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/put_bits.h"
24#include "libavutil/avassert.h"
25#include "avformat.h"
26#include "swf.h"
27
28static void put_swf_tag(AVFormatContext *s, int tag)
29{
30    SWFContext *swf = s->priv_data;
31    AVIOContext *pb = s->pb;
32
33    swf->tag_pos = avio_tell(pb);
34    swf->tag = tag;
35    /* reserve some room for the tag */
36    if (tag & TAG_LONG) {
37        avio_wl16(pb, 0);
38        avio_wl32(pb, 0);
39    } else {
40        avio_wl16(pb, 0);
41    }
42}
43
44static void put_swf_end_tag(AVFormatContext *s)
45{
46    SWFContext *swf = s->priv_data;
47    AVIOContext *pb = s->pb;
48    int64_t pos;
49    int tag_len, tag;
50
51    pos = avio_tell(pb);
52    tag_len = pos - swf->tag_pos - 2;
53    tag = swf->tag;
54    avio_seek(pb, swf->tag_pos, SEEK_SET);
55    if (tag & TAG_LONG) {
56        tag &= ~TAG_LONG;
57        avio_wl16(pb, (tag << 6) | 0x3f);
58        avio_wl32(pb, tag_len - 4);
59    } else {
60        av_assert0(tag_len < 0x3f);
61        avio_wl16(pb, (tag << 6) | tag_len);
62    }
63    avio_seek(pb, pos, SEEK_SET);
64}
65
66static inline void max_nbits(int *nbits_ptr, int val)
67{
68    int n;
69
70    if (val == 0)
71        return;
72    val = abs(val);
73    n = 1;
74    while (val != 0) {
75        n++;
76        val >>= 1;
77    }
78    if (n > *nbits_ptr)
79        *nbits_ptr = n;
80}
81
82static void put_swf_rect(AVIOContext *pb,
83                         int xmin, int xmax, int ymin, int ymax)
84{
85    PutBitContext p;
86    uint8_t buf[256];
87    int nbits, mask;
88
89    init_put_bits(&p, buf, sizeof(buf));
90
91    nbits = 0;
92    max_nbits(&nbits, xmin);
93    max_nbits(&nbits, xmax);
94    max_nbits(&nbits, ymin);
95    max_nbits(&nbits, ymax);
96    mask = (1 << nbits) - 1;
97
98    /* rectangle info */
99    put_bits(&p, 5, nbits);
100    put_bits(&p, nbits, xmin & mask);
101    put_bits(&p, nbits, xmax & mask);
102    put_bits(&p, nbits, ymin & mask);
103    put_bits(&p, nbits, ymax & mask);
104
105    flush_put_bits(&p);
106    avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
107}
108
109static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
110{
111    int nbits, mask;
112
113    put_bits(pb, 1, 1); /* edge */
114    put_bits(pb, 1, 1); /* line select */
115    nbits = 2;
116    max_nbits(&nbits, dx);
117    max_nbits(&nbits, dy);
118
119    mask = (1 << nbits) - 1;
120    put_bits(pb, 4, nbits - 2); /* 16 bits precision */
121    if (dx == 0) {
122        put_bits(pb, 1, 0);
123        put_bits(pb, 1, 1);
124        put_bits(pb, nbits, dy & mask);
125    } else if (dy == 0) {
126        put_bits(pb, 1, 0);
127        put_bits(pb, 1, 0);
128        put_bits(pb, nbits, dx & mask);
129    } else {
130        put_bits(pb, 1, 1);
131        put_bits(pb, nbits, dx & mask);
132        put_bits(pb, nbits, dy & mask);
133    }
134}
135
136#define FRAC_BITS 16
137
138static void put_swf_matrix(AVIOContext *pb,
139                           int a, int b, int c, int d, int tx, int ty)
140{
141    PutBitContext p;
142    uint8_t buf[256];
143    int nbits;
144
145    init_put_bits(&p, buf, sizeof(buf));
146
147    put_bits(&p, 1, 1); /* a, d present */
148    nbits = 1;
149    max_nbits(&nbits, a);
150    max_nbits(&nbits, d);
151    put_bits(&p, 5, nbits); /* nb bits */
152    put_bits(&p, nbits, a);
153    put_bits(&p, nbits, d);
154
155    put_bits(&p, 1, 1); /* b, c present */
156    nbits = 1;
157    max_nbits(&nbits, c);
158    max_nbits(&nbits, b);
159    put_bits(&p, 5, nbits); /* nb bits */
160    put_bits(&p, nbits, c);
161    put_bits(&p, nbits, b);
162
163    nbits = 1;
164    max_nbits(&nbits, tx);
165    max_nbits(&nbits, ty);
166    put_bits(&p, 5, nbits); /* nb bits */
167    put_bits(&p, nbits, tx);
168    put_bits(&p, nbits, ty);
169
170    flush_put_bits(&p);
171    avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
172}
173
174static int swf_write_header(AVFormatContext *s)
175{
176    SWFContext *swf = s->priv_data;
177    AVIOContext *pb = s->pb;
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    for(i=0;i<s->nb_streams;i++) {
188        AVCodecContext *enc = s->streams[i]->codec;
189        if (enc->codec_type == AVMEDIA_TYPE_AUDIO) {
190            if (swf->audio_enc) {
191                av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 audio stream\n");
