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ffmpeg / libavformat / ffmdec.c @ b9edbe99

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1
/*
2
 * FFM (ffserver live feed) demuxer
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 * Copyright (c) 2001 Fabrice Bellard
4
 *
5
 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
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 * 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 "libavutil/intreadwrite.h"
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#include "avformat.h"
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#include "ffm.h"
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#if CONFIG_FFSERVER
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#include <unistd.h>
27

    
28
int64_t ffm_read_write_index(int fd)
29
{
30
    uint8_t buf[8];
31

    
32
    lseek(fd, 8, SEEK_SET);
33
    if (read(fd, buf, 8) != 8)
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        return AVERROR(EIO);
35
    return AV_RB64(buf);
36
}
37

    
38
int ffm_write_write_index(int fd, int64_t pos)
39
{
40
    uint8_t buf[8];
41
    int i;
42

    
43
    for(i=0;i<8;i++)
44
        buf[i] = (pos >> (56 - i * 8)) & 0xff;
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    lseek(fd, 8, SEEK_SET);
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    if (write(fd, buf, 8) != 8)
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        return AVERROR(EIO);
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    return 8;
49
}
50

    
51
void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
52
{
53
    FFMContext *ffm = s->priv_data;
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    ffm->write_index = pos;
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    ffm->file_size = file_size;
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}
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#endif // CONFIG_FFSERVER
58

    
59
static int ffm_is_avail_data(AVFormatContext *s, int size)
60
{
61
    FFMContext *ffm = s->priv_data;
62
    int64_t pos, avail_size;
63
    int len;
64

    
65
    len = ffm->packet_end - ffm->packet_ptr;
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    if (size <= len)
67
        return 1;
68
    pos = url_ftell(s->pb);
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    if (!ffm->write_index) {
70
        if (pos == ffm->file_size);
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            return AVERROR_EOF;
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        avail_size = ffm->file_size - pos;
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    } else {
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    if (pos == ffm->write_index) {
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        /* exactly at the end of stream */
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        return AVERROR(EAGAIN);
77
    } else if (pos < ffm->write_index) {
78
        avail_size = ffm->write_index - pos;
79
    } else {
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        avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
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    }
82
    }
83
    avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
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    if (size <= avail_size)
85
        return 1;
86
    else
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        return AVERROR(EAGAIN);
88
}
89

    
90
/* 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)
93
{
94
    FFMContext *ffm = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    int len, fill_size, size1, frame_offset;
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98
    size1 = size;
99
    while (size > 0) {
100
    redo:
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        len = ffm->packet_end - ffm->packet_ptr;
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        if (len < 0)
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            return -1;
104
        if (len > size)
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            len = size;
106
        if (len == 0) {
107
            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->dts = get_be64(pb);
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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)
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                return -1;
118
            /* if first packet or resynchronization packet, we must
119
               handle it specifically */
120
            if (ffm->first_packet || (frame_offset & 0x8000)) {
121
                if (!frame_offset) {
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                    /* This packet has no frame headers in it */
123
                    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;
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                    }
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                    /* This is bad, we cannot find a valid frame header */
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                    return 0;
129
                }
130
                ffm->first_packet = 0;
131
                if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
132
                    return -1;
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                ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
134
                if (!header)
135
                    break;
136
            } else {
137
                ffm->packet_ptr = ffm->packet;
138
            }
139
            goto redo;
140
        }
141
        memcpy(buf, ffm->packet_ptr, len);
142
        buf += len;
143
        ffm->packet_ptr += len;
144
        size -= len;
145
        header = 0;
146
    }
147
    return size1 - size;
148
}
149

    
150
//#define DEBUG_SEEK
151

    
152
/* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
153
   by the write position inside this function */
154
static void ffm_seek1(AVFormatContext *s, int64_t pos1)
155
{
156
    FFMContext *ffm = s->priv_data;
157
    ByteIOContext *pb = s->pb;
158
    int64_t pos;
159

    
160
    pos = pos1 + ffm->write_index;
161
    if (pos >= ffm->file_size)
162
        pos -= (ffm->file_size - FFM_PACKET_SIZE);
163
#ifdef DEBUG_SEEK
164
    av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
165
#endif
166
    url_fseek(pb, pos, SEEK_SET);
167
}
168

    
169
static int64_t get_dts(AVFormatContext *s, int64_t pos)
170
{
171
    ByteIOContext *pb = s->pb;
172
    int64_t dts;
173

    
174
    ffm_seek1(s, pos);
175
    url_fskip(pb, 4);
176
    dts = get_be64(pb);
177
#ifdef DEBUG_SEEK
178
    av_log(s, AV_LOG_DEBUG, "pts=%0.6f\n", pts / 1000000.0);
179
#endif
180
    return dts;
181
}
182

    
183
static void adjust_write_index(AVFormatContext *s)
184
{
185
    FFMContext *ffm = s->priv_data;
186
    ByteIOContext *pb = s->pb;
187
    int64_t pts;
188
    //int64_t orig_write_index = ffm->write_index;
189
    int64_t pos_min, pos_max;
190
    int64_t pts_start;
191
    int64_t ptr = url_ftell(pb);
192

