path: root/libavformat/rmenc.c (plain)
blob: f9821d18754c1d09295e75fd41cfbf78d5b22654

1	/*
2	* "Real" compatible muxer.
3	* Copyright (c) 2000, 2001 Fabrice Bellard
4	*
5	* This file is part of FFmpeg.
6	*
7	* FFmpeg is free software; you can redistribute it and/or
8	* modify it under the terms of the GNU Lesser General Public
9	* License as published by the Free Software Foundation; either
10	* version 2.1 of the License, or (at your option) any later version.
11	*
12	* FFmpeg is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15	* Lesser General Public License for more details.
16	*
17	* You should have received a copy of the GNU Lesser General Public
18	* License along with FFmpeg; if not, write to the Free Software
19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	*/
21	#include "avformat.h"
22	#include "avio_internal.h"
23	#include "rm.h"
24	#include "libavutil/dict.h"
25
26	typedef struct StreamInfo {
27	int nb_packets;
28	int packet_total_size;
29	int packet_max_size;
30	/* codec related output */
31	int bit_rate;
32	AVRational frame_rate;
33	int nb_frames; /* current frame number */
34	int total_frames; /* total number of frames */
35	int num;
36	AVCodecParameters *par;
37	} StreamInfo;
38
39	typedef struct RMMuxContext {
40	StreamInfo streams[2];
41	StreamInfo *audio_stream, *video_stream;
42	int data_pos; /* position of the data after the header */
43	} RMMuxContext;
44
45	/* in ms */
46	#define BUFFER_DURATION 0
47	/* the header needs at most 7 + 4 + 12 B */
48	#define MAX_HEADER_SIZE (7 + 4 + 12)
49	/* UINT16_MAX is the maximal chunk size */
50	#define MAX_PACKET_SIZE (UINT16_MAX - MAX_HEADER_SIZE)
51
52
53	static void put_str(AVIOContext *s, const char *tag)
54	{
55	avio_wb16(s,strlen(tag));
56	while (*tag) {
57	avio_w8(s, *tag++);
58	}
59	}
60
61	static void put_str8(AVIOContext *s, const char *tag)
62	{
63	avio_w8(s, strlen(tag));
64	while (*tag) {
65	avio_w8(s, *tag++);
66	}
67	}
68
69	static int rv10_write_header(AVFormatContext *ctx,
70	int data_size, int index_pos)
71	{
72	RMMuxContext *rm = ctx->priv_data;
73	AVIOContext *s = ctx->pb;
74	StreamInfo *stream;
75	unsigned char *data_offset_ptr, *start_ptr;
76	const char *desc, *mimetype;
77	int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
78	int bit_rate, v, duration, flags, data_pos;
79	AVDictionaryEntry *tag;
80
81	start_ptr = s->buf_ptr;
82
83	ffio_wfourcc(s, ".RMF");
84	avio_wb32(s,18); /* header size */
85	avio_wb16(s,0);
86	avio_wb32(s,0);
87	avio_wb32(s,4 + ctx->nb_streams); /* num headers */
88
89	ffio_wfourcc(s,"PROP");
90	avio_wb32(s, 50);
91	avio_wb16(s, 0);
92	packet_max_size = 0;
93	packet_total_size = 0;
94	nb_packets = 0;
95	bit_rate = 0;
96	duration = 0;
97	for(i=0;i<ctx->nb_streams;i++) {
98	StreamInfo *stream = &rm->streams[i];
99	bit_rate += stream->bit_rate;
100	if (stream->packet_max_size > packet_max_size)
101	packet_max_size = stream->packet_max_size;
102	nb_packets += stream->nb_packets;
103	packet_total_size += stream->packet_total_size;
104	/* select maximum duration */
105	v = av_rescale_q_rnd(stream->total_frames, (AVRational){1000, 1}, stream->frame_rate, AV_ROUND_ZERO);
106	if (v > duration)
107	duration = v;
108	}
109	avio_wb32(s, bit_rate); /* max bit rate */
110	avio_wb32(s, bit_rate); /* avg bit rate */
111	avio_wb32(s, packet_max_size); /* max packet size */
112	if (nb_packets > 0)
113	packet_avg_size = packet_total_size / nb_packets;
114	else
115	packet_avg_size = 0;
116	avio_wb32(s, packet_avg_size); /* avg packet size */
117	avio_wb32(s, nb_packets); /* num packets */
118	avio_wb32(s, duration); /* duration */
119	avio_wb32(s, BUFFER_DURATION); /* preroll */
120	avio_wb32(s, index_pos); /* index offset */
121	/* computation of data the data offset */
122	data_offset_ptr = s->buf_ptr;