192                return AVERROR_INVALIDDATA;
193            }
194            if (enc->codec_id == AV_CODEC_ID_MP3) {
195                if (!enc->frame_size) {
196                    av_log(s, AV_LOG_ERROR, "audio frame size not set\n");
197                    return -1;
198                }
199                swf->audio_enc = enc;
200                swf->audio_fifo= av_fifo_alloc(AUDIO_FIFO_SIZE);
201                if (!swf->audio_fifo)
202                    return AVERROR(ENOMEM);
203            } else {
204                av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
205                return -1;
206            }
207        } else {
208            if (swf->video_enc) {
209                av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 video stream\n");
210                return AVERROR_INVALIDDATA;
211            }
212            if (enc->codec_id == AV_CODEC_ID_VP6F ||
213                enc->codec_id == AV_CODEC_ID_FLV1 ||
214                enc->codec_id == AV_CODEC_ID_MJPEG) {
215                swf->video_st  = s->streams[i];
216                swf->video_enc = enc;
217            } else {
218                av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
219                return -1;
220            }
221        }
222    }
223
224    if (!swf->video_enc) {
225        /* currently, cannot work correctly if audio only */
226        width = 320;
227        height = 200;
228        rate = 10;
229        rate_base= 1;
230    } else {
231        width = swf->video_enc->width;
232        height = swf->video_enc->height;
233        // TODO: should be avg_frame_rate
234        rate = swf->video_st->time_base.den;
235        rate_base = swf->video_st->time_base.num;
236    }
237
238    if (!swf->audio_enc)
239        swf->samples_per_frame = (44100.0 * rate_base) / rate;
240    else
241        swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;
242
243    avio_write(pb, "FWS", 3);
244
245    if (!strcmp("avm2", s->oformat->name))
246        version = 9;
247    else if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_VP6F)
248        version = 8; /* version 8 and above support VP6 codec */
249    else if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_FLV1)
250        version = 6; /* version 6 and above support FLV1 codec */
251    else
252        version = 4; /* version 4 for mpeg audio support */
253    avio_w8(pb, version);
254
255    avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size
256                                      (will be patched if not streamed) */
257
258    put_swf_rect(pb, 0, width * 20, 0, height * 20);
259    avio_wl16(pb, (rate * 256) / rate_base); /* frame rate */
260    swf->duration_pos = avio_tell(pb);
261    avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
262
263    /* avm2/swf v9 (also v8?) files require a file attribute tag */
264    if (version == 9) {
265        put_swf_tag(s, TAG_FILEATTRIBUTES);
266        avio_wl32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
267        put_swf_end_tag(s);
268    }
269
270    /* define a shape with the jpeg inside */
271    if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_MJPEG) {
272        put_swf_tag(s, TAG_DEFINESHAPE);
273
274        avio_wl16(pb, SHAPE_ID); /* ID of shape */
275        /* bounding rectangle */
276        put_swf_rect(pb, 0, width, 0, height);
277        /* style info */
278        avio_w8(pb, 1); /* one fill style */
279        avio_w8(pb, 0x41); /* clipped bitmap fill */
280        avio_wl16(pb, BITMAP_ID); /* bitmap ID */
281        /* position of the bitmap */
282        put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
283                       0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
284        avio_w8(pb, 0); /* no line style */
285
286        /* shape drawing */
287        init_put_bits(&p, buf1, sizeof(buf1));
288        put_bits(&p, 4, 1); /* one fill bit */
289        put_bits(&p, 4, 0); /* zero line bit */
290
291        put_bits(&p, 1, 0); /* not an edge */
292        put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
293        put_bits(&p, 5, 1); /* nbits */
294        put_bits(&p, 1, 0); /* X */
295        put_bits(&p, 1, 0); /* Y */
296        put_bits(&p, 1, 1); /* set fill style 1 */
297
298        /* draw the rectangle ! */
