777 lines
		
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			777 lines
		
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * RTP input format
 | |
|  * Copyright (c) 2002 Fabrice Bellard
 | |
|  *
 | |
|  * This file is part of Libav.
 | |
|  *
 | |
|  * Libav is free software; you can redistribute it and/or
 | |
|  * modify it under the terms of the GNU Lesser General Public
 | |
|  * License as published by the Free Software Foundation; either
 | |
|  * version 2.1 of the License, or (at your option) any later version.
 | |
|  *
 | |
|  * Libav is distributed in the hope that it will be useful,
 | |
|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 | |
|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 | |
|  * Lesser General Public License for more details.
 | |
|  *
 | |
|  * You should have received a copy of the GNU Lesser General Public
 | |
|  * License along with Libav; if not, write to the Free Software
 | |
|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 | |
|  */
 | |
| 
 | |
| #include "libavutil/mathematics.h"
 | |
| #include "libavcodec/get_bits.h"
 | |
| #include "avformat.h"
 | |
| #include "mpegts.h"
 | |
| #include "url.h"
 | |
| 
 | |
| #include <unistd.h>
 | |
| #include <strings.h>
 | |
| #include "network.h"
 | |
| 
 | |
| #include "rtpdec.h"
 | |
| #include "rtpdec_formats.h"
 | |
| 
 | |
| //#define DEBUG
 | |
| 
 | |
| /* TODO: - add RTCP statistics reporting (should be optional).
 | |
| 
 | |
|          - add support for h263/mpeg4 packetized output : IDEA: send a
 | |
|          buffer to 'rtp_write_packet' contains all the packets for ONE
 | |
|          frame. Each packet should have a four byte header containing
 | |
|          the length in big endian format (same trick as
 | |
|          'ffio_open_dyn_packet_buf')
 | |
| */
 | |
| 
 | |
| static RTPDynamicProtocolHandler ff_realmedia_mp3_dynamic_handler = {
 | |
|     .enc_name           = "X-MP3-draft-00",
 | |
|     .codec_type         = AVMEDIA_TYPE_AUDIO,
 | |
|     .codec_id           = CODEC_ID_MP3ADU,
 | |
| };
 | |
| 
 | |
| /* statistics functions */
 | |
| static RTPDynamicProtocolHandler *RTPFirstDynamicPayloadHandler= NULL;
 | |
| 
 | |
| void ff_register_dynamic_payload_handler(RTPDynamicProtocolHandler *handler)
 | |
| {
 | |
|     handler->next= RTPFirstDynamicPayloadHandler;
 | |
|     RTPFirstDynamicPayloadHandler= handler;
 | |
| }
 | |
| 
 | |
| void av_register_rtp_dynamic_payload_handlers(void)
 | |
| {
 | |
|     ff_register_dynamic_payload_handler(&ff_mp4v_es_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_mpeg4_generic_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_amr_nb_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_amr_wb_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_h263_1998_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_h263_2000_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_h264_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_vorbis_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_theora_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_qdm2_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_svq3_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_mp4a_latm_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_vp8_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_qcelp_dynamic_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_realmedia_mp3_dynamic_handler);
 | |
| 
 | |
|     ff_register_dynamic_payload_handler(&ff_ms_rtp_asf_pfv_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_ms_rtp_asf_pfa_handler);
 | |
| 
 | |
|     ff_register_dynamic_payload_handler(&ff_qt_rtp_aud_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_qt_rtp_vid_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_quicktime_rtp_aud_handler);
 | |
|     ff_register_dynamic_payload_handler(&ff_quicktime_rtp_vid_handler);
 | |
| }
 | |
| 
 | |
| RTPDynamicProtocolHandler *ff_rtp_handler_find_by_name(const char *name,
 | |
|                                                   enum AVMediaType codec_type)
 | |
| {
 | |
|     RTPDynamicProtocolHandler *handler;
 | |
|     for (handler = RTPFirstDynamicPayloadHandler;
 | |
