libavformat/rmenc.c

   1 /*
   2  * "Real" compatible muxer.
   3  * Copyright (c) 2000, 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 #include "avformat.h"
  22 #include "rm.h"
  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 } RMMuxContext;
  42
  43 /* in ms */
  44 #define BUFFER_DURATION 0
  45
  46
  47 static void put_str(ByteIOContext *s, const char *tag)
  48 {
  49     put_be16(s,strlen(tag));
  50     while (*tag) {
  51         put_byte(s, *tag++);
  52     }
  53 }
  54
  55 static void put_str8(ByteIOContext *s, const char *tag)
  56 {
  57     put_byte(s, strlen(tag));
  58     while (*tag) {
  59         put_byte(s, *tag++);
  60     }
  61 }
  62
  63 static void rv10_write_header(AVFormatContext *ctx,
  64                               int data_size, int index_pos)
  65 {
  66     RMMuxContext *rm = ctx->priv_data;
  67     ByteIOContext *s = ctx->pb;
  68     StreamInfo *stream;
  69     unsigned char *data_offset_ptr, *start_ptr;
  70     const char *desc, *mimetype;
  71     int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
  72     int bit_rate, v, duration, flags, data_pos;
  73
  74     start_ptr = s->buf_ptr;
  75
  76     put_tag(s, ".RMF");
  77     put_be32(s,18); /* header size */
  78     put_be16(s,0);
  79     put_be32(s,0);
  80     put_be32(s,4 + ctx->nb_streams); /* num headers */
  81
  82     put_tag(s,"PROP");
  83     put_be32(s, 50);
  84     put_be16(s, 0);
  85     packet_max_size = 0;
  86     packet_total_size = 0;
  87     nb_packets = 0;
  88     bit_rate = 0;
  89     duration = 0;
  90     for(i=0;i<ctx->nb_streams;i++) {
  91         StreamInfo *stream = &rm->streams[i];
  92         bit_rate += stream->bit_rate;
  93         if (stream->packet_max_size > packet_max_size)
  94             packet_max_size = stream->packet_max_size;
  95         nb_packets += stream->nb_packets;
  96         packet_total_size += stream->packet_total_size;
  97         /* select maximum duration */
  98         v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);
  99         if (v > duration)
 100             duration = v;
 101     }
 102     put_be32(s, bit_rate); /* max bit rate */
 103     put_be32(s, bit_rate); /* avg bit rate */
 104     put_be32(s, packet_max_size);        /* max packet size */
 105     if (nb_packets > 0)
 106         packet_avg_size = packet_total_size / nb_packets;
 107     else
 108         packet_avg_size = 0;
 109     put_be32(s, packet_avg_size);        /* avg packet size */
 110     put_be32(s, nb_packets);  /* num packets */
 111     put_be32(s, duration); /* duration */
 112     put_be32(s, BUFFER_DURATION);           /* preroll */
 113     put_be32(s, index_pos);           /* index offset */
 114     /* computation of data the data offset */
 115     data_offset_ptr = s->buf_ptr;
 116     put_be32(s, 0);           /* data offset : will be patched after */
 117     put_be16(s, ctx->nb_streams);    /* num streams */
 118     flags = 1 | 2; /* save allowed & perfect play */
 119     if (url_is_streamed(s))
 120         flags |= 4; /* live broadcast */
 121     put_be16(s, flags);
 122
 123     /* comments */
 124
 125     put_tag(s,"CONT");
 126     size = strlen(ctx->title) + strlen(ctx->author) + strlen(ctx->copyright) +
 127         strlen(ctx->comment) + 4 * 2 + 10;
 128     put_be32(s,size);
 129     put_be16(s,0);
 130     put_str(s, ctx->title);
 131     put_str(s, ctx->author);
 132     put_str(s, ctx->copyright);
 133     put_str(s, ctx->comment);
 134
 135     for(i=0;i<ctx->nb_streams;i++) {
 136         int codec_data_size;
 137
 138         stream = &rm->streams[i];
 139
 140         if (stream->enc->codec_type == CODEC_TYPE_AUDIO) {
 141             desc = "The Audio Stream";
 142             mimetype = "audio/x-pn-realaudio";
 143             codec_data_size = 73;
 144         } else {
 145             desc = "The Video Stream";
 146             mimetype = "video/x-pn-realvideo";