299        put_swf_line_edge(&p, width, 0);
300        put_swf_line_edge(&p, 0, height);
301        put_swf_line_edge(&p, -width, 0);
302        put_swf_line_edge(&p, 0, -height);
303
304        /* end of shape */
305        put_bits(&p, 1, 0); /* not an edge */
306        put_bits(&p, 5, 0);
307
308        flush_put_bits(&p);
309        avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);
310
311        put_swf_end_tag(s);
312    }
313
314    if (swf->audio_enc && swf->audio_enc->codec_id == AV_CODEC_ID_MP3) {
315        int v = 0;
316
317        /* start sound */
318        put_swf_tag(s, TAG_STREAMHEAD2);
319        switch(swf->audio_enc->sample_rate) {
320        case 11025: v |= 1 << 2; break;
321        case 22050: v |= 2 << 2; break;
322        case 44100: v |= 3 << 2; break;
323        default:
324            /* not supported */
325            av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
326            return -1;
327        }
328        v |= 0x02; /* 16 bit playback */
329        if (swf->audio_enc->channels == 2)
330            v |= 0x01; /* stereo playback */
331        avio_w8(s->pb, v);
332        v |= 0x20; /* mp3 compressed */
333        avio_w8(s->pb, v);
334        avio_wl16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
335        avio_wl16(s->pb, 0);
336
337        put_swf_end_tag(s);
338    }
339
340    avio_flush(s->pb);
341    return 0;
342}
343
344static int swf_write_video(AVFormatContext *s,
345                           AVCodecContext *enc, const uint8_t *buf, int size)
346{
347    SWFContext *swf = s->priv_data;
348    AVIOContext *pb = s->pb;
349
350    /* Flash Player limit */
351    if (swf->swf_frame_number == 16000)
352        av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
353
354    if (enc->codec_id == AV_CODEC_ID_VP6F ||
355        enc->codec_id == AV_CODEC_ID_FLV1) {
356        if (swf->video_frame_number == 0) {
357            /* create a new video object */
358            put_swf_tag(s, TAG_VIDEOSTREAM);
359            avio_wl16(pb, VIDEO_ID);
360            swf->vframes_pos = avio_tell(pb);
361            avio_wl16(pb, 15000); /* hard flash player limit */
362            avio_wl16(pb, enc->width);
363            avio_wl16(pb, enc->height);
364            avio_w8(pb, 0);
365            avio_w8(pb,ff_codec_get_tag(ff_swf_codec_tags, enc->codec_id));
366            put_swf_end_tag(s);
367
368            /* place the video object for the first time */
369            put_swf_tag(s, TAG_PLACEOBJECT2);
370            avio_w8(pb, 0x36);
371            avio_wl16(pb, 1);
372            avio_wl16(pb, VIDEO_ID);
373            put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
374            avio_wl16(pb, swf->video_frame_number);
375            avio_write(pb, "video", 5);
376            avio_w8(pb, 0x00);
377            put_swf_end_tag(s);
378        } else {
379            /* mark the character for update */
380            put_swf_tag(s, TAG_PLACEOBJECT2);
381            avio_w8(pb, 0x11);
382            avio_wl16(pb, 1);
383            avio_wl16(pb, swf->video_frame_number);
384            put_swf_end_tag(s);
385        }
386
387        /* set video frame data */
388        put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
389        avio_wl16(pb, VIDEO_ID);
390        avio_wl16(pb, swf->video_frame_number++);
391        avio_write(pb, buf, size);
392        put_swf_end_tag(s);
393    } else if (enc->codec_id == AV_CODEC_ID_MJPEG) {
394        if (swf->swf_frame_number > 0) {
395            /* remove the shape */
396            put_swf_tag(s, TAG_REMOVEOBJECT);
397            avio_wl16(pb, SHAPE_ID); /* shape ID */
398            avio_wl16(pb, 1); /* depth */
399            put_swf_end_tag(s);
400
401            /* free the bitmap */
402            put_swf_tag(s, TAG_FREECHARACTER);
403            avio_wl16(pb, BITMAP_ID);
404            put_swf_end_tag(s);
405        }
406
407        put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
408
409        avio_wl16(pb, BITMAP_ID); /* ID of the image */
410
411        /* a dummy jpeg header seems to be required */
412        avio_wb32(pb, 0xffd8ffd9);
413        /* write the jpeg image */
414        avio_write(pb, buf, size);
415
416        put_swf_end_tag(s);
417
418        /* draw the shape */
419
420        put_swf_tag(s, TAG_PLACEOBJECT);
