summaryrefslogtreecommitdiff
path: root/libavformat/swfenc.c
blob: 2d341dcc47e0c46498cd94bb7bcf98d8a2490b27 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
/*
 * Flash Compatible Streaming Format muxer
 * Copyright (c) 2000 Fabrice Bellard.
 * Copyright (c) 2003 Tinic Uro.
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "libavcodec/bitstream.h"
#include "avformat.h"
#include "swf.h"

static void put_swf_tag(AVFormatContext *s, int tag)
{
    SWFContext *swf = s->priv_data;
    ByteIOContext *pb = s->pb;

    swf->tag_pos = url_ftell(pb);
    swf->tag = tag;
    /* reserve some room for the tag */
    if (tag & TAG_LONG) {
        put_le16(pb, 0);
        put_le32(pb, 0);
    } else {
        put_le16(pb, 0);
    }
}

static void put_swf_end_tag(AVFormatContext *s)
{
    SWFContext *swf = s->priv_data;
    ByteIOContext *pb = s->pb;
    offset_t pos;
    int tag_len, tag;

    pos = url_ftell(pb);
    tag_len = pos - swf->tag_pos - 2;
    tag = swf->tag;
    url_fseek(pb, swf->tag_pos, SEEK_SET);
    if (tag & TAG_LONG) {
        tag &= ~TAG_LONG;
        put_le16(pb, (tag << 6) | 0x3f);
        put_le32(pb, tag_len - 4);
    } else {
        assert(tag_len < 0x3f);
        put_le16(pb, (tag << 6) | tag_len);
    }
    url_fseek(pb, pos, SEEK_SET);
}

static inline void max_nbits(int *nbits_ptr, int val)
{
    int n;

    if (val == 0)
        return;
    val = abs(val);
    n = 1;
    while (val != 0) {
        n++;
        val >>= 1;
    }
    if (n > *nbits_ptr)
        *nbits_ptr = n;
}

static void put_swf_rect(ByteIOContext *pb,
                         int xmin, int xmax, int ymin, int ymax)
{
    PutBitContext p;
    uint8_t buf[256];
    int nbits, mask;

    init_put_bits(&p, buf, sizeof(buf));

    nbits = 0;
    max_nbits(&nbits, xmin);
    max_nbits(&nbits, xmax);
    max_nbits(&nbits, ymin);
    max_nbits(&nbits, ymax);
    mask = (1 << nbits) - 1;

    /* rectangle info */
    put_bits(&p, 5, nbits);
    put_bits(&p, nbits, xmin & mask);
    put_bits(&p, nbits, xmax & mask);
    put_bits(&p, nbits, ymin & mask);
    put_bits(&p, nbits, ymax & mask);

    flush_put_bits(&p);
    put_buffer(pb, buf, pbBufPtr(&p) - p.buf);
}

static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
{
    int nbits, mask;

    put_bits(pb, 1, 1); /* edge */
    put_bits(pb, 1, 1); /* line select */
    nbits = 2;
    max_nbits(&nbits, dx);
    max_nbits(&nbits, dy);

    mask = (1 << nbits) - 1;
    put_bits(pb, 4, nbits - 2); /* 16 bits precision */
    if (dx == 0) {
        put_bits(pb, 1, 0);
        put_bits(pb, 1, 1);
        put_bits(pb, nbits, dy & mask);
    } else if (dy == 0) {
        put_bits(pb, 1, 0);
        put_bits(pb, 1, 0);
        put_bits(pb, nbits, dx & mask);
    } else {
        put_bits(pb, 1, 1);
        put_bits(pb, nbits, dx & mask);
        put_bits(pb, nbits, dy & mask);
    }
}