 147             codec_data_size = 34;
 148         }
 149
 150         put_tag(s,"MDPR");
 151         size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
 152         put_be32(s, size);
 153         put_be16(s, 0);
 154
 155         put_be16(s, i); /* stream number */
 156         put_be32(s, stream->bit_rate); /* max bit rate */
 157         put_be32(s, stream->bit_rate); /* avg bit rate */
 158         put_be32(s, stream->packet_max_size);        /* max packet size */
 159         if (stream->nb_packets > 0)
 160             packet_avg_size = stream->packet_total_size /
 161                 stream->nb_packets;
 162         else
 163             packet_avg_size = 0;
 164         put_be32(s, packet_avg_size);        /* avg packet size */
 165         put_be32(s, 0);           /* start time */
 166         put_be32(s, BUFFER_DURATION);           /* preroll */
 167         /* duration */
 168         if (url_is_streamed(s) || !stream->total_frames)
 169             put_be32(s, (int)(3600 * 1000));
 170         else
 171             put_be32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));
 172         put_str8(s, desc);
 173         put_str8(s, mimetype);
 174         put_be32(s, codec_data_size);
 175
 176         if (stream->enc->codec_type == CODEC_TYPE_AUDIO) {
 177             int coded_frame_size, fscode, sample_rate;
 178             sample_rate = stream->enc->sample_rate;
 179             coded_frame_size = (stream->enc->bit_rate *
 180                                 stream->enc->frame_size) / (8 * sample_rate);
 181             /* audio codec info */
 182             put_tag(s, ".ra");
 183             put_byte(s, 0xfd);
 184             put_be32(s, 0x00040000); /* version */
 185             put_tag(s, ".ra4");
 186             put_be32(s, 0x01b53530); /* stream length */
 187             put_be16(s, 4); /* unknown */
 188             put_be32(s, 0x39); /* header size */
 189
 190             switch(sample_rate) {
 191             case 48000:
 192             case 24000:
 193             case 12000:
 194                 fscode = 1;
 195                 break;
 196             default:
 197             case 44100:
 198             case 22050:
 199             case 11025:
 200                 fscode = 2;
 201                 break;
 202             case 32000:
 203             case 16000:
 204             case 8000:
 205                 fscode = 3;
 206             }
 207             put_be16(s, fscode); /* codec additional info, for AC-3, seems
 208                                      to be a frequency code */
 209             /* special hack to compensate rounding errors... */
 210             if (coded_frame_size == 557)
 211                 coded_frame_size--;
 212             put_be32(s, coded_frame_size); /* frame length */
 213             put_be32(s, 0x51540); /* unknown */
 214             put_be32(s, 0x249f0); /* unknown */
 215             put_be32(s, 0x249f0); /* unknown */
 216             put_be16(s, 0x01);
 217             /* frame length : seems to be very important */
 218             put_be16(s, coded_frame_size);
 219             put_be32(s, 0); /* unknown */
 220             put_be16(s, stream->enc->sample_rate); /* sample rate */
 221             put_be32(s, 0x10); /* unknown */
 222             put_be16(s, stream->enc->channels);
 223             put_str8(s, "Int0"); /* codec name */
 224             put_str8(s, "dnet"); /* codec name */
 225             put_be16(s, 0); /* title length */
 226             put_be16(s, 0); /* author length */
 227             put_be16(s, 0); /* copyright length */
 228             put_byte(s, 0); /* end of header */
 229         } else {
 230             /* video codec info */
 231             put_be32(s,34); /* size */
 232             if(stream->enc->codec_id == CODEC_ID_RV10)
 233                 put_tag(s,"VIDORV10");
 234             else
 235                 put_tag(s,"VIDORV20");
 236             put_be16(s, stream->enc->width);
