libavformat/ffmdec.c

   1 /*
   2  * FFM (ffserver live feed) demuxer
   3  * Copyright (c) 2001 Fabrice Bellard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   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
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * 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
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/intreadwrite.h"
  23 #include "avformat.h"
  24 #include "ffm.h"
  25 #if CONFIG_FFSERVER
  26 #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)
  34         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;
  45     lseek(fd, 8, SEEK_SET);
  46     if (write(fd, buf, 8) != 8)
  47         return AVERROR(EIO);
  48     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;
  54     ffm->write_index = pos;
  55     ffm->file_size = file_size;
  56 }
  57 #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;
  66     if (size <= len)
  67         return 1;
  68     pos = url_ftell(s->pb);
  69     if (!ffm->write_index) {
  70         if (pos == ffm->file_size)
  71             return AVERROR_EOF;
  72         avail_size = ffm->file_size - pos;
  73     } else {
  74     if (pos == ffm->write_index) {
  75         /* exactly at the end of stream */
  76         return AVERROR(EAGAIN);
  77     } else if (pos < ffm->write_index) {
  78         avail_size = ffm->write_index - pos;
  79     } else {
  80         avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
  81     }
  82     }
  83     avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
  84     if (size <= avail_size)
  85         return 1;
  86     else
  87         return AVERROR(EAGAIN);
  88 }
  89
  90 static int ffm_resync(AVFormatContext *s, int state)
  91 {
  92     av_log(s, AV_LOG_ERROR, "resyncing\n");
  93     while (state != PACKET_ID) {
  94         if (url_feof(s->pb)) {
  95             av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
  96             return -1;
  97         }
  98         state = (state << 8) | get_byte(s->pb);
  99     }
 100     return 0;
 101 }
 102
 103 /* first is true if we read the frame header */
 104 static int ffm_read_data(AVFormatContext *s,
 105                          uint8_t *buf, int size, int header)
 106 {
 107     FFMContext *ffm = s->priv_data;
 108     ByteIOContext *pb = s->pb;
 109     int len, fill_size, size1, frame_offset, id;
 110
 111     size1 = size;
 112     while (size > 0) {
 113     redo:
 114         len = ffm->packet_end - ffm->packet_ptr;
 115         if (len < 0)
 116             return -1;
 117         if (len > size)
 118             len = size;
 119         if (len == 0) {
 120             if (url_ftell(pb) == ffm->file_size)
 121                 url_fseek(pb, ffm->packet_size, SEEK_SET);
 122     retry_read:
 123             id = get_be16(pb); /* PACKET_ID */
 124             if (id != PACKET_ID)
 125                 if (ffm_resync(s, id) < 0)
 126                     return -1;
 127             fill_size = get_be16(pb);
 128             ffm->dts = get_be64(pb);
 129             frame_offset = get_be16(pb);
 130             get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
 131             ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
 132             if (ffm->packet_end < ffm->packet || frame_offset < 0)
 133                 return -1;
 134             /* if first packet or resynchronization packet, we must
 135                handle it specifically */
 136             if (ffm->first_packet || (frame_offset & 0x8000)) {
 137                 if (!frame_offset) {
 138                     /* This packet has no frame headers in it */
 139                     if (url_ftell(pb) >= ffm->packet_size * 3) {
 140                         url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
 141                         goto retry_read;
 142                     }
 143                     /* This is bad, we cannot find a valid frame header */
 144                     return 0;
 145                 }
 146                 ffm->first_packet = 0;
 147                 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
