mirror of
https://gitlab.freedesktop.org/pulseaudio/pulseaudio.git
synced 2025-11-03 09:01:50 -05:00
raop: Packet retransmission support for UDP
This patch adds an RTP audio packet retransmission support and a circular buffer implementation for it. This patch was originally written by Matthias Wabersich [1] and later debugged and integrated into the latest tree by Hajime Fujita [1]: https://bugs.freedesktop.org/show_bug.cgi?id=42804#c44
This commit is contained in:
Matthias Wabersich
Tanu Kaskinen
parent
402bb7ce48
commit
29385da239
5 changed files with 316 additions and 12 deletions
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@ -1155,7 +1155,8 @@ librtp_la_LIBADD = $(AM_LIBADD) libpulsecore-@PA_MAJORMINOR@.la libpulsecommon-@
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libraop_la_SOURCES = \
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modules/raop/raop_client.c modules/raop/raop_client.h \
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modules/raop/base64.c modules/raop/base64.h
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modules/raop/base64.c modules/raop/base64.h \
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modules/raop/raop_packet_buffer.h modules/raop/raop_packet_buffer.c
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libraop_la_CFLAGS = $(AM_CFLAGS) $(OPENSSL_CFLAGS) -I$(top_srcdir)/src/modules/rtp
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libraop_la_LDFLAGS = $(AM_LDFLAGS) $(AM_LIBLDFLAGS) -avoid-version
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libraop_la_LIBADD = $(AM_LIBADD) $(OPENSSL_LIBS) libpulsecore-@PA_MAJORMINOR@.la librtp.la libpulsecommon-@PA_MAJORMINOR@.la libpulse.la
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@ -59,7 +59,8 @@
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#include "rtsp_client.h"
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#include "base64.h"
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#define UDP_FRAMES_PER_PACKET 352
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#include "raop_packet_buffer.h"
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#define AES_CHUNKSIZE 16
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#define JACK_STATUS_DISCONNECTED 0
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@ -77,6 +78,8 @@
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#define UDP_DEFAULT_CONTROL_PORT 6001
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#define UDP_DEFAULT_TIMING_PORT 6002
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#define UDP_DEFAULT_PKT_BUF_SIZE 1000
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typedef enum {
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UDP_PAYLOAD_TIMING_REQUEST = 0x52,
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UDP_PAYLOAD_TIMING_RESPONSE = 0x53,
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@ -155,6 +158,8 @@ struct pa_raop_client {
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pa_raop_client_disconnected_cb_t udp_disconnected_callback;
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void *udp_disconnected_userdata;
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pa_raop_packet_buffer *packet_buffer;
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};
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/* Timming packet header (8x8):
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@ -548,12 +553,35 @@ static void udp_build_audio_header(pa_raop_client *c, uint32_t *buffer, size_t s
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buffer[2] = htonl(c->udp_ssrc);
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}
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static ssize_t udp_send_audio_packet(pa_raop_client *c, uint8_t *buffer, size_t size) {
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/* Audio retransmission header:
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* [0] RTP v2: 0x80
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* [1] Payload type: 0x56 + 0x80 (marker == on)
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* [2] Unknown; seems always 0x01
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* [3] Unknown; seems some random number around 0x20~0x40
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* [4,5] Original RTP header htons(0x8060)
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* [6,7] Packet sequence number to be retransmitted
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* [8,11] Original RTP timestamp on the lost packet */
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static void udp_build_retrans_header(uint32_t *buffer, size_t size, uint16_t seq_num) {
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uint8_t x = 0x30; /* FIXME: what's this?? */
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pa_assert(size >= sizeof(uint32_t) * 2);
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buffer[0] = htonl((uint32_t) 0x80000000
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| ((uint32_t) UDP_PAYLOAD_RETRANSMIT_REPLY | 0x80) << 16
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| 0x0100
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| x);
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buffer[1] = htonl((uint32_t) 0x80600000 | seq_num);
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}
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static ssize_t udp_send_audio_packet(pa_raop_client *c, bool retrans, uint8_t *buffer, size_t size) {
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ssize_t length;
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int fd = retrans ? c->udp_control_fd : c->udp_stream_fd;
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length = pa_write(c->udp_stream_fd, buffer, size, NULL);
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c->seq++;
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length = pa_write(fd, buffer, size, NULL);
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if (length < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
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pa_log_debug("Discarding audio packet %d due to EAGAIN", c->seq);
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length = size;
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}
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return length;
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}
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@ -965,6 +993,8 @@ static void udp_rtsp_cb(pa_rtsp_client *rtsp, pa_rtsp_state state, pa_headerlist
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pa_log_debug("RTSP control channel closed (teardown)");
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pa_raop_pb_clear(c->packet_buffer);
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pa_rtsp_client_free(c->rtsp);
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pa_xfree(c->sid);
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c->rtsp = NULL;
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@ -1001,6 +1031,8 @@ static void udp_rtsp_cb(pa_rtsp_client *rtsp, pa_rtsp_state state, pa_headerlist
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pa_log_debug("RTSP control channel closed (disconnected)");
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pa_raop_pb_clear(c->packet_buffer);
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pa_rtsp_client_free(c->rtsp);
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pa_xfree(c->sid);
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c->rtsp = NULL;
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@ -1064,7 +1096,8 @@ pa_raop_client* pa_raop_client_new(pa_core *core, const char *host, pa_raop_prot
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pa_raop_client_free(c);
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return NULL;
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}
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}
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} else
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c->packet_buffer = pa_raop_pb_new(UDP_DEFAULT_PKT_BUF_SIZE);
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return c;
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}