#define FRAC_BITS 16

static void put_swf_matrix(ByteIOContext *pb,
                           int a, int b, int c, int d, int tx, int ty)
{
    PutBitContext p;
    uint8_t buf[256];
    int nbits;

    init_put_bits(&p, buf, sizeof(buf));

    put_bits(&p, 1, 1); /* a, d present */
    nbits = 1;
    max_nbits(&nbits, a);
    max_nbits(&nbits, d);
    put_bits(&p, 5, nbits); /* nb bits */
    put_bits(&p, nbits, a);
    put_bits(&p, nbits, d);

    put_bits(&p, 1, 1); /* b, c present */
    nbits = 1;
    max_nbits(&nbits, c);
    max_nbits(&nbits, b);
    put_bits(&p, 5, nbits); /* nb bits */
    put_bits(&p, nbits, c);
    put_bits(&p, nbits, b);

    nbits = 1;
    max_nbits(&nbits, tx);
    max_nbits(&nbits, ty);
    put_bits(&p, 5, nbits); /* nb bits */
    put_bits(&p, nbits, tx);
    put_bits(&p, nbits, ty);

    flush_put_bits(&p);
    put_buffer(pb, buf, pbBufPtr(&p) - p.buf);
}

static int swf_write_header(AVFormatContext *s)
{
    SWFContext *swf = s->priv_data;
    ByteIOContext *pb = s->pb;
    PutBitContext p;
    uint8_t buf1[256];
    int i, width, height, rate, rate_base;
    int version;

    swf->sound_samples = 0;
    swf->swf_frame_number = 0;
    swf->video_frame_number = 0;

    for(i=0;i<s->nb_streams;i++) {
        AVCodecContext *enc = s->streams[i]->codec;
        if (enc->codec_type == CODEC_TYPE_AUDIO) {
            if (enc->codec_id == CODEC_ID_MP3) {
                if (!enc->frame_size) {
                    av_log(s, AV_LOG_ERROR, "audio frame size not set\n");
                    return -1;
                }
                swf->audio_enc = enc;
                av_fifo_init(&swf->audio_fifo, AUDIO_FIFO_SIZE);
            } else {
                av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
                return -1;
            }
        } else {
            if (enc->codec_id == CODEC_ID_VP6F ||
                enc->codec_id == CODEC_ID_FLV1 ||
                enc->codec_id == CODEC_ID_MJPEG) {
                swf->video_enc = enc;
            } else {
                av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
                return -1;
            }
        }
    }

    if (!swf->video_enc) {
        /* currently, cannot work correctly if audio only */
        width = 320;
        height = 200;
        rate = 10;
        rate_base= 1;
    } else {
        width = swf->video_enc->width;
        height = swf->video_enc->height;
        rate = swf->video_enc->time_base.den;
        rate_base = swf->video_enc->time_base.num;
    }

    if (!swf->audio_enc)
        swf->samples_per_frame = (44100. * rate_base) / rate;
    else
        swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;

    put_tag(pb, "FWS");

    if (!strcmp("avm2", s->oformat->name))
        version = 9;
    else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_VP6F)
        version = 8; /* version 8 and above support VP6 codec */
    else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_FLV1)
        version = 6; /* version 6 and above support FLV1 codec */
    else
        version = 4; /* version 4 for mpeg audio support */
    put_byte(pb, version);

    put_le32(pb, DUMMY_FILE_SIZE); /* dummy size
                                      (will be patched if not streamed) */

    put_swf_rect(pb, 0, width * 20, 0, height * 20);
    put_le16(pb, (rate * 256) / rate_base); /* frame rate */
    swf->duration_pos = url_ftell(pb);
    put_le16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */

    /* avm2/swf v9 (also v8?) files require a file attribute tag */
    if (version == 9) {
        put_swf_tag(s, TAG_FILEATTRIBUTES);
        put_le32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
        put_swf_end_tag(s);
    }

    /* define a shape with the jpeg inside */
    if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_MJPEG) {
        put_swf_tag(s, TAG_DEFINESHAPE);

        put_le16(pb, SHAPE_ID); /* ID of shape */
        /* bounding rectangle */
        put_swf_rect(pb, 0, width, 0, height);
        /* style info */
        put_byte(pb, 1); /* one fill style */
        put_byte(pb, 0x41); /* clipped bitmap fill */
        put_le16(pb, BITMAP_ID); /* bitmap ID */
        /* position of the bitmap */
        put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
                       0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
        put_byte(pb, 0); /* no line style */