|          handler; handler = handler->next)
 | |
|         if (!strcasecmp(name, handler->enc_name) &&
 | |
|             codec_type == handler->codec_type)
 | |
|             return handler;
 | |
|     return NULL;
 | |
| }
 | |
| 
 | |
| RTPDynamicProtocolHandler *ff_rtp_handler_find_by_id(int id,
 | |
|                                                 enum AVMediaType codec_type)
 | |
| {
 | |
|     RTPDynamicProtocolHandler *handler;
 | |
|     for (handler = RTPFirstDynamicPayloadHandler;
 | |
|          handler; handler = handler->next)
 | |
|         if (handler->static_payload_id && handler->static_payload_id == id &&
 | |
|             codec_type == handler->codec_type)
 | |
|             return handler;
 | |
|     return NULL;
 | |
| }
 | |
| 
 | |
| static int rtcp_parse_packet(RTPDemuxContext *s, const unsigned char *buf, int len)
 | |
| {
 | |
|     int payload_len;
 | |
|     while (len >= 2) {
 | |
|         switch (buf[1]) {
 | |
|         case RTCP_SR:
 | |
|             if (len < 16) {
 | |
|                 av_log(NULL, AV_LOG_ERROR, "Invalid length for RTCP SR packet\n");
 | |
|                 return AVERROR_INVALIDDATA;
 | |
|             }
 | |
|             payload_len = (AV_RB16(buf + 2) + 1) * 4;
 | |
| 
 | |
|             s->last_rtcp_ntp_time = AV_RB64(buf + 8);
 | |
|             s->last_rtcp_timestamp = AV_RB32(buf + 16);
 | |
|             if (s->first_rtcp_ntp_time == AV_NOPTS_VALUE) {
 | |
|                 s->first_rtcp_ntp_time = s->last_rtcp_ntp_time;
 | |
|                 if (!s->base_timestamp)
 | |
|                     s->base_timestamp = s->last_rtcp_timestamp;
 | |
|                 s->rtcp_ts_offset = s->last_rtcp_timestamp - s->base_timestamp;
 | |
|             }
 | |
| 
 | |
|             buf += payload_len;
 | |
|             len -= payload_len;
 | |
|             break;
 | |
|         case RTCP_BYE:
 | |
|             return -RTCP_BYE;
 | |
|         default:
 | |
|             return -1;
 | |
|         }
 | |
|     }
 | |
|     return -1;
 | |
| }
 | |
| 
 | |
| #define RTP_SEQ_MOD (1<<16)
 | |
| 
 | |
| /**
 | |
| * called on parse open packet
 | |
| */
 | |
| static void rtp_init_statistics(RTPStatistics *s, uint16_t base_sequence) // called on parse open packet.
 | |
| {
 | |
|     memset(s, 0, sizeof(RTPStatistics));
 | |
|     s->max_seq= base_sequence;
 | |
|     s->probation= 1;
 | |
| }
 | |
| 
 | |
| /**
 | |
| * called whenever there is a large jump in sequence numbers, or when they get out of probation...
 | |
| */
 | |
| static void rtp_init_sequence(RTPStatistics *s, uint16_t seq)
 | |
| {
 | |
|     s->max_seq= seq;
 | |
|     s->cycles= 0;
 | |
|     s->base_seq= seq -1;
 | |
|     s->bad_seq= RTP_SEQ_MOD + 1;
 | |
|     s->received= 0;
 | |
|     s->expected_prior= 0;
 | |
|     s->received_prior= 0;
 | |
|     s->jitter= 0;
 | |
|     s->transit= 0;
 | |
| }
 | |
| 
 | |
| /**
 | |
| * returns 1 if we should handle this packet.
 | |
| */
 | |
| static int rtp_valid_packet_in_sequence(RTPStatistics *s, uint16_t seq)
 | |
| {
 | |
|     uint16_t udelta= seq - s->max_seq;
 | |
|     const int MAX_DROPOUT= 3000;
 | |
|     const int MAX_MISORDER = 100;
 | |
|     const int MIN_SEQUENTIAL = 2;
 | |
| 
 | |
|     /* source not valid until MIN_SEQUENTIAL packets with sequence seq. numbers have been received */
 | |
|     if(s->probation)
 | |
|     {
 | |
|         if(seq==s->max_seq + 1) {
 | |
|             s->probation--;
 | |
|             s->max_seq= seq;
 | |
|             if(s->probation==0) {
 | |
|                 rtp_init_sequence(s, seq);
 | |
|                 s->received++;
 | |
|                 return 1;
 | |
|             }
 | |
|         } else {
 | |
|             s->probation= MIN_SEQUENTIAL - 1;
 | |
|             s->max_seq = seq;
 | |
|         }
 | |
|     } else if (udelta < MAX_DROPOUT) {
 | |
|         // in order, with permissible gap
 | |
|         if(seq < s->max_seq) {
 | |
|             //sequence number wrapped; count antother 64k cycles
 | |
|             s->cycles += RTP_SEQ_MOD;
 | |
|         }
 | |
|         s->max_seq= seq;
 | |
|     } else if (udelta <= RTP_SEQ_MOD - MAX_MISORDER) {
 | |
|         // sequence made a large jump...
