libav/rm.c

   1 /*
   2  * "Real" compatible mux and demux.
   3  * Copyright (c) 2000, 2001 Fabrice Bellard.
   4  *
   5  * 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  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * 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  */
  19 #include "avformat.h"
  20
  21 /* in ms */
  22 #define BUFFER_DURATION 0
  23
  24 typedef struct {
  25     int nb_packets;
  26     int packet_total_size;
  27     int packet_max_size;
  28     /* codec related output */
  29     int bit_rate;
  30     float frame_rate;
  31     int nb_frames;    /* current frame number */
  32     int total_frames; /* total number of frames */
  33     int num;
  34     AVCodecContext *enc;
  35 } StreamInfo;
  36
  37 typedef struct {
  38     StreamInfo streams[2];
  39     StreamInfo *audio_stream, *video_stream;
  40     int data_pos; /* position of the data after the header */
  41     int nb_packets;
  42 } RMContext;
  43
  44 static void put_str(ByteIOContext *s, const char *tag)
  45 {
  46     put_be16(s,strlen(tag));
  47     while (*tag) {
  48         put_byte(s, *tag++);
  49     }
  50 }
  51
  52 static void put_str8(ByteIOContext *s, const char *tag)
  53 {
  54     put_byte(s, strlen(tag));
  55     while (*tag) {
  56         put_byte(s, *tag++);
  57     }
  58 }
  59
  60 static void rv10_write_header(AVFormatContext *ctx,
  61                               int data_size, int index_pos)
  62 {
  63     RMContext *rm = ctx->priv_data;
  64     ByteIOContext *s = &ctx->pb;
  65     StreamInfo *stream;
  66     unsigned char *data_offset_ptr, *start_ptr;
  67     const char *desc, *mimetype;
  68     int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
  69     int bit_rate, v, duration, flags, data_pos;
  70
  71     start_ptr = s->buf_ptr;
  72
  73     put_tag(s, ".RMF");
  74     put_be32(s,18); /* header size */
  75     put_be16(s,0);
  76     put_be32(s,0);
  77     put_be32(s,4 + ctx->nb_streams); /* num headers */
  78
  79     put_tag(s,"PROP");
  80     put_be32(s, 50);
  81     put_be16(s, 0);
  82     packet_max_size = 0;
  83     packet_total_size = 0;
  84     nb_packets = 0;
  85     bit_rate = 0;
  86     duration = 0;
  87     for(i=0;i<ctx->nb_streams;i++) {
  88         StreamInfo *stream = &rm->streams[i];
  89         bit_rate += stream->bit_rate;
  90         if (stream->packet_max_size > packet_max_size)
  91             packet_max_size = stream->packet_max_size;
  92         nb_packets += stream->nb_packets;
  93         packet_total_size += stream->packet_total_size;
  94         /* select maximum duration */
  95         v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);
  96         if (v > duration)
  97             duration = v;
  98     }
  99     put_be32(s, bit_rate); /* max bit rate */
 100     put_be32(s, bit_rate); /* avg bit rate */
 101     put_be32(s, packet_max_size);        /* max packet size */
 102     if (nb_packets > 0)
 103         packet_avg_size = packet_total_size / nb_packets;
 104     else
 105         packet_avg_size = 0;
 106     put_be32(s, packet_avg_size);        /* avg packet size */
 107     put_be32(s, nb_packets);  /* num packets */
 108     put_be32(s, duration); /* duration */
 109     put_be32(s, BUFFER_DURATION);           /* preroll */
 110     put_be32(s, index_pos);           /* index offset */
 111     /* computation of data the data offset */
 112     data_offset_ptr = s->buf_ptr;
 113     put_be32(s, 0);           /* data offset : will be patched after */
 114     put_be16(s, ctx->nb_streams);    /* num streams */
 115     flags = 1 | 2; /* save allowed & perfect play */
 116     if (url_is_streamed(s))
 117         flags |= 4; /* live broadcast */
 118     put_be16(s, flags);
 119
 120     /* comments */
 121
 122     put_tag(s,"CONT");
 123     size = strlen(ctx->title) + strlen(ctx->author) + strlen(ctx->copyright) +
 124         strlen(ctx->comment) + 4 * 2 + 10;
 125     put_be32(s,size);
 126     put_be16(s,0);
 127     put_str(s, ctx->title);
 128     put_str(s, ctx->author);
