swf.c@ 10184

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1	/*
2	* Flash Compatible Streaming Format
3	* Copyright (c) 2000 Fabrice Bellard.
4	* Copyright (c) 2003 Tinic Uro.
5	*
6	* This library is free software; you can redistribute it and/or
7	* modify it under the terms of the GNU Lesser General Public
8	* License as published by the Free Software Foundation; either
9	* version 2 of the License, or (at your option) any later version.
10	*
11	* This library is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14	* Lesser General Public License for more details.
15	*
16	* You should have received a copy of the GNU Lesser General Public
17	* License along with this library; if not, write to the Free Software
18	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19	*/
20	#include "avformat.h"
21	#include "bitstream.h"
22
23	/* should have a generic way to indicate probable size */
24	#define DUMMY_FILE_SIZE (100 * 1024 * 1024)
25	#define DUMMY_DURATION 600 /* in seconds */
26
27	#define TAG_END 0
28	#define TAG_SHOWFRAME 1
29	#define TAG_DEFINESHAPE 2
30	#define TAG_FREECHARACTER 3
31	#define TAG_PLACEOBJECT 4
32	#define TAG_REMOVEOBJECT 5
33	#define TAG_STREAMHEAD 18
34	#define TAG_STREAMBLOCK 19
35	#define TAG_JPEG2 21
36	#define TAG_PLACEOBJECT2 26
37	#define TAG_STREAMHEAD2 45
38	#define TAG_VIDEOSTREAM 60
39	#define TAG_VIDEOFRAME 61
40
41	#define TAG_LONG 0x100
42
43	/* flags for shape definition */
44	#define FLAG_MOVETO 0x01
45	#define FLAG_SETFILL0 0x02
46	#define FLAG_SETFILL1 0x04
47
48	#define SWF_VIDEO_CODEC_FLV1 0x02
49
50	#define AUDIO_FIFO_SIZE 65536
51
52	/* character id used */
53	#define BITMAP_ID 0
54	#define VIDEO_ID 0
55	#define SHAPE_ID 1
56
57	#undef NDEBUG
58	#include <assert.h>
59
60	typedef struct {
61
62	offset_t duration_pos;
63	offset_t tag_pos;
64
65	int samples_per_frame;
66	int sound_samples;
67	int video_samples;
68	int swf_frame_number;
69	int video_frame_number;
70	int ms_per_frame;
71	int ch_id;
72	int tag;
73
74	uint8_t *audio_fifo;
75	int audio_in_pos;
76	int audio_out_pos;
77	int audio_size;
78
79	int video_type;
80	int audio_type;
81	} SWFContext;
82
83	static const int sSampleRates[3][4] = {
84	{44100, 48000, 32000, 0},
85	{22050, 24000, 16000, 0},
86	{11025, 12000, 8000, 0},
87	};
88
89	static const int sBitRates[2][3][15] = {
90	{ { 0, 32, 64, 96,128,160,192,224,256,288,320,352,384,416,448},
91	{ 0, 32, 48, 56, 64, 80, 96,112,128,160,192,224,256,320,384},
92	{ 0, 32, 40, 48, 56, 64, 80, 96,112,128,160,192,224,256,320}
93	},
94	{ { 0, 32, 48, 56, 64, 80, 96,112,128,144,160,176,192,224,256},
95	{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160},
96	{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96,112,128,144,160}
97	},
98	};
99
100	static const int sSamplesPerFrame[3][3] =
101	{
102	{ 384, 1152, 1152 },
103	{ 384, 1152, 576 },
104	{ 384, 1152, 576 }
105	};
106
107	static const int sBitsPerSlot[3] = {
108	32,
109	8,
110	8
111	};
112
113	static int swf_mp3_info(void data, int byteSize, int samplesPerFrame, int sampleRate, int *isMono )
114	{
