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ffmpeg / libav / ffm.c @ 50d5d129

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1 de6d9b64 Fabrice Bellard
/*
2
 * FFM (ffserver live feed) encoder and decoder
3 66d2ff2a Fabrice Bellard
 * Copyright (c) 2001 Fabrice Bellard.
4 de6d9b64 Fabrice Bellard
 *
5 66d2ff2a Fabrice Bellard
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9 de6d9b64 Fabrice Bellard
 *
10 66d2ff2a Fabrice Bellard
 * This library is distributed in the hope that it will be useful,
11 de6d9b64 Fabrice Bellard
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 66d2ff2a Fabrice Bellard
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14 de6d9b64 Fabrice Bellard
 *
15 66d2ff2a Fabrice Bellard
 * You should have received a copy of the GNU Lesser General Public
16
 * License along with this library; if not, write to the Free Software
17
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18 de6d9b64 Fabrice Bellard
 */
19
#include "avformat.h"
20 8be1c656 Fabrice Bellard
#include <unistd.h>
21 de6d9b64 Fabrice Bellard
22
/* The FFM file is made of blocks of fixed size */
23
#define FFM_HEADER_SIZE 14
24
#define PACKET_ID       0x666d
25
26
/* each packet contains frames (which can span several packets */
27 20f01548 Philip Gladstone
#define FRAME_HEADER_SIZE    8
28 de6d9b64 Fabrice Bellard
#define FLAG_KEY_FRAME       0x01
29
30
typedef struct FFMStream {
31
    INT64 pts;
32
} FFMStream;
33
34
enum {
35
    READ_HEADER,
36
    READ_DATA,
37
};
38
39
typedef struct FFMContext {
40
    /* only reading mode */
41
    offset_t write_index, file_size;
42 4606ac8d Zdenek Kabelac
    int read_state;
43 de6d9b64 Fabrice Bellard
    UINT8 header[FRAME_HEADER_SIZE];
44
45
    /* read and write */
46
    int first_packet; /* true if first packet, needed to set the discontinuity tag */
47
    int packet_size;
48
    int frame_offset;
49
    INT64 pts;
50
    UINT8 *packet_ptr, *packet_end;
51 66d2ff2a Fabrice Bellard
    UINT8 packet[FFM_PACKET_SIZE];
52 de6d9b64 Fabrice Bellard
} FFMContext;
53
54 c9a65ca8 Fabrice Bellard
/* disable pts hack for testing */
55
int ffm_nopts = 0;
56
57 de6d9b64 Fabrice Bellard
static void flush_packet(AVFormatContext *s)
58
{
59
    FFMContext *ffm = s->priv_data;
60
    int fill_size, h;
61
    ByteIOContext *pb = &s->pb;
62
63
    fill_size = ffm->packet_end - ffm->packet_ptr;
64
    memset(ffm->packet_ptr, 0, fill_size);
65 4606ac8d Zdenek Kabelac
66 de6d9b64 Fabrice Bellard
    /* put header */
67 4606ac8d Zdenek Kabelac
    put_be16(pb, PACKET_ID);
68 de6d9b64 Fabrice Bellard
    put_be16(pb, fill_size);
69
    put_be64(pb, ffm->pts);
70
    h = ffm->frame_offset;
71
    if (ffm->first_packet)
72
        h |= 0x8000;
73
    put_be16(pb, h);
74
    put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet);
75
76
    /* prepare next packet */
77
    ffm->frame_offset = 0; /* no key frame */
78
    ffm->pts = 0; /* no pts */
79
    ffm->packet_ptr = ffm->packet;
80
    ffm->first_packet = 0;
81
}
82
83
/* 'first' is true if first data of a frame */
84 4606ac8d Zdenek Kabelac
static void ffm_write_data(AVFormatContext *s,
85
                           UINT8 *buf, int size,
86 de6d9b64 Fabrice Bellard
                           INT64 pts, int first)
87
{
88
    FFMContext *ffm = s->priv_data;
89
    int len;
90
91
    if (first && ffm->frame_offset == 0)
92
        ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
93
    if (first && ffm->pts == 0)
94
        ffm->pts = pts;
95
96
    /* write as many packets as needed */
97
    while (size > 0) {
98