 | |
|         if(seq==s->bad_seq) {
 | |
|             // two sequential packets-- assume that the other side restarted without telling us; just resync.
 | |
|             rtp_init_sequence(s, seq);
 | |
|         } else {
 | |
|             s->bad_seq= (seq + 1) & (RTP_SEQ_MOD-1);
 | |
|             return 0;
 | |
|         }
 | |
|     } else {
 | |
|         // duplicate or reordered packet...
 | |
|     }
 | |
|     s->received++;
 | |
|     return 1;
 | |
| }
 | |
| 
 | |
| int rtp_check_and_send_back_rr(RTPDemuxContext *s, int count)
 | |
| {
 | |
|     AVIOContext *pb;
 | |
|     uint8_t *buf;
 | |
|     int len;
 | |
|     int rtcp_bytes;
 | |
|     RTPStatistics *stats= &s->statistics;
 | |
|     uint32_t lost;
 | |
|     uint32_t extended_max;
 | |
|     uint32_t expected_interval;
 | |
|     uint32_t received_interval;
 | |
|     uint32_t lost_interval;
 | |
|     uint32_t expected;
 | |
|     uint32_t fraction;
 | |
|     uint64_t ntp_time= s->last_rtcp_ntp_time; // TODO: Get local ntp time?
 | |
| 
 | |
|     if (!s->rtp_ctx || (count < 1))
 | |
|         return -1;
 | |
| 
 | |
|     /* TODO: I think this is way too often; RFC 1889 has algorithm for this */
 | |
|     /* XXX: mpeg pts hardcoded. RTCP send every 0.5 seconds */
 | |
|     s->octet_count += count;
 | |
|     rtcp_bytes = ((s->octet_count - s->last_octet_count) * RTCP_TX_RATIO_NUM) /
 | |
|         RTCP_TX_RATIO_DEN;
 | |
|     rtcp_bytes /= 50; // mmu_man: that's enough for me... VLC sends much less btw !?
 | |
|     if (rtcp_bytes < 28)
 | |
|         return -1;
 | |
|     s->last_octet_count = s->octet_count;
 | |
| 
 | |
|     if (avio_open_dyn_buf(&pb) < 0)
 | |
|         return -1;
 | |
| 
 | |
|     // Receiver Report
 | |
|     avio_w8(pb, (RTP_VERSION << 6) + 1); /* 1 report block */
 | |
|     avio_w8(pb, RTCP_RR);
 | |
|     avio_wb16(pb, 7); /* length in words - 1 */
 | |
|     // our own SSRC: we use the server's SSRC + 1 to avoid conflicts
 | |
|     avio_wb32(pb, s->ssrc + 1);
 | |
|     avio_wb32(pb, s->ssrc); // server SSRC
 | |
|     // some placeholders we should really fill...
 | |
|     // RFC 1889/p64
 | |
|     extended_max= stats->cycles + stats->max_seq;
 | |
|     expected= extended_max - stats->base_seq + 1;
 | |
|     lost= expected - stats->received;
 | |
|     lost= FFMIN(lost, 0xffffff); // clamp it since it's only 24 bits...
 | |
|     expected_interval= expected - stats->expected_prior;
 | |
|     stats->expected_prior= expected;
 | |
|     received_interval= stats->received - stats->received_prior;
 | |
|     stats->received_prior= stats->received;
 | |
|     lost_interval= expected_interval - received_interval;
 | |
|     if (expected_interval==0 || lost_interval<=0) fraction= 0;
 | |
|     else fraction = (lost_interval<<8)/expected_interval;
 | |
| 
 | |
|     fraction= (fraction<<24) | lost;
 | |
| 
 | |
|     avio_wb32(pb, fraction); /* 8 bits of fraction, 24 bits of total packets lost */
 | |
|     avio_wb32(pb, extended_max); /* max sequence received */
 | |
|     avio_wb32(pb, stats->jitter>>4); /* jitter */
 | |
| 
 | |
|     if(s->last_rtcp_ntp_time==AV_NOPTS_VALUE)
 | |
|     {
 | |
|         avio_wb32(pb, 0); /* last SR timestamp */
 | |
|         avio_wb32(pb, 0); /* delay since last SR */
 | |
|     } else {
 | |
|         uint32_t middle_32_bits= s->last_rtcp_ntp_time>>16; // this is valid, right? do we need to handle 64 bit values special?