123	avio_wb32(s, 0); /* data offset : will be patched after */
124	avio_wb16(s, ctx->nb_streams); /* num streams */
125	flags = 1 | 2; /* save allowed & perfect play */
126	if (!(s->seekable & AVIO_SEEKABLE_NORMAL))
127	flags |= 4; /* live broadcast */
128	avio_wb16(s, flags);
129
130	/* comments */
131
132	ffio_wfourcc(s,"CONT");
133	size = 4 * 2 + 10;
134	for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
135	tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
136	if(tag) size += strlen(tag->value);
137	}
138	avio_wb32(s,size);
139	avio_wb16(s,0);
140	for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
141	tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
142	put_str(s, tag ? tag->value : "");
143	}
144
145	for(i=0;i<ctx->nb_streams;i++) {
146	int codec_data_size;
147
148	stream = &rm->streams[i];
149
150	if (stream->par->codec_type == AVMEDIA_TYPE_AUDIO) {
151	desc = "The Audio Stream";
152	mimetype = "audio/x-pn-realaudio";
153	codec_data_size = 73;
154	} else {
155	desc = "The Video Stream";
156	mimetype = "video/x-pn-realvideo";
157	codec_data_size = 34;
158	}
159
160	ffio_wfourcc(s,"MDPR");
161	size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
162	avio_wb32(s, size);
163	avio_wb16(s, 0);
164
165	avio_wb16(s, i); /* stream number */
166	avio_wb32(s, stream->bit_rate); /* max bit rate */
167	avio_wb32(s, stream->bit_rate); /* avg bit rate */
168	avio_wb32(s, stream->packet_max_size); /* max packet size */
169	if (stream->nb_packets > 0)
170	packet_avg_size = stream->packet_total_size /
171	stream->nb_packets;
172	else
173	packet_avg_size = 0;
174	avio_wb32(s, packet_avg_size); /* avg packet size */
175	avio_wb32(s, 0); /* start time */
176	avio_wb32(s, BUFFER_DURATION); /* preroll */
177	/* duration */
178	if (!(s->seekable & AVIO_SEEKABLE_NORMAL) || !stream->total_frames)
179	avio_wb32(s, (int)(3600 * 1000));
180	else
181	avio_wb32(s, av_rescale_q_rnd(stream->total_frames, (AVRational){1000, 1}, stream->frame_rate, AV_ROUND_ZERO));
182	put_str8(s, desc);
183	put_str8(s, mimetype);
184	avio_wb32(s, codec_data_size);
185
186	if (stream->par->codec_type == AVMEDIA_TYPE_AUDIO) {
187	int coded_frame_size, fscode, sample_rate;
188	int frame_size = av_get_audio_frame_duration2(stream->par, 0);
189	sample_rate = stream->par->sample_rate;
190	coded_frame_size = (stream->par->bit_rate *
191	frame_size) / (8 * sample_rate);
192	/* audio codec info */
193	avio_write(s, ".ra", 3);
194	avio_w8(s, 0xfd);
195	avio_wb32(s, 0x00040000); /* version */
196	ffio_wfourcc(s, ".ra4");
197	avio_wb32(s, 0x01b53530); /* stream length */
198	avio_wb16(s, 4); /* unknown */
199	avio_wb32(s, 0x39); /* header size */
200
201	switch(sample_rate) {
202	case 48000:
203	case 24000:
204	case 12000:
205	fscode = 1;
206	break;
207	default:
208	case 44100:
209	case 22050:
210	case 11025:
211	fscode = 2;
212	break;
213	case 32000:
214	case 16000:
215	case 8000:
216	fscode = 3;
217	}
218	avio_wb16(s, fscode); /* codec additional info, for AC-3, seems
219	to be a frequency code */
220	/* special hack to compensate rounding errors... */
221	if (coded_frame_size == 557)
222	coded_frame_size--;
223	avio_wb32(s, coded_frame_size); /* frame length */
224	avio_wb32(s, 0x51540); /* unknown */
225	avio_wb32(s, stream->par->bit_rate / 8 * 60); /* bytes per minute */
226	avio_wb32(s, stream->par->bit_rate / 8 * 60); /* bytes per minute */
227	avio_wb16(s, 0x01);
228	/* frame length : seems to be very important */
229	avio_wb16(s, coded_frame_size);
230	avio_wb32(s, 0); /* unknown */
231	avio_wb16(s, stream->par->sample_rate); /* sample rate */
232	avio_wb32(s, 0x10); /* unknown */
233	avio_wb16(s, stream->par->channels);
234	put_str8(s, "Int0"); /* codec name */
235	if (stream->par->codec_tag) {
236	avio_w8(s, 4); /* tag length */