115	uint8_t dataTmp = (uint8_t )data;
116	uint32_t header = ( (uint32_t)dataTmp[0] << 24 ) \| ( (uint32_t)dataTmp[1] << 16 ) \| ( (uint32_t)dataTmp[2] << 8 ) \| (uint32_t)dataTmp[3];
117	int layerID = 3 - ((header >> 17) & 0x03);
118	int bitRateID = ((header >> 12) & 0x0f);
119	int sampleRateID = ((header >> 10) & 0x03);
120	int bitRate = 0;
121	int bitsPerSlot = sBitsPerSlot[layerID];
122	int isPadded = ((header >> 9) & 0x01);
123
124	if ( (( header >> 21 ) & 0x7ff) != 0x7ff ) {
125	return 0;
126	}
127
128	*isMono = ((header >> 6) & 0x03) == 0x03;
129
130	if ( (header >> 19 ) & 0x01 ) {
131	*sampleRate = sSampleRates[0][sampleRateID];
132	bitRate = sBitRates[0][layerID][bitRateID] * 1000;
133	*samplesPerFrame = sSamplesPerFrame[0][layerID];
134	} else {
135	if ( (header >> 20) & 0x01 ) {
136	*sampleRate = sSampleRates[1][sampleRateID];
137	bitRate = sBitRates[1][layerID][bitRateID] * 1000;
138	*samplesPerFrame = sSamplesPerFrame[1][layerID];
139	} else {
140	*sampleRate = sSampleRates[2][sampleRateID];
141	bitRate = sBitRates[1][layerID][bitRateID] * 1000;
142	*samplesPerFrame = sSamplesPerFrame[2][layerID];
143	}
144	}
145
146	byteSize = ( ( ( ( samplesPerFrame * (bitRate / bitsPerSlot) ) / *sampleRate ) + isPadded ) );
147
148	return 1;
149	}
150
151	#ifdef CONFIG_MUXERS
152	static void put_swf_tag(AVFormatContext *s, int tag)
153	{
154	SWFContext *swf = s->priv_data;
155	ByteIOContext *pb = &s->pb;
156
157	swf->tag_pos = url_ftell(pb);
158	swf->tag = tag;
159	/* reserve some room for the tag */
160	if (tag & TAG_LONG) {
161	put_le16(pb, 0);
162	put_le32(pb, 0);
163	} else {
164	put_le16(pb, 0);
165	}
166	}
167
168	static void put_swf_end_tag(AVFormatContext *s)
169	{
170	SWFContext *swf = s->priv_data;
171	ByteIOContext *pb = &s->pb;
172	offset_t pos;
173	int tag_len, tag;
174
175	pos = url_ftell(pb);
176	tag_len = pos - swf->tag_pos - 2;
177	tag = swf->tag;
178	url_fseek(pb, swf->tag_pos, SEEK_SET);
179	if (tag & TAG_LONG) {
180	tag &= ~TAG_LONG;
181	put_le16(pb, (tag << 6) \| 0x3f);
182	put_le32(pb, tag_len - 4);
183	} else {
184	assert(tag_len < 0x3f);
185	put_le16(pb, (tag << 6) \| tag_len);
186	}
187	url_fseek(pb, pos, SEEK_SET);
188	}
189
190	static inline void max_nbits(int *nbits_ptr, int val)
191	{
192	int n;
193
194	if (val == 0)
195	return;
196	val = abs(val);
197	n = 1;
198	while (val != 0) {
199	n++;
200	val >>= 1;
201	}
202	if (n > *nbits_ptr)
203	*nbits_ptr = n;
204	}
205
206	static void put_swf_rect(ByteIOContext *pb,
207	int xmin, int xmax, int ymin, int ymax)
208	{
209	PutBitContext p;
210	uint8_t buf[256];
211	int nbits, mask;
212
213	init_put_bits(&p, buf, sizeof(buf));
214
215	nbits = 0;
216	max_nbits(&nbits, xmin);
217	max_nbits(&nbits, xmax);
218	max_nbits(&nbits, ymin);
219	max_nbits(&nbits, ymax);
220	mask = (1 << nbits) - 1;
221
222	/* rectangle info */
223	put_bits(&p, 5, nbits);
224	put_bits(&p, nbits, xmin & mask);
225	put_bits(&p, nbits, xmax & mask);
226	put_bits(&p, nbits, ymin & mask);
227	put_bits(&p, nbits, ymax & mask);
228
229	flush_put_bits(&p);
230	put_buffer(pb, buf, pbBufPtr(&p) - p.buf);
231	}