 129     put_str(s, ctx->copyright);
 130     put_str(s, ctx->comment);
 131
 132     for(i=0;i<ctx->nb_streams;i++) {
 133         int codec_data_size;
 134
 135         stream = &rm->streams[i];
 136
 137         if (stream->enc->codec_type == CODEC_TYPE_AUDIO) {
 138             desc = "The Audio Stream";
 139             mimetype = "audio/x-pn-realaudio";
 140             codec_data_size = 73;
 141         } else {
 142             desc = "The Video Stream";
 143             mimetype = "video/x-pn-realvideo";
 144             codec_data_size = 34;
 145         }
 146
 147         put_tag(s,"MDPR");
 148         size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
 149         put_be32(s, size);
 150         put_be16(s, 0);
 151
 152         put_be16(s, i); /* stream number */
 153         put_be32(s, stream->bit_rate); /* max bit rate */
 154         put_be32(s, stream->bit_rate); /* avg bit rate */
 155         put_be32(s, stream->packet_max_size);        /* max packet size */
 156         if (stream->nb_packets > 0)
 157             packet_avg_size = stream->packet_total_size /
 158                 stream->nb_packets;
 159         else
 160             packet_avg_size = 0;
 161         put_be32(s, packet_avg_size);        /* avg packet size */
 162         put_be32(s, 0);           /* start time */
 163         put_be32(s, BUFFER_DURATION);           /* preroll */
 164         /* duration */
 165         if (url_is_streamed(s) || !stream->total_frames)
 166             put_be32(s, (int)(3600 * 1000));
 167         else
 168             put_be32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));
 169         put_str8(s, desc);
 170         put_str8(s, mimetype);
 171         put_be32(s, codec_data_size);
 172
 173         if (stream->enc->codec_type == CODEC_TYPE_AUDIO) {
 174             int coded_frame_size, fscode, sample_rate;
 175             sample_rate = stream->enc->sample_rate;
 176             coded_frame_size = (stream->enc->bit_rate *
 177                                 stream->enc->frame_size) / (8 * sample_rate);
 178             /* audio codec info */
 179             put_tag(s, ".ra");
 180             put_byte(s, 0xfd);
 181             put_be32(s, 0x00040000); /* version */
 182             put_tag(s, ".ra4");
 183             put_be32(s, 0x01b53530); /* stream length */
 184             put_be16(s, 4); /* unknown */
 185             put_be32(s, 0x39); /* header size */
 186
 187             switch(sample_rate) {
 188             case 48000:
 189             case 24000:
 190             case 12000:
 191                 fscode = 1;
 192                 break;
 193             default:
 194             case 44100:
 195             case 22050:
 196             case 11025:
 197                 fscode = 2;
 198                 break;
 199             case 32000:
 200             case 16000:
 201             case 8000:
 202                 fscode = 3;
 203             }
 204             put_be16(s, fscode); /* codec additional info, for AC3, seems
 205                                      to be a frequency code */
 206             /* special hack to compensate rounding errors... */
 207             if (coded_frame_size == 557)
 208                 coded_frame_size--;
 209             put_be32(s, coded_frame_size); /* frame length */
 210             put_be32(s, 0x51540); /* unknown */
 211             put_be32(s, 0x249f0); /* unknown */
 212             put_be32(s, 0x249f0); /* unknown */
 213             put_be16(s, 0x01);
 214             /* frame length : seems to be very important */
 215             put_be16(s, coded_frame_size);
 216             put_be32(s, 0); /* unknown */
 217             put_be16(s, stream->enc->sample_rate); /* sample rate */
 218             put_be32(s, 0x10); /* unknown */
 219             put_be16(s, stream->enc->channels);
 220             put_str8(s, "Int0"); /* codec name */
 221             put_str8(s, "dnet"); /* codec name */
 222             put_be16(s, 0); /* title length */
 223             put_be16(s, 0); /* author length */
 224             put_be16(s, 0); /* copyright length */
