3 * Copyright (c) 2002 Fabrice Bellard
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "libavutil/mathematics.h"
26 #include "libavutil/random_seed.h"
27 #include "libavutil/opt.h"
31 static const AVOption options[] = {
32 FF_RTP_FLAG_OPTS(RTPMuxContext, flags),
33 { "payload_type", "Specify RTP payload type", offsetof(RTPMuxContext, payload_type), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, 127, AV_OPT_FLAG_ENCODING_PARAM },
34 { "ssrc", "Stream identifier", offsetof(RTPMuxContext, ssrc), AV_OPT_TYPE_INT, { .i64 = 0 }, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
35 { "cname", "CNAME to include in RTCP SR packets", offsetof(RTPMuxContext, cname), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
36 { "seq", "Starting sequence number", offsetof(RTPMuxContext, seq), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 65535, AV_OPT_FLAG_ENCODING_PARAM },
40 static const AVClass rtp_muxer_class = {
41 .class_name = "RTP muxer",
42 .item_name = av_default_item_name,
44 .version = LIBAVUTIL_VERSION_INT,
47 #define RTCP_SR_SIZE 28
49 static int is_supported(enum AVCodecID id)
52 case AV_CODEC_ID_H263:
53 case AV_CODEC_ID_H263P:
54 case AV_CODEC_ID_H264:
55 case AV_CODEC_ID_MPEG1VIDEO:
56 case AV_CODEC_ID_MPEG2VIDEO:
57 case AV_CODEC_ID_MPEG4:
61 case AV_CODEC_ID_PCM_ALAW:
62 case AV_CODEC_ID_PCM_MULAW:
63 case AV_CODEC_ID_PCM_S8:
64 case AV_CODEC_ID_PCM_S16BE:
65 case AV_CODEC_ID_PCM_S16LE:
66 case AV_CODEC_ID_PCM_U16BE:
67 case AV_CODEC_ID_PCM_U16LE:
68 case AV_CODEC_ID_PCM_U8:
69 case AV_CODEC_ID_MPEG2TS:
70 case AV_CODEC_ID_AMR_NB:
71 case AV_CODEC_ID_AMR_WB:
72 case AV_CODEC_ID_VORBIS:
73 case AV_CODEC_ID_THEORA:
75 case AV_CODEC_ID_ADPCM_G722:
76 case AV_CODEC_ID_ADPCM_G726:
77 case AV_CODEC_ID_ILBC:
78 case AV_CODEC_ID_MJPEG:
79 case AV_CODEC_ID_SPEEX:
80 case AV_CODEC_ID_OPUS:
87 static int rtp_write_header(AVFormatContext *s1)
89 RTPMuxContext *s = s1->priv_data;
93 if (s1->nb_streams != 1) {
94 av_log(s1, AV_LOG_ERROR, "Only one stream supported in the RTP muxer\n");
95 return AVERROR(EINVAL);
98 if (!is_supported(st->codec->codec_id)) {
99 av_log(s1, AV_LOG_ERROR, "Unsupported codec %x\n", st->codec->codec_id);
104 if (s->payload_type < 0) {
105 /* Re-validate non-dynamic payload types */
106 if (st->id < RTP_PT_PRIVATE)
107 st->id = ff_rtp_get_payload_type(s1, st->codec, -1);
109 s->payload_type = st->id;
111 /* private option takes priority */
112 st->id = s->payload_type;
115 s->base_timestamp = av_get_random_seed();
116 s->timestamp = s->base_timestamp;
117 s->cur_timestamp = 0;
119 s->ssrc = av_get_random_seed();
121 s->first_rtcp_ntp_time = ff_ntp_time();
122 if (s1->start_time_realtime)
123 /* Round the NTP time to whole milliseconds. */
124 s->first_rtcp_ntp_time = (s1->start_time_realtime / 1000) * 1000 +
126 // Pick a random sequence start number, but in the lower end of the
127 // available range, so that any wraparound doesn't happen immediately.
128 // (Immediate wraparound would be an issue for SRTP.)