 237             put_be16(s, stream->enc->height);
 238             put_be16(s, (int) stream->frame_rate); /* frames per seconds ? */
 239             put_be32(s,0);     /* unknown meaning */
 240             put_be16(s, (int) stream->frame_rate);  /* unknown meaning */
 241             put_be32(s,0);     /* unknown meaning */
 242             put_be16(s, 8);    /* unknown meaning */
 243             /* Seems to be the codec version: only use basic H263. The next
 244                versions seems to add a diffential DC coding as in
 245                MPEG... nothing new under the sun */
 246             if(stream->enc->codec_id == CODEC_ID_RV10)
 247                 put_be32(s,0x10000000);
 248             else
 249                 put_be32(s,0x20103001);
 250             //put_be32(s,0x10003000);
 251         }
 252     }
 253
 254     /* patch data offset field */
 255     data_pos = s->buf_ptr - start_ptr;
 256     rm->data_pos = data_pos;
 257     data_offset_ptr[0] = data_pos >> 24;
 258     data_offset_ptr[1] = data_pos >> 16;
 259     data_offset_ptr[2] = data_pos >> 8;
 260     data_offset_ptr[3] = data_pos;
 261
 262     /* data stream */
 263     put_tag(s,"DATA");
 264     put_be32(s,data_size + 10 + 8);
 265     put_be16(s,0);
 266
 267     put_be32(s, nb_packets); /* number of packets */
 268     put_be32(s,0); /* next data header */
 269 }
 270
 271 static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
 272                                 int length, int key_frame)
 273 {
 274     int timestamp;
 275     ByteIOContext *s = ctx->pb;
 276
 277     stream->nb_packets++;
 278     stream->packet_total_size += length;
 279     if (length > stream->packet_max_size)
 280         stream->packet_max_size =  length;
 281
 282     put_be16(s,0); /* version */
 283     put_be16(s,length + 12);
 284     put_be16(s, stream->num); /* stream number */
 285     timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate;
 286     put_be32(s, timestamp); /* timestamp */
 287     put_byte(s, 0); /* reserved */
 288     put_byte(s, key_frame ? 2 : 0); /* flags */
 289 }
 290
 291 static int rm_write_header(AVFormatContext *s)
 292 {
 293     RMMuxContext *rm = s->priv_data;
 294     StreamInfo *stream;
 295     int n;
 296     AVCodecContext *codec;
 297
 298     for(n=0;n<s->nb_streams;n++) {
 299         s->streams[n]->id = n;
 300         codec = s->streams[n]->codec;
 301         stream = &rm->streams[n];
 302         memset(stream, 0, sizeof(StreamInfo));
 303         stream->num = n;
 304         stream->bit_rate = codec->bit_rate;
 305         stream->enc = codec;
 306
 307         switch(codec->codec_type) {
 308         case CODEC_TYPE_AUDIO:
 309             rm->audio_stream = stream;
 310             stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size;
 311             /* XXX: dummy values */
 312             stream->packet_max_size = 1024;
 313             stream->nb_packets = 0;
 314             stream->total_frames = stream->nb_packets;
 315             break;
 316         case CODEC_TYPE_VIDEO:
 317             rm->video_stream = stream;
 318             stream->frame_rate = (float)codec->time_base.den / (float)codec->time_base.num;
 319             /* XXX: dummy values */
 320             stream->packet_max_size = 4096;
 321             stream->nb_packets = 0;
 322             stream->total_frames = stream->nb_packets;
 323             break;
 324         default:
 325             return -1;
 326         }
 327     }
 328
 329     rv10_write_header(s, 0, 0);
 330     put_flush_packet(s->pb);
 331     return 0;
 332 }
 333
 334 static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
 335 {
 336     uint8_t *buf1;
 337     RMMuxContext *rm = s->priv_data;
 338     ByteIOContext *pb = s->pb;
 339     StreamInfo *stream = rm->audio_stream;
 340     int i;
 341
 342     /* XXX: suppress this malloc */
 343     buf1= (uint8_t*) av_malloc( size * sizeof(uint8_t) );
 344
