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     PutBitContext p;
 178     uint8_t buf1[256];
 179     int i, width, height, rate, rate_base;
 180     int version;
 181
 182     swf->sound_samples = 0;
 183     swf->swf_frame_number = 0;
 184     swf->video_frame_number = 0;
 185
 186     for(i=0;i<s->nb_streams;i++) {
 187         AVCodecContext *enc = s->streams[i]->codec;
 188         if (enc->codec_type == CODEC_TYPE_AUDIO) {
 189             if (enc->codec_id == CODEC_ID_MP3) {
 190                 if (!enc->frame_size) {
 191                     av_log(s, AV_LOG_ERROR, "audio frame size not set\n");
 192                     return -1;
 193                 }
 194                 swf->audio_enc = enc;
 195                 av_fifo_init(&swf->audio_fifo, AUDIO_FIFO_SIZE);
 196             } else {
 197                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
 198                 return -1;
 199             }
 200         } else {
 201             if (enc->codec_id == CODEC_ID_VP6F ||
 202                 enc->codec_id == CODEC_ID_FLV1 ||
 203                 enc->codec_id == CODEC_ID_MJPEG) {
 204                 swf->video_enc = enc;
 205             } else {
 206                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
 207                 return -1;
 208             }
 209         }
 210     }
 211
 212     if (!swf->video_enc) {
 213         /* currently, cannot work correctly if audio only */
 214         width = 320;
 215         height = 200;
 216         rate = 10;
 217         rate_base= 1;
 218     } else {
 219         width = swf->video_enc->width;
 220         height = swf->video_enc->height;
 221         rate = swf->video_enc->time_base.den;
 222         rate_base = swf->video_enc->time_base.num;
 223     }
 224
 225     if (!swf->audio_enc)
 226         swf->samples_per_frame = (44100. * rate_base) / rate;
 227     else
 228         swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;
 229
 230     put_tag(pb, "FWS");
 231
 232     if (!strcmp("avm2", s->oformat->name))
 233         version = 9;
 234     else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_VP6F)
 235         version = 8; /* version 8 and above support VP6 codec */
 236     else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_FLV1)
 237         version = 6; /* version 6 and above support FLV1 codec */
 238     else
 239         version = 4; /* version 4 for mpeg audio support */
 240     put_byte(pb, version);
 241
 242     put_le32(pb, DUMMY_FILE_SIZE); /* dummy size
 243                                       (will be patched if not streamed) */
 244
 245     put_swf_rect(pb, 0, width * 20, 0, height * 20);
 246     put_le16(pb, (rate * 256) / rate_base); /* frame rate */
 247     swf->duration_pos = url_ftell(pb);
 248     put_le16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
 249
 250     /* avm2/swf v9 (also v8?) files require a file attribute tag */
 251     if (version == 9) {
 252         put_swf_tag(s, TAG_FILEATTRIBUTES);
 253         put_le32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
 254         put_swf_end_tag(s);
 255     }
 256
 257     /* define a shape with the jpeg inside */
 258     if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_MJPEG) {
 259         put_swf_tag(s, TAG_DEFINESHAPE);
 260
 261         put_le16(pb, SHAPE_ID); /* ID of shape */
 262         /* bounding rectangle */
 263         put_swf_rect(pb, 0, width, 0, height);
 264         /* style info */
 265         put_byte(pb, 1); /* one fill style */
 266         put_byte(pb, 0x41); /* clipped bitmap fill */
 267         put_le16(pb, BITMAP_ID); /* bitmap ID */
 268         /* position of the bitmap */
 269         put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
 270                        0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
 271         put_byte(pb, 0); /* no line style */
 272
 273         /* shape drawing */
 274         init_put_bits(&p, buf1, sizeof(buf1));
 275         put_bits(&p, 4, 1); /* one fill bit */
 276         put_bits(&p, 4, 0); /* zero line bit */
 277
 278         put_bits(&p, 1, 0); /* not an edge */
 279         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