232
233	static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
234	{
235	int nbits, mask;
236
237	put_bits(pb, 1, 1); /* edge */
238	put_bits(pb, 1, 1); /* line select */
239	nbits = 2;
240	max_nbits(&nbits, dx);
241	max_nbits(&nbits, dy);
242
243	mask = (1 << nbits) - 1;
244	put_bits(pb, 4, nbits - 2); /* 16 bits precision */
245	if (dx == 0) {
246	put_bits(pb, 1, 0);
247	put_bits(pb, 1, 1);
248	put_bits(pb, nbits, dy & mask);
249	} else if (dy == 0) {
250	put_bits(pb, 1, 0);
251	put_bits(pb, 1, 0);
252	put_bits(pb, nbits, dx & mask);
253	} else {
254	put_bits(pb, 1, 1);
255	put_bits(pb, nbits, dx & mask);
256	put_bits(pb, nbits, dy & mask);
257	}
258	}
259
260	#define FRAC_BITS 16
261
262	/* put matrix */
263	static void put_swf_matrix(ByteIOContext *pb,
264	int a, int b, int c, int d, int tx, int ty)
265	{
266	PutBitContext p;
267	uint8_t buf[256];
268	int nbits;
269
270	init_put_bits(&p, buf, sizeof(buf));
271
272	put_bits(&p, 1, 1); /* a, d present */
273	nbits = 1;
274	max_nbits(&nbits, a);
275	max_nbits(&nbits, d);
276	put_bits(&p, 5, nbits); /* nb bits */
277	put_bits(&p, nbits, a);
278	put_bits(&p, nbits, d);
279
280	put_bits(&p, 1, 1); /* b, c present */
281	nbits = 1;
282	max_nbits(&nbits, c);
283	max_nbits(&nbits, b);
284	put_bits(&p, 5, nbits); /* nb bits */
285	put_bits(&p, nbits, c);
286	put_bits(&p, nbits, b);
287
288	nbits = 1;
289	max_nbits(&nbits, tx);
290	max_nbits(&nbits, ty);
291	put_bits(&p, 5, nbits); /* nb bits */
292	put_bits(&p, nbits, tx);
293	put_bits(&p, nbits, ty);
294
295	flush_put_bits(&p);
296	put_buffer(pb, buf, pbBufPtr(&p) - p.buf);
297	}
298
299	/* */
300	static int swf_write_header(AVFormatContext *s)
301	{
302	SWFContext *swf;
303	ByteIOContext *pb = &s->pb;
304	AVCodecContext enc, audio_enc, *video_enc;
305	PutBitContext p;
306	uint8_t buf1[256];
307	int i, width, height, rate, rate_base;
308
309	swf = av_malloc(sizeof(SWFContext));
310	if (!swf)
311	return -1;
312	s->priv_data = swf;
313
314	swf->ch_id = -1;
315	swf->audio_in_pos = 0;
316	swf->audio_out_pos = 0;
317	swf->audio_size = 0;
318	swf->audio_fifo = av_malloc(AUDIO_FIFO_SIZE);
319	swf->sound_samples = 0;
320	swf->video_samples = 0;
321	swf->swf_frame_number = 0;
322	swf->video_frame_number = 0;
323
324	video_enc = NULL;
325	audio_enc = NULL;
326	for(i=0;i<s->nb_streams;i++) {
327	enc = s->streams[i]->codec;
328	if (enc->codec_type == CODEC_TYPE_AUDIO)
329	audio_enc = enc;
330	else {
331	if ( enc->codec_id == CODEC_ID_FLV1 \|\| enc->codec_id == CODEC_ID_MJPEG ) {
332	video_enc = enc;
333	} else {
334	av_log(enc, AV_LOG_ERROR, "SWF only supports FLV1 and MJPEG\n");
335	return -1;
336	}
337	}
338	}
339
340	if (!video_enc) {
341	/* currenty, cannot work correctly if audio only */
342	swf->video_type = 0;
343	width = 320;
344	height = 200;
345	rate = 10;
346	rate_base= 1;
347	} else {
348	swf->video_type = video_enc->codec_id;
349	width = video_enc->width;
350	height = video_enc->height;
351	rate = video_enc->time_base.den;
352	rate_base = video_enc->time_base.num;
353	}
354
355	if (!audio_enc ) {
356	swf->audio_type = 0;