 | |
|         uint32_t delay_since_last= ntp_time - s->last_rtcp_ntp_time;
 | |
| 
 | |
|         avio_wb32(pb, middle_32_bits); /* last SR timestamp */
 | |
|         avio_wb32(pb, delay_since_last); /* delay since last SR */
 | |
|     }
 | |
| 
 | |
|     // CNAME
 | |
|     avio_w8(pb, (RTP_VERSION << 6) + 1); /* 1 report block */
 | |
|     avio_w8(pb, RTCP_SDES);
 | |
|     len = strlen(s->hostname);
 | |
|     avio_wb16(pb, (6 + len + 3) / 4); /* length in words - 1 */
 | |
|     avio_wb32(pb, s->ssrc);
 | |
|     avio_w8(pb, 0x01);
 | |
|     avio_w8(pb, len);
 | |
|     avio_write(pb, s->hostname, len);
 | |
|     // padding
 | |
|     for (len = (6 + len) % 4; len % 4; len++) {
 | |
|         avio_w8(pb, 0);
 | |
|     }
 | |
| 
 | |
|     avio_flush(pb);
 | |
|     len = avio_close_dyn_buf(pb, &buf);
 | |
|     if ((len > 0) && buf) {
 | |
|         int av_unused result;
 | |
|         av_dlog(s->ic, "sending %d bytes of RR\n", len);
 | |
|         result= ffurl_write(s->rtp_ctx, buf, len);
 | |
|         av_dlog(s->ic, "result from ffurl_write: %d\n", result);
 | |
|         av_free(buf);
 | |
|     }
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| void rtp_send_punch_packets(URLContext* rtp_handle)
 | |
| {
 | |
|     AVIOContext *pb;
 | |
|     uint8_t *buf;
 | |
|     int len;
 | |
| 
 | |
|     /* Send a small RTP packet */
 | |
|     if (avio_open_dyn_buf(&pb) < 0)
 | |
|         return;
 | |
| 
 | |
|     avio_w8(pb, (RTP_VERSION << 6));
 | |
|     avio_w8(pb, 0); /* Payload type */
 | |
|     avio_wb16(pb, 0); /* Seq */
 | |
|     avio_wb32(pb, 0); /* Timestamp */
 | |
|     avio_wb32(pb, 0); /* SSRC */
 | |
| 
 | |
|     avio_flush(pb);
 | |
|     len = avio_close_dyn_buf(pb, &buf);
 | |
|     if ((len > 0) && buf)
 | |
|         ffurl_write(rtp_handle, buf, len);
 | |
|     av_free(buf);
 | |
| 
 | |
|     /* Send a minimal RTCP RR */
 | |
|     if (avio_open_dyn_buf(&pb) < 0)
 | |
|         return;
 | |
| 
 | |
|     avio_w8(pb, (RTP_VERSION << 6));
 | |
|     avio_w8(pb, RTCP_RR); /* receiver report */
 | |
|     avio_wb16(pb, 1); /* length in words - 1 */
 | |
|     avio_wb32(pb, 0); /* our own SSRC */
 | |
| 
 | |
|     avio_flush(pb);
 | |
|     len = avio_close_dyn_buf(pb, &buf);
 | |
|     if ((len > 0) && buf)
 | |
|         ffurl_write(rtp_handle, buf, len);
 | |
|     av_free(buf);
 | |
| }
 | |
| 
 | |
| 
 | |
| /**
 | |
|  * open a new RTP parse context for stream 'st'. 'st' can be NULL for
 | |
|  * MPEG2TS streams to indicate that they should be demuxed inside the
 | |
|  * rtp demux (otherwise CODEC_ID_MPEG2TS packets are returned)
 | |
|  */
 | |
| RTPDemuxContext *rtp_parse_open(AVFormatContext *s1, AVStream *st, URLContext *rtpc, int payload_type, int queue_size)
 | |
| {
 | |
|     RTPDemuxContext *s;
 | |
| 
 | |
|     s = av_mallocz(sizeof(RTPDemuxContext));
 | |
|     if (!s)
 | |
|         return NULL;
 | |
|     s->payload_type = payload_type;
 | |
|     s->last_rtcp_ntp_time = AV_NOPTS_VALUE;
 | |
|     s->first_rtcp_ntp_time = AV_NOPTS_VALUE;
 | |
|     s->ic = s1;
 | |
|     s->st = st;
 | |
|     s->queue_size = queue_size;
 | |
|     rtp_init_statistics(&s->statistics, 0); // do we know the initial sequence from sdp?