        len = ffm->packet_end - ffm->packet_ptr;
99
        if (len > size)
100
            len = size;
101
        memcpy(ffm->packet_ptr, buf, len);
102 4606ac8d Zdenek Kabelac
103 de6d9b64 Fabrice Bellard
        ffm->packet_ptr += len;
104
        buf += len;
105
        size -= len;
106
        if (ffm->packet_ptr >= ffm->packet_end) {
107
            /* special case : no pts in packet : we leave the current one */
108
            if (ffm->pts == 0)
109
                ffm->pts = pts;
110
111
            flush_packet(s);
112
        }
113
    }
114
}
115
116
static int ffm_write_header(AVFormatContext *s)
117
{
118 c9a65ca8 Fabrice Bellard
    FFMContext *ffm = s->priv_data;
119 de6d9b64 Fabrice Bellard
    AVStream *st;
120
    FFMStream *fst;
121
    ByteIOContext *pb = &s->pb;
122
    AVCodecContext *codec;
123
    int bit_rate, i;
124
125
    ffm->packet_size = FFM_PACKET_SIZE;
126 4606ac8d Zdenek Kabelac
127 de6d9b64 Fabrice Bellard
    /* header */
128
    put_tag(pb, "FFM1");
129
    put_be32(pb, ffm->packet_size);
130
    /* XXX: store write position in other file ? */
131
    put_be64(pb, ffm->packet_size); /* current write position */
132
133
    put_be32(pb, s->nb_streams);
134
    bit_rate = 0;
135
    for(i=0;i<s->nb_streams;i++) {
136
        st = s->streams[i];
137
        bit_rate += st->codec.bit_rate;
138
    }
139
    put_be32(pb, bit_rate);
140
141
    /* list of streams */
142
    for(i=0;i<s->nb_streams;i++) {
143
        st = s->streams[i];
144 16300e23 Philip Gladstone
        fst = av_mallocz(sizeof(FFMStream));
145 de6d9b64 Fabrice Bellard
        if (!fst)
146
            goto fail;
147
        st->priv_data = fst;
148
149
        codec = &st->codec;
150
        /* generic info */
151
        put_be32(pb, codec->codec_id);
152
        put_byte(pb, codec->codec_type);
153
        put_be32(pb, codec->bit_rate);
154 81e0d0b4 Mark Hills
        put_be32(pb, codec->quality);
155 ccac2e27 Philip Gladstone
        put_be32(pb, codec->flags);
156 de6d9b64 Fabrice Bellard
        /* specific info */
157
        switch(codec->codec_type) {
158
        case CODEC_TYPE_VIDEO:
159
            put_be32(pb, (codec->frame_rate * 1000) / FRAME_RATE_BASE);
160
            put_be16(pb, codec->width);
161
            put_be16(pb, codec->height);
162 20f01548 Philip Gladstone
            put_be16(pb, codec->gop_size);
163
            put_byte(pb, codec->qmin);
164
            put_byte(pb, codec->qmax);
165
            put_byte(pb, codec->max_qdiff);
166
            put_be16(pb, (int) (codec->qcompress * 10000.0));
167
            put_be16(pb, (int) (codec->qblur * 10000.0));
168 3884a3c3 Philip Gladstone
            put_be32(pb, codec->bit_rate_tolerance);
169 3b4b29dc Fabrice Bellard
            put_strz(pb, codec->rc_eq);
170 75bdb984 Philip Gladstone
            put_be32(pb, codec->rc_max_rate);
171
            put_be32(pb, codec->rc_min_rate);
172
            put_be32(pb, codec->rc_buffer_size);
173 3b4b29dc Fabrice Bellard
            put_be64_double(pb, codec->i_quant_factor);
174
            put_be64_double(pb, codec->b_quant_factor);
175
            put_be64_double(pb, codec->i_quant_offset);
176
            put_be64_double(pb, codec->b_quant_offset);
177 75bdb984 Philip Gladstone
            put_be32(pb, codec->dct_algo);
178 de6d9b64 Fabrice Bellard
            break;
179
        case CODEC_TYPE_AUDIO:
180
            put_be32(pb, codec->sample_rate);
181
            put_le16(pb, codec->channels);
182 20f01548 Philip Gladstone
            put_le16(pb, codec->frame_size);
183 de6d9b64 Fabrice Bellard
            break;