357	swf->samples_per_frame = ( 44100. * rate_base ) / rate;
358	} else {
359	swf->audio_type = audio_enc->codec_id;
360	swf->samples_per_frame = ( ( audio_enc->sample_rate ) * rate_base ) / rate;
361	}
362
363	put_tag(pb, "FWS");
364	if ( video_enc && video_enc->codec_id == CODEC_ID_FLV1 ) {
365	put_byte(pb, 6); /* version (version 6 and above support FLV1 codec) */
366	} else {
367	put_byte(pb, 4); /* version (should use 4 for mpeg audio support) */
368	}
369	put_le32(pb, DUMMY_FILE_SIZE); /* dummy size
370	(will be patched if not streamed) */
371
372	put_swf_rect(pb, 0, width * 20, 0, height * 20);
373	put_le16(pb, (rate * 256) / rate_base); /* frame rate */
374	swf->duration_pos = url_ftell(pb);
375	put_le16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
376
377	/* define a shape with the jpeg inside */
378	if ( video_enc && video_enc->codec_id == CODEC_ID_FLV1 ) {
379	} else if ( video_enc && video_enc->codec_id == CODEC_ID_MJPEG ) {
380	put_swf_tag(s, TAG_DEFINESHAPE);
381
382	put_le16(pb, SHAPE_ID); /* ID of shape */
383	/* bounding rectangle */
384	put_swf_rect(pb, 0, width, 0, height);
385	/* style info */
386	put_byte(pb, 1); /* one fill style */
387	put_byte(pb, 0x41); /* clipped bitmap fill */
388	put_le16(pb, BITMAP_ID); /* bitmap ID */
389	/* position of the bitmap */
390	put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
391	0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
392	put_byte(pb, 0); /* no line style */
393
394	/* shape drawing */
395	init_put_bits(&p, buf1, sizeof(buf1));
396	put_bits(&p, 4, 1); /* one fill bit */
397	put_bits(&p, 4, 0); /* zero line bit */
398
399	put_bits(&p, 1, 0); /* not an edge */
400	put_bits(&p, 5, FLAG_MOVETO \| FLAG_SETFILL0);
401	put_bits(&p, 5, 1); /* nbits */
402	put_bits(&p, 1, 0); /* X */
403	put_bits(&p, 1, 0); /* Y */
404	put_bits(&p, 1, 1); /* set fill style 1 */
405
406	/* draw the rectangle ! */
407	put_swf_line_edge(&p, width, 0);
408	put_swf_line_edge(&p, 0, height);
409	put_swf_line_edge(&p, -width, 0);
410	put_swf_line_edge(&p, 0, -height);
411
412	/* end of shape */
413	put_bits(&p, 1, 0); /* not an edge */
414	put_bits(&p, 5, 0);
415
416	flush_put_bits(&p);
417	put_buffer(pb, buf1, pbBufPtr(&p) - p.buf);
418
419	put_swf_end_tag(s);
420	}
421
422	if (audio_enc && audio_enc->codec_id == CODEC_ID_MP3 ) {
423	int v;
424
425	/* start sound */
426	put_swf_tag(s, TAG_STREAMHEAD2);
427
428	v = 0;
429	switch(audio_enc->sample_rate) {
430	case 11025:
431	v \|= 1 << 2;
432	break;
433	case 22050:
434	v \|= 2 << 2;
435	break;
436	case 44100:
437	v \|= 3 << 2;
438	break;
439	default:
440	/* not supported */
441	av_free(swf->audio_fifo);
442	av_free(swf);
443	return -1;
444	}
445	v \|= 0x02; /* 16 bit playback */
446	if (audio_enc->channels == 2)
447	v \|= 0x01; /* stereo playback */
448	put_byte(&s->pb, v);
449	v \|= 0x20; /* mp3 compressed */
450	put_byte(&s->pb, v);
451	put_le16(&s->pb, swf->samples_per_frame); /* avg samples per frame */
452	put_le16(&s->pb, 0);
453
454	put_swf_end_tag(s);
455	}
456
457	put_flush_packet(&s->pb);
458	return 0;
459	}
460