    
193

    
194
    pos_min = 0;
195
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
196

    
197
    pts_start = get_dts(s, pos_min);
198

    
199
    pts = get_dts(s, pos_max);
200

    
201
    if (pts - 100000 > pts_start)
202
        goto end;
203

    
204
    ffm->write_index = FFM_PACKET_SIZE;
205

    
206
    pts_start = get_dts(s, pos_min);
207

    
208
    pts = get_dts(s, pos_max);
209

    
210
    if (pts - 100000 <= pts_start) {
211
        while (1) {
212
            int64_t newpos;
213
            int64_t newpts;
214

    
215
            newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
216

    
217
            if (newpos == pos_min)
218
                break;
219

    
220
            newpts = get_dts(s, newpos);
221

    
222
            if (newpts - 100000 <= pts) {
223
                pos_max = newpos;
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                pts = newpts;
225
            } else {
226
                pos_min = newpos;
227
            }
228
        }
229
        ffm->write_index += pos_max;
230
    }
231

    
232
    //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_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
234

    
235
 end:
236
    url_fseek(pb, ptr, SEEK_SET);
237
}
238

    
239

    
240
static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
241
{
242
    FFMContext *ffm = s->priv_data;
243
    AVStream *st;
244
    ByteIOContext *pb = s->pb;
245
    AVCodecContext *codec;
246
    int i, nb_streams;
247
    uint32_t tag;
248

    
249
    /* header */
250
    tag = get_le32(pb);
251
    if (tag != MKTAG('F', 'F', 'M', '1'))
252
        goto fail;
253
    ffm->packet_size = get_be32(pb);
254
    if (ffm->packet_size != FFM_PACKET_SIZE)
255
        goto fail;
256
    ffm->write_index = get_be64(pb);
257
    /* get also filesize */
258
    if (!url_is_streamed(pb)) {
259
        ffm->file_size = url_fsize(pb);
260
        if (ffm->write_index)
261
            adjust_write_index(s);
262
    } else {
263
        ffm->file_size = (UINT64_C(1) << 63) - 1;
264
    }
265

    
266
    nb_streams = get_be32(pb);
267
    get_be32(pb); /* total bitrate */
268
    /* read each stream */
269
    for(i=0;i<nb_streams;i++) {
270
        char rc_eq_buf[128];
271

    
272
        st = av_new_stream(s, 0);
273
        if (!st)
274
            goto fail;
275
        s->streams[i] = st;
276

    
277
        av_set_pts_info(st, 64, 1, 1000000);
278

    
279
        codec = st->codec;
280
        /* generic info */
281
        codec->codec_id = get_be32(pb);
282
        codec->codec_type = get_byte(pb); /* codec_type */
283
        codec->bit_rate = get_be32(pb);
284
        st->quality = get_be32(pb);
285
        codec->flags = get_be32(pb);
286
        codec->flags2 = get_be32(pb);
287
        codec->debug = get_be32(pb);
288
        /* specific info */
289
        switch(codec->codec_type) {
290
        case CODEC_TYPE_VIDEO:
291
            codec->time_base.num = get_be32(pb);
292
            codec->time_base.den = get_be32(pb);
293
            codec->width = get_be16(pb);
294
            codec->height = get_be16(pb);
295
            codec->gop_size = get_be16(pb);
296
            codec->pix_fmt = get_be32(pb);
297
            codec->qmin = get_byte(pb);
298
            codec->qmax = get_byte(pb);
299
            codec->max_qdiff = get_byte(pb);
300
            codec->qcompress = get_be16(pb) / 10000.0;
301
            codec->qblur = get_be16(pb) / 10000.0;
302
            codec->bit_rate_tolerance = get_be32(pb);
303
            codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
304
            codec->rc_max_rate = get_be32(pb);
305
            codec->rc_min_rate = get_be32(pb);
306
            codec->rc_buffer_size = get_be32(pb);
307
            codec->i_quant_factor = av_int2dbl(get_be64(pb));
308
            codec->b_quant_factor = av_int2dbl(get_be64(pb));
309
            codec->i_quant_offset = av_int2dbl(get_be64(pb));
310
            codec->b_quant_offset = av_int2dbl(get_be64(pb));
311
            codec->dct_algo = get_be32(pb);
312
            codec->strict_std_compliance = get_be32(pb);
313
            codec->max_b_frames = get_be32(pb);
314
            codec->luma_elim_threshold = get_be32(pb);
315
            codec->chroma_elim_threshold = get_be32(pb);
316
            codec->mpeg_quant = get_be32(pb);
317
            codec->intra_dc_precision = get_be32(pb);
318
            codec->me_method = get_be32(pb);
319
            codec->mb_decision = get_be32(pb);
320
            codec->nsse_weight = get_be32(pb);
321
            codec->frame_skip_cmp = get_be32(pb);
322
            codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
323
            codec->codec_tag = get_be32(pb);
324
            codec->thread_count = get_byte(pb);
325
            break;
326
        case CODEC_TYPE_AUDIO:
327
            codec->sample_rate = get_be32(pb);
328
            codec->channels = get_le16(pb);
329
            codec->frame_size = get_le16(pb);
330
            break;
331
        default:
332
            goto fail;
333
        }
334
        if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
335
            codec->extradata_size = get_be32(pb);
336
            codec->extradata = av_malloc(codec->extradata_size);
337
            if (!codec->extradata)
338
                return AVERROR(ENOMEM);
339
            get_buffer(pb, codec->extradata, codec->extradata_size);
340
        }
341
    }
342