 148                     return -1;
 149                 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
 150                 if (!header)
 151                     break;
 152             } else {
 153                 ffm->packet_ptr = ffm->packet;
 154             }
 155             goto redo;
 156         }
 157         memcpy(buf, ffm->packet_ptr, len);
 158         buf += len;
 159         ffm->packet_ptr += len;
 160         size -= len;
 161         header = 0;
 162     }
 163     return size1 - size;
 164 }
 165
 166 //#define DEBUG_SEEK
 167
 168 /* ensure that acutal seeking happens between FFM_PACKET_SIZE
 169    and file_size - FFM_PACKET_SIZE */
 170 static void ffm_seek1(AVFormatContext *s, int64_t pos1)
 171 {
 172     FFMContext *ffm = s->priv_data;
 173     ByteIOContext *pb = s->pb;
 174     int64_t pos;
 175
 176     pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
 177     pos = FFMAX(pos, FFM_PACKET_SIZE);
 178 #ifdef DEBUG_SEEK
 179     av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
 180 #endif
 181     url_fseek(pb, pos, SEEK_SET);
 182 }
 183
 184 static int64_t get_dts(AVFormatContext *s, int64_t pos)
 185 {
 186     ByteIOContext *pb = s->pb;
 187     int64_t dts;
 188
 189     ffm_seek1(s, pos);
 190     url_fskip(pb, 4);
 191     dts = get_be64(pb);
 192 #ifdef DEBUG_SEEK
 193     av_log(s, AV_LOG_DEBUG, "dts=%0.6f\n", dts / 1000000.0);
 194 #endif
 195     return dts;
 196 }
 197
 198 static void adjust_write_index(AVFormatContext *s)
 199 {
 200     FFMContext *ffm = s->priv_data;
 201     ByteIOContext *pb = s->pb;
 202     int64_t pts;
 203     //int64_t orig_write_index = ffm->write_index;
 204     int64_t pos_min, pos_max;
 205     int64_t pts_start;
 206     int64_t ptr = url_ftell(pb);
 207
 208
 209     pos_min = 0;
 210     pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
 211
 212     pts_start = get_dts(s, pos_min);
 213
 214     pts = get_dts(s, pos_max);
 215
 216     if (pts - 100000 > pts_start)
 217         goto end;
 218
 219     ffm->write_index = FFM_PACKET_SIZE;
 220
 221     pts_start = get_dts(s, pos_min);
 222
 223     pts = get_dts(s, pos_max);
 224
 225     if (pts - 100000 <= pts_start) {
 226         while (1) {
 227             int64_t newpos;
 228             int64_t newpts;
 229
 230             newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
 231
 232             if (newpos == pos_min)
 233                 break;
 234
 235             newpts = get_dts(s, newpos);
 236
 237             if (newpts - 100000 <= pts) {
 238                 pos_max = newpos;
 239                 pts = newpts;
 240             } else {
 241                 pos_min = newpos;
 242             }
 243         }
 244         ffm->write_index += pos_max;
 245     }
 246
 247     //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
 248     //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
 249
 250  end:
 251     url_fseek(pb, ptr, SEEK_SET);
 252 }
 253
 254
 255 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
 256 {
 257     FFMContext *ffm = s->priv_data;
 258     AVStream *st;
 259     ByteIOContext *pb = s->pb;
 260     AVCodecContext *codec;
 261     int i, nb_streams;
 262     uint32_t tag;
 263
 264     /* header */
 265     tag = get_le32(pb);
 266     if (tag != MKTAG('F', 'F', 'M', '1'))
 267         goto fail;
 268     ffm->packet_size = get_be32(pb);
 269     if (ffm->packet_size != FFM_PACKET_SIZE)
 270         goto fail;
 271     ffm->write_index = get_be64(pb);
 272     /* get also filesize */
 273     if (!url_is_streamed(pb)) {
 274         ffm->file_size = url_fsize(pb);
 275         if (ffm->write_index)
 276             adjust_write_index(s);
 277     } else {
 278         ffm->file_size = (UINT64_C(1) << 63) - 1;
 279     }
 280
 281     nb_streams = get_be32(pb);
 282     get_be32(pb); /* total bitrate */
 283     /* read each stream */
 284     for(i=0;i<nb_streams;i++) {
 285         char rc_eq_buf[128];
 286
 287         st = av_new_stream(s, 0);
 288         if (!st)
 289             goto fail;
 290
 291         av_set_pts_info(st, 64, 1, 1000000);
