libavformat/swfenc.c

   1 /*
   2  * Flash Compatible Streaming Format muxer
   3  * Copyright (c) 2000 Fabrice Bellard.
   4  * Copyright (c) 2003 Tinic Uro.
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "libavcodec/bitstream.h"
  24 #include "avformat.h"
  25 #include "swf.h"
  26
  27 static void put_swf_tag(AVFormatContext *s, int tag)
  28 {
  29     SWFContext *swf = s->priv_data;
  30     ByteIOContext *pb = s->pb;
  31
  32     swf->tag_pos = url_ftell(pb);
  33     swf->tag = tag;
  34     /* reserve some room for the tag */
  35     if (tag & TAG_LONG) {
  36         put_le16(pb, 0);
  37         put_le32(pb, 0);
  38     } else {
  39         put_le16(pb, 0);
  40     }
  41 }
  42
  43 static void put_swf_end_tag(AVFormatContext *s)
  44 {
  45     SWFContext *swf = s->priv_data;
  46     ByteIOContext *pb = s->pb;
  47     offset_t pos;
  48     int tag_len, tag;
  49
  50     pos = url_ftell(pb);
  51     tag_len = pos - swf->tag_pos - 2;
  52     tag = swf->tag;
  53     url_fseek(pb, swf->tag_pos, SEEK_SET);
  54     if (tag & TAG_LONG) {
  55         tag &= ~TAG_LONG;
  56         put_le16(pb, (tag << 6) | 0x3f);
  57         put_le32(pb, tag_len - 4);
  58     } else {
  59         assert(tag_len < 0x3f);
  60         put_le16(pb, (tag << 6) | tag_len);
  61     }
  62     url_fseek(pb, pos, SEEK_SET);
  63 }
  64
  65 static inline void max_nbits(int *nbits_ptr, int val)
  66 {
  67     int n;
  68
  69     if (val == 0)
  70         return;
  71     val = abs(val);
  72     n = 1;
  73     while (val != 0) {
  74         n++;
  75         val >>= 1;
  76     }
  77     if (n > *nbits_ptr)
  78         *nbits_ptr = n;
  79 }
  80
  81 static void put_swf_rect(ByteIOContext *pb,
  82                          int xmin, int xmax, int ymin, int ymax)
  83 {
  84     PutBitContext p;
  85     uint8_t buf[256];
  86     int nbits, mask;
  87
  88     init_put_bits(&p, buf, sizeof(buf));
  89
  90     nbits = 0;
  91     max_nbits(&nbits, xmin);
  92     max_nbits(&nbits, xmax);
  93     max_nbits(&nbits, ymin);
  94     max_nbits(&nbits, ymax);
  95     mask = (1 << nbits) - 1;
  96
  97     /* rectangle info */
  98     put_bits(&p, 5, nbits);
  99     put_bits(&p, nbits, xmin & mask);
 100     put_bits(&p, nbits, xmax & mask);
 101     put_bits(&p, nbits, ymin & mask);
 102     put_bits(&p, nbits, ymax & mask);
 103
 104     flush_put_bits(&p);
 105     put_buffer(pb, buf, pbBufPtr(&p) - p.buf);
 106 }
 107
 108 static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
 109 {
 110     int nbits, mask;
 111
 112     put_bits(pb, 1, 1); /* edge */
 113     put_bits(pb, 1, 1); /* line select */
 114     nbits = 2;
 115     max_nbits(&nbits, dx);
 116     max_nbits(&nbits, dy);
 117
 118     mask = (1 << nbits) - 1;
 119     put_bits(pb, 4, nbits - 2); /* 16 bits precision */
 120     if (dx == 0) {
 121         put_bits(pb, 1, 0);
 122         put_bits(pb, 1, 1);
 123         put_bits(pb, nbits, dy & mask);
 124     } else if (dy == 0) {
 125         put_bits(pb, 1, 0);
 126         put_bits(pb, 1, 0);
 127         put_bits(pb, nbits, dx & mask);
 128     } else {
 129         put_bits(pb, 1, 1);
 130         put_bits(pb, nbits, dx & mask);
 131         put_bits(pb, nbits, dy & mask);
 132     }
 133 }
 134
 135 #define FRAC_BITS 16
 136
 137 static void put_swf_matrix(ByteIOContext *pb,
 138                            int a, int b, int c, int d, int tx, int ty)
 139 {
 140     PutBitContext p;
 141     uint8_t buf[256];
