ffm.c 19.1 KB
Newer Older
Fabrice Bellard's avatar
Fabrice Bellard committed
1 2
/*
 * FFM (ffserver live feed) encoder and decoder
3
 * Copyright (c) 2001 Fabrice Bellard.
Fabrice Bellard's avatar
Fabrice Bellard committed
4
 *
5 6 7 8
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
Fabrice Bellard's avatar
Fabrice Bellard committed
9
 *
10
 * This library is distributed in the hope that it will be useful,
Fabrice Bellard's avatar
Fabrice Bellard committed
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 13
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
Fabrice Bellard's avatar
Fabrice Bellard committed
14
 *
15 16 17
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
Fabrice Bellard's avatar
Fabrice Bellard committed
18 19
 */
#include "avformat.h"
Fabrice Bellard's avatar
Fabrice Bellard committed
20
#include <unistd.h>
Fabrice Bellard's avatar
Fabrice Bellard committed
21 22 23 24 25 26

/* The FFM file is made of blocks of fixed size */
#define FFM_HEADER_SIZE 14
#define PACKET_ID       0x666d

/* each packet contains frames (which can span several packets */
27
#define FRAME_HEADER_SIZE    8
Fabrice Bellard's avatar
Fabrice Bellard committed
28 29 30
#define FLAG_KEY_FRAME       0x01

typedef struct FFMStream {
31
    int64_t pts;
Fabrice Bellard's avatar
Fabrice Bellard committed
32 33 34 35 36 37 38 39 40 41
} FFMStream;

enum {
    READ_HEADER,
    READ_DATA,
};

typedef struct FFMContext {
    /* only reading mode */
    offset_t write_index, file_size;
42
    int read_state;
43
    uint8_t header[FRAME_HEADER_SIZE];
Fabrice Bellard's avatar
Fabrice Bellard committed
44 45 46 47 48

    /* read and write */
    int first_packet; /* true if first packet, needed to set the discontinuity tag */
    int packet_size;
    int frame_offset;
49 50 51
    int64_t pts;
    uint8_t *packet_ptr, *packet_end;
    uint8_t packet[FFM_PACKET_SIZE];
Fabrice Bellard's avatar
Fabrice Bellard committed
52 53
} FFMContext;

Fabrice Bellard's avatar
Fabrice Bellard committed
54 55 56
/* disable pts hack for testing */
int ffm_nopts = 0;

Fabrice Bellard's avatar
Fabrice Bellard committed
57 58 59 60 61 62 63 64
static void flush_packet(AVFormatContext *s)
{
    FFMContext *ffm = s->priv_data;
    int fill_size, h;
    ByteIOContext *pb = &s->pb;

    fill_size = ffm->packet_end - ffm->packet_ptr;
    memset(ffm->packet_ptr, 0, fill_size);
65

Fabrice Bellard's avatar
Fabrice Bellard committed
66
    /* put header */
67
    put_be16(pb, PACKET_ID);
Fabrice Bellard's avatar
Fabrice Bellard committed
68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83
    put_be16(pb, fill_size);
    put_be64(pb, ffm->pts);
    h = ffm->frame_offset;
    if (ffm->first_packet)
        h |= 0x8000;
    put_be16(pb, h);
    put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet);

    /* prepare next packet */
    ffm->frame_offset = 0; /* no key frame */
    ffm->pts = 0; /* no pts */
    ffm->packet_ptr = ffm->packet;
    ffm->first_packet = 0;
}

/* 'first' is true if first data of a frame */
84
static void ffm_write_data(AVFormatContext *s,
85 86
                           uint8_t *buf, int size,
                           int64_t pts, int first)
Fabrice Bellard's avatar
Fabrice Bellard committed
87 88 89 90 91 92 93 94 95 96 97 98 99 100 101
{
    FFMContext *ffm = s->priv_data;
    int len;

    if (first && ffm->frame_offset == 0)
        ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
    if (first && ffm->pts == 0)
        ffm->pts = pts;

