libavformat/rmenc.c

   1 /*
   2  * "Real" compatible muxer.
   3  * Copyright (c) 2000, 2001 Fabrice Bellard
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include "avformat.h"
  22 #include "avio_internal.h"
  23 #include "rm.h"
  24 #include "libavutil/dict.h"
  25
  26 typedef struct StreamInfo {
  27     int nb_packets;
  28     int packet_total_size;
  29     int packet_max_size;
  30     /* codec related output */
  31     int bit_rate;
  32     float frame_rate;
  33     int nb_frames;    /* current frame number */
  34     int total_frames; /* total number of frames */
  35     int num;
  36     AVCodecContext *enc;
  37 } StreamInfo;
  38
  39 typedef struct RMMuxContext {
  40     StreamInfo streams[2];
  41     StreamInfo *audio_stream, *video_stream;
  42     int data_pos; /* position of the data after the header */
  43 } RMMuxContext;
  44
  45 /* in ms */
  46 #define BUFFER_DURATION 0
  47 /* the header needs at most 7 + 4 + 12 B */
  48 #define MAX_HEADER_SIZE (7 + 4 + 12)
  49 /* UINT16_MAX is the maximal chunk size */
  50 #define MAX_PACKET_SIZE (UINT16_MAX - MAX_HEADER_SIZE)
  51
  52
  53 static void put_str(AVIOContext *s, const char *tag)
  54 {
  55     avio_wb16(s,strlen(tag));
  56     while (*tag) {
  57         avio_w8(s, *tag++);
  58     }
  59 }
  60
  61 static void put_str8(AVIOContext *s, const char *tag)
  62 {
  63     avio_w8(s, strlen(tag));
  64     while (*tag) {
  65         avio_w8(s, *tag++);
  66     }
  67 }
  68
  69 static int rv10_write_header(AVFormatContext *ctx,
  70                              int data_size, int index_pos)
  71 {
  72     RMMuxContext *rm = ctx->priv_data;
  73     AVIOContext *s = ctx->pb;
  74     StreamInfo *stream;
  75     unsigned char *data_offset_ptr, *start_ptr;
  76     const char *desc, *mimetype;
  77     int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
  78     int bit_rate, v, duration, flags, data_pos;
  79     AVDictionaryEntry *tag;
  80
  81     start_ptr = s->buf_ptr;
  82
  83     ffio_wfourcc(s, ".RMF");
  84     avio_wb32(s,18); /* header size */
  85     avio_wb16(s,0);
  86     avio_wb32(s,0);
  87     avio_wb32(s,4 + ctx->nb_streams); /* num headers */
  88
  89     ffio_wfourcc(s,"PROP");
  90     avio_wb32(s, 50);
  91     avio_wb16(s, 0);
  92     packet_max_size = 0;
  93     packet_total_size = 0;
  94     nb_packets = 0;
  95     bit_rate = 0;
  96     duration = 0;
  97     for(i=0;i<ctx->nb_streams;i++) {
  98         StreamInfo *stream = &rm->streams[i];
  99         bit_rate += stream->bit_rate;
 100         if (stream->packet_max_size > packet_max_size)
 101             packet_max_size = stream->packet_max_size;
 102         nb_packets += stream->nb_packets;
 103         packet_total_size += stream->packet_total_size;
 104         /* select maximum duration */
 105         v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);
 106         if (v > duration)
 107             duration = v;
 108     }
 109     avio_wb32(s, bit_rate); /* max bit rate */
 110     avio_wb32(s, bit_rate); /* avg bit rate */
 111     avio_wb32(s, packet_max_size);        /* max packet size */
 112     if (nb_packets > 0)
 113         packet_avg_size = packet_total_size / nb_packets;
 114     else
 115         packet_avg_size = 0;
 116     avio_wb32(s, packet_avg_size);        /* avg packet size */
 117     avio_wb32(s, nb_packets);  /* num packets */
 118     avio_wb32(s, duration); /* duration */
 119     avio_wb32(s, BUFFER_DURATION);           /* preroll */
 120     avio_wb32(s, index_pos);           /* index offset */
 121     /* computation of data the data offset */
 122     data_offset_ptr = s->buf_ptr;
 123     avio_wb32(s, 0);           /* data offset : will be patched after */
 124     avio_wb16(s, ctx->nb_streams);    /* num streams */
 125     flags = 1 | 2; /* save allowed & perfect play */
 126     if (!s->seekable)
 127         flags |= 4; /* live broadcast */
 128     avio_wb16(s, flags);
 129
 130     /* comments */
 131
 132     ffio_wfourcc(s,"CONT");
 133     size =  4 * 2 + 10;
 134     for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
 135         tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
 136         if(tag) size += strlen(tag->value);
 137     }
 138     avio_wb32(s,size);
 139     avio_wb16(s,0);
 140     for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