 225             put_byte(s, 0); /* end of header */
 226         } else {
 227             /* video codec info */
 228             put_be32(s,34); /* size */
 229             put_tag(s,"VIDORV10");
 230             put_be16(s, stream->enc->width);
 231             put_be16(s, stream->enc->height);
 232             put_be16(s, (int) stream->frame_rate); /* frames per seconds ? */
 233             put_be32(s,0);     /* unknown meaning */
 234             put_be16(s, (int) stream->frame_rate);  /* unknown meaning */
 235             put_be32(s,0);     /* unknown meaning */
 236             put_be16(s, 8);    /* unknown meaning */
 237             /* Seems to be the codec version: only use basic H263. The next
 238                versions seems to add a diffential DC coding as in
 239                MPEG... nothing new under the sun */
 240             put_be32(s,0x10000000);
 241             //put_be32(s,0x10003000);
 242         }
 243     }
 244
 245     /* patch data offset field */
 246     data_pos = s->buf_ptr - start_ptr;
 247     rm->data_pos = data_pos;
 248     data_offset_ptr[0] = data_pos >> 24;
 249     data_offset_ptr[1] = data_pos >> 16;
 250     data_offset_ptr[2] = data_pos >> 8;
 251     data_offset_ptr[3] = data_pos;
 252
 253     /* data stream */
 254     put_tag(s,"DATA");
 255     put_be32(s,data_size + 10 + 8);
 256     put_be16(s,0);
 257
 258     put_be32(s, nb_packets); /* number of packets */
 259     put_be32(s,0); /* next data header */
 260 }
 261
 262 static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
 263                                 int length, int key_frame)
 264 {
 265     int timestamp;
 266     ByteIOContext *s = &ctx->pb;
 267
 268     stream->nb_packets++;
 269     stream->packet_total_size += length;
 270     if (length > stream->packet_max_size)
 271         stream->packet_max_size =  length;
 272
 273     put_be16(s,0); /* version */
 274     put_be16(s,length + 12);
 275     put_be16(s, stream->num); /* stream number */
 276     timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate;
 277     put_be32(s, timestamp); /* timestamp */
 278     put_byte(s, 0); /* reserved */
 279     put_byte(s, key_frame ? 2 : 0); /* flags */
 280 }
 281
 282 static int rm_write_header(AVFormatContext *s)
 283 {
 284     RMContext *rm = s->priv_data;
 285     StreamInfo *stream;
 286     int n;
 287     AVCodecContext *codec;
 288
 289     for(n=0;n<s->nb_streams;n++) {
 290         s->streams[n]->id = n;
 291         codec = &s->streams[n]->codec;
 292         stream = &rm->streams[n];
 293         memset(stream, 0, sizeof(StreamInfo));
 294         stream->num = n;
 295         stream->bit_rate = codec->bit_rate;
 296         stream->enc = codec;
 297
 298         switch(codec->codec_type) {
 299         case CODEC_TYPE_AUDIO:
 300             rm->audio_stream = stream;
 301             stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size;
 302             /* XXX: dummy values */
 303             stream->packet_max_size = 1024;
 304             stream->nb_packets = 0;
 305             stream->total_frames = stream->nb_packets;
 306             break;
 307         case CODEC_TYPE_VIDEO:
 308             rm->video_stream = stream;
 309             stream->frame_rate = (float)codec->frame_rate / (float)FRAME_RATE_BASE;
 310             /* XXX: dummy values */
 311             stream->packet_max_size = 4096;
 312             stream->nb_packets = 0;
 313             stream->total_frames = stream->nb_packets;
 314             break;
 315         default:
 316             av_abort();
 317         }
 318     }
 319
 320     rv10_write_header(s, 0, 0);
 321     put_flush_packet(&s->pb);
 322     return 0;
 323 }
 324
 325 static int rm_write_audio(AVFormatContext *s, UINT8 *buf, int size)
 326 {
 327     UINT8 *buf1;
 328     RMContext *rm = s->priv_data;
 329     ByteIOContext *pb = &s->pb;
 330     StreamInfo *stream = rm->audio_stream;
 331     int i;
 332
 333     /* XXX: suppress this malloc */
 334     buf1= (UINT8*) av_malloc( size * sizeof(UINT8) );
 335