    /* write as many packets as needed */
    while (size > 0) {
        len = ffm->packet_end - ffm->packet_ptr;
        if (len > size)
            len = size;
        memcpy(ffm->packet_ptr, buf, len);
102

Fabrice Bellard's avatar
Fabrice Bellard committed
103 104 105 106 107 108 109 110 111 112 113 114 115 116 117
        ffm->packet_ptr += len;
        buf += len;
        size -= len;
        if (ffm->packet_ptr >= ffm->packet_end) {
            /* special case : no pts in packet : we leave the current one */
            if (ffm->pts == 0)
                ffm->pts = pts;

            flush_packet(s);
        }
    }
}

static int ffm_write_header(AVFormatContext *s)
{
Fabrice Bellard's avatar
Fabrice Bellard committed
118
    FFMContext *ffm = s->priv_data;
Fabrice Bellard's avatar
Fabrice Bellard committed
119 120 121 122 123 124 125
    AVStream *st;
    FFMStream *fst;
    ByteIOContext *pb = &s->pb;
    AVCodecContext *codec;
    int bit_rate, i;

    ffm->packet_size = FFM_PACKET_SIZE;
126

Fabrice Bellard's avatar
Fabrice Bellard committed
127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
    /* header */
    put_tag(pb, "FFM1");
    put_be32(pb, ffm->packet_size);
    /* XXX: store write position in other file ? */
    put_be64(pb, ffm->packet_size); /* current write position */

    put_be32(pb, s->nb_streams);
    bit_rate = 0;
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        bit_rate += st->codec.bit_rate;
    }
    put_be32(pb, bit_rate);

    /* list of streams */
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
144
        fst = av_mallocz(sizeof(FFMStream));
Fabrice Bellard's avatar
Fabrice Bellard committed
145 146 147 148 149 150 151 152 153
        if (!fst)
            goto fail;
        st->priv_data = fst;

        codec = &st->codec;
        /* generic info */
        put_be32(pb, codec->codec_id);
        put_byte(pb, codec->codec_type);
        put_be32(pb, codec->bit_rate);
Michael Niedermayer's avatar
cleanup  
Michael Niedermayer committed
154
	put_be32(pb, st->quality);
155
        put_be32(pb, codec->flags);
Fabrice Bellard's avatar
Fabrice Bellard committed
156 157 158
        /* specific info */
        switch(codec->codec_type) {
        case CODEC_TYPE_VIDEO:
159 160
            put_be32(pb, codec->frame_rate_base);
            put_be32(pb, codec->frame_rate);
Fabrice Bellard's avatar
Fabrice Bellard committed
161 162
            put_be16(pb, codec->width);
            put_be16(pb, codec->height);
163 164 165 166 167 168
            put_be16(pb, codec->gop_size);
            put_byte(pb, codec->qmin);
            put_byte(pb, codec->qmax);
            put_byte(pb, codec->max_qdiff);
            put_be16(pb, (int) (codec->qcompress * 10000.0));
            put_be16(pb, (int) (codec->qblur * 10000.0));
169
            put_be32(pb, codec->bit_rate_tolerance);
170
            put_strz(pb, codec->rc_eq);
171 172 173
            put_be32(pb, codec->rc_max_rate);
            put_be32(pb, codec->rc_min_rate);
            put_be32(pb, codec->rc_buffer_size);
174 175 176 177
            put_be64_double(pb, codec->i_quant_factor);
            put_be64_double(pb, codec->b_quant_factor);
            put_be64_double(pb, codec->i_quant_offset);
            put_be64_double(pb, codec->b_quant_offset);
178
            put_be32(pb, codec->dct_algo);
Fabrice Bellard's avatar
Fabrice Bellard committed
179 180 181 182
            break;
        case CODEC_TYPE_AUDIO:
            put_be32(pb, codec->sample_rate);
            put_le16(pb, codec->channels);
183
            put_le16(pb, codec->frame_size);
Fabrice Bellard's avatar
Fabrice Bellard committed
184
            break;
185
        default:
186
            av_abort();
Fabrice Bellard's avatar
Fabrice Bellard committed
187 188
        }
        /* hack to have real time */
Fabrice Bellard's avatar
Fabrice Bellard committed
189 190 191
        if (ffm_nopts)
            fst->pts = 0;
        else
192
            fst->pts = av_gettime();
Fabrice Bellard's avatar
Fabrice Bellard committed
193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211
    }