 141         tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
 142         put_str(s, tag ? tag->value : "");
 143     }
 144
 145     for(i=0;i<ctx->nb_streams;i++) {
 146         int codec_data_size;
 147
 148         stream = &rm->streams[i];
 149
 150         if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
 151             desc = "The Audio Stream";
 152             mimetype = "audio/x-pn-realaudio";
 153             codec_data_size = 73;
 154         } else {
 155             desc = "The Video Stream";
 156             mimetype = "video/x-pn-realvideo";
 157             codec_data_size = 34;
 158         }
 159
 160         ffio_wfourcc(s,"MDPR");
 161         size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
 162         avio_wb32(s, size);
 163         avio_wb16(s, 0);
 164
 165         avio_wb16(s, i); /* stream number */
 166         avio_wb32(s, stream->bit_rate); /* max bit rate */
 167         avio_wb32(s, stream->bit_rate); /* avg bit rate */
 168         avio_wb32(s, stream->packet_max_size);        /* max packet size */
 169         if (stream->nb_packets > 0)
 170             packet_avg_size = stream->packet_total_size /
 171                 stream->nb_packets;
 172         else
 173             packet_avg_size = 0;
 174         avio_wb32(s, packet_avg_size);        /* avg packet size */
 175         avio_wb32(s, 0);           /* start time */
 176         avio_wb32(s, BUFFER_DURATION);           /* preroll */
 177         /* duration */
 178         if (!s->seekable || !stream->total_frames)
 179             avio_wb32(s, (int)(3600 * 1000));
 180         else
 181             avio_wb32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));
 182         put_str8(s, desc);
 183         put_str8(s, mimetype);
 184         avio_wb32(s, codec_data_size);
 185
 186         if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
 187             int coded_frame_size, fscode, sample_rate;
 188             int frame_size = av_get_audio_frame_duration(stream->enc, 0);
 189             sample_rate = stream->enc->sample_rate;
 190             coded_frame_size = (stream->enc->bit_rate *
 191                                 frame_size) / (8 * sample_rate);
 192             /* audio codec info */
 193             avio_write(s, ".ra", 3);
 194             avio_w8(s, 0xfd);
 195             avio_wb32(s, 0x00040000); /* version */
 196             ffio_wfourcc(s, ".ra4");
 197             avio_wb32(s, 0x01b53530); /* stream length */
 198             avio_wb16(s, 4); /* unknown */
 199             avio_wb32(s, 0x39); /* header size */
 200
 201             switch(sample_rate) {
 202             case 48000:
 203             case 24000:
 204             case 12000:
 205                 fscode = 1;
 206                 break;
 207             default:
 208             case 44100:
 209             case 22050:
 210             case 11025:
 211                 fscode = 2;
 212                 break;
 213             case 32000:
 214             case 16000:
 215             case 8000:
 216                 fscode = 3;
 217             }
 218             avio_wb16(s, fscode); /* codec additional info, for AC-3, seems
 219                                      to be a frequency code */
 220             /* special hack to compensate rounding errors... */
 221             if (coded_frame_size == 557)
 222                 coded_frame_size--;
 223             avio_wb32(s, coded_frame_size); /* frame length */
 224             avio_wb32(s, 0x51540); /* unknown */
 225             avio_wb32(s, 0x249f0); /* unknown */
 226             avio_wb32(s, 0x249f0); /* unknown */
 227             avio_wb16(s, 0x01);
 228             /* frame length : seems to be very important */
 229             avio_wb16(s, coded_frame_size);
 230             avio_wb32(s, 0); /* unknown */
 231             avio_wb16(s, stream->enc->sample_rate); /* sample rate */
 232             avio_wb32(s, 0x10); /* unknown */
 233             avio_wb16(s, stream->enc->channels);
 234             put_str8(s, "Int0"); /* codec name */
 235             if (stream->enc->codec_tag) {
 236                 avio_w8(s, 4); /* tag length */
 237                 avio_wl32(s, stream->enc->codec_tag);
 238             } else {
 239                 av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");
 240                 return -1;
 241             }