 142     int nbits;
 143
 144     init_put_bits(&p, buf, sizeof(buf));
 145
 146     put_bits(&p, 1, 1); /* a, d present */
 147     nbits = 1;
 148     max_nbits(&nbits, a);
 149     max_nbits(&nbits, d);
 150     put_bits(&p, 5, nbits); /* nb bits */
 151     put_bits(&p, nbits, a);
 152     put_bits(&p, nbits, d);
 153
 154     put_bits(&p, 1, 1); /* b, c present */
 155     nbits = 1;
 156     max_nbits(&nbits, c);
 157     max_nbits(&nbits, b);
 158     put_bits(&p, 5, nbits); /* nb bits */
 159     put_bits(&p, nbits, c);
 160     put_bits(&p, nbits, b);
 161
 162     nbits = 1;
 163     max_nbits(&nbits, tx);
 164     max_nbits(&nbits, ty);
 165     put_bits(&p, 5, nbits); /* nb bits */
 166     put_bits(&p, nbits, tx);
 167     put_bits(&p, nbits, ty);
 168
 169     flush_put_bits(&p);
 170     put_buffer(pb, buf, pbBufPtr(&p) - p.buf);
 171 }
 172
 173 static int swf_write_header(AVFormatContext *s)
 174 {
 175     SWFContext *swf = s->priv_data;
 176     ByteIOContext *pb = s->pb;
 177     AVCodecContext *enc, *audio_enc, *video_enc;
 178     PutBitContext p;
 179     uint8_t buf1[256];
 180     int i, width, height, rate, rate_base;
 181     int version;
 182
 183     swf->sound_samples = 0;
 184     swf->swf_frame_number = 0;
 185     swf->video_frame_number = 0;
 186
 187     video_enc = NULL;
 188     audio_enc = NULL;
 189     for(i=0;i<s->nb_streams;i++) {
 190         enc = s->streams[i]->codec;
 191         if (enc->codec_type == CODEC_TYPE_AUDIO) {
 192             if (enc->codec_id == CODEC_ID_MP3) {
 193                 if (!enc->frame_size) {
 194                     av_log(s, AV_LOG_ERROR, "audio frame size not set\n");
 195                     return -1;
 196                 }
 197                 audio_enc = enc;
 198                 av_fifo_init(&swf->audio_fifo, AUDIO_FIFO_SIZE);
 199             } else {
 200                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
 201                 return -1;
 202             }
 203         } else {
 204             if (enc->codec_id == CODEC_ID_VP6F ||
 205                 enc->codec_id == CODEC_ID_FLV1 ||
 206                 enc->codec_id == CODEC_ID_MJPEG) {
 207                 video_enc = enc;
 208             } else {
 209                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
 210                 return -1;
 211             }
 212         }
 213     }
 214
 215     if (!video_enc) {
 216         /* currently, cannot work correctly if audio only */
 217         swf->video_type = 0;
 218         width = 320;
 219         height = 200;
 220         rate = 10;
 221         rate_base= 1;
 222     } else {
 223         swf->video_type = video_enc->codec_id;
 224         width = video_enc->width;
 225         height = video_enc->height;
 226         rate = video_enc->time_base.den;
 227         rate_base = video_enc->time_base.num;
 228     }
 229
 230     if (!audio_enc) {
 231         swf->audio_type = 0;
 232         swf->samples_per_frame = (44100. * rate_base) / rate;
 233     } else {
 234         swf->audio_type = audio_enc->codec_id;
 235         swf->samples_per_frame = (audio_enc->sample_rate * rate_base) / rate;
 236     }
 237
 238     put_tag(pb, "FWS");
 239
 240     if (!strcmp("avm2", s->oformat->name))
 241         version = 9;
 242     else if (video_enc && video_enc->codec_id == CODEC_ID_VP6F)
 243         version = 8; /* version 8 and above support VP6 codec */
 244     else if (video_enc && video_enc->codec_id == CODEC_ID_FLV1)
