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 is_avm2;
 182
 183     swf->audio_in_pos = 0;
 184     swf->sound_samples = 0;
 185     swf->swf_frame_number = 0;
 186     swf->video_frame_number = 0;
 187
 188     video_enc = NULL;
 189     audio_enc = NULL;
 190     for(i=0;i<s->nb_streams;i++) {
 191         enc = s->streams[i]->codec;
 192         if (enc->codec_type == CODEC_TYPE_AUDIO) {
 193             if (enc->codec_id == CODEC_ID_MP3) {
 194                 if (!enc->frame_size) {
 195                     av_log(s, AV_LOG_ERROR, "audio frame size not set\n");
 196                     return -1;
 197                 }
 198                 audio_enc = enc;
 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     is_avm2 = !strcmp("avm2", s->oformat->name);
 239
 240     put_tag(pb, "FWS");
 241     if (is_avm2)
 242         put_byte(pb, 9);
 243     else if (video_enc && video_enc->codec_id == CODEC_ID_VP6F)
 244         put_byte(pb, 8); /* version (version 8 and above support VP6 codec) */
 245     else if (video_enc && video_enc->codec_id == CODEC_ID_FLV1)
 246         put_byte(pb, 6); /* version (version 6 and above support FLV1 codec) */
 247     else
 248         put_byte(pb, 4); /* version (should use 4 for mpeg audio support) */
 249     put_le32(pb, DUMMY_FILE_SIZE); /* dummy size
 250                                       (will be patched if not streamed) */
 251
 252     put_swf_rect(pb, 0, width * 20, 0, height * 20);
 253     put_le16(pb, (rate * 256) / rate_base); /* frame rate */
 254     swf->duration_pos = url_ftell(pb);
 255     put_le16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
 256
 257     /* avm2/swf v9 (also v8?) files require a file attribute tag */
 258     if (is_avm2) {
 259         put_swf_tag(s, TAG_FILEATTRIBUTES);
 260         put_le32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
 261         put_swf_end_tag(s);
 262     }
 263
 264     /* define a shape with the jpeg inside */
 265     if (video_enc && video_enc->codec_id == CODEC_ID_MJPEG) {
 266         put_swf_tag(s, TAG_DEFINESHAPE);
 267
 268         put_le16(pb, SHAPE_ID); /* ID of shape */
 269         /* bounding rectangle */
 270         put_swf_rect(pb, 0, width, 0, height);
 271         /* style info */
 272         put_byte(pb, 1); /* one fill style */
 273         put_byte(pb, 0x41); /* clipped bitmap fill */
 274         put_le16(pb, BITMAP_ID); /* bitmap ID */
 275         /* position of the bitmap */
 276         put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
 277                        0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
 278         put_byte(pb, 0); /* no line style */
 279
 280         /* shape drawing */
 281         init_put_bits(&p, buf1, sizeof(buf1));
 282         put_bits(&p, 4, 1); /* one fill bit */
 283         put_bits(&p, 4, 0); /* zero line bit */
 284
 285         put_bits(&p, 1, 0); /* not an edge */
 286         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
 287         put_bits(&p, 5, 1); /* nbits */
 288         put_bits(&p, 1, 0); /* X */
 289         put_bits(&p, 1, 0); /* Y */
 290         put_bits(&p, 1, 1); /* set fill style 1 */
 291
 292         /* draw the rectangle ! */
 293         put_swf_line_edge(&p, width, 0);
 294         put_swf_line_edge(&p, 0, height);
 295         put_swf_line_edge(&p, -width, 0);
 296         put_swf_line_edge(&p, 0, -height);
 297
 298         /* end of shape */
 299         put_bits(&p, 1, 0); /* not an edge */
 300         put_bits(&p, 5, 0);
 301
 302         flush_put_bits(&p);
 303         put_buffer(pb, buf1, pbBufPtr(&p) - p.buf);
 304
 305         put_swf_end_tag(s);
 306     }
 307
 308     if (audio_enc && audio_enc->codec_id == CODEC_ID_MP3) {
 309         int v;
 310
 311         /* start sound */
 312         put_swf_tag(s, TAG_STREAMHEAD2);
 313