    /* flush until end of block reached */
    while ((url_ftell(pb) % ffm->packet_size) != 0)
        put_byte(pb, 0);

    put_flush_packet(pb);

    /* init packet mux */
    ffm->packet_ptr = ffm->packet;
    ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
    ffm->frame_offset = 0;
    ffm->pts = 0;
    ffm->first_packet = 1;

    return 0;
 fail:
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
212
        av_freep(&st->priv_data);
Fabrice Bellard's avatar
Fabrice Bellard committed
213 214 215 216 217
    }
    return -1;
}

static int ffm_write_packet(AVFormatContext *s, int stream_index,
218
                            uint8_t *buf, int size, int force_pts)
Fabrice Bellard's avatar
Fabrice Bellard committed
219 220 221
{
    AVStream *st = s->streams[stream_index];
    FFMStream *fst = st->priv_data;
222 223
    int64_t pts;
    uint8_t header[FRAME_HEADER_SIZE];
224 225 226 227 228
    int duration;

    if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
        duration = ((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0);
    } else {
229
        duration = (1000000.0 * st->codec.frame_rate_base / (float)st->codec.frame_rate);
230
    }
Fabrice Bellard's avatar
Fabrice Bellard committed
231 232 233 234 235

    pts = fst->pts;
    /* packet size & key_frame */
    header[0] = stream_index;
    header[1] = 0;
Michael Niedermayer's avatar
Michael Niedermayer committed
236
    if (st->codec.coded_frame->key_frame) //if st->codec.coded_frame==NULL then there is a bug somewhere else
Fabrice Bellard's avatar
Fabrice Bellard committed
237 238 239 240
        header[1] |= FLAG_KEY_FRAME;
    header[2] = (size >> 16) & 0xff;
    header[3] = (size >> 8) & 0xff;
    header[4] = size & 0xff;
241 242 243
    header[5] = (duration >> 16) & 0xff;
    header[6] = (duration >> 8) & 0xff;
    header[7] = duration & 0xff;
Fabrice Bellard's avatar
Fabrice Bellard committed
244 245 246
    ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
    ffm_write_data(s, buf, size, pts, 0);

247
    fst->pts += duration;
Fabrice Bellard's avatar
Fabrice Bellard committed
248 249 250 251 252 253 254 255 256 257 258 259 260 261 262
    return 0;
}

static int ffm_write_trailer(AVFormatContext *s)
{
    ByteIOContext *pb = &s->pb;
    FFMContext *ffm = s->priv_data;
    int i;

    /* flush packets */
    if (ffm->packet_ptr > ffm->packet)
        flush_packet(s);

    put_flush_packet(pb);

263
    if (!url_is_streamed(pb)) {
264
        int64_t size;
265 266 267 268 269 270 271
        /* update the write offset */
        size = url_ftell(pb);
        url_fseek(pb, 8, SEEK_SET);
        put_be64(pb, size);
        put_flush_packet(pb);
    }

Fabrice Bellard's avatar
Fabrice Bellard committed
272
    for(i=0;i<s->nb_streams;i++)
273
        av_freep(&s->streams[i]->priv_data);
Fabrice Bellard's avatar
Fabrice Bellard committed
274 275 276 277 278 279 280 281 282 283 284 285
    return 0;
}