461	static int swf_write_video(AVFormatContext *s,
462	AVCodecContext enc, const uint8_t buf, int size)
463	{
464	SWFContext *swf = s->priv_data;
465	ByteIOContext *pb = &s->pb;
466	int c = 0;
467	int outSize = 0;
468	int outSamples = 0;
469
470	/* Flash Player limit */
471	if ( swf->swf_frame_number == 16000 ) {
472	av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
473	}
474
475	if ( swf->audio_type ) {
476	/* Prescan audio data for this swf frame */
477	retry_swf_audio_packet:
478	if ( ( swf->audio_size-outSize ) >= 4 ) {
479	int mp3FrameSize = 0;
480	int mp3SampleRate = 0;
481	int mp3IsMono = 0;
482	int mp3SamplesPerFrame = 0;
483
484	/* copy out mp3 header from ring buffer */
485	uint8_t header[4];
486	for (c=0; c<4; c++) {
487	header[c] = swf->audio_fifo[(swf->audio_in_pos+outSize+c) % AUDIO_FIFO_SIZE];
488	}
489
490	if ( swf_mp3_info(header,&mp3FrameSize,&mp3SamplesPerFrame,&mp3SampleRate,&mp3IsMono) ) {
491	if ( ( swf->audio_size-outSize ) >= mp3FrameSize ) {
492	outSize += mp3FrameSize;
493	outSamples += mp3SamplesPerFrame;
494	if ( ( swf->sound_samples + outSamples + swf->samples_per_frame ) < swf->video_samples ) {
495	goto retry_swf_audio_packet;
496	}
497	}
498	} else {
499	/* invalid mp3 data, skip forward
500	we need to do this since the Flash Player
501	does not like custom headers */
502	swf->audio_in_pos ++;
503	swf->audio_size --;
504	swf->audio_in_pos %= AUDIO_FIFO_SIZE;
505	goto retry_swf_audio_packet;
506	}
507	}
508
509	/* audio stream is behind video stream, bail */
510	if ( ( swf->sound_samples + outSamples + swf->samples_per_frame ) < swf->video_samples ) {
511	return 0;
512	}
513	}
514
515	if ( swf->video_type == CODEC_ID_FLV1 ) {
516	if ( swf->video_frame_number == 0 ) {
517	/* create a new video object */
518	put_swf_tag(s, TAG_VIDEOSTREAM);
519	put_le16(pb, VIDEO_ID);
520	put_le16(pb, 15000 ); /* hard flash player limit */
521	put_le16(pb, enc->width);
522	put_le16(pb, enc->height);
523	put_byte(pb, 0);
524	put_byte(pb, SWF_VIDEO_CODEC_FLV1);
525	put_swf_end_tag(s);
526
527	/* place the video object for the first time */
528	put_swf_tag(s, TAG_PLACEOBJECT2);
529	put_byte(pb, 0x36);
530	put_le16(pb, 1);
531	put_le16(pb, VIDEO_ID);
532	put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
533	put_le16(pb, swf->video_frame_number );
534	put_byte(pb, 'v');
535	put_byte(pb, 'i');
536	put_byte(pb, 'd');
537	put_byte(pb, 'e');
538	put_byte(pb, 'o');
539	put_byte(pb, 0x00);
540	put_swf_end_tag(s);
541	} else {
542	/* mark the character for update */
543	put_swf_tag(s, TAG_PLACEOBJECT2);
544	put_byte(pb, 0x11);
545	put_le16(pb, 1);
546	put_le16(pb, swf->video_frame_number );
547	put_swf_end_tag(s);
548	}
549
550	/* set video frame data */
551	put_swf_tag(s, TAG_VIDEOFRAME \| TAG_LONG);
552	put_le16(pb, VIDEO_ID);
553	put_le16(pb, swf->video_frame_number++ );
554	put_buffer(pb, buf, size);
555	put_swf_end_tag(s);
556	} else if ( swf->video_type == CODEC_ID_MJPEG ) {
557	if (swf->swf_frame_number > 0) {
558	/* remove the shape */
559	put_swf_tag(s, TAG_REMOVEOBJECT);
560	put_le16(pb, SHAPE_ID); /* shape ID */