 280         put_bits(&p, 5, 1); /* nbits */
 281         put_bits(&p, 1, 0); /* X */
 282         put_bits(&p, 1, 0); /* Y */
 283         put_bits(&p, 1, 1); /* set fill style 1 */
 284
 285         /* draw the rectangle ! */
 286         put_swf_line_edge(&p, width, 0);
 287         put_swf_line_edge(&p, 0, height);
 288         put_swf_line_edge(&p, -width, 0);
 289         put_swf_line_edge(&p, 0, -height);
 290
 291         /* end of shape */
 292         put_bits(&p, 1, 0); /* not an edge */
 293         put_bits(&p, 5, 0);
 294
 295         flush_put_bits(&p);
 296         put_buffer(pb, buf1, pbBufPtr(&p) - p.buf);
 297
 298         put_swf_end_tag(s);
 299     }
 300
 301     if (swf->audio_enc && swf->audio_enc->codec_id == CODEC_ID_MP3) {
 302         int v = 0;
 303
 304         /* start sound */
 305         put_swf_tag(s, TAG_STREAMHEAD2);
 306         switch(swf->audio_enc->sample_rate) {
 307         case 11025: v |= 1 << 2; break;
 308         case 22050: v |= 2 << 2; break;
 309         case 44100: v |= 3 << 2; break;
 310         default:
 311             /* not supported */
 312             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
 313             return -1;
 314         }
 315         v |= 0x02; /* 16 bit playback */
 316         if (swf->audio_enc->channels == 2)
 317             v |= 0x01; /* stereo playback */
 318         put_byte(s->pb, v);
 319         v |= 0x20; /* mp3 compressed */
 320         put_byte(s->pb, v);
 321         put_le16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
 322         put_le16(s->pb, 0);
 323
 324         put_swf_end_tag(s);
 325     }
 326
 327     put_flush_packet(s->pb);
 328     return 0;
 329 }
 330
 331 static int swf_write_video(AVFormatContext *s,
 332                            AVCodecContext *enc, const uint8_t *buf, int size)
 333 {
 334     SWFContext *swf = s->priv_data;
 335     ByteIOContext *pb = s->pb;
 336
 337     /* Flash Player limit */
 338     if (swf->swf_frame_number == 16000)
 339         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
 340
 341     if (enc->codec_id == CODEC_ID_VP6F ||
 342         enc->codec_id == CODEC_ID_FLV1) {
 343         if (swf->video_frame_number == 0) {
 344             /* create a new video object */
 345             put_swf_tag(s, TAG_VIDEOSTREAM);
 346             put_le16(pb, VIDEO_ID);
 347             put_le16(pb, 15000); /* hard flash player limit */
 348             put_le16(pb, enc->width);
 349             put_le16(pb, enc->height);
 350             put_byte(pb, 0);
 351             put_byte(pb,codec_get_tag(swf_codec_tags,enc->codec_id));
 352             put_swf_end_tag(s);
 353
 354             /* place the video object for the first time */
 355             put_swf_tag(s, TAG_PLACEOBJECT2);
 356             put_byte(pb, 0x36);
 357             put_le16(pb, 1);
 358             put_le16(pb, VIDEO_ID);
 359             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
 360             put_le16(pb, swf->video_frame_number);
 361             put_tag(pb, "video");
 362             put_byte(pb, 0x00);
 363             put_swf_end_tag(s);
 364         } else {
 365             /* mark the character for update */
 366             put_swf_tag(s, TAG_PLACEOBJECT2);
 367             put_byte(pb, 0x11);
 368             put_le16(pb, 1);
 369             put_le16(pb, swf->video_frame_number);
 370             put_swf_end_tag(s);
 371         }
 372
 373         /* set video frame data */
 374         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
 375         put_le16(pb, VIDEO_ID);
 376         put_le16(pb, swf->video_frame_number++);
 377         put_buffer(pb, buf, size);
 378         put_swf_end_tag(s);
 379     } else if (enc->codec_id == CODEC_ID_MJPEG) {
 380         if (swf->swf_frame_number > 0) {
 381             /* remove the shape */
 382             put_swf_tag(s, TAG_REMOVEOBJECT);
 383             put_le16(pb, SHAPE_ID); /* shape ID */
 384             put_le16(pb, 1); /* depth */
 385             put_swf_end_tag(s);
 386
 387             /* free the bitmap */
 388             put_swf_tag(s, TAG_FREECHARACTER);
 389             put_le16(pb, BITMAP_ID);
 390             put_swf_end_tag(s);
 391         }
 392