/* ffm demux */

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

    len = ffm->packet_end - ffm->packet_ptr;
286 287 288 289 290
    if (!ffm_nopts) {
        /* XXX: I don't understand this test, so I disabled it for testing */
        if (size <= len)
            return 1;
    }
Fabrice Bellard's avatar
Fabrice Bellard committed
291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307
    pos = url_ftell(&s->pb);
    if (pos == ffm->write_index) {
        /* exactly at the end of stream */
        return 0;
    } else if (pos < ffm->write_index) {
        avail_size = ffm->write_index - pos;
    } else {
        avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
    }
    avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
    if (size <= avail_size)
        return 1;
    else
        return 0;
}

/* first is true if we read the frame header */
308
static int ffm_read_data(AVFormatContext *s,
309
                         uint8_t *buf, int size, int first)
Fabrice Bellard's avatar
Fabrice Bellard committed
310 311 312 313 314 315 316 317 318 319 320 321 322 323
{
    FFMContext *ffm = s->priv_data;
    ByteIOContext *pb = &s->pb;
    int len, fill_size, size1, frame_offset;

    size1 = size;
    while (size > 0) {
    redo:
        len = ffm->packet_end - ffm->packet_ptr;
        if (len > size)
            len = size;
        if (len == 0) {
            if (url_ftell(pb) == ffm->file_size)
                url_fseek(pb, ffm->packet_size, SEEK_SET);
324
    retry_read:
Fabrice Bellard's avatar
Fabrice Bellard committed
325 326 327 328 329 330 331 332 333
            get_be16(pb); /* PACKET_ID */
            fill_size = get_be16(pb);
            ffm->pts = get_be64(pb);
            frame_offset = get_be16(pb);
            get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
            ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
            /* if first packet or resynchronization packet, we must
               handle it specifically */
            if (ffm->first_packet || (frame_offset & 0x8000)) {
334 335 336 337 338 339 340 341 342
                if (!frame_offset) {
                    /* This packet has no frame headers in it */
                    if (url_ftell(pb) >= ffm->packet_size * 3) {
                        url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
                        goto retry_read;
                    }
                    /* This is bad, we cannot find a valid frame header */
                    return 0;
                }
Fabrice Bellard's avatar
Fabrice Bellard committed
343
                ffm->first_packet = 0;
344
                if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
345
                    av_abort();
Fabrice Bellard's avatar
Fabrice Bellard committed
346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365
                ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
                if (!first)
                    break;
            } else {
                ffm->packet_ptr = ffm->packet;
            }
            goto redo;
        }
        memcpy(buf, ffm->packet_ptr, len);
        buf += len;
        ffm->packet_ptr += len;
        size -= len;
        first = 0;
    }
    return size1 - size;
}


static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
Fabrice Bellard's avatar
Fabrice Bellard committed
366
    FFMContext *ffm = s->priv_data;
Fabrice Bellard's avatar
Fabrice Bellard committed
367 368 369 370
    AVStream *st;
    FFMStream *fst;
    ByteIOContext *pb = &s->pb;
    AVCodecContext *codec;
Fabrice Bellard's avatar
Fabrice Bellard committed
371
    int i, nb_streams;
372
    uint32_t tag;
Fabrice Bellard's avatar
Fabrice Bellard committed
373 374 375 376 377 378 379 380 381 382 383 384 385

    /* header */
    tag = get_le32(pb);
    if (tag != MKTAG('F', 'F', 'M', '1'))
        goto fail;
    ffm->packet_size = get_be32(pb);
    if (ffm->packet_size != FFM_PACKET_SIZE)
        goto fail;
    ffm->write_index = get_be64(pb);
    /* get also filesize */
    if (!url_is_streamed(pb)) {
        ffm->file_size = url_filesize(url_fileno(pb));
    } else {
386
        ffm->file_size = (uint64_t_C(1) << 63) - 1;
Fabrice Bellard's avatar
Fabrice Bellard committed
387 388
    }