130 s->seq = av_get_random_seed() & 0x0fff;
132 s->seq &= 0xffff; // Use the given parameter, wrapped to the right interval
134 if (s1->packet_size) {
135 if (s1->pb->max_packet_size)
136 s1->packet_size = FFMIN(s1->packet_size,
137 s1->pb->max_packet_size);
139 s1->packet_size = s1->pb->max_packet_size;
140 if (s1->packet_size <= 12) {
141 av_log(s1, AV_LOG_ERROR, "Max packet size %d too low\n", s1->packet_size);
144 s->buf = av_malloc(s1->packet_size);
145 if (s->buf == NULL) {
146 return AVERROR(ENOMEM);
148 s->max_payload_size = s1->packet_size - 12;
150 s->max_frames_per_packet = 0;
151 if (s1->max_delay > 0) {
152 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
153 int frame_size = av_get_audio_frame_duration(st->codec, 0);
155 frame_size = st->codec->frame_size;
156 if (frame_size == 0) {
157 av_log(s1, AV_LOG_ERROR, "Cannot respect max delay: frame size = 0\n");
159 s->max_frames_per_packet =
160 av_rescale_q_rnd(s1->max_delay,
162 (AVRational){ frame_size, st->codec->sample_rate },
166 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
167 /* FIXME: We should round down here... */
168 if (st->avg_frame_rate.num > 0 && st->avg_frame_rate.den > 0) {
169 s->max_frames_per_packet = av_rescale_q(s1->max_delay,
170 (AVRational){1, 1000000},
171 av_inv_q(st->avg_frame_rate));
173 s->max_frames_per_packet = 1;
177 avpriv_set_pts_info(st, 32, 1, 90000);
178 switch(st->codec->codec_id) {
179 case AV_CODEC_ID_MP2:
180 case AV_CODEC_ID_MP3:
181 s->buf_ptr = s->buf + 4;
183 case AV_CODEC_ID_MPEG1VIDEO:
184 case AV_CODEC_ID_MPEG2VIDEO:
186 case AV_CODEC_ID_MPEG2TS:
187 n = s->max_payload_size / TS_PACKET_SIZE;
190 s->max_payload_size = n * TS_PACKET_SIZE;
193 case AV_CODEC_ID_H264:
194 /* check for H.264 MP4 syntax */
195 if (st->codec->extradata_size > 4 && st->codec->extradata[0] == 1) {
196 s->nal_length_size = (st->codec->extradata[4] & 0x03) + 1;
199 case AV_CODEC_ID_VORBIS:
200 case AV_CODEC_ID_THEORA:
201 if (!s->max_frames_per_packet) s->max_frames_per_packet = 15;
202 s->max_frames_per_packet = av_clip(s->max_frames_per_packet, 1, 15);
203 s->max_payload_size -= 6; // ident+frag+tdt/vdt+pkt_num+pkt_length
206 case AV_CODEC_ID_ADPCM_G722:
207 /* Due to a historical error, the clock rate for G722 in RTP is
208 * 8000, even if the sample rate is 16000. See RFC 3551. */
209 avpriv_set_pts_info(st, 32, 1, 8000);
211 case AV_CODEC_ID_OPUS:
212 if (st->codec->channels > 2) {
213 av_log(s1, AV_LOG_ERROR, "Multistream opus not supported in RTP\n");
216 /* The opus RTP RFC says that all opus streams should use 48000 Hz
217 * as clock rate, since all opus sample rates can be expressed in
218 * this clock rate, and sample rate changes on the fly are supported. */
219 avpriv_set_pts_info(st, 32, 1, 48000);
221 case AV_CODEC_ID_ILBC:
222 if (st->codec->block_align != 38 && st->codec->block_align != 50) {
223 av_log(s1, AV_LOG_ERROR, "Incorrect iLBC block size specified\n");
226 if (!s->max_frames_per_packet)
227 s->max_frames_per_packet = 1;
228 s->max_frames_per_packet = FFMIN(s->max_frames_per_packet,
229 s->max_payload_size / st->codec->block_align);
231 case AV_CODEC_ID_AMR_NB:
232 case AV_CODEC_ID_AMR_WB:
233 if (!s->max_frames_per_packet)
234 s->max_frames_per_packet = 12;
235 if (st->codec->codec_id == AV_CODEC_ID_AMR_NB)
239 /* max_header_toc_size + the largest AMR payload must fit */
240 if (1 + s->max_frames_per_packet + n > s->max_payload_size) {
241 av_log(s1, AV_LOG_ERROR, "RTP max payload size too small for AMR\n");
244 if (st->codec->channels != 1) {
245 av_log(s1, AV_LOG_ERROR, "Only mono is supported\n");
248 case AV_CODEC_ID_AAC:
252 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
253 avpriv_set_pts_info(st, 32, 1, st->codec->sample_rate);
263 return AVERROR(EINVAL);
266 /* send an rtcp sender report packet */
267 static void rtcp_send_sr(AVFormatContext *s1, int64_t ntp_time, int bye)
269 RTPMuxContext *s = s1->priv_data;
272 av_dlog(s1, "RTCP: %02x %"PRIx64" %x\n", s->payload_type, ntp_time, s->timestamp);
274 s->last_rtcp_ntp_time = ntp_time;
275 rtp_ts = av_rescale_q(ntp_time - s->first_rtcp_ntp_time, (AVRational){1, 1000000},
276 s1->streams[0]->time_base) + s->base_timestamp;
277 avio_w8(s1->pb, RTP_VERSION << 6);
278 avio_w8(s1->pb, RTCP_SR);
279 avio_wb16(s1->pb, 6); /* length in words - 1 */
280 avio_wb32(s1->pb, s->ssrc);
281 avio_wb64(s1->pb, NTP_TO_RTP_FORMAT(ntp_time));
282 avio_wb32(s1->pb, rtp_ts);
283 avio_wb32(s1->pb, s->packet_count);
284 avio_wb32(s1->pb, s->octet_count);
287 int len = FFMIN(strlen(s->cname), 255);
288 avio_w8(s1->pb, (RTP_VERSION << 6) + 1);
289 avio_w8(s1->pb, RTCP_SDES);
290 avio_wb16(s1->pb, (7 + len + 3) / 4); /* length in words - 1 */
292 avio_wb32(s1->pb, s->ssrc);
293 avio_w8(s1->pb, 0x01); /* CNAME */
294 avio_w8(s1->pb, len);
295 avio_write(s1->pb, s->cname, len);
296 avio_w8(s1->pb, 0); /* END */
297 for (len = (7 + len) % 4; len % 4; len++)
302 avio_w8(s1->pb, (RTP_VERSION << 6) | 1);
303 avio_w8(s1->pb, RTCP_BYE);
304 avio_wb16(s1->pb, 1); /* length in words - 1 */
305 avio_wb32(s1->pb, s->ssrc);
311 /* send an rtp packet. sequence number is incremented, but the caller
312 must update the timestamp itself */
313 void ff_rtp_send_data(AVFormatContext *s1, const uint8_t *buf1, int len, int m)
315 RTPMuxContext *s = s1->priv_data;
317 av_dlog(s1, "rtp_send_data size=%d\n", len);
319 /* build the RTP header */
320 avio_w8(s1->pb, RTP_VERSION << 6);
321 avio_w8(s1->pb, (s->payload_type & 0x7f) | ((m & 0x01) << 7));
322 avio_wb16(s1->pb, s->seq);
323 avio_wb32(s1->pb, s->timestamp);
324 avio_wb32(s1->pb, s->ssrc);
326 avio_write(s1->pb, buf1, len);
329 s->seq = (s->seq + 1) & 0xffff;
330 s->octet_count += len;
334 /* send an integer number of samples and compute time stamp and fill
335 the rtp send buffer before sending. */
336 static int rtp_send_samples(AVFormatContext *s1,
337 const uint8_t *buf1, int size, int sample_size_bits)
339 RTPMuxContext *s = s1->priv_data;
340 int len, max_packet_size, n;
341 /* Calculate the number of bytes to get samples aligned on a byte border */
342 int aligned_samples_size = sample_size_bits/av_gcd(sample_size_bits, 8);
344 max_packet_size = (s->max_payload_size / aligned_samples_size) * aligned_samples_size;
345 /* Not needed, but who knows. Don't check if samples aren't an even number of bytes. */
346 if ((sample_size_bits % 8) == 0 && ((8 * size) % sample_size_bits) != 0)