561	put_le16(pb, 1); /* depth */
562	put_swf_end_tag(s);
563
564	/* free the bitmap */
565	put_swf_tag(s, TAG_FREECHARACTER);
566	put_le16(pb, BITMAP_ID);
567	put_swf_end_tag(s);
568	}
569
570	put_swf_tag(s, TAG_JPEG2 \| TAG_LONG);
571
572	put_le16(pb, BITMAP_ID); /* ID of the image */
573
574	/* a dummy jpeg header seems to be required */
575	put_byte(pb, 0xff);
576	put_byte(pb, 0xd8);
577	put_byte(pb, 0xff);
578	put_byte(pb, 0xd9);
579	/* write the jpeg image */
580	put_buffer(pb, buf, size);
581
582	put_swf_end_tag(s);
583
584	/* draw the shape */
585
586	put_swf_tag(s, TAG_PLACEOBJECT);
587	put_le16(pb, SHAPE_ID); /* shape ID */
588	put_le16(pb, 1); /* depth */
589	put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
590	put_swf_end_tag(s);
591	} else {
592	/* invalid codec */
593	}
594
595	swf->swf_frame_number ++;
596
597	swf->video_samples += swf->samples_per_frame;
598
599	/* streaming sound always should be placed just before showframe tags */
600	if ( outSize > 0 ) {
601	put_swf_tag(s, TAG_STREAMBLOCK \| TAG_LONG);
602	put_le16(pb, outSamples);
603	put_le16(pb, 0);
604	for (c=0; c<outSize; c++) {
605	put_byte(pb,swf->audio_fifo[(swf->audio_in_pos+c) % AUDIO_FIFO_SIZE]);
606	}
607	put_swf_end_tag(s);
608
609	/* update FIFO */
610	swf->sound_samples += outSamples;
611	swf->audio_in_pos += outSize;
612	swf->audio_size -= outSize;
613	swf->audio_in_pos %= AUDIO_FIFO_SIZE;
614	}
615
616	/* output the frame */
617	put_swf_tag(s, TAG_SHOWFRAME);
618	put_swf_end_tag(s);
619
620	put_flush_packet(&s->pb);
621
622	return 0;
623	}
624
625	static int swf_write_audio(AVFormatContext *s,
626	AVCodecContext enc, const uint8_t buf, int size)
627	{
628	SWFContext *swf = s->priv_data;
629	int c = 0;
630
631	/* Flash Player limit */
632	if ( swf->swf_frame_number == 16000 ) {
633	av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
634	}
635
636	if (enc->codec_id == CODEC_ID_MP3 ) {
637	for (c=0; c<size; c++) {
638	swf->audio_fifo[(swf->audio_out_pos+c)%AUDIO_FIFO_SIZE] = buf[c];
639	}
640	swf->audio_size += size;
641	swf->audio_out_pos += size;
642	swf->audio_out_pos %= AUDIO_FIFO_SIZE;
643	}
644
645	/* if audio only stream make sure we add swf frames */
646	if ( swf->video_type == 0 ) {
647	swf_write_video(s, enc, 0, 0);
648	}
649
650	return 0;
651	}
652
653	static int swf_write_packet(AVFormatContext s, AVPacket pkt)
654	{
655	AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
656	if (codec->codec_type == CODEC_TYPE_AUDIO)
657	return swf_write_audio(s, codec, pkt->data, pkt->size);
658	else
659	return swf_write_video(s, codec, pkt->data, pkt->size);
660	}
661
662	static int swf_write_trailer(AVFormatContext *s)
663	{
664	SWFContext *swf = s->priv_data;
665	ByteIOContext *pb = &s->pb;
666	AVCodecContext enc, video_enc;
667	int file_size, i;
668
669	video_enc = NULL;
670	for(i=0;i<s->nb_streams;i++) {
671	enc = s->streams[i]->codec;
672	if (enc->codec_type == CODEC_TYPE_VIDEO)
673	video_enc = enc;
674	}
675
676	put_swf_tag(s, TAG_END);
677	put_swf_end_tag(s);
678
679	put_flush_packet(&s->pb);
680