 393         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
 394
 395         put_le16(pb, BITMAP_ID); /* ID of the image */
 396
 397         /* a dummy jpeg header seems to be required */
 398         put_be32(pb, 0xffd8ffd9);
 399         /* write the jpeg image */
 400         put_buffer(pb, buf, size);
 401
 402         put_swf_end_tag(s);
 403
 404         /* draw the shape */
 405
 406         put_swf_tag(s, TAG_PLACEOBJECT);
 407         put_le16(pb, SHAPE_ID); /* shape ID */
 408         put_le16(pb, 1); /* depth */
 409         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
 410         put_swf_end_tag(s);
 411     }
 412
 413     swf->swf_frame_number++;
 414
 415     /* streaming sound always should be placed just before showframe tags */
 416     if (swf->audio_enc && av_fifo_size(&swf->audio_fifo)) {
 417         int frame_size = av_fifo_size(&swf->audio_fifo);
 418         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
 419         put_le16(pb, swf->sound_samples);
 420         put_le16(pb, 0); // seek samples
 421         av_fifo_generic_read(&swf->audio_fifo, frame_size, &put_buffer, pb);
 422         put_swf_end_tag(s);
 423
 424         /* update FIFO */
 425         swf->sound_samples = 0;
 426     }
 427
 428     /* output the frame */
 429     put_swf_tag(s, TAG_SHOWFRAME);
 430     put_swf_end_tag(s);
 431
 432     put_flush_packet(s->pb);
 433
 434     return 0;
 435 }
 436
 437 static int swf_write_audio(AVFormatContext *s,
 438                            AVCodecContext *enc, const uint8_t *buf, int size)
 439 {
 440     SWFContext *swf = s->priv_data;
 441
 442     /* Flash Player limit */
 443     if (swf->swf_frame_number == 16000)
 444         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
 445
 446     if (av_fifo_size(&swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
 447         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
 448         return -1;
 449     }
 450
 451     av_fifo_generic_write(&swf->audio_fifo, buf, size, NULL);
 452     swf->sound_samples += enc->frame_size;
 453
 454     /* if audio only stream make sure we add swf frames */
 455     if (!swf->video_enc)
 456         swf_write_video(s, enc, 0, 0);
 457
 458     return 0;
 459 }
 460
 461 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
 462 {
 463     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
 464     if (codec->codec_type == CODEC_TYPE_AUDIO)
 465         return swf_write_audio(s, codec, pkt->data, pkt->size);
 466     else
 467         return swf_write_video(s, codec, pkt->data, pkt->size);
 468 }
 469
 470 static int swf_write_trailer(AVFormatContext *s)
 471 {
 472     SWFContext *swf = s->priv_data;
 473     ByteIOContext *pb = s->pb;
 474     AVCodecContext *enc, *video_enc;
 475     int file_size, i;
 476
 477     video_enc = NULL;
 478     for(i=0;i<s->nb_streams;i++) {
 479         enc = s->streams[i]->codec;
 480         if (enc->codec_type == CODEC_TYPE_VIDEO)
 481             video_enc = enc;
 482         else
 483             av_fifo_free(&swf->audio_fifo);
 484     }
 485
 486     put_swf_tag(s, TAG_END);
 487     put_swf_end_tag(s);
 488
 489     put_flush_packet(s->pb);
 490
 491     /* patch file size and number of frames if not streamed */
 492     if (!url_is_streamed(s->pb) && video_enc) {
 493         file_size = url_ftell(pb);
 494         url_fseek(pb, 4, SEEK_SET);
 495         put_le32(pb, file_size);
 496         url_fseek(pb, swf->duration_pos, SEEK_SET);
 497         put_le16(pb, swf->video_frame_number);
 498         url_fseek(pb, file_size, SEEK_SET);
 499     }
 500     return 0;
 501 }
 502
 503 #ifdef CONFIG_SWF_MUXER
 504 AVOutputFormat swf_muxer = {
 505     "swf",
 506     NULL_IF_CONFIG_SMALL("Flash format"),
 507     "application/x-shockwave-flash",
 508     "swf",
 509     sizeof(SWFContext),
 510     CODEC_ID_MP3,
 511     CODEC_ID_FLV1,
 512     swf_write_header,
 513     swf_write_packet,
 514     swf_write_trailer,
 515 };
 516 #endif
 517 #ifdef CONFIG_AVM2_MUXER
 518 AVOutputFormat avm2_muxer = {
 519     "avm2",
 520     NULL_IF_CONFIG_SMALL("Flash 9 (AVM2) format"),
 521     "application/x-shockwave-flash",
 522     NULL,
 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