 245         version = 6; /* version 6 and above support FLV1 codec */
 246     else
 247         version = 4; /* version 4 for mpeg audio support */
 248     put_byte(pb, version);
 249
 250     put_le32(pb, DUMMY_FILE_SIZE); /* dummy size
 251                                       (will be patched if not streamed) */
 252
 253     put_swf_rect(pb, 0, width * 20, 0, height * 20);
 254     put_le16(pb, (rate * 256) / rate_base); /* frame rate */
 255     swf->duration_pos = url_ftell(pb);
 256     put_le16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
 257
 258     /* avm2/swf v9 (also v8?) files require a file attribute tag */
 259     if (version == 9) {
 260         put_swf_tag(s, TAG_FILEATTRIBUTES);
 261         put_le32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
 262         put_swf_end_tag(s);
 263     }
 264
 265     /* define a shape with the jpeg inside */
 266     if (video_enc && video_enc->codec_id == CODEC_ID_MJPEG) {
 267         put_swf_tag(s, TAG_DEFINESHAPE);
 268
 269         put_le16(pb, SHAPE_ID); /* ID of shape */
 270         /* bounding rectangle */
 271         put_swf_rect(pb, 0, width, 0, height);
 272         /* style info */
 273         put_byte(pb, 1); /* one fill style */
 274         put_byte(pb, 0x41); /* clipped bitmap fill */
 275         put_le16(pb, BITMAP_ID); /* bitmap ID */
 276         /* position of the bitmap */
 277         put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
 278                        0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
 279         put_byte(pb, 0); /* no line style */
 280
 281         /* shape drawing */
 282         init_put_bits(&p, buf1, sizeof(buf1));
 283         put_bits(&p, 4, 1); /* one fill bit */
 284         put_bits(&p, 4, 0); /* zero line bit */
 285
 286         put_bits(&p, 1, 0); /* not an edge */
 287         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
 288         put_bits(&p, 5, 1); /* nbits */
 289         put_bits(&p, 1, 0); /* X */
 290         put_bits(&p, 1, 0); /* Y */
 291         put_bits(&p, 1, 1); /* set fill style 1 */
 292
 293         /* draw the rectangle ! */
 294         put_swf_line_edge(&p, width, 0);
 295         put_swf_line_edge(&p, 0, height);
 296         put_swf_line_edge(&p, -width, 0);
 297         put_swf_line_edge(&p, 0, -height);
 298
 299         /* end of shape */
 300         put_bits(&p, 1, 0); /* not an edge */
 301         put_bits(&p, 5, 0);
 302
 303         flush_put_bits(&p);
 304         put_buffer(pb, buf1, pbBufPtr(&p) - p.buf);
 305
 306         put_swf_end_tag(s);
 307     }
 308
 309     if (audio_enc && audio_enc->codec_id == CODEC_ID_MP3) {
 310         int v = 0;
 311
 312         /* start sound */
 313         put_swf_tag(s, TAG_STREAMHEAD2);
 314         switch(audio_enc->sample_rate) {
 315         case 11025: v |= 1 << 2; break;
 316         case 22050: v |= 2 << 2; break;
 317         case 44100: v |= 3 << 2; break;
 318         default:
 319             /* not supported */
 320             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
 321             return -1;
 322         }
 323         v |= 0x02; /* 16 bit playback */
 324         if (audio_enc->channels == 2)
 325             v |= 0x01; /* stereo playback */
 326         put_byte(s->pb, v);
 327         v |= 0x20; /* mp3 compressed */
 328         put_byte(s->pb, v);
 329         put_le16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
 330         put_le16(s->pb, 0);
 331