Fabrice Bellard's avatar
Fabrice Bellard committed
389
    nb_streams = get_be32(pb);
Fabrice Bellard's avatar
Fabrice Bellard committed
390 391
    get_be32(pb); /* total bitrate */
    /* read each stream */
Fabrice Bellard's avatar
Fabrice Bellard committed
392
    for(i=0;i<nb_streams;i++) {
393 394
        char rc_eq_buf[128];

Fabrice Bellard's avatar
Fabrice Bellard committed
395
        st = av_new_stream(s, 0);
Fabrice Bellard's avatar
Fabrice Bellard committed
396 397
        if (!st)
            goto fail;
398
        fst = av_mallocz(sizeof(FFMStream));
Fabrice Bellard's avatar
Fabrice Bellard committed
399 400 401 402 403 404 405 406 407
        if (!fst)
            goto fail;
        st->priv_data = fst;

        codec = &st->codec;
        /* generic info */
        st->codec.codec_id = get_be32(pb);
        st->codec.codec_type = get_byte(pb); /* codec_type */
        codec->bit_rate = get_be32(pb);
Michael Niedermayer's avatar
cleanup  
Michael Niedermayer committed
408
	st->quality = get_be32(pb);
409
        codec->flags = get_be32(pb);
Fabrice Bellard's avatar
Fabrice Bellard committed
410 411 412
        /* specific info */
        switch(codec->codec_type) {
        case CODEC_TYPE_VIDEO:
413 414
            codec->frame_rate_base = get_be32(pb);
            codec->frame_rate = get_be32(pb);
Fabrice Bellard's avatar
Fabrice Bellard committed
415 416
            codec->width = get_be16(pb);
            codec->height = get_be16(pb);
417 418 419 420 421 422
            codec->gop_size = get_be16(pb);
            codec->qmin = get_byte(pb);
            codec->qmax = get_byte(pb);
            codec->max_qdiff = get_byte(pb);
            codec->qcompress = get_be16(pb) / 10000.0;
            codec->qblur = get_be16(pb) / 10000.0;
423
            codec->bit_rate_tolerance = get_be32(pb);
Fabrice Bellard's avatar
Fabrice Bellard committed
424
            codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
425 426 427
            codec->rc_max_rate = get_be32(pb);
            codec->rc_min_rate = get_be32(pb);
            codec->rc_buffer_size = get_be32(pb);
428 429 430 431
            codec->i_quant_factor = get_be64_double(pb);
            codec->b_quant_factor = get_be64_double(pb);
            codec->i_quant_offset = get_be64_double(pb);
            codec->b_quant_offset = get_be64_double(pb);
432
            codec->dct_algo = get_be32(pb);
Fabrice Bellard's avatar
Fabrice Bellard committed
433 434 435 436
            break;
        case CODEC_TYPE_AUDIO:
            codec->sample_rate = get_be32(pb);
            codec->channels = get_le16(pb);
437
            codec->frame_size = get_le16(pb);
Fabrice Bellard's avatar
Fabrice Bellard committed
438
            break;
439
        default:
440
            goto fail;
Fabrice Bellard's avatar
Fabrice Bellard committed
441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460
        }

    }

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

    /* init packet demux */
    ffm->packet_ptr = ffm->packet;
    ffm->packet_end = ffm->packet;
    ffm->frame_offset = 0;
    ffm->pts = 0;
    ffm->read_state = READ_HEADER;
    ffm->first_packet = 1;
    return 0;
 fail:
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        if (st) {
461
            av_freep(&st->priv_data);
462
            av_free(st);
Fabrice Bellard's avatar
Fabrice Bellard committed
463 464 465 466 467 468 469 470 471 472
        }
    }
    return -1;
}