 314         v = 0;
 315         switch(audio_enc->sample_rate) {
 316         case 11025:
 317             v |= 1 << 2;
 318             break;
 319         case 22050:
 320             v |= 2 << 2;
 321             break;
 322         case 44100:
 323             v |= 3 << 2;
 324             break;
 325         default:
 326             /* not supported */
 327             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
 328             return -1;
 329         }
 330         v |= 0x02; /* 16 bit playback */
 331         if (audio_enc->channels == 2)
 332             v |= 0x01; /* stereo playback */
 333         put_byte(s->pb, v);
 334         v |= 0x20; /* mp3 compressed */
 335         put_byte(s->pb, v);
 336         put_le16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
 337         put_le16(s->pb, 0);
 338
 339         put_swf_end_tag(s);
 340     }
 341
 342     put_flush_packet(s->pb);
 343     return 0;
 344 }
 345
 346 static int swf_write_video(AVFormatContext *s,
 347                            AVCodecContext *enc, const uint8_t *buf, int size)
 348 {
 349     SWFContext *swf = s->priv_data;
 350     ByteIOContext *pb = s->pb;
 351
 352     /* Flash Player limit */
 353     if (swf->swf_frame_number == 16000)
 354         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
 355
 356     if (swf->video_type == CODEC_ID_VP6F ||
 357         swf->video_type == CODEC_ID_FLV1) {
 358         if (swf->video_frame_number == 0) {
 359             /* create a new video object */
 360             put_swf_tag(s, TAG_VIDEOSTREAM);
 361             put_le16(pb, VIDEO_ID);
 362             put_le16(pb, 15000); /* hard flash player limit */
 363             put_le16(pb, enc->width);
 364             put_le16(pb, enc->height);
 365             put_byte(pb, 0);
 366             put_byte(pb,codec_get_tag(swf_codec_tags,swf->video_type));
 367             put_swf_end_tag(s);
 368
 369             /* place the video object for the first time */
 370             put_swf_tag(s, TAG_PLACEOBJECT2);
 371             put_byte(pb, 0x36);
 372             put_le16(pb, 1);
 373             put_le16(pb, VIDEO_ID);
 374             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
 375             put_le16(pb, swf->video_frame_number);
 376             put_tag(pb, "video");
 377             put_byte(pb, 0x00);
 378             put_swf_end_tag(s);
 379         } else {
 380             /* mark the character for update */
 381             put_swf_tag(s, TAG_PLACEOBJECT2);
 382             put_byte(pb, 0x11);
 383             put_le16(pb, 1);
 384             put_le16(pb, swf->video_frame_number);
 385             put_swf_end_tag(s);
 386         }
 387
 388         /* set video frame data */
 389         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
 390         put_le16(pb, VIDEO_ID);
 391         put_le16(pb, swf->video_frame_number++);
 392         put_buffer(pb, buf, size);
 393         put_swf_end_tag(s);
 394     } else if (swf->video_type == CODEC_ID_MJPEG) {
 395         if (swf->swf_frame_number > 0) {
 396             /* remove the shape */
 397             put_swf_tag(s, TAG_REMOVEOBJECT);
 398             put_le16(pb, SHAPE_ID); /* shape ID */
 399             put_le16(pb, 1); /* depth */
 400             put_swf_end_tag(s);
 401
 402             /* free the bitmap */
 403             put_swf_tag(s, TAG_FREECHARACTER);
 404             put_le16(pb, BITMAP_ID);
 405             put_swf_end_tag(s);
 406         }
 407
 408         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
 409
 410         put_le16(pb, BITMAP_ID); /* ID of the image */
 411
 412         /* a dummy jpeg header seems to be required */
 413         put_be32(pb, 0xffd8ffd9);
 414         /* write the jpeg image */
 415         put_buffer(pb, buf, size);
 416
 417         put_swf_end_tag(s);
 418