        /* shape drawing */
        init_put_bits(&p, buf1, sizeof(buf1));
        put_bits(&p, 4, 1); /* one fill bit */
        put_bits(&p, 4, 0); /* zero line bit */

        put_bits(&p, 1, 0); /* not an edge */
        put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
        put_bits(&p, 5, 1); /* nbits */
        put_bits(&p, 1, 0); /* X */
        put_bits(&p, 1, 0); /* Y */
        put_bits(&p, 1, 1); /* set fill style 1 */

        /* draw the rectangle ! */
        put_swf_line_edge(&p, width, 0);
        put_swf_line_edge(&p, 0, height);
        put_swf_line_edge(&p, -width, 0);
        put_swf_line_edge(&p, 0, -height);

        /* end of shape */
        put_bits(&p, 1, 0); /* not an edge */
        put_bits(&p, 5, 0);

        flush_put_bits(&p);
        put_buffer(pb, buf1, pbBufPtr(&p) - p.buf);

        put_swf_end_tag(s);
    }

    if (swf->audio_enc && swf->audio_enc->codec_id == CODEC_ID_MP3) {
        int v = 0;

        /* start sound */
        put_swf_tag(s, TAG_STREAMHEAD2);
        switch(swf->audio_enc->sample_rate) {
        case 11025: v |= 1 << 2; break;
        case 22050: v |= 2 << 2; break;
        case 44100: v |= 3 << 2; break;
        default:
            /* not supported */
            av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
            return -1;
        }
        v |= 0x02; /* 16 bit playback */
        if (swf->audio_enc->channels == 2)
            v |= 0x01; /* stereo playback */
        put_byte(s->pb, v);
        v |= 0x20; /* mp3 compressed */
        put_byte(s->pb, v);
        put_le16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
        put_le16(s->pb, 0);

        put_swf_end_tag(s);
    }

    put_flush_packet(s->pb);
    return 0;
}

static int swf_write_video(AVFormatContext *s,
                           AVCodecContext *enc, const uint8_t *buf, int size)
{
    SWFContext *swf = s->priv_data;
    ByteIOContext *pb = s->pb;

    /* Flash Player limit */
    if (swf->swf_frame_number == 16000)
        av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");

    if (enc->codec_id == CODEC_ID_VP6F ||
        enc->codec_id == CODEC_ID_FLV1) {
        if (swf->video_frame_number == 0) {
            /* create a new video object */
            put_swf_tag(s, TAG_VIDEOSTREAM);
            put_le16(pb, VIDEO_ID);
            swf->vframes_pos = url_ftell(pb);
            put_le16(pb, 15000); /* hard flash player limit */
            put_le16(pb, enc->width);
            put_le16(pb, enc->height);
            put_byte(pb, 0);
            put_byte(pb,codec_get_tag(swf_codec_tags,enc->codec_id));
            put_swf_end_tag(s);

            /* place the video object for the first time */
            put_swf_tag(s, TAG_PLACEOBJECT2);
            put_byte(pb, 0x36);
            put_le16(pb, 1);
            put_le16(pb, VIDEO_ID);
            put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
            put_le16(pb, swf->video_frame_number);
            put_tag(pb, "video");
            put_byte(pb, 0x00);
            put_swf_end_tag(s);
        } else {
            /* mark the character for update */
            put_swf_tag(s, TAG_PLACEOBJECT2);
            put_byte(pb, 0x11);
            put_le16(pb, 1);
            put_le16(pb, swf->video_frame_number);
            put_swf_end_tag(s);
        }

        /* set video frame data */
        put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
        put_le16(pb, VIDEO_ID);
        put_le16(pb, swf->video_frame_number++);
        put_buffer(pb, buf, size);
        put_swf_end_tag(s);
    } else if (enc->codec_id == CODEC_ID_MJPEG) {
        if (swf->swf_frame_number > 0) {
            /* remove the shape */
            put_swf_tag(s, TAG_REMOVEOBJECT);
            put_le16(pb, SHAPE_ID); /* shape ID */
            put_le16(pb, 1); /* depth */
            put_swf_end_tag(s);

            /* free the bitmap */
            put_swf_tag(s, TAG_FREECHARACTER);
            put_le16(pb, BITMAP_ID);
            put_swf_end_tag(s);
        }

        put_swf_tag(s, TAG_JPEG2 | TAG_LONG);

        put_le16(pb, BITMAP_ID); /* ID of the image */

        /* a dummy jpeg header seems to be required */
        put_be32(pb, 0xffd8ffd9);
        /* write the jpeg image */
        put_buffer(pb, buf, size);

        put_swf_end_tag(s);