 336     write_packet_header(s, stream, size, stream->enc->key_frame);
 337
 338     /* for AC3, the words seems to be reversed */
 339     for(i=0;i<size;i+=2) {
 340         buf1[i] = buf[i+1];
 341         buf1[i+1] = buf[i];
 342     }
 343     put_buffer(pb, buf1, size);
 344     put_flush_packet(pb);
 345     stream->nb_frames++;
 346     av_free(buf1);
 347     return 0;
 348 }
 349
 350 static int rm_write_video(AVFormatContext *s, UINT8 *buf, int size)
 351 {
 352     RMContext *rm = s->priv_data;
 353     ByteIOContext *pb = &s->pb;
 354     StreamInfo *stream = rm->video_stream;
 355     int key_frame = stream->enc->key_frame;
 356
 357     /* XXX: this is incorrect: should be a parameter */
 358
 359     /* Well, I spent some time finding the meaning of these bits. I am
 360        not sure I understood everything, but it works !! */
 361 #if 1
 362     write_packet_header(s, stream, size + 7, key_frame);
 363     /* bit 7: '1' if final packet of a frame converted in several packets */
 364     put_byte(pb, 0x81);
 365     /* bit 7: '1' if I frame. bits 6..0 : sequence number in current
 366        frame starting from 1 */
 367     if (key_frame) {
 368         put_byte(pb, 0x81);
 369     } else {
 370         put_byte(pb, 0x01);
 371     }
 372     put_be16(pb, 0x4000 | (size)); /* total frame size */
 373     put_be16(pb, 0x4000 | (size));              /* offset from the start or the end */
 374 #else
 375     /* full frame */
 376     write_packet_header(s, size + 6);
 377     put_byte(pb, 0xc0);
 378     put_be16(pb, 0x4000 | size); /* total frame size */
 379     put_be16(pb, 0x4000 + packet_number * 126); /* position in stream */
 380 #endif
 381     put_byte(pb, stream->nb_frames & 0xff);
 382
 383     put_buffer(pb, buf, size);
 384     put_flush_packet(pb);
 385
 386     stream->nb_frames++;
 387     return 0;
 388 }
 389
 390 static int rm_write_packet(AVFormatContext *s, int stream_index,
 391                            UINT8 *buf, int size, int force_pts)
 392 {
 393     if (s->streams[stream_index]->codec.codec_type ==
 394         CODEC_TYPE_AUDIO)
 395         return rm_write_audio(s, buf, size);
 396     else
 397         return rm_write_video(s, buf, size);
 398 }
 399
 400 static int rm_write_trailer(AVFormatContext *s)
 401 {
 402     RMContext *rm = s->priv_data;
 403     int data_size, index_pos, i;
 404     ByteIOContext *pb = &s->pb;
 405
 406     if (!url_is_streamed(&s->pb)) {
 407         /* end of file: finish to write header */
 408         index_pos = url_fseek(pb, 0, SEEK_CUR);
 409         data_size = index_pos - rm->data_pos;
 410
 411         /* index */
 412         put_tag(pb, "INDX");
 413         put_be32(pb, 10 + 10 * s->nb_streams);
 414         put_be16(pb, 0);
 415
 416         for(i=0;i<s->nb_streams;i++) {
 417             put_be32(pb, 0); /* zero indices */
 418             put_be16(pb, i); /* stream number */
 419             put_be32(pb, 0); /* next index */
 420         }
 421         /* undocumented end header */
 422         put_be32(pb, 0);
 423         put_be32(pb, 0);
 424
 425         url_fseek(pb, 0, SEEK_SET);
 426         for(i=0;i<s->nb_streams;i++)
 427             rm->streams[i].total_frames = rm->streams[i].nb_frames;
 428         rv10_write_header(s, data_size, index_pos);
 429     } else {
 430         /* undocumented end header */
 431         put_be32(pb, 0);
 432         put_be32(pb, 0);
 433     }
 434     put_flush_packet(pb);
 435     return 0;
 436 }
 437
 438 /***************************************************/
 439
 440 static void get_str(ByteIOContext *pb, char *buf, int buf_size)
 441 {
 442     int len, i;
 443     char *q;
 444
 445     len = get_be16(pb);
 446     q = buf;
 447     for(i=0;i<len;i++) {
 448         if (i < buf_size - 1)
 449             *q++ = get_byte(pb);
 450     }
 451     *q = '\0';
 452 }
 453
 454 static void get_str8(ByteIOContext *pb, char *buf, int buf_size)
 455 {
 456     int len, i;
 457     char *q;
 458
 459     len = get_byte(pb);
 460     q = buf;
 461     for(i=0;i<len;i++) {
 462         if (i < buf_size - 1)