184 20f01548 Philip Gladstone
        default:
185 789bee12 Philip Gladstone
            av_abort();
186 de6d9b64 Fabrice Bellard
        }
187
        /* hack to have real time */
188 c9a65ca8 Fabrice Bellard
        if (ffm_nopts)
189
            fst->pts = 0;
190
        else
191 a11bf0bd Fabrice Bellard
            fst->pts = av_gettime();
192 de6d9b64 Fabrice Bellard
    }
193
194
    /* flush until end of block reached */
195
    while ((url_ftell(pb) % ffm->packet_size) != 0)
196
        put_byte(pb, 0);
197
198
    put_flush_packet(pb);
199
200
    /* init packet mux */
201
    ffm->packet_ptr = ffm->packet;
202
    ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
203
    ffm->frame_offset = 0;
204
    ffm->pts = 0;
205
    ffm->first_packet = 1;
206
207
    return 0;
208
 fail:
209
    for(i=0;i<s->nb_streams;i++) {
210
        st = s->streams[i];
211 789bee12 Philip Gladstone
        av_freep(&st->priv_data);
212 de6d9b64 Fabrice Bellard
    }
213
    return -1;
214
}
215
216
static int ffm_write_packet(AVFormatContext *s, int stream_index,
217 10bb7023 Juanjo
                            UINT8 *buf, int size, int force_pts)
218 de6d9b64 Fabrice Bellard
{
219
    AVStream *st = s->streams[stream_index];
220
    FFMStream *fst = st->priv_data;
221
    INT64 pts;
222
    UINT8 header[FRAME_HEADER_SIZE];
223 20f01548 Philip Gladstone
    int duration;
224
225
    if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
226
        duration = ((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0);
227
    } else {
228
        duration = (1000000.0 * FRAME_RATE_BASE / (float)st->codec.frame_rate);
229
    }
230 de6d9b64 Fabrice Bellard
231
    pts = fst->pts;
232
    /* packet size & key_frame */
233
    header[0] = stream_index;
234
    header[1] = 0;
235
    if (st->codec.key_frame)
236
        header[1] |= FLAG_KEY_FRAME;
237
    header[2] = (size >> 16) & 0xff;
238
    header[3] = (size >> 8) & 0xff;
239
    header[4] = size & 0xff;
240 20f01548 Philip Gladstone
    header[5] = (duration >> 16) & 0xff;
241
    header[6] = (duration >> 8) & 0xff;
242
    header[7] = duration & 0xff;
243 de6d9b64 Fabrice Bellard
    ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
244
    ffm_write_data(s, buf, size, pts, 0);
245
246 20f01548 Philip Gladstone
    fst->pts += duration;
247 de6d9b64 Fabrice Bellard
    return 0;
248
}
249
250
static int ffm_write_trailer(AVFormatContext *s)
251
{
252
    ByteIOContext *pb = &s->pb;
253
    FFMContext *ffm = s->priv_data;
254
    int i;
255
256
    /* flush packets */
257
    if (ffm->packet_ptr > ffm->packet)
258
        flush_packet(s);
259
260
    put_flush_packet(pb);
261
262 66d2ff2a Fabrice Bellard
    if (!url_is_streamed(pb)) {
263
        INT64 size;
264
        /* update the write offset */
265
        size = url_ftell(pb);
266
        url_fseek(pb, 8, SEEK_SET);
267
        put_be64(pb, size);
268
        put_flush_packet(pb);
269
    }
270
271 de6d9b64 Fabrice Bellard
    for(i=0;i<s->nb_streams;i++)
272 789bee12 Philip Gladstone
        av_freep(&s->streams[i]->priv_data);
273 de6d9b64 Fabrice Bellard
    return 0;
274
}
275
276
/* ffm demux */
277
278
static int ffm_is_avail_data(AVFormatContext *s, int size)
279
{
280
    FFMContext *ffm = s->priv_data;
281
    offset_t pos, avail_size;
282
    int len;
283
284
    len = ffm->packet_end - ffm->packet_ptr;
285 66d2ff2a Fabrice Bellard
    if (!ffm_nopts) {
286
        /* XXX: I don't understand this test, so I disabled it for testing */
287
        if (size <= len)
288
            return 1;
289
    }
290 de6d9b64 Fabrice Bellard