 242             avio_wb16(s, 0); /* title length */
 243             avio_wb16(s, 0); /* author length */
 244             avio_wb16(s, 0); /* copyright length */
 245             avio_w8(s, 0); /* end of header */
 246         } else {
 247             /* video codec info */
 248             avio_wb32(s,34); /* size */
 249             ffio_wfourcc(s, "VIDO");
 250             if(stream->enc->codec_id == AV_CODEC_ID_RV10)
 251                 ffio_wfourcc(s,"RV10");
 252             else
 253                 ffio_wfourcc(s,"RV20");
 254             avio_wb16(s, stream->enc->width);
 255             avio_wb16(s, stream->enc->height);
 256             avio_wb16(s, (int) stream->frame_rate); /* frames per seconds ? */
 257             avio_wb32(s,0);     /* unknown meaning */
 258             avio_wb16(s, (int) stream->frame_rate);  /* unknown meaning */
 259             avio_wb32(s,0);     /* unknown meaning */
 260             avio_wb16(s, 8);    /* unknown meaning */
 261             /* Seems to be the codec version: only use basic H263. The next
 262                versions seems to add a diffential DC coding as in
 263                MPEG... nothing new under the sun */
 264             if(stream->enc->codec_id == AV_CODEC_ID_RV10)
 265                 avio_wb32(s,0x10000000);
 266             else
 267                 avio_wb32(s,0x20103001);
 268             //avio_wb32(s,0x10003000);
 269         }
 270     }
 271
 272     /* patch data offset field */
 273     data_pos = s->buf_ptr - start_ptr;
 274     rm->data_pos = data_pos;
 275     data_offset_ptr[0] = data_pos >> 24;
 276     data_offset_ptr[1] = data_pos >> 16;
 277     data_offset_ptr[2] = data_pos >> 8;
 278     data_offset_ptr[3] = data_pos;
 279
 280     /* data stream */
 281     ffio_wfourcc(s, "DATA");
 282     avio_wb32(s,data_size + 10 + 8);
 283     avio_wb16(s,0);
 284
 285     avio_wb32(s, nb_packets); /* number of packets */
 286     avio_wb32(s,0); /* next data header */
 287     return 0;
 288 }
 289
 290 static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
 291                                 int length, int key_frame)
 292 {
 293     int timestamp;
 294     AVIOContext *s = ctx->pb;
 295
 296     stream->nb_packets++;
 297     stream->packet_total_size += length;
 298     if (length > stream->packet_max_size)
 299         stream->packet_max_size =  length;
 300
 301     avio_wb16(s,0); /* version */
 302     avio_wb16(s,length + 12);
 303     avio_wb16(s, stream->num); /* stream number */
 304     timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate;
 305     avio_wb32(s, timestamp); /* timestamp */
 306     avio_w8(s, 0); /* reserved */
 307     avio_w8(s, key_frame ? 2 : 0); /* flags */
 308 }
 309
 310 static int rm_write_header(AVFormatContext *s)
 311 {
 312     RMMuxContext *rm = s->priv_data;
 313     StreamInfo *stream;
 314     int n;
 315     AVCodecContext *codec;
 316
 317     for(n=0;n<s->nb_streams;n++) {
 318         AVStream *st = s->streams[n];
 319         int frame_size;
 320
 321         s->streams[n]->id = n;
 322         codec = s->streams[n]->codec;
 323         stream = &rm->streams[n];
 324         memset(stream, 0, sizeof(StreamInfo));
 325         stream->num = n;
 326         stream->bit_rate = codec->bit_rate;
 327         stream->enc = codec;
 328
 329         switch(codec->codec_type) {
 330         case AVMEDIA_TYPE_AUDIO:
 331             rm->audio_stream = stream;
 332             frame_size = av_get_audio_frame_duration(codec, 0);
 333             stream->frame_rate = (float)codec->sample_rate / (float)frame_size;
 334             /* XXX: dummy values */
 335             stream->packet_max_size = 1024;
 336             stream->nb_packets = 0;
 337             stream->total_frames = stream->nb_packets;
 338             break;
 339         case AVMEDIA_TYPE_VIDEO:
 340             rm->video_stream = stream;
 341             // TODO: should be avg_frame_rate
 342             stream->frame_rate = (float)st->time_base.den / (float)st->time_base.num;
 343             /* XXX: dummy values */
 344             stream->packet_max_size = 4096;
 345             stream->nb_packets = 0;
 346             stream->total_frames = stream->nb_packets;
 347             break;
 348         default:
 349             return -1;
 350         }
 351     }
 352
 353     if (rv10_write_header(s, 0, 0))
 354         return AVERROR_INVALIDDATA;
