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