 332         put_swf_end_tag(s);
 333     }
 334
 335     put_flush_packet(s->pb);
 336     return 0;
 337 }
 338
 339 static int swf_write_video(AVFormatContext *s,
 340                            AVCodecContext *enc, const uint8_t *buf, int size)
 341 {
 342     SWFContext *swf = s->priv_data;
 343     ByteIOContext *pb = s->pb;
 344
 345     /* Flash Player limit */
 346     if (swf->swf_frame_number == 16000)
 347         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
 348
 349     if (swf->video_type == CODEC_ID_VP6F ||
 350         swf->video_type == CODEC_ID_FLV1) {
 351         if (swf->video_frame_number == 0) {
 352             /* create a new video object */
 353             put_swf_tag(s, TAG_VIDEOSTREAM);
 354             put_le16(pb, VIDEO_ID);
 355             put_le16(pb, 15000); /* hard flash player limit */
 356             put_le16(pb, enc->width);
 357             put_le16(pb, enc->height);
 358             put_byte(pb, 0);
 359             put_byte(pb,codec_get_tag(swf_codec_tags,swf->video_type));
 360             put_swf_end_tag(s);
 361
 362             /* place the video object for the first time */
 363             put_swf_tag(s, TAG_PLACEOBJECT2);
 364             put_byte(pb, 0x36);
 365             put_le16(pb, 1);
 366             put_le16(pb, VIDEO_ID);
 367             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
 368             put_le16(pb, swf->video_frame_number);
 369             put_tag(pb, "video");
 370             put_byte(pb, 0x00);
 371             put_swf_end_tag(s);
 372         } else {
 373             /* mark the character for update */
 374             put_swf_tag(s, TAG_PLACEOBJECT2);
 375             put_byte(pb, 0x11);
 376             put_le16(pb, 1);
 377             put_le16(pb, swf->video_frame_number);
 378             put_swf_end_tag(s);
 379         }
 380
 381         /* set video frame data */
 382         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
 383         put_le16(pb, VIDEO_ID);
 384         put_le16(pb, swf->video_frame_number++);
 385         put_buffer(pb, buf, size);
 386         put_swf_end_tag(s);
 387     } else if (swf->video_type == CODEC_ID_MJPEG) {
 388         if (swf->swf_frame_number > 0) {
 389             /* remove the shape */
 390             put_swf_tag(s, TAG_REMOVEOBJECT);
 391             put_le16(pb, SHAPE_ID); /* shape ID */
 392             put_le16(pb, 1); /* depth */
 393             put_swf_end_tag(s);
 394
 395             /* free the bitmap */
 396             put_swf_tag(s, TAG_FREECHARACTER);
 397             put_le16(pb, BITMAP_ID);
 398             put_swf_end_tag(s);
 399         }
 400
 401         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
 402
 403         put_le16(pb, BITMAP_ID); /* ID of the image */
 404
 405         /* a dummy jpeg header seems to be required */
 406         put_be32(pb, 0xffd8ffd9);
 407         /* write the jpeg image */
 408         put_buffer(pb, buf, size);
 409
 410         put_swf_end_tag(s);
 411
 412         /* draw the shape */
 413
 414         put_swf_tag(s, TAG_PLACEOBJECT);
 415         put_le16(pb, SHAPE_ID); /* shape ID */
 416         put_le16(pb, 1); /* depth */
 417         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
 418         put_swf_end_tag(s);
 419     }
 420
 421     swf->swf_frame_number ++;
 422
 423     /* streaming sound always should be placed just before showframe tags */
 424     if (swf->audio_type && av_fifo_size(&swf->audio_fifo)) {