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@ -1072,6 +1105,7 @@ pa_raop_client* pa_raop_client_new(pa_core *core, const char *host, pa_raop_prot
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void pa_raop_client_free(pa_raop_client *c) {
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pa_assert(c);
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pa_raop_pb_delete(c->packet_buffer);
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if (c->rtsp)
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pa_rtsp_client_free(c->rtsp);
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if (c->sid)
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@ -1188,14 +1222,48 @@ int pa_raop_client_udp_handle_timing_packet(pa_raop_client *c, const uint8_t pac
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return rv;
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}
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static int udp_resend_packets(pa_raop_client *c, uint16_t seq_num, uint16_t num_packets) {
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int rv = -1;
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uint8_t *data = NULL;
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ssize_t len = 0;
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int i = 0;
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pa_assert(c);
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pa_assert(num_packets > 0);
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pa_assert(c->packet_buffer);
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for (i = seq_num; i < seq_num + num_packets; i++) {
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len = pa_raop_pb_read_packet(c->packet_buffer, i, (uint8_t **) &data);
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if (len > 0) {
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ssize_t r;
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/* Obtained buffer has a header room for retransmission
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header */
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udp_build_retrans_header((uint32_t *) data, len, seq_num);
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r = udp_send_audio_packet(c, true /* retrans */, data, len);
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if (r == len)
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rv = 0;
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else
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rv = -1;
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} else
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pa_log_debug("Packet not found in retrans buffer: %u", i);
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}
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return rv;
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}
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int pa_raop_client_udp_handle_control_packet(pa_raop_client *c, const uint8_t packet[], ssize_t size) {
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uint8_t payload = 0;
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int rv = 0;
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uint16_t seq_num;
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uint16_t num_packets;
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pa_assert(c);
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pa_assert(packet);
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if (size != 20 || packet[0] != 0x80)
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if ((size != 20 && size != 8) || packet[0] != 0x80)
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{
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pa_log_debug("Received an invalid control packet.");
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return 1;
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@ -1206,12 +1274,24 @@ int pa_raop_client_udp_handle_control_packet(pa_raop_client *c, const uint8_t pa
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payload = packet[1] ^ 0x80;
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switch (payload) {
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case UDP_PAYLOAD_RETRANSMIT_REQUEST:
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/* Packet retransmission not implemented yet... */
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/* rv = ... */
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pa_assert(size == 8);
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/* Requested start sequence number */
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seq_num = ((uint16_t) packet[4]) << 8;
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seq_num |= (uint16_t) packet[5];
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/* Number of requested packets starting at requested seq. number */
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num_packets = (uint16_t) packet[6] << 8;
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num_packets |= (uint16_t) packet[7];
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pa_log_debug("Resending %d packets starting at %d", num_packets, seq_num);
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rv = udp_resend_packets(c, seq_num, num_packets);
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break;
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case UDP_PAYLOAD_RETRANSMIT_REPLY:
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pa_log_debug("Received a retransmit reply packet on control port (this should never happen)");
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break;
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default:
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pa_log_debug("Got an unexpected payload type on control channel !");
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pa_log_debug("Got an unexpected payload type on control channel: %u !", payload);
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return 1;
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}
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@ -1248,7 +1328,14 @@ ssize_t pa_raop_client_udp_send_audio_packet(pa_raop_client *c, pa_memchunk *blo
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pa_assert(buf);
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pa_assert(block->length > 0);
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udp_build_audio_header(c, (uint32_t *) (buf + block->index), block->length);
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len = udp_send_audio_packet(c, buf + block->index, block->length);
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len = udp_send_audio_packet(c, false, buf + block->index, block->length);
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/* Store packet for resending in the packet buffer */
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pa_raop_pb_write_packet(c->packet_buffer, c->seq, buf + block->index,
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block->length);
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c->seq++;
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pa_memblock_release(block->memblock);
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if (len > 0) {
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@ -25,6 +25,8 @@
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#include <pulsecore/core.h>
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#include <pulsecore/memchunk.h>
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#define UDP_FRAMES_PER_PACKET 352
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typedef enum pa_raop_protocol {
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RAOP_TCP,
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RAOP_UDP,
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172
src/modules/raop/raop_packet_buffer.c
Normal file
172
src/modules/raop/raop_packet_buffer.c
Normal file
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@ -0,0 +1,172 @@
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/***
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Circular buffer for RTP audio packets with random access support
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by RTP sequence number.