 | |
|     if (!strcmp(ff_rtp_enc_name(payload_type), "MP2T")) {
 | |
|         s->ts = ff_mpegts_parse_open(s->ic);
 | |
|         if (s->ts == NULL) {
 | |
|             av_free(s);
 | |
|             return NULL;
 | |
|         }
 | |
|     } else {
 | |
|         switch(st->codec->codec_id) {
 | |
|         case CODEC_ID_MPEG1VIDEO:
 | |
|         case CODEC_ID_MPEG2VIDEO:
 | |
|         case CODEC_ID_MP2:
 | |
|         case CODEC_ID_MP3:
 | |
|         case CODEC_ID_MPEG4:
 | |
|         case CODEC_ID_H263:
 | |
|         case CODEC_ID_H264:
 | |
|             st->need_parsing = AVSTREAM_PARSE_FULL;
 | |
|             break;
 | |
|         case CODEC_ID_ADPCM_G722:
 | |
|             /* According to RFC 3551, the stream clock rate is 8000
 | |
|              * even if the sample rate is 16000. */
 | |
|             if (st->codec->sample_rate == 8000)
 | |
|                 st->codec->sample_rate = 16000;
 | |
|             break;
 | |
|         default:
 | |
|             break;
 | |
|         }
 | |
|     }
 | |
|     // needed to send back RTCP RR in RTSP sessions
 | |
|     s->rtp_ctx = rtpc;
 | |
|     gethostname(s->hostname, sizeof(s->hostname));
 | |
|     return s;
 | |
| }
 | |
| 
 | |
| void
 | |
| rtp_parse_set_dynamic_protocol(RTPDemuxContext *s, PayloadContext *ctx,
 | |
|                                RTPDynamicProtocolHandler *handler)
 | |
| {
 | |
|     s->dynamic_protocol_context = ctx;
 | |
|     s->parse_packet = handler->parse_packet;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * This was the second switch in rtp_parse packet.  Normalizes time, if required, sets stream_index, etc.
 | |
|  */
 | |
| static void finalize_packet(RTPDemuxContext *s, AVPacket *pkt, uint32_t timestamp)
 | |
| {
 | |
|     if (pkt->pts != AV_NOPTS_VALUE || pkt->dts != AV_NOPTS_VALUE)
 | |
|         return; /* Timestamp already set by depacketizer */
 | |
|     if (s->last_rtcp_ntp_time != AV_NOPTS_VALUE && timestamp != RTP_NOTS_VALUE) {
 | |
|         int64_t addend;
 | |
|         int delta_timestamp;
 | |
| 
 | |
|         /* compute pts from timestamp with received ntp_time */
 | |
|         delta_timestamp = timestamp - s->last_rtcp_timestamp;
 | |
|         /* convert to the PTS timebase */
 | |
|         addend = av_rescale(s->last_rtcp_ntp_time - s->first_rtcp_ntp_time, s->st->time_base.den, (uint64_t)s->st->time_base.num << 32);
 | |
|         pkt->pts = s->range_start_offset + s->rtcp_ts_offset + addend +
 | |
|                    delta_timestamp;
 | |
|         return;
 | |
|     }
 | |
|     if (timestamp == RTP_NOTS_VALUE)
 | |
|         return;
 | |
|     if (!s->base_timestamp)
 | |
|         s->base_timestamp = timestamp;
 | |
|     pkt->pts = s->range_start_offset + timestamp - s->base_timestamp;
 | |
| }
 | |
| 
 | |
| static int rtp_parse_packet_internal(RTPDemuxContext *s, AVPacket *pkt,
 | |
|                                      const uint8_t *buf, int len)
 | |
| {
 | |
|     unsigned int ssrc, h;
 | |
|     int payload_type, seq, ret, flags = 0;
 | |
|     int ext;
 | |
|     AVStream *st;
 | |
|     uint32_t timestamp;
 | |
|     int rv= 0;
 | |
| 
 | |
|     ext = buf[0] & 0x10;
 | |
|     payload_type = buf[1] & 0x7f;
 | |
|     if (buf[1] & 0x80)
 | |
|         flags |= RTP_FLAG_MARKER;
 | |
|     seq  = AV_RB16(buf + 2);
 | |
|     timestamp = AV_RB32(buf + 4);
 | |
|     ssrc = AV_RB32(buf + 8);
 | |
|     /* store the ssrc in the RTPDemuxContext */
 | |
|     s->ssrc = ssrc;
 | |
| 
 | |
|     /* NOTE: we can handle only one payload type */
 | |
|     if (s->payload_type != payload_type)
 | |
|         return -1;
 | |
| 
 | |
|     st = s->st;
 | |
|     // only do something with this if all the rtp checks pass...