 292
 293         codec = st->codec;
 294         /* generic info */
 295         codec->codec_id = get_be32(pb);
 296         codec->codec_type = get_byte(pb); /* codec_type */
 297         codec->bit_rate = get_be32(pb);
 298         st->quality = get_be32(pb);
 299         codec->flags = get_be32(pb);
 300         codec->flags2 = get_be32(pb);
 301         codec->debug = get_be32(pb);
 302         /* specific info */
 303         switch(codec->codec_type) {
 304         case CODEC_TYPE_VIDEO:
 305             codec->time_base.num = get_be32(pb);
 306             codec->time_base.den = get_be32(pb);
 307             codec->width = get_be16(pb);
 308             codec->height = get_be16(pb);
 309             codec->gop_size = get_be16(pb);
 310             codec->pix_fmt = get_be32(pb);
 311             codec->qmin = get_byte(pb);
 312             codec->qmax = get_byte(pb);
 313             codec->max_qdiff = get_byte(pb);
 314             codec->qcompress = get_be16(pb) / 10000.0;
 315             codec->qblur = get_be16(pb) / 10000.0;
 316             codec->bit_rate_tolerance = get_be32(pb);
 317             codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
 318             codec->rc_max_rate = get_be32(pb);
 319             codec->rc_min_rate = get_be32(pb);
 320             codec->rc_buffer_size = get_be32(pb);
 321             codec->i_quant_factor = av_int2dbl(get_be64(pb));
 322             codec->b_quant_factor = av_int2dbl(get_be64(pb));
 323             codec->i_quant_offset = av_int2dbl(get_be64(pb));
 324             codec->b_quant_offset = av_int2dbl(get_be64(pb));
 325             codec->dct_algo = get_be32(pb);
 326             codec->strict_std_compliance = get_be32(pb);
 327             codec->max_b_frames = get_be32(pb);
 328             codec->luma_elim_threshold = get_be32(pb);
 329             codec->chroma_elim_threshold = get_be32(pb);
 330             codec->mpeg_quant = get_be32(pb);
 331             codec->intra_dc_precision = get_be32(pb);
 332             codec->me_method = get_be32(pb);
 333             codec->mb_decision = get_be32(pb);
 334             codec->nsse_weight = get_be32(pb);
 335             codec->frame_skip_cmp = get_be32(pb);
 336             codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
 337             codec->codec_tag = get_be32(pb);
 338             codec->thread_count = get_byte(pb);
 339             break;
 340         case CODEC_TYPE_AUDIO:
 341             codec->sample_rate = get_be32(pb);
 342             codec->channels = get_le16(pb);
 343             codec->frame_size = get_le16(pb);
 344             break;
 345         default:
 346             goto fail;
 347         }
 348         if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
 349             codec->extradata_size = get_be32(pb);
 350             codec->extradata = av_malloc(codec->extradata_size);
 351             if (!codec->extradata)
 352                 return AVERROR(ENOMEM);
 353             get_buffer(pb, codec->extradata, codec->extradata_size);
 354         }
 355     }
 356
 357     /* get until end of block reached */
 358     while ((url_ftell(pb) % ffm->packet_size) != 0)
 359         get_byte(pb);
 360
 361     /* init packet demux */
 362     ffm->packet_ptr = ffm->packet;
 363     ffm->packet_end = ffm->packet;
 364     ffm->frame_offset = 0;
 365     ffm->dts = 0;
 366     ffm->read_state = READ_HEADER;
 367     ffm->first_packet = 1;
 368     return 0;
 369  fail:
 370     for(i=0;i<s->nb_streams;i++) {
 371         st = s->streams[i];
 372         if (st) {
 373             av_free(st);
 374         }
 375     }
 376     return -1;
 377 }
 378
 379 /* return < 0 if eof */
 380 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
 381 {
 382     int size;
 383     FFMContext *ffm = s->priv_data;
 384     int duration, ret;
 385
 386     switch(ffm->read_state) {
 387     case READ_HEADER:
 388         if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
 389             return ret;
 390
 391         dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