347 return AVERROR(EINVAL);
351 len = FFMIN(max_packet_size, size);
354 memcpy(s->buf_ptr, buf1, len);
358 s->timestamp = s->cur_timestamp + n * 8 / sample_size_bits;
359 ff_rtp_send_data(s1, s->buf, s->buf_ptr - s->buf, 0);
360 n += (s->buf_ptr - s->buf);
365 static void rtp_send_mpegaudio(AVFormatContext *s1,
366 const uint8_t *buf1, int size)
368 RTPMuxContext *s = s1->priv_data;
369 int len, count, max_packet_size;
371 max_packet_size = s->max_payload_size;
373 /* test if we must flush because not enough space */
374 len = (s->buf_ptr - s->buf);
375 if ((len + size) > max_packet_size) {
377 ff_rtp_send_data(s1, s->buf, s->buf_ptr - s->buf, 0);
378 s->buf_ptr = s->buf + 4;
381 if (s->buf_ptr == s->buf + 4) {
382 s->timestamp = s->cur_timestamp;
386 if (size > max_packet_size) {
387 /* big packet: fragment */
390 len = max_packet_size - 4;
393 /* build fragmented packet */
396 s->buf[2] = count >> 8;
398 memcpy(s->buf + 4, buf1, len);
399 ff_rtp_send_data(s1, s->buf, len + 4, 0);
405 if (s->buf_ptr == s->buf + 4) {
406 /* no fragmentation possible */
412 memcpy(s->buf_ptr, buf1, size);
417 static void rtp_send_raw(AVFormatContext *s1,
418 const uint8_t *buf1, int size)
420 RTPMuxContext *s = s1->priv_data;
421 int len, max_packet_size;
423 max_packet_size = s->max_payload_size;
426 len = max_packet_size;
430 s->timestamp = s->cur_timestamp;
431 ff_rtp_send_data(s1, buf1, len, (len == size));
438 /* NOTE: size is assumed to be an integer multiple of TS_PACKET_SIZE */
439 static void rtp_send_mpegts_raw(AVFormatContext *s1,
440 const uint8_t *buf1, int size)
442 RTPMuxContext *s = s1->priv_data;
445 while (size >= TS_PACKET_SIZE) {
446 len = s->max_payload_size - (s->buf_ptr - s->buf);
449 memcpy(s->buf_ptr, buf1, len);
454 out_len = s->buf_ptr - s->buf;
455 if (out_len >= s->max_payload_size) {
456 ff_rtp_send_data(s1, s->buf, out_len, 0);
462 static int rtp_send_ilbc(AVFormatContext *s1, const uint8_t *buf, int size)
464 RTPMuxContext *s = s1->priv_data;
465 AVStream *st = s1->streams[0];
466 int frame_duration = av_get_audio_frame_duration(st->codec, 0);
467 int frame_size = st->codec->block_align;
468 int frames = size / frame_size;
471 int n = FFMIN(s->max_frames_per_packet - s->num_frames, frames);
473 if (!s->num_frames) {
475 s->timestamp = s->cur_timestamp;
477 memcpy(s->buf_ptr, buf, n * frame_size);
480 s->buf_ptr += n * frame_size;
481 buf += n * frame_size;
482 s->cur_timestamp += n * frame_duration;
484 if (s->num_frames == s->max_frames_per_packet) {
485 ff_rtp_send_data(s1, s->buf, s->buf_ptr - s->buf, 1);
492 static int rtp_write_packet(AVFormatContext *s1, AVPacket *pkt)
494 RTPMuxContext *s = s1->priv_data;
495 AVStream *st = s1->streams[0];
499 av_dlog(s1, "%d: write len=%d\n", pkt->stream_index, size);
501 rtcp_bytes = ((s->octet_count - s->last_octet_count) * RTCP_TX_RATIO_NUM) /
503 if ((s->first_packet || ((rtcp_bytes >= RTCP_SR_SIZE) &&
504 (ff_ntp_time() - s->last_rtcp_ntp_time > 5000000))) &&
505 !(s->flags & FF_RTP_FLAG_SKIP_RTCP)) {
506 rtcp_send_sr(s1, ff_ntp_time(), 0);
507 s->last_octet_count = s->octet_count;
510 s->cur_timestamp = s->base_timestamp + pkt->pts;