/* return < 0 if eof */
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    int size;
    FFMContext *ffm = s->priv_data;
473
    int duration;
Fabrice Bellard's avatar
Fabrice Bellard committed
474 475 476

    switch(ffm->read_state) {
    case READ_HEADER:
477
        if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
Fabrice Bellard's avatar
Fabrice Bellard committed
478
            return -EAGAIN;
479
        }
Fabrice Bellard's avatar
Fabrice Bellard committed
480
#if 0
481
        printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n",
Fabrice Bellard's avatar
Fabrice Bellard committed
482 483
               url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
#endif
484 485
        if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) != 
            FRAME_HEADER_SIZE)
Fabrice Bellard's avatar
Fabrice Bellard committed
486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502
            return -EAGAIN;
#if 0
        {
            int i;
            for(i=0;i<FRAME_HEADER_SIZE;i++)
                printf("%02x ", ffm->header[i]);
            printf("\n");
        }
#endif
        ffm->read_state = READ_DATA;
        /* fall thru */
    case READ_DATA:
        size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4];
        if (!ffm_is_avail_data(s, size)) {
            return -EAGAIN;
        }

503 504
        duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];

Fabrice Bellard's avatar
Fabrice Bellard committed
505 506 507 508
        av_new_packet(pkt, size);
        pkt->stream_index = ffm->header[0];
        if (ffm->header[1] & FLAG_KEY_FRAME)
            pkt->flags |= PKT_FLAG_KEY;
509

Fabrice Bellard's avatar
Fabrice Bellard committed
510 511 512 513 514 515
        ffm->read_state = READ_HEADER;
        if (ffm_read_data(s, pkt->data, size, 0) != size) {
            /* bad case: desynchronized packet. we cancel all the packet loading */
            av_free_packet(pkt);
            return -EAGAIN;
        }
516 517
        pkt->pts = ffm->pts;
        pkt->duration = duration;
Fabrice Bellard's avatar
Fabrice Bellard committed
518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541
        break;
    }
    return 0;
}

//#define DEBUG_SEEK

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

    pos = pos1 + ffm->write_index;
    if (pos >= ffm->file_size)
        pos -= (ffm->file_size - FFM_PACKET_SIZE);
#ifdef DEBUG_SEEK
    printf("seek to %Lx -> %Lx\n", pos1, pos);
#endif
    url_fseek(pb, pos, SEEK_SET);
}

542
static int64_t get_pts(AVFormatContext *s, offset_t pos)
Fabrice Bellard's avatar
Fabrice Bellard committed
543 544
{
    ByteIOContext *pb = &s->pb;
545
    int64_t pts;
Fabrice Bellard's avatar
Fabrice Bellard committed
546

547
    ffm_seek1(s, pos);
Fabrice Bellard's avatar
Fabrice Bellard committed
548 549 550 551 552 553 554 555 556 557 558
    url_fskip(pb, 4);
    pts = get_be64(pb);
#ifdef DEBUG_SEEK
    printf("pts=%0.6f\n", pts / 1000000.0);
#endif
    return pts;
}

/* seek to a given time in the file. The file read pointer is
   positionned at or before pts. XXX: the following code is quite
   approximative */
559
static int ffm_seek(AVFormatContext *s, int64_t wanted_pts)
Fabrice Bellard's avatar
Fabrice Bellard committed
560 561 562
{
    FFMContext *ffm = s->priv_data;
    offset_t pos_min, pos_max, pos;
563
    int64_t pts_min, pts_max, pts;
Fabrice Bellard's avatar
Fabrice Bellard committed
564 565 566 567 568 569 570 571 572 573 574 575 576
    double pos1;