    pos = url_ftell(&s->pb);
291
    if (pos == ffm->write_index) {
292
        /* exactly at the end of stream */
293
        return 0;
294
    } else if (pos < ffm->write_index) {
295
        avail_size = ffm->write_index - pos;
296
    } else {
297
        avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
298
    }
299
    avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
300
    if (size <= avail_size)
301
        return 1;
302
    else
303
        return 0;
304
}
305
306
/* first is true if we read the frame header */
307 4606ac8d Zdenek Kabelac
static int ffm_read_data(AVFormatContext *s,
308 66d2ff2a Fabrice Bellard
                         UINT8 *buf, int size, int first)
309 de6d9b64 Fabrice Bellard
{
310
    FFMContext *ffm = s->priv_data;
311
    ByteIOContext *pb = &s->pb;
312
    int len, fill_size, size1, frame_offset;
313
314
    size1 = size;
315
    while (size > 0) {
316
    redo:
317
        len = ffm->packet_end - ffm->packet_ptr;
318
        if (len > size)
319
            len = size;
320
        if (len == 0) {
321
            if (url_ftell(pb) == ffm->file_size)
322
                url_fseek(pb, ffm->packet_size, SEEK_SET);
323 5e57424d Philip Gladstone
    retry_read:
324 de6d9b64 Fabrice Bellard
            get_be16(pb); /* PACKET_ID */
325
            fill_size = get_be16(pb);
326
            ffm->pts = get_be64(pb);
327
            frame_offset = get_be16(pb);
328
            get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
329
            ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
330
            /* if first packet or resynchronization packet, we must
331
               handle it specifically */
332
            if (ffm->first_packet || (frame_offset & 0x8000)) {
333 5e57424d Philip Gladstone
                if (!frame_offset) {
334
                    /* This packet has no frame headers in it */
335
                    if (url_ftell(pb) >= ffm->packet_size * 3) {
336
                        url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
337
                        goto retry_read;
338
                    }
339
                    /* This is bad, we cannot find a valid frame header */
340
                    return 0;
341
                }
342 de6d9b64 Fabrice Bellard
                ffm->first_packet = 0;
343 5e57424d Philip Gladstone
                if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
344 789bee12 Philip Gladstone
                    av_abort();
345 de6d9b64 Fabrice Bellard
                ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
346
                if (!first)
347
                    break;
348
            } else {
349
                ffm->packet_ptr = ffm->packet;
350
            }
351
            goto redo;
352
        }
353
        memcpy(buf, ffm->packet_ptr, len);
354
        buf += len;
355
        ffm->packet_ptr += len;
356
        size -= len;
357
        first = 0;
358
    }
359
    return size1 - size;
360
}
361
362
363
static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
364
{
365 c9a65ca8 Fabrice Bellard
    FFMContext *ffm = s->priv_data;
366 de6d9b64 Fabrice Bellard
    AVStream *st;
367
    FFMStream *fst;
368
    ByteIOContext *pb = &s->pb;
369
    AVCodecContext *codec;
370
    int i;
371
    UINT32 tag;
372
373
    /* header */
374
    tag = get_le32(pb);
375
    if (tag != MKTAG('F', 'F', 'M', '1'))
376
        goto fail;
377
    ffm->packet_size = get_be32(pb);
378
    if (ffm->packet_size != FFM_PACKET_SIZE)
379
        goto fail;
380
    ffm->write_index = get_be64(pb);
381
    /* get also filesize */