    
343
    /* get until end of block reached */
344
    while ((url_ftell(pb) % ffm->packet_size) != 0)
345
        get_byte(pb);
346

    
347
    /* init packet demux */
348
    ffm->packet_ptr = ffm->packet;
349
    ffm->packet_end = ffm->packet;
350
    ffm->frame_offset = 0;
351
    ffm->dts = 0;
352
    ffm->read_state = READ_HEADER;
353
    ffm->first_packet = 1;
354
    return 0;
355
 fail:
356
    for(i=0;i<s->nb_streams;i++) {
357
        st = s->streams[i];
358
        if (st) {
359
            av_free(st);
360
        }
361
    }
362
    return -1;
363
}
364

    
365
/* return < 0 if eof */
366
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
367
{
368
    int size;
369
    FFMContext *ffm = s->priv_data;
370
    int duration, ret;
371

    
372
    switch(ffm->read_state) {
373
    case READ_HEADER:
374
        if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
375
            return ret;
376

    
377
        dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
378
               url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
379
        if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
380
            FRAME_HEADER_SIZE)
381
            return -1;
382
        if (ffm->header[1] & FLAG_DTS)
383
            if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
384
                return -1;
385
#if 0
386
        av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
387
#endif
388
        ffm->read_state = READ_DATA;
389
        /* fall thru */
390
    case READ_DATA:
391
        size = AV_RB24(ffm->header + 2);
392
        if ((ret = ffm_is_avail_data(s, size)) < 0)
393
            return ret;
394

    
395
        duration = AV_RB24(ffm->header + 5);
396

    
397
        av_new_packet(pkt, size);
398
        pkt->stream_index = ffm->header[0];
399
        if ((unsigned)pkt->stream_index >= s->nb_streams) {
400
            av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
401
            av_free_packet(pkt);
402
            ffm->read_state = READ_HEADER;
403
            return -1;
404
        }
405
        pkt->pos = url_ftell(s->pb);
406
        if (ffm->header[1] & FLAG_KEY_FRAME)
407
            pkt->flags |= PKT_FLAG_KEY;
408

    
409
        ffm->read_state = READ_HEADER;
410
        if (ffm_read_data(s, pkt->data, size, 0) != size) {
411
            /* bad case: desynchronized packet. we cancel all the packet loading */
412
            av_free_packet(pkt);
413
            return -1;
414
        }
415
        pkt->pts = AV_RB64(ffm->header+8);
416
        if (ffm->header[1] & FLAG_DTS)
417
            pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
418
        else
419
            pkt->dts = pkt->pts;
420
        pkt->duration = duration;
421
        break;
422
    }
423
    return 0;
424
}
425

    
426
/* seek to a given time in the file. The file read pointer is
427
   positioned at or before pts. XXX: the following code is quite
428
   approximative */
429
static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
430
{
431
    FFMContext *ffm = s->priv_data;
432
    int64_t pos_min, pos_max, pos;
433
    int64_t pts_min, pts_max, pts;
434
    double pos1;
435

    
436
#ifdef DEBUG_SEEK
437
    av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
438
#endif
439
    /* find the position using linear interpolation (better than
440
       dichotomy in typical cases) */
441
    pos_min = 0;
442
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
443
    while (pos_min <= pos_max) {
444
        pts_min = get_dts(s, pos_min);
445
        pts_max = get_dts(s, pos_max);
446
        /* linear interpolation */
447
        pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
448
            (double)(pts_max - pts_min);
449
        pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
450
        if (pos <= pos_min)
451
            pos = pos_min;
452
        else if (pos >= pos_max)
453
            pos = pos_max;
454
        pts = get_dts(s, pos);
455
        /* check if we are lucky */
456
        if (pts == wanted_pts) {
457
            goto found;
458
        } else if (pts > wanted_pts) {
459
            pos_max = pos - FFM_PACKET_SIZE;
460
        } else {
461
            pos_min = pos + FFM_PACKET_SIZE;
462
        }
463
    }
464
    pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
465
    if (pos > 0)
466
        pos -= FFM_PACKET_SIZE;
467
 found:
468
    ffm_seek1(s, pos);
469

    
470
    /* reset read state */
471
    ffm->read_state = READ_HEADER;
472
    ffm->packet_ptr = ffm->packet;
473
    ffm->packet_end = ffm->packet;
474
    ffm->first_packet = 1;
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 (FFserver live feed) format"),
491
    sizeof(FFMContext),
492
    ffm_probe,
493
    ffm_read_header,
494
    ffm_read_packet,
495
    NULL,
496
    ffm_seek,
497
};