#ifdef DEBUG_SEEK
    printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
#endif
    /* find the position using linear interpolation (better than
       dichotomy in typical cases) */
    pos_min = 0;
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
    while (pos_min <= pos_max) {
        pts_min = get_pts(s, pos_min);
        pts_max = get_pts(s, pos_max);
        /* linear interpolation */
577
        pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
Fabrice Bellard's avatar
Fabrice Bellard committed
578
            (double)(pts_max - pts_min);
579
        pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
Fabrice Bellard's avatar
Fabrice Bellard committed
580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603
        if (pos <= pos_min)
            pos = pos_min;
        else if (pos >= pos_max)
            pos = pos_max;
        pts = get_pts(s, pos);
        /* check if we are lucky */
        if (pts == wanted_pts) {
            goto found;
        } else if (pts > wanted_pts) {
            pos_max = pos - FFM_PACKET_SIZE;
        } else {
            pos_min = pos + FFM_PACKET_SIZE;
        }
    }
    pos = pos_min;
    if (pos > 0)
        pos -= FFM_PACKET_SIZE;
 found:
    ffm_seek1(s, pos);
    return 0;
}

offset_t ffm_read_write_index(int fd)
{
604
    uint8_t buf[8];
Fabrice Bellard's avatar
Fabrice Bellard committed
605 606 607 608 609 610
    offset_t pos;
    int i;

    lseek(fd, 8, SEEK_SET);
    read(fd, buf, 8);
    pos = 0;
611
    for(i=0;i<8;i++)
Fabrice Bellard's avatar
Fabrice Bellard committed
612
        pos |= (int64_t)buf[i] << (56 - i * 8);
Fabrice Bellard's avatar
Fabrice Bellard committed
613 614 615 616 617
    return pos;
}

void ffm_write_write_index(int fd, offset_t pos)
{
618
    uint8_t buf[8];
Fabrice Bellard's avatar
Fabrice Bellard committed
619 620
    int i;

621
    for(i=0;i<8;i++)
Fabrice Bellard's avatar
Fabrice Bellard committed
622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640
        buf[i] = (pos >> (56 - i * 8)) & 0xff;
    lseek(fd, 8, SEEK_SET);
    write(fd, buf, 8);
}

void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
{
    FFMContext *ffm = s->priv_data;
    ffm->write_index = pos;
    ffm->file_size = file_size;
}

static int ffm_read_close(AVFormatContext *s)
{
    AVStream *st;
    int i;

    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
641
        av_freep(&st->priv_data);
Fabrice Bellard's avatar
Fabrice Bellard committed
642 643 644 645
    }
    return 0;
}

646 647
static int ffm_probe(AVProbeData *p)
{
648 649 650
    if (p->buf_size >= 4 &&
        p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' && 
        p->buf[3] == '1')
651 652 653 654
        return AVPROBE_SCORE_MAX + 1;
    return 0;
}

Zdenek Kabelac's avatar
Zdenek Kabelac committed
655
static AVInputFormat ffm_iformat = {
Fabrice Bellard's avatar
Fabrice Bellard committed
656 657
    "ffm",
    "ffm format",
658
    sizeof(FFMContext),
659
    ffm_probe,
Fabrice Bellard's avatar
Fabrice Bellard committed
660 661 662 663 664 665
    ffm_read_header,
    ffm_read_packet,
    ffm_read_close,
    ffm_seek,
};

Zdenek Kabelac's avatar
Zdenek Kabelac committed
666
static AVOutputFormat ffm_oformat = {
Fabrice Bellard's avatar
Fabrice Bellard committed
667 668 669 670
    "ffm",
    "ffm format",
    "",
    "ffm",
671
    sizeof(FFMContext),
Fabrice Bellard's avatar
Fabrice Bellard committed
672 673 674 675 676 677 678
    /* not really used */
    CODEC_ID_MP2,
    CODEC_ID_MPEG1VIDEO,
    ffm_write_header,
    ffm_write_packet,
    ffm_write_trailer,
};
Fabrice Bellard's avatar
Fabrice Bellard committed
679 680 681 682 683 684 685

int ffm_init(void)
{
    av_register_input_format(&ffm_iformat);
    av_register_output_format(&ffm_oformat);
    return 0;
}