382
    if (!url_is_streamed(pb)) {
383
        ffm->file_size = url_filesize(url_fileno(pb));
384
    } else {
385 8be1c656 Fabrice Bellard
        ffm->file_size = (UINT64_C(1) << 63) - 1;
386 de6d9b64 Fabrice Bellard
    }
387
388
    s->nb_streams = get_be32(pb);
389
    get_be32(pb); /* total bitrate */
390
    /* read each stream */
391
    for(i=0;i<s->nb_streams;i++) {
392 75bdb984 Philip Gladstone
        char rc_eq_buf[128];
393
394 de6d9b64 Fabrice Bellard
        st = av_mallocz(sizeof(AVStream));
395
        if (!st)
396
            goto fail;
397
        s->streams[i] = st;
398 16300e23 Philip Gladstone
        fst = av_mallocz(sizeof(FFMStream));
399 de6d9b64 Fabrice Bellard
        if (!fst)
400
            goto fail;
401
        st->priv_data = fst;
402
403
        codec = &st->codec;
404
        /* generic info */
405
        st->codec.codec_id = get_be32(pb);
406
        st->codec.codec_type = get_byte(pb); /* codec_type */
407
        codec->bit_rate = get_be32(pb);
408 81e0d0b4 Mark Hills
        codec->quality = get_be32(pb);
409 ccac2e27 Philip Gladstone
        codec->flags = get_be32(pb);
410 de6d9b64 Fabrice Bellard
        /* specific info */
411
        switch(codec->codec_type) {
412
        case CODEC_TYPE_VIDEO:
413
            codec->frame_rate = ((INT64)get_be32(pb) * FRAME_RATE_BASE) / 1000;
414
            codec->width = get_be16(pb);
415
            codec->height = get_be16(pb);
416 20f01548 Philip Gladstone
            codec->gop_size = get_be16(pb);
417
            codec->qmin = get_byte(pb);
418
            codec->qmax = get_byte(pb);
419
            codec->max_qdiff = get_byte(pb);
420
            codec->qcompress = get_be16(pb) / 10000.0;
421
            codec->qblur = get_be16(pb) / 10000.0;
422 3884a3c3 Philip Gladstone
            codec->bit_rate_tolerance = get_be32(pb);
423 3b4b29dc Fabrice Bellard
            codec->rc_eq = strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
424 75bdb984 Philip Gladstone
            codec->rc_max_rate = get_be32(pb);
425
            codec->rc_min_rate = get_be32(pb);
426
            codec->rc_buffer_size = get_be32(pb);
427 3b4b29dc Fabrice Bellard
            codec->i_quant_factor = get_be64_double(pb);
428
            codec->b_quant_factor = get_be64_double(pb);
429
            codec->i_quant_offset = get_be64_double(pb);
430
            codec->b_quant_offset = get_be64_double(pb);
431 75bdb984 Philip Gladstone
            codec->dct_algo = get_be32(pb);
432 de6d9b64 Fabrice Bellard
            break;
433
        case CODEC_TYPE_AUDIO:
434
            codec->sample_rate = get_be32(pb);
435
            codec->channels = get_le16(pb);
436 20f01548 Philip Gladstone
            codec->frame_size = get_le16(pb);
437 de6d9b64 Fabrice Bellard
            break;
438 20f01548 Philip Gladstone
        default:
439 75bdb984 Philip Gladstone
            goto fail;
440 de6d9b64 Fabrice Bellard
        }
441
442
    }
443
444
    /* get until end of block reached */
445
    while ((url_ftell(pb) % ffm->packet_size) != 0)
446
        get_byte(pb);
447
448
    /* init packet demux */
449
    ffm->packet_ptr = ffm->packet;
450
    ffm->packet_end = ffm->packet;
451
    ffm->frame_offset = 0;
452
    ffm->pts = 0;
453
    ffm->read_state = READ_HEADER;
454
    ffm->first_packet = 1;
455
    return 0;
456
 fail:
457
    for(i=0;i<s->nb_streams;i++) {
458
        st = s->streams[i];
459
        if (st) {
460 789bee12 Philip Gladstone
            av_freep(&st->priv_data);
461 1ea4f593 Fabrice Bellard
            av_free(st);
462 de6d9b64 Fabrice Bellard
        }
463