681	/* patch file size and number of frames if not streamed */
682	if (!url_is_streamed(&s->pb) && video_enc) {
683	file_size = url_ftell(pb);
684	url_fseek(pb, 4, SEEK_SET);
685	put_le32(pb, file_size);
686	url_fseek(pb, swf->duration_pos, SEEK_SET);
687	put_le16(pb, video_enc->frame_number);
688	}
689
690	av_free(swf->audio_fifo);
691
692	return 0;
693	}
694	#endif //CONFIG_MUXERS
695
696	/*********************************************/
697	/* Extract FLV encoded frame and MP3 from swf
698	Note that the detection of the real frame
699	is inaccurate at this point as it can be
700	quite tricky to determine, you almost certainly
701	will get a bad audio/video sync */
702
703	static int get_swf_tag(ByteIOContext pb, int len_ptr)
704	{
705	int tag, len;
706
707	if (url_feof(pb))
708	return -1;
709
710	tag = get_le16(pb);
711	len = tag & 0x3f;
712	tag = tag >> 6;
713	if (len == 0x3f) {
714	len = get_le32(pb);
715	}
716	// av_log(NULL, AV_LOG_DEBUG, "Tag: %d - Len: %d\n", tag, len);
717	*len_ptr = len;
718	return tag;
719	}
720
721
722	static int swf_probe(AVProbeData *p)
723	{
724	/* check file header */
725	if (p->buf_size <= 16)
726	return 0;
727	if ((p->buf[0] == 'F' \|\| p->buf[0] == 'C') && p->buf[1] == 'W' &&
728	p->buf[2] == 'S')
729	return AVPROBE_SCORE_MAX;
730	else
731	return 0;
732	}
733
734	static int swf_read_header(AVFormatContext s, AVFormatParameters ap)
735	{
736	SWFContext *swf = 0;
737	ByteIOContext *pb = &s->pb;
738	int nbits, len, frame_rate, tag, v;
739	offset_t firstTagOff;
740	AVStream *ast = 0;
741	AVStream *vst = 0;
742
743	swf = av_malloc(sizeof(SWFContext));
744	if (!swf)
745	return -1;
746	s->priv_data = swf;
747
748	tag = get_be32(pb) & 0xffffff00;
749
750	if (tag == MKBETAG('C', 'W', 'S', 0))
751	{
752	av_log(s, AV_LOG_ERROR, "Compressed SWF format not supported\n");
753	return AVERROR_IO;
754	}
755	if (tag != MKBETAG('F', 'W', 'S', 0))
756	return AVERROR_IO;
757	get_le32(pb);
758	/* skip rectangle size */
759	nbits = get_byte(pb) >> 3;
760	len = (4 * nbits - 3 + 7) / 8;
761	url_fskip(pb, len);
762	frame_rate = get_le16(pb);
763	get_le16(pb); /* frame count */
764
765	/* The Flash Player converts 8.8 frame rates
766	to milliseconds internally. Do the same to get
767	a correct framerate */
768	swf->ms_per_frame = ( 1000 * 256 ) / frame_rate;
769	swf->samples_per_frame = 0;
770	swf->ch_id = -1;
771
772	firstTagOff = url_ftell(pb);
773	for(;;) {
774	tag = get_swf_tag(pb, &len);
775	if (tag < 0) {
776	if ( ast \|\| vst ) {
777	if ( vst && ast ) {
778	vst->codec->time_base.den = ast->codec->sample_rate / swf->samples_per_frame;
779	vst->codec->time_base.num = 1;
780	}
781	break;
782	}
783	av_log(s, AV_LOG_ERROR, "No media found in SWF\n");
784	return AVERROR_IO;
785	}
786	if ( tag == TAG_VIDEOSTREAM && !vst) {
787	swf->ch_id = get_le16(pb);
788	get_le16(pb);
789	get_le16(pb);
790	get_le16(pb);
791	get_byte(pb);
792	/* Check for FLV1 */
793	if ( get_byte(pb) == SWF_VIDEO_CODEC_FLV1 ) {
794	vst = av_new_stream(s, 0);
795	av_set_pts_info(vst, 24, 1, 1000); /* 24 bit pts in ms */
796
797	vst->codec->codec_type = CODEC_TYPE_VIDEO;