 392                url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
 393         if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
 394             FRAME_HEADER_SIZE)
 395             return -1;
 396         if (ffm->header[1] & FLAG_DTS)
 397             if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
 398                 return -1;
 399 #if 0
 400         av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
 401 #endif
 402         ffm->read_state = READ_DATA;
 403         /* fall thru */
 404     case READ_DATA:
 405         size = AV_RB24(ffm->header + 2);
 406         if ((ret = ffm_is_avail_data(s, size)) < 0)
 407             return ret;
 408
 409         duration = AV_RB24(ffm->header + 5);
 410
 411         av_new_packet(pkt, size);
 412         pkt->stream_index = ffm->header[0];
 413         if ((unsigned)pkt->stream_index >= s->nb_streams) {
 414             av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
 415             av_free_packet(pkt);
 416             ffm->read_state = READ_HEADER;
 417             return -1;
 418         }
 419         pkt->pos = url_ftell(s->pb);
 420         if (ffm->header[1] & FLAG_KEY_FRAME)
 421             pkt->flags |= PKT_FLAG_KEY;
 422
 423         ffm->read_state = READ_HEADER;
 424         if (ffm_read_data(s, pkt->data, size, 0) != size) {
 425             /* bad case: desynchronized packet. we cancel all the packet loading */
 426             av_free_packet(pkt);
 427             return -1;
 428         }
 429         pkt->pts = AV_RB64(ffm->header+8);
 430         if (ffm->header[1] & FLAG_DTS)
 431             pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
 432         else
 433             pkt->dts = pkt->pts;
 434         pkt->duration = duration;
 435         break;
 436     }
 437     return 0;
 438 }
 439
 440 /* seek to a given time in the file. The file read pointer is
 441    positioned at or before pts. XXX: the following code is quite
 442    approximative */
 443 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
 444 {
 445     FFMContext *ffm = s->priv_data;
 446     int64_t pos_min, pos_max, pos;
 447     int64_t pts_min, pts_max, pts;
 448     double pos1;
 449
 450 #ifdef DEBUG_SEEK
 451     av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
 452 #endif
 453     /* find the position using linear interpolation (better than
 454        dichotomy in typical cases) */
 455     pos_min = FFM_PACKET_SIZE;
 456     pos_max = ffm->file_size - FFM_PACKET_SIZE;
 457     while (pos_min <= pos_max) {
 458         pts_min = get_dts(s, pos_min);
 459         pts_max = get_dts(s, pos_max);
 460         /* linear interpolation */
 461         pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
 462             (double)(pts_max - pts_min);
 463         pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
 464         if (pos <= pos_min)
 465             pos = pos_min;
 466         else if (pos >= pos_max)
 467             pos = pos_max;
 468         pts = get_dts(s, pos);
 469         /* check if we are lucky */
 470         if (pts == wanted_pts) {
 471             goto found;
 472         } else if (pts > wanted_pts) {
 473             pos_max = pos - FFM_PACKET_SIZE;
 474         } else {
 475             pos_min = pos + FFM_PACKET_SIZE;
 476         }
 477     }
 478     pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
 479
 480  found:
 481     ffm_seek1(s, pos);
 482
 483     /* reset read state */
 484     ffm->read_state = READ_HEADER;
 485     ffm->packet_ptr = ffm->packet;
 486     ffm->packet_end = ffm->packet;
 487     ffm->first_packet = 1;
 488
 489     return 0;
 490 }
 491
 492 static int ffm_probe(AVProbeData *p)
 493 {
 494     if (
 495         p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
 496         p->buf[3] == '1')
 497         return AVPROBE_SCORE_MAX + 1;
 498     return 0;
 499 }
 500
 501 AVInputFormat ffm_demuxer = {
 502     "ffm",
 503     NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),
 504     sizeof(FFMContext),
 505     ffm_probe,
 506     ffm_read_header,
 507     ffm_read_packet,
 508     NULL,
 509     ffm_seek,
 510 };