    }
464
    return -1;
465
}
466
467
/* return < 0 if eof */
468
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
469
{
470
    int size;
471
    FFMContext *ffm = s->priv_data;
472 20f01548 Philip Gladstone
    int duration;
473 de6d9b64 Fabrice Bellard
474
    switch(ffm->read_state) {
475
    case READ_HEADER:
476 66d2ff2a Fabrice Bellard
        if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
477 de6d9b64 Fabrice Bellard
            return -EAGAIN;
478 66d2ff2a Fabrice Bellard
        }
479 de6d9b64 Fabrice Bellard
#if 0
480 4606ac8d Zdenek Kabelac
        printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n",
481 de6d9b64 Fabrice Bellard
               url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
482
#endif
483 66d2ff2a Fabrice Bellard
        if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) != 
484
            FRAME_HEADER_SIZE)
485 de6d9b64 Fabrice Bellard
            return -EAGAIN;
486
#if 0
487
        {
488
            int i;
489
            for(i=0;i<FRAME_HEADER_SIZE;i++)
490
                printf("%02x ", ffm->header[i]);
491
            printf("\n");
492
        }
493
#endif
494
        ffm->read_state = READ_DATA;
495
        /* fall thru */
496
    case READ_DATA:
497
        size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4];
498
        if (!ffm_is_avail_data(s, size)) {
499
            return -EAGAIN;
500
        }
501
502 20f01548 Philip Gladstone
        duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];
503
504 de6d9b64 Fabrice Bellard
        av_new_packet(pkt, size);
505
        pkt->stream_index = ffm->header[0];
506
        if (ffm->header[1] & FLAG_KEY_FRAME)
507
            pkt->flags |= PKT_FLAG_KEY;
508 4606ac8d Zdenek Kabelac
509 de6d9b64 Fabrice Bellard
        ffm->read_state = READ_HEADER;
510
        if (ffm_read_data(s, pkt->data, size, 0) != size) {
511
            /* bad case: desynchronized packet. we cancel all the packet loading */
512
            av_free_packet(pkt);
513
            return -EAGAIN;
514
        }
515 20f01548 Philip Gladstone
        pkt->pts = ffm->pts;
516
        pkt->duration = duration;
517 de6d9b64 Fabrice Bellard
        break;
518
    }
519
    return 0;
520
}
521
522
//#define DEBUG_SEEK
523
524
/* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
525
   by the write position inside this function */
526
static void ffm_seek1(AVFormatContext *s, offset_t pos1)
527
{
528
    FFMContext *ffm = s->priv_data;
529
    ByteIOContext *pb = &s->pb;
530
    offset_t pos;
531
532
    pos = pos1 + ffm->write_index;
533
    if (pos >= ffm->file_size)
534
        pos -= (ffm->file_size - FFM_PACKET_SIZE);
535
#ifdef DEBUG_SEEK
536
    printf("seek to %Lx -> %Lx\n", pos1, pos);
537
#endif
538
    url_fseek(pb, pos, SEEK_SET);
539
}
540
541
static INT64 get_pts(AVFormatContext *s, offset_t pos)
542
{
543
    ByteIOContext *pb = &s->pb;
544
    INT64 pts;
545
546 4606ac8d Zdenek Kabelac
    ffm_seek1(s, pos);
547 de6d9b64 Fabrice Bellard
    url_fskip(pb, 4);
548
    pts = get_be64(pb);
549
#ifdef DEBUG_SEEK
550
    printf("pts=%0.6f\n", pts / 1000000.0);
551
#endif
552
    return pts;
553
}
554
555
/* seek to a given time in the file. The file read pointer is
556
   positionned at or before pts. XXX: the following code is quite
557
   approximative */
558
static int ffm_seek(AVFormatContext *s, INT64 wanted_pts)
559
{
560
    FFMContext *ffm = s->priv_data;
561
    offset_t pos_min, pos_max, pos;
562
    INT64 pts_min, pts_max, pts;
563
    double pos1;
564
565
#ifdef DEBUG_SEEK
566
    printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