 | |
|     if(!rtp_valid_packet_in_sequence(&s->statistics, seq))
 | |
|     {
 | |
|         av_log(st?st->codec:NULL, AV_LOG_ERROR, "RTP: PT=%02x: bad cseq %04x expected=%04x\n",
 | |
|                payload_type, seq, ((s->seq + 1) & 0xffff));
 | |
|         return -1;
 | |
|     }
 | |
| 
 | |
|     if (buf[0] & 0x20) {
 | |
|         int padding = buf[len - 1];
 | |
|         if (len >= 12 + padding)
 | |
|             len -= padding;
 | |
|     }
 | |
| 
 | |
|     s->seq = seq;
 | |
|     len -= 12;
 | |
|     buf += 12;
 | |
| 
 | |
|     /* RFC 3550 Section 5.3.1 RTP Header Extension handling */
 | |
|     if (ext) {
 | |
|         if (len < 4)
 | |
|             return -1;
 | |
|         /* calculate the header extension length (stored as number
 | |
|          * of 32-bit words) */
 | |
|         ext = (AV_RB16(buf + 2) + 1) << 2;
 | |
| 
 | |
|         if (len < ext)
 | |
|             return -1;
 | |
|         // skip past RTP header extension
 | |
|         len -= ext;
 | |
|         buf += ext;
 | |
|     }
 | |
| 
 | |
|     if (!st) {
 | |
|         /* specific MPEG2TS demux support */
 | |
|         ret = ff_mpegts_parse_packet(s->ts, pkt, buf, len);
 | |
|         /* The only error that can be returned from ff_mpegts_parse_packet
 | |
|          * is "no more data to return from the provided buffer", so return
 | |
|          * AVERROR(EAGAIN) for all errors */
 | |
|         if (ret < 0)
 | |
|             return AVERROR(EAGAIN);
 | |
|         if (ret < len) {
 | |
|             s->read_buf_size = len - ret;
 | |
|             memcpy(s->buf, buf + ret, s->read_buf_size);
 | |
|             s->read_buf_index = 0;
 | |
|             return 1;
 | |
|         }
 | |
|         return 0;
 | |
|     } else if (s->parse_packet) {
 | |
|         rv = s->parse_packet(s->ic, s->dynamic_protocol_context,
 | |
|                              s->st, pkt, ×tamp, buf, len, flags);
 | |
|     } else {
 | |
|         // at this point, the RTP header has been stripped;  This is ASSUMING that there is only 1 CSRC, which in't wise.
 | |
|         switch(st->codec->codec_id) {
 | |
|         case CODEC_ID_MP2:
 | |
|         case CODEC_ID_MP3:
 | |
|             /* better than nothing: skip mpeg audio RTP header */
 | |
|             if (len <= 4)
 | |
|                 return -1;
 | |
|             h = AV_RB32(buf);
 | |
|             len -= 4;
 | |
|             buf += 4;
 | |
|             av_new_packet(pkt, len);
 | |
|             memcpy(pkt->data, buf, len);
 | |
|             break;
 | |
|         case CODEC_ID_MPEG1VIDEO:
 | |
|         case CODEC_ID_MPEG2VIDEO:
 | |
|             /* better than nothing: skip mpeg video RTP header */
 | |
|             if (len <= 4)
 | |
|                 return -1;
 | |
|             h = AV_RB32(buf);
 | |
|             buf += 4;
 | |
|             len -= 4;
 | |
|             if (h & (1 << 26)) {
 | |
|                 /* mpeg2 */
 | |
|                 if (len <= 4)
 | |
|                     return -1;
 | |
|                 buf += 4;
 | |
|                 len -= 4;
 | |
|             }
 | |
|             av_new_packet(pkt, len);
 | |
|             memcpy(pkt->data, buf, len);
 | |
|             break;
 | |
|         default:
 | |
|             av_new_packet(pkt, len);
 | |
|             memcpy(pkt->data, buf, len);
 | |
|             break;
 | |
|         }
 | |
| 
 | |
|         pkt->stream_index = st->index;
 | |
|     }
 | |
| 
 | |
|     // now perform timestamp things....