 463             *q++ = get_byte(pb);
 464     }
 465     *q = '\0';
 466 }
 467
 468 static int rm_read_header(AVFormatContext *s, AVFormatParameters *ap)
 469 {
 470     RMContext *rm = s->priv_data;
 471     AVStream *st;
 472     ByteIOContext *pb = &s->pb;
 473     unsigned int tag, v;
 474     int tag_size, size, codec_data_size, i;
 475     INT64 codec_pos;
 476     unsigned int h263_hack_version;
 477     char buf[128];
 478     int flags = 0;
 479
 480     if (get_le32(pb) != MKTAG('.', 'R', 'M', 'F'))
 481         return -EIO;
 482
 483     get_be32(pb); /* header size */
 484     get_be16(pb);
 485     get_be32(pb);
 486     get_be32(pb); /* number of headers */
 487
 488     for(;;) {
 489         if (url_feof(pb))
 490             goto fail;
 491         tag = get_le32(pb);
 492         tag_size = get_be32(pb);
 493         get_be16(pb);
 494 #if 0
 495         printf("tag=%c%c%c%c (%08x) size=%d\n",
 496                (tag) & 0xff,
 497                (tag >> 8) & 0xff,
 498                (tag >> 16) & 0xff,
 499                (tag >> 24) & 0xff,
 500                tag,
 501                tag_size);
 502 #endif
 503         if (tag_size < 10)
 504             goto fail;
 505         switch(tag) {
 506         case MKTAG('P', 'R', 'O', 'P'):
 507             /* file header */
 508             get_be32(pb); /* max bit rate */
 509             get_be32(pb); /* avg bit rate */
 510             get_be32(pb); /* max packet size */
 511             get_be32(pb); /* avg packet size */
 512             get_be32(pb); /* nb packets */
 513             get_be32(pb); /* duration */
 514             get_be32(pb); /* preroll */
 515             get_be32(pb); /* index offset */
 516             get_be32(pb); /* data offset */
 517             get_be16(pb); /* nb streams */
 518             flags = get_be16(pb); /* flags */
 519             break;
 520         case MKTAG('C', 'O', 'N', 'T'):
 521             get_str(pb, s->title, sizeof(s->title));
 522             get_str(pb, s->author, sizeof(s->author));
 523             get_str(pb, s->copyright, sizeof(s->copyright));
 524             get_str(pb, s->comment, sizeof(s->comment));
 525             break;
 526         case MKTAG('M', 'D', 'P', 'R'):
 527             st = av_mallocz(sizeof(AVStream));
 528             if (!st)
 529                 goto fail;
 530             s->streams[s->nb_streams++] = st;
 531             st->id = get_be16(pb);
 532             get_be32(pb); /* max bit rate */
 533             st->codec.bit_rate = get_be32(pb); /* bit rate */
 534             get_be32(pb); /* max packet size */
 535             get_be32(pb); /* avg packet size */
 536             get_be32(pb); /* start time */
 537             get_be32(pb); /* preroll */
 538             get_be32(pb); /* duration */
 539             get_str8(pb, buf, sizeof(buf)); /* desc */
 540             get_str8(pb, buf, sizeof(buf)); /* mimetype */
 541             codec_data_size = get_be32(pb);
 542             codec_pos = url_ftell(pb);
 543
 544             v = get_be32(pb);
 545             if (v == MKTAG(0xfd, 'a', 'r', '.')) {
 546                 /* ra type header */
 547                 get_be32(pb); /* version */
 548                 get_be32(pb); /* .ra4 */
 549                 get_be32(pb);
 550                 get_be16(pb);
 551                 get_be32(pb); /* header size */
 552                 get_be16(pb); /* add codec info */
 553                 get_be32(pb); /* coded frame size */
 554                 get_be32(pb); /* ??? */
 555                 get_be32(pb); /* ??? */
 556                 get_be32(pb); /* ??? */
 557                 get_be16(pb); /* 1 */
 558                 get_be16(pb); /* coded frame size */
 559                 get_be32(pb);
 560                 st->codec.sample_rate = get_be16(pb);
 561                 get_be32(pb);
 562                 st->codec.channels = get_be16(pb);
 563                 get_str8(pb, buf, sizeof(buf)); /* desc */
 564                 get_str8(pb, buf, sizeof(buf)); /* desc */
 565                 st->codec.codec_type = CODEC_TYPE_AUDIO;