 355     avio_flush(s->pb);
 356     return 0;
 357 }
 358
 359 static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
 360 {
 361     RMMuxContext *rm = s->priv_data;
 362     AVIOContext *pb = s->pb;
 363     StreamInfo *stream = rm->audio_stream;
 364     int i;
 365
 366     write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
 367
 368     if (stream->enc->codec_id == AV_CODEC_ID_AC3) {
 369         /* for AC-3, the words seem to be reversed */
 370         for (i = 0; i < size; i += 2) {
 371             avio_w8(pb, buf[i + 1]);
 372             avio_w8(pb, buf[i]);
 373         }
 374     } else {
 375         avio_write(pb, buf, size);
 376     }
 377     stream->nb_frames++;
 378     return 0;
 379 }
 380
 381 static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
 382 {
 383     RMMuxContext *rm = s->priv_data;
 384     AVIOContext *pb = s->pb;
 385     StreamInfo *stream = rm->video_stream;
 386     int key_frame = !!(flags & AV_PKT_FLAG_KEY);
 387
 388     /* XXX: this is incorrect: should be a parameter */
 389
 390     /* Well, I spent some time finding the meaning of these bits. I am
 391        not sure I understood everything, but it works !! */
 392 #if 1
 393     if (size > MAX_PACKET_SIZE) {
 394         avpriv_report_missing_feature(s, "Muxing packets larger than 64 kB");
 395         return AVERROR(ENOSYS);
 396     }
 397     write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
 398     /* bit 7: '1' if final packet of a frame converted in several packets */
 399     avio_w8(pb, 0x81);
 400     /* bit 7: '1' if I frame. bits 6..0 : sequence number in current
 401        frame starting from 1 */
 402     if (key_frame) {
 403         avio_w8(pb, 0x81);
 404     } else {
 405         avio_w8(pb, 0x01);
 406     }
 407     if(size >= 0x4000){
 408         avio_wb32(pb, size); /* total frame size */
 409         avio_wb32(pb, size); /* offset from the start or the end */
 410     }else{
 411         avio_wb16(pb, 0x4000 | size); /* total frame size */
 412         avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */
 413     }
 414 #else
 415     /* full frame */
 416     write_packet_header(s, size + 6);
 417     avio_w8(pb, 0xc0);
 418     avio_wb16(pb, 0x4000 + size); /* total frame size */
 419     avio_wb16(pb, 0x4000 + packet_number * 126); /* position in stream */
 420 #endif
 421     avio_w8(pb, stream->nb_frames & 0xff);
 422
 423     avio_write(pb, buf, size);
 424
 425     stream->nb_frames++;
 426     return 0;
 427 }
 428
 429 static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
 430 {
 431     if (s->streams[pkt->stream_index]->codec->codec_type ==
 432         AVMEDIA_TYPE_AUDIO)
 433         return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
 434     else
 435         return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
 436 }
 437
 438 static int rm_write_trailer(AVFormatContext *s)
 439 {
 440     RMMuxContext *rm = s->priv_data;
 441     int data_size, index_pos, i;
 442     AVIOContext *pb = s->pb;
 443
 444     if (s->pb->seekable) {
 445         /* end of file: finish to write header */
 446         index_pos = avio_tell(pb);
 447         data_size = index_pos - rm->data_pos;
 448
 449         /* FIXME: write index */
 450
 451         /* undocumented end header */
 452         avio_wb32(pb, 0);
 453         avio_wb32(pb, 0);
 454
 455         avio_seek(pb, 0, SEEK_SET);
 456         for(i=0;i<s->nb_streams;i++)
 457             rm->streams[i].total_frames = rm->streams[i].nb_frames;
 458         rv10_write_header(s, data_size, 0);
 459     } else {
 460         /* undocumented end header */
 461         avio_wb32(pb, 0);
 462         avio_wb32(pb, 0);
 463     }
 464
 465     return 0;
 466 }
 467
 468
 469 AVOutputFormat ff_rm_muxer = {
 470     .name              = "rm",
 471     .long_name         = NULL_IF_CONFIG_SMALL("RealMedia"),
 472     .mime_type         = "application/vnd.rn-realmedia",
 473     .extensions        = "rm,ra",
 474     .priv_data_size    = sizeof(RMMuxContext),
 475     .audio_codec       = AV_CODEC_ID_AC3,
 476     .video_codec       = AV_CODEC_ID_RV10,
 477     .write_header      = rm_write_header,
 478     .write_packet      = rm_write_packet,
 479     .write_trailer     = rm_write_trailer,
 480     .codec_tag         = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },
 481 };