567
#endif
568
    /* find the position using linear interpolation (better than
569
       dichotomy in typical cases) */
570
    pos_min = 0;
571
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
572
    while (pos_min <= pos_max) {
573
        pts_min = get_pts(s, pos_min);
574
        pts_max = get_pts(s, pos_max);
575
        /* linear interpolation */
576 4606ac8d Zdenek Kabelac
        pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
577 de6d9b64 Fabrice Bellard
            (double)(pts_max - pts_min);
578
        pos = (((INT64)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
579
        if (pos <= pos_min)
580
            pos = pos_min;
581
        else if (pos >= pos_max)
582
            pos = pos_max;
583
        pts = get_pts(s, pos);
584
        /* check if we are lucky */
585
        if (pts == wanted_pts) {
586
            goto found;
587
        } else if (pts > wanted_pts) {
588
            pos_max = pos - FFM_PACKET_SIZE;
589
        } else {
590
            pos_min = pos + FFM_PACKET_SIZE;
591
        }
592
    }
593
    pos = pos_min;
594
    if (pos > 0)
595
        pos -= FFM_PACKET_SIZE;
596
 found:
597
    ffm_seek1(s, pos);
598
    return 0;
599
}
600
601
offset_t ffm_read_write_index(int fd)
602
{
603
    UINT8 buf[8];
604
    offset_t pos;
605
    int i;
606
607
    lseek(fd, 8, SEEK_SET);
608
    read(fd, buf, 8);
609
    pos = 0;
610 4606ac8d Zdenek Kabelac
    for(i=0;i<8;i++)
611 de6d9b64 Fabrice Bellard
        pos |= buf[i] << (56 - i * 8);
612
    return pos;
613
}
614
615
void ffm_write_write_index(int fd, offset_t pos)
616
{
617
    UINT8 buf[8];
618
    int i;
619
620 4606ac8d Zdenek Kabelac
    for(i=0;i<8;i++)
621 de6d9b64 Fabrice Bellard
        buf[i] = (pos >> (56 - i * 8)) & 0xff;
622
    lseek(fd, 8, SEEK_SET);
623
    write(fd, buf, 8);
624
}
625
626
void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
627
{
628
    FFMContext *ffm = s->priv_data;
629
    ffm->write_index = pos;
630
    ffm->file_size = file_size;
631
}
632
633
static int ffm_read_close(AVFormatContext *s)
634
{
635
    AVStream *st;
636
    int i;
637
638
    for(i=0;i<s->nb_streams;i++) {
639
        st = s->streams[i];
640 789bee12 Philip Gladstone
        av_freep(&st->priv_data);
641 de6d9b64 Fabrice Bellard
    }
642
    return 0;
643
}
644
645 07c4ed85 Philip Gladstone
static int ffm_probe(AVProbeData *p)
646
{
647 66d2ff2a Fabrice Bellard
    if (p->buf_size >= 4 &&
648
        p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' && 
649
        p->buf[3] == '1')
650 07c4ed85 Philip Gladstone
        return AVPROBE_SCORE_MAX + 1;
651
    return 0;
652
}
653
654 c18a2692 Zdenek Kabelac
static AVInputFormat ffm_iformat = {
655 c9a65ca8 Fabrice Bellard
    "ffm",
656
    "ffm format",
657 66d2ff2a Fabrice Bellard
    sizeof(FFMContext),
658 07c4ed85 Philip Gladstone
    ffm_probe,
659 c9a65ca8 Fabrice Bellard
    ffm_read_header,
660
    ffm_read_packet,
661
    ffm_read_close,
662
    ffm_seek,
663
};
664
665 c18a2692 Zdenek Kabelac
static AVOutputFormat ffm_oformat = {
666 de6d9b64 Fabrice Bellard
    "ffm",
667
    "ffm format",
668
    "",
669
    "ffm",
670 66d2ff2a Fabrice Bellard
    sizeof(FFMContext),
671 de6d9b64 Fabrice Bellard
    /* not really used */
672
    CODEC_ID_MP2,
673
    CODEC_ID_MPEG1VIDEO,
674
    ffm_write_header,
675
    ffm_write_packet,
676
    ffm_write_trailer,
677
};
678 c9a65ca8 Fabrice Bellard
679
int ffm_init(void)
680
{
681
    av_register_input_format(&ffm_iformat);
682
    av_register_output_format(&ffm_oformat);
683
    return 0;
684
}