798	vst->codec->codec_id = CODEC_ID_FLV1;
799	if ( swf->samples_per_frame ) {
800	vst->codec->time_base.den = 1000. / swf->ms_per_frame;
801	vst->codec->time_base.num = 1;
802	}
803	}
804	} else if ( ( tag == TAG_STREAMHEAD \|\| tag == TAG_STREAMHEAD2 ) && !ast) {
805	/* streaming found */
806	get_byte(pb);
807	v = get_byte(pb);
808	swf->samples_per_frame = get_le16(pb);
809	if (len!=4)
810	url_fskip(pb,len-4);
811	/* if mp3 streaming found, OK */
812	if ((v & 0x20) != 0) {
813	if ( tag == TAG_STREAMHEAD2 ) {
814	get_le16(pb);
815	}
816	ast = av_new_stream(s, 1);
817	av_set_pts_info(ast, 24, 1, 1000); /* 24 bit pts in ms */
818	if (!ast)
819	return -ENOMEM;
820
821	if (v & 0x01)
822	ast->codec->channels = 2;
823	else
824	ast->codec->channels = 1;
825
826	switch((v>> 2) & 0x03) {
827	case 1:
828	ast->codec->sample_rate = 11025;
829	break;
830	case 2:
831	ast->codec->sample_rate = 22050;
832	break;
833	case 3:
834	ast->codec->sample_rate = 44100;
835	break;
836	default:
837	av_free(ast);
838	return AVERROR_IO;
839	}
840	ast->codec->codec_type = CODEC_TYPE_AUDIO;
841	ast->codec->codec_id = CODEC_ID_MP3;
842	}
843	} else {
844	url_fskip(pb, len);
845	}
846	}
847	url_fseek(pb, firstTagOff, SEEK_SET);
848
849	return 0;
850	}
851
852	static int swf_read_packet(AVFormatContext s, AVPacket pkt)
853	{
854	SWFContext *swf = s->priv_data;
855	ByteIOContext *pb = &s->pb;
856	AVStream *st = 0;
857	int tag, len, i, frame;
858
859	for(;;) {
860	tag = get_swf_tag(pb, &len);
861	if (tag < 0)
862	return AVERROR_IO;
863	if (tag == TAG_VIDEOFRAME) {
864	for( i=0; i<s->nb_streams; i++ ) {
865	st = s->streams[i];
866	if (st->id == 0) {
867	if ( get_le16(pb) == swf->ch_id ) {
868	frame = get_le16(pb);
869	av_get_packet(pb, pkt, len-4);
870	pkt->pts = frame * swf->ms_per_frame;
871	pkt->stream_index = st->index;
872	return pkt->size;
873	} else {
874	url_fskip(pb, len-2);
875	continue;
876	}
877	}
878	}
879	url_fskip(pb, len);
880	} else if (tag == TAG_STREAMBLOCK) {
881	for( i=0; i<s->nb_streams; i++ ) {
882	st = s->streams[i];
883	if (st->id == 1) {
884	av_get_packet(pb, pkt, len);
885	pkt->stream_index = st->index;
886	return pkt->size;
887	}
888	}
889	url_fskip(pb, len);
890	} else {
891	url_fskip(pb, len);
892	}
893	}
894	return 0;
895	}
896
897	static int swf_read_close(AVFormatContext *s)
898	{
899	return 0;
900	}
901
902	static AVInputFormat swf_demuxer = {
903	"swf",
904	"Flash format",
905	sizeof(SWFContext),
906	swf_probe,
907	swf_read_header,
908	swf_read_packet,
909	swf_read_close,
910	};
911
912	#ifdef CONFIG_MUXERS
913	static AVOutputFormat swf_muxer = {
914	"swf",
915	"Flash format",
916	"application/x-shockwave-flash",
917	"swf",
918	sizeof(SWFContext),
919	CODEC_ID_MP3,
920	CODEC_ID_FLV1,
921	swf_write_header,
922	swf_write_packet,
923	swf_write_trailer,
924	};
925	#endif //CONFIG_MUXERS
926
927	int swf_init(void)
928	{
929	av_register_input_format(&swf_demuxer);
930	#ifdef CONFIG_MUXERS
931	av_register_output_format(&swf_muxer);
932	#endif //CONFIG_MUXERS
933	return 0;
934	}

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