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
27static 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
43static void put_swf_end_tag(AVFormatContext *s)
44{
45    SWFContext *swf = s->priv_data;
46    ByteIOContext *pb = s->pb;
47    int64_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
65static 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
81static 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
108static 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
137static 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
173static 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
331static 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            swf->vframes_pos = url_ftell(pb);
348            put_le16(pb, 15000); /* hard flash player limit */
349            put_le16(pb, enc->width);
350            put_le16(pb, enc->height);
351            put_byte(pb, 0);
352            put_byte(pb,codec_get_tag(swf_codec_tags,enc->codec_id));
353            put_swf_end_tag(s);
354
355            /* place the video object for the first time */
356            put_swf_tag(s, TAG_PLACEOBJECT2);
357            put_byte(pb, 0x36);
358            put_le16(pb, 1);
359            put_le16(pb, VIDEO_ID);
360            put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
361            put_le16(pb, swf->video_frame_number);
362            put_tag(pb, "video");
363            put_byte(pb, 0x00);
364            put_swf_end_tag(s);
365        } else {
366            /* mark the character for update */
367            put_swf_tag(s, TAG_PLACEOBJECT2);
368            put_byte(pb, 0x11);
369            put_le16(pb, 1);
370            put_le16(pb, swf->video_frame_number);
371            put_swf_end_tag(s);
372        }
373
374        /* set video frame data */
375        put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
376        put_le16(pb, VIDEO_ID);
377        put_le16(pb, swf->video_frame_number++);
378        put_buffer(pb, buf, size);
379        put_swf_end_tag(s);
380    } else if (enc->codec_id == CODEC_ID_MJPEG) {
381        if (swf->swf_frame_number > 0) {
382            /* remove the shape */
383            put_swf_tag(s, TAG_REMOVEOBJECT);
384            put_le16(pb, SHAPE_ID); /* shape ID */
385            put_le16(pb, 1); /* depth */
386            put_swf_end_tag(s);
387
388            /* free the bitmap */
389            put_swf_tag(s, TAG_FREECHARACTER);
390            put_le16(pb, BITMAP_ID);
391            put_swf_end_tag(s);
392        }
393
394        put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
395
396        put_le16(pb, BITMAP_ID); /* ID of the image */
397
398        /* a dummy jpeg header seems to be required */
399        put_be32(pb, 0xffd8ffd9);
400        /* write the jpeg image */
401        put_buffer(pb, buf, size);
402
403        put_swf_end_tag(s);
404
405        /* draw the shape */
406
407        put_swf_tag(s, TAG_PLACEOBJECT);
408        put_le16(pb, SHAPE_ID); /* shape ID */
409        put_le16(pb, 1); /* depth */
410        put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
411        put_swf_end_tag(s);
412    }
413
414    swf->swf_frame_number++;
415
416    /* streaming sound always should be placed just before showframe tags */
417    if (swf->audio_enc && av_fifo_size(&swf->audio_fifo)) {
418        int frame_size = av_fifo_size(&swf->audio_fifo);
419        put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
420        put_le16(pb, swf->sound_samples);
421        put_le16(pb, 0); // seek samples
422        av_fifo_generic_read(&swf->audio_fifo, frame_size, &put_buffer, pb);
423        put_swf_end_tag(s);
424
425        /* update FIFO */
426        swf->sound_samples = 0;
427    }
428
429    /* output the frame */
430    put_swf_tag(s, TAG_SHOWFRAME);
431    put_swf_end_tag(s);
432
433    put_flush_packet(s->pb);
434
435    return 0;
436}
437
438static int swf_write_audio(AVFormatContext *s,
439                           AVCodecContext *enc, uint8_t *buf, int size)
440{
441    SWFContext *swf = s->priv_data;
442
443    /* Flash Player limit */
444    if (swf->swf_frame_number == 16000)
445        av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
446
447    if (av_fifo_size(&swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
448        av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
449        return -1;
450    }
451
452    av_fifo_generic_write(&swf->audio_fifo, buf, size, NULL);
453    swf->sound_samples += enc->frame_size;
454
455    /* if audio only stream make sure we add swf frames */
456    if (!swf->video_enc)
457        swf_write_video(s, enc, 0, 0);
458
459    return 0;
460}
461
462static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
463{
464    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
465    if (codec->codec_type == CODEC_TYPE_AUDIO)
466        return swf_write_audio(s, codec, pkt->data, pkt->size);
467    else
468        return swf_write_video(s, codec, pkt->data, pkt->size);
469}
470
471static int swf_write_trailer(AVFormatContext *s)
472{
473    SWFContext *swf = s->priv_data;
474    ByteIOContext *pb = s->pb;
475    AVCodecContext *enc, *video_enc;
476    int file_size, i;
477
478    video_enc = NULL;
479    for(i=0;i<s->nb_streams;i++) {
480        enc = s->streams[i]->codec;
481        if (enc->codec_type == CODEC_TYPE_VIDEO)
482            video_enc = enc;
483        else
484            av_fifo_free(&swf->audio_fifo);
485    }
486
487    put_swf_tag(s, TAG_END);
488    put_swf_end_tag(s);
489
490    put_flush_packet(s->pb);
491
492    /* patch file size and number of frames if not streamed */
493    if (!url_is_streamed(s->pb) && video_enc) {
494        file_size = url_ftell(pb);
495        url_fseek(pb, 4, SEEK_SET);
496        put_le32(pb, file_size);
497        url_fseek(pb, swf->duration_pos, SEEK_SET);
498        put_le16(pb, swf->video_frame_number);
499        url_fseek(pb, swf->vframes_pos, SEEK_SET);
500        put_le16(pb, swf->video_frame_number);
501        url_fseek(pb, file_size, SEEK_SET);
502    }
503    return 0;
504}
505
506#if CONFIG_SWF_MUXER
507AVOutputFormat swf_muxer = {
508    "swf",
509    NULL_IF_CONFIG_SMALL("Flash format"),
510    "application/x-shockwave-flash",
511    "swf",
512    sizeof(SWFContext),
513    CODEC_ID_MP3,
514    CODEC_ID_FLV1,
515    swf_write_header,
516    swf_write_packet,
517    swf_write_trailer,
518};
519#endif
520#if CONFIG_AVM2_MUXER
521AVOutputFormat avm2_muxer = {
522    "avm2",
523    NULL_IF_CONFIG_SMALL("Flash 9 (AVM2) format"),
524    "application/x-shockwave-flash",
525    NULL,
526    sizeof(SWFContext),
527    CODEC_ID_MP3,
528    CODEC_ID_FLV1,
529    swf_write_header,
530    swf_write_packet,
531    swf_write_trailer,
532};
533#endif
534