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Copyright 2013 Matthias Wabersich, Hajime Fujita
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This is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published
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by the Free Software Foundation; either version 2.1 of the License,
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or (at your option) any later version.
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This is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with PulseAudio; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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USA.
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***/
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#include <stdlib.h>
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#include <limits.h>
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include <pulsecore/core-error.h>
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#include "raop_client.h"
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#include "raop_packet_buffer.h"
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/* FRAMES_PER_PACKET*2*2 + sizeof(udp_audio_header) + sizeof(ALAC header), unencoded */
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#define PACKET_SIZE_MAX (UDP_FRAMES_PER_PACKET*2*2 + 12 + 7)
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/* Header room for packet retransmission header */
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#define RETRANS_HEADER_ROOM 4
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/* Packet element */
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struct pa_raop_packet_element {
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uint16_t seq_num; /* RTP sequence number (in host byte order) */
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ssize_t length; /* Actual packet length */
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/* Packet data including RTP header */
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uint8_t data[PACKET_SIZE_MAX + RETRANS_HEADER_ROOM];
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};
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/* Buffer struct */
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struct pa_raop_packet_buffer {
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size_t size; /* max number of packets in buffer */
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size_t start; /* index of oldest packet */
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size_t count; /* number of packets in buffer */
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uint16_t first_seq_num; /* Sequence number of first packet in buffer */
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uint16_t latest_seq_num; /* Debug purpose */
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pa_raop_packet_element *packets; /* Packet element pointer */
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};
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pa_raop_packet_buffer *pa_raop_pb_new(size_t size) {
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pa_raop_packet_buffer *pb = pa_xmalloc0(sizeof(*pb));
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pb->size = size;
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pb->packets = (pa_raop_packet_element *)
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pa_xmalloc(size * sizeof(pa_raop_packet_element));
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pa_raop_pb_clear(pb);
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return pb;
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}
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void pa_raop_pb_clear(pa_raop_packet_buffer *pb) {
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pb->start = 0;
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pb->count = 0;
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pb->first_seq_num = 0;
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pb->latest_seq_num = 0;
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memset(pb->packets, 0, pb->size * sizeof(pa_raop_packet_element));
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}
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void pa_raop_pb_delete(pa_raop_packet_buffer *pb) {
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pa_xfree(pb->packets);
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pa_xfree(pb);
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}
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static int pb_is_full(pa_raop_packet_buffer *pb) {
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return pb->count == pb->size;
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}
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static int pb_is_empty(pa_raop_packet_buffer *pb) {
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return pb->count == 0;
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}
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static pa_raop_packet_element *pb_prepare_write(pa_raop_packet_buffer *pb, uint16_t seq) {
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size_t end = (pb->start + pb->count) % pb->size;
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pa_raop_packet_element *packet;
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/* Set first packet sequence number in buffer if buffer is empty */
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if (pb_is_empty(pb))
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pb->first_seq_num = seq;
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else
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pa_assert((uint16_t) (pb->latest_seq_num + 1) == seq);
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packet = &pb->packets[end];
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if (pb_is_full(pb)) {
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pb->start = (pb->start + 1) % pb->size; /* full, overwrite */
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/* Set first packet sequence number in buffer
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to new start packet sequence number */
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pb->first_seq_num = pb->packets[pb->start].seq_num;
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} else
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++ pb->count;
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pb->latest_seq_num = seq;
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return packet;
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}