421        avio_wl16(pb, SHAPE_ID); /* shape ID */
422        avio_wl16(pb, 1); /* depth */
423        put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
424        put_swf_end_tag(s);
425    }
426
427    swf->swf_frame_number++;
428
429    /* streaming sound always should be placed just before showframe tags */
430    if (swf->audio_enc && av_fifo_size(swf->audio_fifo)) {
431        int frame_size = av_fifo_size(swf->audio_fifo);
432        put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
433        avio_wl16(pb, swf->sound_samples);
434        avio_wl16(pb, 0); // seek samples
435        av_fifo_generic_read(swf->audio_fifo, pb, frame_size, (void*)avio_write);
436        put_swf_end_tag(s);
437
438        /* update FIFO */
439        swf->sound_samples = 0;
440    }
441
442    /* output the frame */
443    put_swf_tag(s, TAG_SHOWFRAME);
444    put_swf_end_tag(s);
445
446    return 0;
447}
448
449static int swf_write_audio(AVFormatContext *s,
450                           AVCodecContext *enc, uint8_t *buf, int size)
451{
452    SWFContext *swf = s->priv_data;
453
454    /* Flash Player limit */
455    if (swf->swf_frame_number == 16000)
456        av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
457
458    if (av_fifo_size(swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
459        av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
460        return -1;
461    }
462
463    av_fifo_generic_write(swf->audio_fifo, buf, size, NULL);
464    swf->sound_samples += enc->frame_size;
465
466    /* if audio only stream make sure we add swf frames */
467    if (!swf->video_enc)
468        swf_write_video(s, enc, 0, 0);
469
470    return 0;
471}
472
473static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
474{
475    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
476    if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
477        return swf_write_audio(s, codec, pkt->data, pkt->size);
478    else
479        return swf_write_video(s, codec, pkt->data, pkt->size);
480}
481
482static int swf_write_trailer(AVFormatContext *s)
483{
484    SWFContext *swf = s->priv_data;
485    AVIOContext *pb = s->pb;
486    AVCodecContext *enc, *video_enc;
487    int file_size, i;
488
489    video_enc = NULL;
490    for(i=0;i<s->nb_streams;i++) {
491        enc = s->streams[i]->codec;
492        if (enc->codec_type == AVMEDIA_TYPE_VIDEO)
493            video_enc = enc;
494        else {
495            av_fifo_freep(&swf->audio_fifo);
496        }
497    }
498
499    put_swf_tag(s, TAG_END);
500    put_swf_end_tag(s);
501
502    /* patch file size and number of frames if not streamed */
503    if (s->pb->seekable && video_enc) {
504        file_size = avio_tell(pb);
505        avio_seek(pb, 4, SEEK_SET);
506        avio_wl32(pb, file_size);
507        avio_seek(pb, swf->duration_pos, SEEK_SET);
508        avio_wl16(pb, swf->video_frame_number);
509        if (swf->vframes_pos) {
510        avio_seek(pb, swf->vframes_pos, SEEK_SET);
511        avio_wl16(pb, swf->video_frame_number);
512        }
513        avio_seek(pb, file_size, SEEK_SET);
514    }
515    return 0;
516}
517
518#if CONFIG_SWF_MUXER
519AVOutputFormat ff_swf_muxer = {
520    .name              = "swf",
521    .long_name         = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash)"),
522    .mime_type         = "application/x-shockwave-flash",
523    .extensions        = "swf",
524    .priv_data_size    = sizeof(SWFContext),
525    .audio_codec       = AV_CODEC_ID_MP3,
526    .video_codec       = AV_CODEC_ID_FLV1,
527    .write_header      = swf_write_header,
528    .write_packet      = swf_write_packet,
529    .write_trailer     = swf_write_trailer,
530    .flags             = AVFMT_TS_NONSTRICT,
531};
532#endif
533#if CONFIG_AVM2_MUXER
534AVOutputFormat ff_avm2_muxer = {
535    .name              = "avm2",
536    .long_name         = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash) (AVM2)"),
537    .mime_type         = "application/x-shockwave-flash",
538    .priv_data_size    = sizeof(SWFContext),
539    .audio_codec       = AV_CODEC_ID_MP3,
540    .video_codec       = AV_CODEC_ID_FLV1,
541    .write_header      = swf_write_header,
542    .write_packet      = swf_write_packet,
543    .write_trailer     = swf_write_trailer,
544    .flags             = AVFMT_TS_NONSTRICT,
545};
546#endif
547