 | |
|     finalize_packet(s, pkt, timestamp);
 | |
| 
 | |
|     return rv;
 | |
| }
 | |
| 
 | |
| void ff_rtp_reset_packet_queue(RTPDemuxContext *s)
 | |
| {
 | |
|     while (s->queue) {
 | |
|         RTPPacket *next = s->queue->next;
 | |
|         av_free(s->queue->buf);
 | |
|         av_free(s->queue);
 | |
|         s->queue = next;
 | |
|     }
 | |
|     s->seq       = 0;
 | |
|     s->queue_len = 0;
 | |
|     s->prev_ret  = 0;
 | |
| }
 | |
| 
 | |
| static void enqueue_packet(RTPDemuxContext *s, uint8_t *buf, int len)
 | |
| {
 | |
|     uint16_t seq = AV_RB16(buf + 2);
 | |
|     RTPPacket *cur = s->queue, *prev = NULL, *packet;
 | |
| 
 | |
|     /* Find the correct place in the queue to insert the packet */
 | |
|     while (cur) {
 | |
|         int16_t diff = seq - cur->seq;
 | |
|         if (diff < 0)
 | |
|             break;
 | |
|         prev = cur;
 | |
|         cur = cur->next;
 | |
|     }
 | |
| 
 | |
|     packet = av_mallocz(sizeof(*packet));
 | |
|     if (!packet)
 | |
|         return;
 | |
|     packet->recvtime = av_gettime();
 | |
|     packet->seq = seq;
 | |
|     packet->len = len;
 | |
|     packet->buf = buf;
 | |
|     packet->next = cur;
 | |
|     if (prev)
 | |
|         prev->next = packet;
 | |
|     else
 | |
|         s->queue = packet;
 | |
|     s->queue_len++;
 | |
| }
 | |
| 
 | |
| static int has_next_packet(RTPDemuxContext *s)
 | |
| {
 | |
|     return s->queue && s->queue->seq == (uint16_t) (s->seq + 1);
 | |
| }
 | |
| 
 | |
| int64_t ff_rtp_queued_packet_time(RTPDemuxContext *s)
 | |
| {
 | |
|     return s->queue ? s->queue->recvtime : 0;
 | |
| }
 | |
| 
 | |
| static int rtp_parse_queued_packet(RTPDemuxContext *s, AVPacket *pkt)
 | |
| {
 | |
|     int rv;
 | |
|     RTPPacket *next;
 | |
| 
 | |
|     if (s->queue_len <= 0)
 | |
|         return -1;
 | |
| 
 | |
|     if (!has_next_packet(s))
 | |
|         av_log(s->st ? s->st->codec : NULL, AV_LOG_WARNING,
 | |
|                "RTP: missed %d packets\n", s->queue->seq - s->seq - 1);
 | |
| 
 | |
|     /* Parse the first packet in the queue, and dequeue it */
 | |
|     rv = rtp_parse_packet_internal(s, pkt, s->queue->buf, s->queue->len);
 | |
|     next = s->queue->next;
 | |
|     av_free(s->queue->buf);
 | |
|     av_free(s->queue);
 | |
|     s->queue = next;
 | |
|     s->queue_len--;
 | |
|     return rv;
 | |
| }
 | |
| 
 | |
| static int rtp_parse_one_packet(RTPDemuxContext *s, AVPacket *pkt,
 | |
|                      uint8_t **bufptr, int len)
 | |
| {
 | |
|     uint8_t* buf = bufptr ? *bufptr : NULL;
 | |
|     int ret, flags = 0;
 | |
|     uint32_t timestamp;
 | |
|     int rv= 0;
 | |
| 
 | |
|     if (!buf) {
 | |
|         /* If parsing of the previous packet actually returned 0 or an error,
 | |
|          * there's nothing more to be parsed from that packet, but we may have
 | |
|          * indicated that we can return the next enqueued packet. */
 | |
|         if (s->prev_ret <= 0)
 | |
|             return rtp_parse_queued_packet(s, pkt);
 | |
|         /* return the next packets, if any */
 | |
|         if(s->st && s->parse_packet) {
 | |
|             /* timestamp should be overwritten by parse_packet, if not,
 | |
|              * the packet is left with pts == AV_NOPTS_VALUE */
 | |
|             timestamp = RTP_NOTS_VALUE;
 | |
|             rv= s->parse_packet(s->ic, s->dynamic_protocol_context,
 | |
|                                 s->st, pkt, ×tamp, NULL, 0, flags);
 | |
|             finalize_packet(s, pkt, timestamp);
 | |
|             return rv;
 | |
|         } else {
 | |
|             // TODO: Move to a dynamic packet handler (like above)
 | |
|             if (s->read_buf_index >= s->read_buf_size)
 | |
|                 return AVERROR(EAGAIN);
 | |
|             ret = ff_mpegts_parse_packet(s->ts, pkt, s->buf + s->read_buf_index,
 | |
|                                       s->read_buf_size - s->read_buf_index);
 | |
|             if (ret < 0)
 | |
|                 return AVERROR(EAGAIN);
 | |
|             s->read_buf_index += ret;
 | |
|             if (s->read_buf_index < s->read_buf_size)