 566                 if (!strcmp(buf, "dnet")) {
 567                     st->codec.codec_id = CODEC_ID_AC3;
 568                 } else {
 569                     st->codec.codec_id = CODEC_ID_NONE;
 570                     pstrcpy(st->codec.codec_name, sizeof(st->codec.codec_name),
 571                             buf);
 572                 }
 573             } else {
 574                 if (get_le32(pb) != MKTAG('V', 'I', 'D', 'O')) {
 575                 fail1:
 576                     fprintf(stderr, "Unsupported video codec\n");
 577                     goto fail;
 578                 }
 579                 st->codec.codec_tag = get_le32(pb);
 580                 if (st->codec.codec_tag != MKTAG('R', 'V', '1', '0'))
 581                     goto fail1;
 582                 st->codec.width = get_be16(pb);
 583                 st->codec.height = get_be16(pb);
 584                 st->codec.frame_rate = get_be16(pb) * FRAME_RATE_BASE;
 585                 st->codec.codec_type = CODEC_TYPE_VIDEO;
 586                 get_be32(pb);
 587                 get_be16(pb);
 588                 get_be32(pb);
 589                 get_be16(pb);
 590                 /* modification of h263 codec version (!) */
 591                 h263_hack_version = get_be32(pb);
 592                 switch(h263_hack_version) {
 593                 case 0x10000000:
 594                     st->codec.sub_id = 0;
 595                     st->codec.codec_id = CODEC_ID_RV10;
 596                     break;
 597                 case 0x10003000:
 598                 case 0x10003001:
 599                     st->codec.sub_id = 3;
 600                     st->codec.codec_id = CODEC_ID_RV10;
 601                     break;
 602                 default:
 603                     /* not handled */
 604                     st->codec.codec_id = CODEC_ID_NONE;
 605                     break;
 606                 }
 607             }
 608             /* skip codec info */
 609             size = url_ftell(pb) - codec_pos;
 610             url_fskip(pb, codec_data_size - size);
 611             break;
 612         case MKTAG('D', 'A', 'T', 'A'):
 613             goto header_end;
 614         default:
 615             /* unknown tag: skip it */
 616             url_fskip(pb, tag_size - 10);
 617             break;
 618         }
 619     }
 620  header_end:
 621     rm->nb_packets = get_be32(pb); /* number of packets */
 622     if (!rm->nb_packets && (flags & 4))
 623         rm->nb_packets = 3600 * 25;
 624     get_be32(pb); /* next data header */
 625     return 0;
 626
 627  fail:
 628     for(i=0;i<s->nb_streams;i++) {
 629         av_free(s->streams[i]);
 630     }
 631     return -EIO;
 632 }
 633
 634 static int get_num(ByteIOContext *pb, int *len)
 635 {
 636     int n, n1;
 637
 638     n = get_be16(pb);
 639     (*len)-=2;
 640     if (n >= 0x4000) {
 641         return n - 0x4000;
 642     } else {
 643         n1 = get_be16(pb);
 644         (*len)-=2;
 645         return (n << 16) | n1;
 646     }
 647 }
 648
 649 static int rm_read_packet(AVFormatContext *s, AVPacket *pkt)
 650 {
 651     RMContext *rm = s->priv_data;
 652     ByteIOContext *pb = &s->pb;
 653     AVStream *st;
 654     int len, num, timestamp, i, tmp, j;
 655     UINT8 *ptr;
 656     int flags;
 657
 658  redo:
 659     if (rm->nb_packets == 0)
 660         return -EIO;
 661     get_be16(pb);
 662     len = get_be16(pb);
 663     if (len < 12)
 664         return -EIO;
 665     num = get_be16(pb);
 666     timestamp = get_be32(pb);
 667     get_byte(pb); /* reserved */
 668     flags = get_byte(pb); /* flags */
 669     rm->nb_packets--;
 670     len -= 12;
 671
 672     st = NULL;
 673     for(i=0;i<s->nb_streams;i++) {
 674         st = s->streams[i];
 675         if (num == st->id)
 676             break;
 677     }
 678     if (i == s->nb_streams) {
 679         /* skip packet if unknown number */
 680         url_fskip(pb, len);
 681         goto redo;
 682     }
 683
 684 #if 0 // XXX/FIXME this is done in the codec currently, but should be done here ...