 419         /* draw the shape */
 420
 421         put_swf_tag(s, TAG_PLACEOBJECT);
 422         put_le16(pb, SHAPE_ID); /* shape ID */
 423         put_le16(pb, 1); /* depth */
 424         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
 425         put_swf_end_tag(s);
 426     }
 427
 428     swf->swf_frame_number ++;
 429
 430     /* streaming sound always should be placed just before showframe tags */
 431     if (swf->audio_type && swf->audio_in_pos) {
 432         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
 433         put_le16(pb, swf->sound_samples);
 434         put_le16(pb, 0); // seek samples
 435         put_buffer(pb, swf->audio_fifo, swf->audio_in_pos);
 436         put_swf_end_tag(s);
 437
 438         /* update FIFO */
 439         swf->sound_samples = 0;
 440         swf->audio_in_pos = 0;
 441     }
 442
 443     /* output the frame */
 444     put_swf_tag(s, TAG_SHOWFRAME);
 445     put_swf_end_tag(s);
 446
 447     put_flush_packet(s->pb);
 448
 449     return 0;
 450 }
 451
 452 static int swf_write_audio(AVFormatContext *s,
 453                            AVCodecContext *enc, const uint8_t *buf, int size)
 454 {
 455     SWFContext *swf = s->priv_data;
 456
 457     /* Flash Player limit */
 458     if (swf->swf_frame_number == 16000)
 459         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
 460
 461     if (swf->audio_in_pos + size >= AUDIO_FIFO_SIZE) {
 462         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
 463         return -1;
 464     }
 465
 466     memcpy(swf->audio_fifo +  swf->audio_in_pos, buf, size);
 467     swf->audio_in_pos += size;
 468     swf->sound_samples += enc->frame_size;
 469
 470     /* if audio only stream make sure we add swf frames */
 471     if (swf->video_type == 0)
 472         swf_write_video(s, enc, 0, 0);
 473
 474     return 0;
 475 }
 476
 477 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
 478 {
 479     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
 480     if (codec->codec_type == CODEC_TYPE_AUDIO)
 481         return swf_write_audio(s, codec, pkt->data, pkt->size);
 482     else
 483         return swf_write_video(s, codec, pkt->data, pkt->size);
 484 }
 485
 486 static int swf_write_trailer(AVFormatContext *s)
 487 {
 488     SWFContext *swf = s->priv_data;
 489     ByteIOContext *pb = s->pb;
 490     AVCodecContext *enc, *video_enc;
 491     int file_size, i;
 492
 493     video_enc = NULL;
 494     for(i=0;i<s->nb_streams;i++) {
 495         enc = s->streams[i]->codec;
 496         if (enc->codec_type == CODEC_TYPE_VIDEO)
 497             video_enc = enc;
 498     }
 499
 500     put_swf_tag(s, TAG_END);
 501     put_swf_end_tag(s);
 502
 503     put_flush_packet(s->pb);
 504
 505     /* patch file size and number of frames if not streamed */
 506     if (!url_is_streamed(s->pb) && video_enc) {
 507         file_size = url_ftell(pb);
 508         url_fseek(pb, 4, SEEK_SET);
 509         put_le32(pb, file_size);
 510         url_fseek(pb, swf->duration_pos, SEEK_SET);
 511         put_le16(pb, video_enc->frame_number);
 512         url_fseek(pb, file_size, SEEK_SET);
 513     }
 514     return 0;
 515 }
 516
 517 #ifdef CONFIG_SWF_MUXER
 518 AVOutputFormat swf_muxer = {
 519     "swf",
 520     "Flash format",
 521     "application/x-shockwave-flash",
 522     "swf",
 523     sizeof(SWFContext),
 524     CODEC_ID_MP3,
 525     CODEC_ID_FLV1,
 526     swf_write_header,
 527     swf_write_packet,
 528     swf_write_trailer,
 529 };
 530 #endif
 531 #ifdef CONFIG_AVM2_MUXER
 532 AVOutputFormat avm2_muxer = {
 533     "avm2",
 534     "Flash 9 (AVM2) format",
 535     "application/x-shockwave-flash",
 536     NULL,
 537     sizeof(SWFContext),
 538     CODEC_ID_MP3,
 539     CODEC_ID_FLV1,
 540     swf_write_header,
 541     swf_write_packet,
 542     swf_write_trailer,
 543 };
 544 #endif