237	avio_wl32(s, stream->par->codec_tag);
238	} else {
239	av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");
240	return -1;
241	}
242	avio_wb16(s, 0); /* title length */
243	avio_wb16(s, 0); /* author length */
244	avio_wb16(s, 0); /* copyright length */
245	avio_w8(s, 0); /* end of header */
246	} else {
247	/* video codec info */
248	avio_wb32(s,34); /* size */
249	ffio_wfourcc(s, "VIDO");
250	if(stream->par->codec_id == AV_CODEC_ID_RV10)
251	ffio_wfourcc(s,"RV10");
252	else
253	ffio_wfourcc(s,"RV20");
254	avio_wb16(s, stream->par->width);
255	avio_wb16(s, stream->par->height);
256
257	if (stream->frame_rate.num / stream->frame_rate.den > 65535) {
258	av_log(s, AV_LOG_ERROR, "Frame rate %d is too high\n", stream->frame_rate.num / stream->frame_rate.den);
259	return AVERROR(EINVAL);
260	}
261
262	avio_wb16(s, stream->frame_rate.num / stream->frame_rate.den); /* frames per seconds ? */
263	avio_wb32(s,0); /* unknown meaning */
264	avio_wb16(s, stream->frame_rate.num / stream->frame_rate.den); /* unknown meaning */
265	avio_wb32(s,0); /* unknown meaning */
266	avio_wb16(s, 8); /* unknown meaning */
267	/* Seems to be the codec version: only use basic H.263. The next
268	versions seems to add a differential DC coding as in
269	MPEG... nothing new under the sun. */
270	if(stream->par->codec_id == AV_CODEC_ID_RV10)
271	avio_wb32(s,0x10000000);
272	else
273	avio_wb32(s,0x20103001);
274	//avio_wb32(s,0x10003000);
275	}
276	}
277
278	/* patch data offset field */
279	data_pos = s->buf_ptr - start_ptr;
280	rm->data_pos = data_pos;
281	data_offset_ptr[0] = data_pos >> 24;
282	data_offset_ptr[1] = data_pos >> 16;
283	data_offset_ptr[2] = data_pos >> 8;
284	data_offset_ptr[3] = data_pos;
285
286	/* data stream */
287	ffio_wfourcc(s, "DATA");
288	avio_wb32(s,data_size + 10 + 8);
289	avio_wb16(s,0);
290
291	avio_wb32(s, nb_packets); /* number of packets */
292	avio_wb32(s,0); /* next data header */
293	return 0;
294	}
295
296	static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
297	int length, int key_frame)
298	{
299	int timestamp;
300	AVIOContext *s = ctx->pb;
301
302	stream->nb_packets++;
303	stream->packet_total_size += length;
304	if (length > stream->packet_max_size)
305	stream->packet_max_size = length;
306
307	avio_wb16(s,0); /* version */
308	avio_wb16(s,length + 12);
309	avio_wb16(s, stream->num); /* stream number */
310	timestamp = av_rescale_q_rnd(stream->nb_frames, (AVRational){1000, 1}, stream->frame_rate, AV_ROUND_ZERO);
311	avio_wb32(s, timestamp); /* timestamp */
312	avio_w8(s, 0); /* reserved */
313	avio_w8(s, key_frame ? 2 : 0); /* flags */
314	}
315
316	static int rm_write_header(AVFormatContext *s)
317	{
318	RMMuxContext *rm = s->priv_data;
319	StreamInfo *stream;
320	int n;
321	AVCodecParameters *par;
322
323	if (s->nb_streams > 2) {
324	av_log(s, AV_LOG_ERROR, "At most 2 streams are currently supported for muxing in RM\n");
325	return AVERROR_PATCHWELCOME;
326	}
327
328	for(n=0;n<s->nb_streams;n++) {
329	AVStream *st = s->streams[n];
330	int frame_size;
331
332	s->streams[n]->id = n;
333	par = s->streams[n]->codecpar;
334	stream = &rm->streams[n];
335	memset(stream, 0, sizeof(StreamInfo));
336	stream->num = n;
337	stream->bit_rate = par->bit_rate;
338	stream->par = par;
339
340	switch (par->codec_type) {
341	case AVMEDIA_TYPE_AUDIO:
342	rm->audio_stream = stream;
343	frame_size = av_get_audio_frame_duration2(par, 0);
344	stream->frame_rate = (AVRational){par->sample_rate, frame_size};
345	/* XXX: dummy values */
346	stream->packet_max_size = 1024;
347	stream->nb_packets = 0;
348	stream->total_frames = stream->nb_packets;
349	break;
350	case AVMEDIA_TYPE_VIDEO:
351	rm->video_stream = stream;
352	// TODO: should be avg_frame_rate
353	stream->frame_rate = av_inv_q(st->time_base);