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/* Write packet data to packet buffer */
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void pa_raop_pb_write_packet(pa_raop_packet_buffer *pb, uint16_t seq_num, const uint8_t *packet_data, ssize_t packet_length) {
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pa_raop_packet_element *packet;
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pa_assert(pb);
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pa_assert(packet_data);
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pa_assert(packet_length <= PACKET_SIZE_MAX);
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packet = pb_prepare_write(pb, seq_num);
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packet->seq_num = seq_num;
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packet->length = packet_length + RETRANS_HEADER_ROOM;
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/* Insert RETRANS_HEADER_ROOM bytes in front of packet data,
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for retransmission header */
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memset(packet->data, 0, RETRANS_HEADER_ROOM);
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memcpy(packet->data + RETRANS_HEADER_ROOM, packet_data, packet_length);
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}
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/* l < r?, considers wrapping */
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static bool seq_lt(uint16_t l, uint16_t r) {
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return l - r > USHRT_MAX/2;
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}
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/* Random access to packet from buffer by sequence number for (re-)sending. */
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ssize_t pa_raop_pb_read_packet(pa_raop_packet_buffer *pb, uint16_t seq_num, uint8_t **packet_data) {
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uint16_t index = 0; /* Index of requested packet */
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pa_raop_packet_element *packet;
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/* If the buffer is empty, there is no use in calculating indices */
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if (pb_is_empty(pb))
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return -1;
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/* If the requested packet is too old (seq_num below first seq number
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in buffer) or too young (seq_num greater than current seq number),
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do nothing and return */
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if (seq_lt(seq_num, pb->first_seq_num))
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return -1;
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index = (uint16_t) (seq_num - pb->first_seq_num);
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if (index >= pb->count)
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return -1;
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/* Index of the requested packet in the buffer is calculated
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using the first sequence number stored in the buffer.
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The offset (seq_num - first_seq_num) is used to access the array. */
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packet = &pb->packets[(pb->start + index) % pb->size];
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pa_assert(packet->data[RETRANS_HEADER_ROOM + 2] == (seq_num >> 8));
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pa_assert(packet->data[RETRANS_HEADER_ROOM + 3] == (seq_num & 0xff));
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pa_assert(packet_data);
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*packet_data = packet->data;
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return packet->length;
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}
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42
src/modules/raop/raop_packet_buffer.h
Normal file
42
src/modules/raop/raop_packet_buffer.h
Normal file
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@ -0,0 +1,42 @@
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#ifndef RAOP_PACKET_BUFFER_H_INCLUDED
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#define RAOP_PACKET_BUFFER_H_INCLUDED
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/***
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Circular buffer for RTP audio packets with random access support
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by RTP sequence number.
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Copyright 2013 Matthias Wabersich, Hajime Fujita
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This is free software; you can redistribute it and/or modify
|
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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,
|
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or (at your option) any later version.
|
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|
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This is distributed in the hope that it will be useful, but
|
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WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
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General Public License for more details.
|
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|
||||
You should have received a copy of the GNU Lesser General Public License
|
||||
along with PulseAudio; if not, write to the Free Software
|
||||
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
|
||||
USA.
|
||||
|
||||
***/
|
||||
|
||||
struct pa_raop_packet_element;
|
||||
typedef struct pa_raop_packet_element pa_raop_packet_element;
|
||||
|
||||
struct pa_raop_packet_buffer;
|
||||
typedef struct pa_raop_packet_buffer pa_raop_packet_buffer;
|
||||
|
||||
/* Allocates a new circular packet buffer
|
||||
size: Maximum number of packets to store */
|
||||
pa_raop_packet_buffer *pa_raop_pb_new(size_t size);
|
||||
void pa_raop_pb_clear(pa_raop_packet_buffer *pb);
|
||||
void pa_raop_pb_delete(pa_raop_packet_buffer *pb);
|
||||
|
||||
void pa_raop_pb_write_packet(pa_raop_packet_buffer *pb, uint16_t seq_num, const uint8_t *packet_data, ssize_t packet_length);
|
||||
ssize_t pa_raop_pb_read_packet(pa_raop_packet_buffer *pb, uint16_t seq_num, uint8_t **packet_data);
|
||||
|
||||
#endif /* RAOP_PACKET_BUFFER_H_INCLUDED */
|
||||
Loading…
Add table
Add a link
Reference in a new issue