 | |
|                 return 1;
 | |
|             else
 | |
|                 return 0;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     if (len < 12)
 | |
|         return -1;
 | |
| 
 | |
|     if ((buf[0] & 0xc0) != (RTP_VERSION << 6))
 | |
|         return -1;
 | |
|     if (buf[1] >= RTCP_SR && buf[1] <= RTCP_APP) {
 | |
|         return rtcp_parse_packet(s, buf, len);
 | |
|     }
 | |
| 
 | |
|     if ((s->seq == 0 && !s->queue) || s->queue_size <= 1) {
 | |
|         /* First packet, or no reordering */
 | |
|         return rtp_parse_packet_internal(s, pkt, buf, len);
 | |
|     } else {
 | |
|         uint16_t seq = AV_RB16(buf + 2);
 | |
|         int16_t diff = seq - s->seq;
 | |
|         if (diff < 0) {
 | |
|             /* Packet older than the previously emitted one, drop */
 | |
|             av_log(s->st ? s->st->codec : NULL, AV_LOG_WARNING,
 | |
|                    "RTP: dropping old packet received too late\n");
 | |
|             return -1;
 | |
|         } else if (diff <= 1) {
 | |
|             /* Correct packet */
 | |
|             rv = rtp_parse_packet_internal(s, pkt, buf, len);
 | |
|             return rv;
 | |
|         } else {
 | |
|             /* Still missing some packet, enqueue this one. */
 | |
|             enqueue_packet(s, buf, len);
 | |
|             *bufptr = NULL;
 | |
|             /* Return the first enqueued packet if the queue is full,
 | |
|              * even if we're missing something */
 | |
|             if (s->queue_len >= s->queue_size)
 | |
|                 return rtp_parse_queued_packet(s, pkt);
 | |
|             return -1;
 | |
|         }
 | |
|     }
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * Parse an RTP or RTCP packet directly sent as a buffer.
 | |
|  * @param s RTP parse context.
 | |
|  * @param pkt returned packet
 | |
|  * @param bufptr pointer to the input buffer or NULL to read the next packets
 | |
|  * @param len buffer len
 | |
|  * @return 0 if a packet is returned, 1 if a packet is returned and more can follow
 | |
|  * (use buf as NULL to read the next). -1 if no packet (error or no more packet).
 | |
|  */
 | |
| int rtp_parse_packet(RTPDemuxContext *s, AVPacket *pkt,
 | |
|                      uint8_t **bufptr, int len)
 | |
| {
 | |
|     int rv = rtp_parse_one_packet(s, pkt, bufptr, len);
 | |
|     s->prev_ret = rv;
 | |
|     while (rv == AVERROR(EAGAIN) && has_next_packet(s))
 | |
|         rv = rtp_parse_queued_packet(s, pkt);
 | |
|     return rv ? rv : has_next_packet(s);
 | |
| }
 | |
| 
 | |
| void rtp_parse_close(RTPDemuxContext *s)
 | |
| {
 | |
|     ff_rtp_reset_packet_queue(s);
 | |
|     if (!strcmp(ff_rtp_enc_name(s->payload_type), "MP2T")) {
 | |
|         ff_mpegts_parse_close(s->ts);
 | |
|     }
 | |
|     av_free(s);
 | |
| }
 | |
| 
 | |
| int ff_parse_fmtp(AVStream *stream, PayloadContext *data, const char *p,
 | |
|                   int (*parse_fmtp)(AVStream *stream,
 | |
|                                     PayloadContext *data,
 | |
|                                     char *attr, char *value))
 | |
| {
 | |
|     char attr[256];
 | |
|     char *value;
 | |
|     int res;
 | |
|     int value_size = strlen(p) + 1;
 | |
| 
 | |
|     if (!(value = av_malloc(value_size))) {
 | |
|         av_log(stream, AV_LOG_ERROR, "Failed to allocate data for FMTP.");
 | |
|         return AVERROR(ENOMEM);
 | |
|     }
 | |
| 
 | |
|     // remove protocol identifier
 | |
|     while (*p && *p == ' ') p++; // strip spaces
 | |
|     while (*p && *p != ' ') p++; // eat protocol identifier
 | |
|     while (*p && *p == ' ') p++; // strip trailing spaces
 | |
| 
 | |
|     while (ff_rtsp_next_attr_and_value(&p,
 | |
|                                        attr, sizeof(attr),
 | |
|                                        value, value_size)) {
 | |
| 
 | |
|         res = parse_fmtp(stream, data, attr, value);
 | |
|         if (res < 0 && res != AVERROR_PATCHWELCOME) {
 | |
|             av_free(value);
 | |
|             return res;
 | |
|         }
 | |
|     }
 | |
|     av_free(value);
 | |
|     return 0;
 | |
| }
 |