354	/* XXX: dummy values */
355	stream->packet_max_size = 4096;
356	stream->nb_packets = 0;
357	stream->total_frames = stream->nb_packets;
358	break;
359	default:
360	return -1;
361	}
362	}
363
364	if (rv10_write_header(s, 0, 0))
365	return AVERROR_INVALIDDATA;
366	avio_flush(s->pb);
367	return 0;
368	}
369
370	static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
371	{
372	RMMuxContext *rm = s->priv_data;
373	AVIOContext *pb = s->pb;
374	StreamInfo *stream = rm->audio_stream;
375	int i;
376
377	write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
378
379	if (stream->par->codec_id == AV_CODEC_ID_AC3) {
380	/* for AC-3, the words seem to be reversed */
381	for (i = 0; i < size; i += 2) {
382	avio_w8(pb, buf[i + 1]);
383	avio_w8(pb, buf[i]);
384	}
385	} else {
386	avio_write(pb, buf, size);
387	}
388	stream->nb_frames++;
389	return 0;
390	}
391
392	static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
393	{
394	RMMuxContext *rm = s->priv_data;
395	AVIOContext *pb = s->pb;
396	StreamInfo *stream = rm->video_stream;
397	int key_frame = !!(flags & AV_PKT_FLAG_KEY);
398
399	/* XXX: this is incorrect: should be a parameter */
400
401	/* Well, I spent some time finding the meaning of these bits. I am
402	not sure I understood everything, but it works !! */
403	if (size > MAX_PACKET_SIZE) {
404	av_log(s, AV_LOG_ERROR, "Muxing packets larger than 64 kB (%d) is not supported\n", size);
405	return AVERROR_PATCHWELCOME;
406	}
407	write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
408	/* bit 7: '1' if final packet of a frame converted in several packets */
409	avio_w8(pb, 0x81);
410	/* bit 7: '1' if I-frame. bits 6..0 : sequence number in current
411	frame starting from 1 */
412	if (key_frame) {
413	avio_w8(pb, 0x81);
414	} else {
415	avio_w8(pb, 0x01);
416	}
417	if(size >= 0x4000){
418	avio_wb32(pb, size); /* total frame size */
419	avio_wb32(pb, size); /* offset from the start or the end */
420	}else{
421	avio_wb16(pb, 0x4000 | size); /* total frame size */
422	avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */
423	}
424	avio_w8(pb, stream->nb_frames & 0xff);
425
426	avio_write(pb, buf, size);
427
428	stream->nb_frames++;
429	return 0;
430	}
431
432	static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
433	{
434	if (s->streams[pkt->stream_index]->codecpar->codec_type ==
435	AVMEDIA_TYPE_AUDIO)
436	return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
437	else
438	return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
439	}
440
441	static int rm_write_trailer(AVFormatContext *s)
442	{
443	RMMuxContext *rm = s->priv_data;
444	int data_size, index_pos, i;
445	AVIOContext *pb = s->pb;
446
447	if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
448	/* end of file: finish to write header */
449	index_pos = avio_tell(pb);
450	data_size = index_pos - rm->data_pos;
451
452	/* FIXME: write index */
453
454	/* undocumented end header */
455	avio_wb32(pb, 0);
456	avio_wb32(pb, 0);
457
458	avio_seek(pb, 0, SEEK_SET);
459	for(i=0;i<s->nb_streams;i++)
460	rm->streams[i].total_frames = rm->streams[i].nb_frames;
461	rv10_write_header(s, data_size, 0);
462	} else {
463	/* undocumented end header */
464	avio_wb32(pb, 0);
465	avio_wb32(pb, 0);
466	}
467
468	return 0;
469	}
470
471
472	AVOutputFormat ff_rm_muxer = {
473	.name = "rm",
474	.long_name = NULL_IF_CONFIG_SMALL("RealMedia"),
475	.mime_type = "application/vnd.rn-realmedia",
476	.extensions = "rm,ra",
477	.priv_data_size = sizeof(RMMuxContext),
478	.audio_codec = AV_CODEC_ID_AC3,
479	.video_codec = AV_CODEC_ID_RV10,
480	.write_header = rm_write_header,
481	.write_packet = rm_write_packet,
482	.write_trailer = rm_write_trailer,
483	.codec_tag = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },
484	};
485