 345     write_packet_header(s, stream, size, !!(flags & PKT_FLAG_KEY));
 346
 347     /* for AC-3, the words seem to be reversed */
 348     for(i=0;i<size;i+=2) {
 349         buf1[i] = buf[i+1];
 350         buf1[i+1] = buf[i];
 351     }
 352     put_buffer(pb, buf1, size);
 353     put_flush_packet(pb);
 354     stream->nb_frames++;
 355     av_free(buf1);
 356     return 0;
 357 }
 358
 359 static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
 360 {
 361     RMMuxContext *rm = s->priv_data;
 362     ByteIOContext *pb = s->pb;
 363     StreamInfo *stream = rm->video_stream;
 364     int key_frame = !!(flags & PKT_FLAG_KEY);
 365
 366     /* XXX: this is incorrect: should be a parameter */
 367
 368     /* Well, I spent some time finding the meaning of these bits. I am
 369        not sure I understood everything, but it works !! */
 370 #if 1
 371     write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
 372     /* bit 7: '1' if final packet of a frame converted in several packets */
 373     put_byte(pb, 0x81);
 374     /* bit 7: '1' if I frame. bits 6..0 : sequence number in current
 375        frame starting from 1 */
 376     if (key_frame) {
 377         put_byte(pb, 0x81);
 378     } else {
 379         put_byte(pb, 0x01);
 380     }
 381     if(size >= 0x4000){
 382         put_be32(pb, size); /* total frame size */
 383         put_be32(pb, size); /* offset from the start or the end */
 384     }else{
 385         put_be16(pb, 0x4000 | size); /* total frame size */
 386         put_be16(pb, 0x4000 | size); /* offset from the start or the end */
 387     }
 388 #else
 389     /* full frame */
 390     write_packet_header(s, size + 6);
 391     put_byte(pb, 0xc0);
 392     put_be16(pb, 0x4000 + size); /* total frame size */
 393     put_be16(pb, 0x4000 + packet_number * 126); /* position in stream */
 394 #endif
 395     put_byte(pb, stream->nb_frames & 0xff);
 396
 397     put_buffer(pb, buf, size);
 398     put_flush_packet(pb);
 399
 400     stream->nb_frames++;
 401     return 0;
 402 }
 403
 404 static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
 405 {
 406     if (s->streams[pkt->stream_index]->codec->codec_type ==
 407         CODEC_TYPE_AUDIO)
 408         return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
 409     else
 410         return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
 411 }
 412
 413 static int rm_write_trailer(AVFormatContext *s)
 414 {
 415     RMMuxContext *rm = s->priv_data;
 416     int data_size, index_pos, i;
 417     ByteIOContext *pb = s->pb;
 418
 419     if (!url_is_streamed(s->pb)) {
 420         /* end of file: finish to write header */
 421         index_pos = url_fseek(pb, 0, SEEK_CUR);
 422         data_size = index_pos - rm->data_pos;
 423
 424         /* index */
 425         put_tag(pb, "INDX");
 426         put_be32(pb, 10 + 10 * s->nb_streams);
 427         put_be16(pb, 0);
 428
 429         for(i=0;i<s->nb_streams;i++) {
 430             put_be32(pb, 0); /* zero indexes */
 431             put_be16(pb, i); /* stream number */
 432             put_be32(pb, 0); /* next index */
 433         }
 434         /* undocumented end header */
 435         put_be32(pb, 0);
 436         put_be32(pb, 0);
 437
 438         url_fseek(pb, 0, SEEK_SET);
 439         for(i=0;i<s->nb_streams;i++)
 440             rm->streams[i].total_frames = rm->streams[i].nb_frames;
 441         rv10_write_header(s, data_size, index_pos);
 442     } else {
 443         /* undocumented end header */
 444         put_be32(pb, 0);
 445         put_be32(pb, 0);
 446     }
 447     put_flush_packet(pb);
 448     return 0;
 449 }
 450
 451
 452 AVOutputFormat rm_muxer = {
 453     "rm",
 454     NULL_IF_CONFIG_SMALL("RM format"),
 455     "application/vnd.rn-realmedia",
 456     "rm,ra",
 457     sizeof(RMMuxContext),
 458     CODEC_ID_AC3,
 459     CODEC_ID_RV10,
 460     rm_write_header,
 461     rm_write_packet,
 462     rm_write_trailer,
 463 };