 425         int frame_size = av_fifo_size(&swf->audio_fifo);
 426         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
 427         put_le16(pb, swf->sound_samples);
 428         put_le16(pb, 0); // seek samples
 429         av_fifo_generic_read(&swf->audio_fifo, frame_size, &put_buffer, pb);
 430         put_swf_end_tag(s);
 431
 432         /* update FIFO */
 433         swf->sound_samples = 0;
 434     }
 435
 436     /* output the frame */
 437     put_swf_tag(s, TAG_SHOWFRAME);
 438     put_swf_end_tag(s);
 439
 440     put_flush_packet(s->pb);
 441
 442     return 0;
 443 }
 444
 445 static int swf_write_audio(AVFormatContext *s,
 446                            AVCodecContext *enc, const uint8_t *buf, int size)
 447 {
 448     SWFContext *swf = s->priv_data;
 449
 450     /* Flash Player limit */
 451     if (swf->swf_frame_number == 16000)
 452         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
 453
 454     if (av_fifo_size(&swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
 455         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
 456         return -1;
 457     }
 458
 459     av_fifo_generic_write(&swf->audio_fifo, buf, size, NULL);
 460     swf->sound_samples += enc->frame_size;
 461
 462     /* if audio only stream make sure we add swf frames */
 463     if (swf->video_type == 0)
 464         swf_write_video(s, enc, 0, 0);
 465
 466     return 0;
 467 }
 468
 469 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
 470 {
 471     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
 472     if (codec->codec_type == CODEC_TYPE_AUDIO)
 473         return swf_write_audio(s, codec, pkt->data, pkt->size);
 474     else
 475         return swf_write_video(s, codec, pkt->data, pkt->size);
 476 }
 477
 478 static int swf_write_trailer(AVFormatContext *s)
 479 {
 480     SWFContext *swf = s->priv_data;
 481     ByteIOContext *pb = s->pb;
 482     AVCodecContext *enc, *video_enc;
 483     int file_size, i;
 484
 485     video_enc = NULL;
 486     for(i=0;i<s->nb_streams;i++) {
 487         enc = s->streams[i]->codec;
 488         if (enc->codec_type == CODEC_TYPE_VIDEO)
 489             video_enc = enc;
 490         else
 491             av_fifo_free(&swf->audio_fifo);
 492     }
 493
 494     put_swf_tag(s, TAG_END);
 495     put_swf_end_tag(s);
 496
 497     put_flush_packet(s->pb);
 498
 499     /* patch file size and number of frames if not streamed */
 500     if (!url_is_streamed(s->pb) && video_enc) {
 501         file_size = url_ftell(pb);
 502         url_fseek(pb, 4, SEEK_SET);
 503         put_le32(pb, file_size);
 504         url_fseek(pb, swf->duration_pos, SEEK_SET);
 505         put_le16(pb, video_enc->frame_number);
 506         url_fseek(pb, file_size, SEEK_SET);
 507     }
 508     return 0;
 509 }
 510
 511 #ifdef CONFIG_SWF_MUXER
 512 AVOutputFormat swf_muxer = {
 513     "swf",
 514     "Flash format",
 515     "application/x-shockwave-flash",
 516     "swf",
 517     sizeof(SWFContext),
 518     CODEC_ID_MP3,
 519     CODEC_ID_FLV1,
 520     swf_write_header,
 521     swf_write_packet,
 522     swf_write_trailer,
 523 };
 524 #endif
 525 #ifdef CONFIG_AVM2_MUXER
 526 AVOutputFormat avm2_muxer = {
 527     "avm2",
 528     "Flash 9 (AVM2) format",
 529     "application/x-shockwave-flash",
 530     NULL,
 531     sizeof(SWFContext),
 532     CODEC_ID_MP3,
 533     CODEC_ID_FLV1,
 534     swf_write_header,
 535     swf_write_packet,
 536     swf_write_trailer,
 537 };
 538 #endif