    double pos1;
423

    
424
#ifdef DEBUG_SEEK
425
    av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
426
#endif
427
    /* find the position using linear interpolation (better than
428
       dichotomy in typical cases) */
429
    pos_min = 0;
430
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
431
    while (pos_min <= pos_max) {
432
        pts_min = get_pts(s, pos_min);
433
        pts_max = get_pts(s, pos_max);
434
        /* linear interpolation */
435
        pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
436
            (double)(pts_max - pts_min);
437
        pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
438
        if (pos <= pos_min)
439
            pos = pos_min;
440
        else if (pos >= pos_max)
441
            pos = pos_max;
442
        pts = get_pts(s, pos);
443
        /* check if we are lucky */
444
        if (pts == wanted_pts) {
445
            goto found;
446
        } else if (pts > wanted_pts) {
447
            pos_max = pos - FFM_PACKET_SIZE;
448
        } else {
449
            pos_min = pos + FFM_PACKET_SIZE;
450
        }
451
    }
452
    pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
453
    if (pos > 0)
454
        pos -= FFM_PACKET_SIZE;
455
 found:
456
    ffm_seek1(s, pos);
457

    
458
    /* reset read state */
459
    ffm->read_state = READ_HEADER;
460
    ffm->packet_ptr = ffm->packet;
461
    ffm->packet_end = ffm->packet;
462
    ffm->first_packet = 1;
463

    
464
    return 0;
465
}
466

    
467
static int ffm_read_close(AVFormatContext *s)
468
{
469
    AVStream *st;
470
    int i;
471

    
472
    for(i=0;i<s->nb_streams;i++) {
473
        st = s->streams[i];
474
        av_freep(&st->priv_data);
475
    }
476
    return 0;
477
}
478

    
479
static int ffm_probe(AVProbeData *p)
480
{
481
    if (
482
        p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
483
        p->buf[3] == '1')
484
        return AVPROBE_SCORE_MAX + 1;
485
    return 0;
486
}
487

    
488
AVInputFormat ffm_demuxer = {
489
    "ffm",
490
    NULL_IF_CONFIG_SMALL("ffm format"),
491
    sizeof(FFMContext),
492
    ffm_probe,
493
    ffm_read_header,
494
    ffm_read_packet,
495
    ffm_read_close,
496
    ffm_seek,
497
};