 685     if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
 686         int full_frame, h, pic_num;
 687
 688         h= get_byte(pb);
 689         if ((h & 0xc0) == 0xc0) {
 690             int len2, pos;
 691             full_frame = 1;
 692             len2= get_num(pb, &len);
 693             pos = get_num(pb, &len);
 694             //printf("pos:%d\n",len);
 695             len -= 2;
 696         } else {
 697             int seq, frame_size, pos;
 698             full_frame = 0;
 699             seq = get_byte(pb);
 700             frame_size = get_num(pb, &len);
 701             pos = get_num(pb, &len);
 702             //printf("seq:%d, size:%d, pos:%d\n",seq,frame_size,pos);
 703             len -= 3;
 704         }
 705         /* picture number */
 706         pic_num= get_byte(pb);
 707
 708         av_new_packet(pkt, len+1);
 709         pkt->stream_index = i;
 710
 711         //XXX/FIXME: is this a good idea?
 712         pkt->data[0]= h; //store header, its needed for decoding
 713
 714         get_buffer(pb, pkt->data+1, len);
 715     }
 716 #endif
 717
 718     av_new_packet(pkt, len);
 719     pkt->stream_index = i;
 720     get_buffer(pb, pkt->data, len);
 721
 722     /* for AC3, needs to swap bytes */
 723     if (st->codec.codec_id == CODEC_ID_AC3) {
 724         ptr = pkt->data;
 725         for(j=0;j<len;j+=2) {
 726             tmp = ptr[0];
 727             ptr[0] = ptr[1];
 728             ptr[1] = tmp;
 729                 ptr += 2;
 730         }
 731     }
 732     return 0;
 733 }
 734
 735 static int rm_read_close(AVFormatContext *s)
 736 {
 737     return 0;
 738 }
 739
 740 static int rm_probe(AVProbeData *p)
 741 {
 742     /* check file header */
 743     if (p->buf_size <= 32)
 744         return 0;
 745     if (p->buf[0] == '.' && p->buf[1] == 'R' &&
 746         p->buf[2] == 'M' && p->buf[3] == 'F' &&
 747         p->buf[4] == 0 && p->buf[5] == 0)
 748         return AVPROBE_SCORE_MAX;
 749     else
 750         return 0;
 751 }
 752
 753 AVInputFormat rm_iformat = {
 754     "rm",
 755     "rm format",
 756     sizeof(RMContext),
 757     rm_probe,
 758     rm_read_header,
 759     rm_read_packet,
 760     rm_read_close,
 761 };
 762
 763 AVOutputFormat rm_oformat = {
 764     "rm",
 765     "rm format",
 766     "audio/x-pn-realaudio",
 767     "rm,ra",
 768     sizeof(RMContext),
 769     CODEC_ID_AC3,
 770     CODEC_ID_RV10,
 771     rm_write_header,
 772     rm_write_packet,
 773     rm_write_trailer,
 774 };
 775
 776 int rm_init(void)
 777 {
 778     av_register_input_format(&rm_iformat);
 779     av_register_output_format(&rm_oformat);
 780     return 0;
 781 }