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