512 switch(st->codec->codec_id) {
513 case AV_CODEC_ID_PCM_MULAW:
514 case AV_CODEC_ID_PCM_ALAW:
515 case AV_CODEC_ID_PCM_U8:
516 case AV_CODEC_ID_PCM_S8:
517 return rtp_send_samples(s1, pkt->data, size, 8 * st->codec->channels);
518 case AV_CODEC_ID_PCM_U16BE:
519 case AV_CODEC_ID_PCM_U16LE:
520 case AV_CODEC_ID_PCM_S16BE:
521 case AV_CODEC_ID_PCM_S16LE:
522 return rtp_send_samples(s1, pkt->data, size, 16 * st->codec->channels);
523 case AV_CODEC_ID_ADPCM_G722:
524 /* The actual sample size is half a byte per sample, but since the
525 * stream clock rate is 8000 Hz while the sample rate is 16000 Hz,
526 * the correct parameter for send_samples_bits is 8 bits per stream
528 return rtp_send_samples(s1, pkt->data, size, 8 * st->codec->channels);
529 case AV_CODEC_ID_ADPCM_G726:
530 return rtp_send_samples(s1, pkt->data, size,
531 st->codec->bits_per_coded_sample * st->codec->channels);
532 case AV_CODEC_ID_MP2:
533 case AV_CODEC_ID_MP3:
534 rtp_send_mpegaudio(s1, pkt->data, size);
536 case AV_CODEC_ID_MPEG1VIDEO:
537 case AV_CODEC_ID_MPEG2VIDEO:
538 ff_rtp_send_mpegvideo(s1, pkt->data, size);
540 case AV_CODEC_ID_AAC:
541 if (s->flags & FF_RTP_FLAG_MP4A_LATM)
542 ff_rtp_send_latm(s1, pkt->data, size);
544 ff_rtp_send_aac(s1, pkt->data, size);
546 case AV_CODEC_ID_AMR_NB:
547 case AV_CODEC_ID_AMR_WB:
548 ff_rtp_send_amr(s1, pkt->data, size);
550 case AV_CODEC_ID_MPEG2TS:
551 rtp_send_mpegts_raw(s1, pkt->data, size);
553 case AV_CODEC_ID_H264:
554 ff_rtp_send_h264(s1, pkt->data, size);
556 case AV_CODEC_ID_H263:
557 if (s->flags & FF_RTP_FLAG_RFC2190) {
558 int mb_info_size = 0;
559 const uint8_t *mb_info =
560 av_packet_get_side_data(pkt, AV_PKT_DATA_H263_MB_INFO,
562 ff_rtp_send_h263_rfc2190(s1, pkt->data, size, mb_info, mb_info_size);
566 case AV_CODEC_ID_H263P:
567 ff_rtp_send_h263(s1, pkt->data, size);
569 case AV_CODEC_ID_VORBIS:
570 case AV_CODEC_ID_THEORA:
571 ff_rtp_send_xiph(s1, pkt->data, size);
573 case AV_CODEC_ID_VP8:
574 ff_rtp_send_vp8(s1, pkt->data, size);
576 case AV_CODEC_ID_ILBC:
577 rtp_send_ilbc(s1, pkt->data, size);
579 case AV_CODEC_ID_MJPEG:
580 ff_rtp_send_jpeg(s1, pkt->data, size);
582 case AV_CODEC_ID_OPUS:
583 if (size > s->max_payload_size) {
584 av_log(s1, AV_LOG_ERROR,
585 "Packet size %d too large for max RTP payload size %d\n",
586 size, s->max_payload_size);
587 return AVERROR(EINVAL);
589 /* Intentional fallthrough */
591 /* better than nothing : send the codec raw data */
592 rtp_send_raw(s1, pkt->data, size);
598 static int rtp_write_trailer(AVFormatContext *s1)
600 RTPMuxContext *s = s1->priv_data;
602 /* If the caller closes and recreates ->pb, this might actually
603 * be NULL here even if it was successfully allocated at the start. */
604 if (s1->pb && (s->flags & FF_RTP_FLAG_SEND_BYE))
605 rtcp_send_sr(s1, ff_ntp_time(), 1);
611 AVOutputFormat ff_rtp_muxer = {
613 .long_name = NULL_IF_CONFIG_SMALL("RTP output"),
614 .priv_data_size = sizeof(RTPMuxContext),
615 .audio_codec = AV_CODEC_ID_PCM_MULAW,
616 .video_codec = AV_CODEC_ID_MPEG4,
617 .write_header = rtp_write_header,
618 .write_packet = rtp_write_packet,
619 .write_trailer = rtp_write_trailer,
620 .priv_class = &rtp_muxer_class,