        /* draw the shape */

        put_swf_tag(s, TAG_PLACEOBJECT);
        put_le16(pb, SHAPE_ID); /* shape ID */
        put_le16(pb, 1); /* depth */
        put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
        put_swf_end_tag(s);
    }

    swf->swf_frame_number++;

    /* streaming sound always should be placed just before showframe tags */
    if (swf->audio_enc && av_fifo_size(&swf->audio_fifo)) {
        int frame_size = av_fifo_size(&swf->audio_fifo);
        put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
        put_le16(pb, swf->sound_samples);
        put_le16(pb, 0); // seek samples
        av_fifo_generic_read(&swf->audio_fifo, frame_size, &put_buffer, pb);
        put_swf_end_tag(s);

        /* update FIFO */
        swf->sound_samples = 0;
    }

    /* output the frame */
    put_swf_tag(s, TAG_SHOWFRAME);
    put_swf_end_tag(s);

    put_flush_packet(s->pb);

    return 0;
}

static int swf_write_audio(AVFormatContext *s,
                           AVCodecContext *enc, const uint8_t *buf, int size)
{
    SWFContext *swf = s->priv_data;

    /* Flash Player limit */
    if (swf->swf_frame_number == 16000)
        av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");

    if (av_fifo_size(&swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
        av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
        return -1;
    }

    av_fifo_generic_write(&swf->audio_fifo, buf, size, NULL);
    swf->sound_samples += enc->frame_size;

    /* if audio only stream make sure we add swf frames */
    if (!swf->video_enc)
        swf_write_video(s, enc, 0, 0);

    return 0;
}

static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
{
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
    if (codec->codec_type == CODEC_TYPE_AUDIO)
        return swf_write_audio(s, codec, pkt->data, pkt->size);
    else
        return swf_write_video(s, codec, pkt->data, pkt->size);
}

static int swf_write_trailer(AVFormatContext *s)
{
    SWFContext *swf = s->priv_data;
    ByteIOContext *pb = s->pb;
    AVCodecContext *enc, *video_enc;
    int file_size, i;

    video_enc = NULL;
    for(i=0;i<s->nb_streams;i++) {
        enc = s->streams[i]->codec;
        if (enc->codec_type == CODEC_TYPE_VIDEO)
            video_enc = enc;
        else
            av_fifo_free(&swf->audio_fifo);
    }

    put_swf_tag(s, TAG_END);
    put_swf_end_tag(s);

    put_flush_packet(s->pb);

    /* patch file size and number of frames if not streamed */
    if (!url_is_streamed(s->pb) && video_enc) {
        file_size = url_ftell(pb);
        url_fseek(pb, 4, SEEK_SET);
        put_le32(pb, file_size);
        url_fseek(pb, swf->duration_pos, SEEK_SET);
        put_le16(pb, swf->video_frame_number);
        url_fseek(pb, swf->vframes_pos, SEEK_SET);
        put_le16(pb, swf->video_frame_number);
        url_fseek(pb, file_size, SEEK_SET);
    }
    return 0;
}

#ifdef CONFIG_SWF_MUXER
AVOutputFormat swf_muxer = {
    "swf",
    NULL_IF_CONFIG_SMALL("Flash format"),
    "application/x-shockwave-flash",
    "swf",
    sizeof(SWFContext),
    CODEC_ID_MP3,
    CODEC_ID_FLV1,
    swf_write_header,
    swf_write_packet,
    swf_write_trailer,
};
#endif
#ifdef CONFIG_AVM2_MUXER
AVOutputFormat avm2_muxer = {
    "avm2",
    NULL_IF_CONFIG_SMALL("Flash 9 (AVM2) format"),
    "application/x-shockwave-flash",
    NULL,
    sizeof(SWFContext),
    CODEC_ID_MP3,
    CODEC_ID_FLV1,
    swf_write_header,
    swf_write_packet,
    swf_write_trailer,
};
#endif