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cleanup in raop_rtp.c for unusual control and data packets

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This commit is contained in:
fduncanh
2022-06-11 04:00:25 -04:00
parent f0b1e3d737
commit 42f37f15b4
1 changed files with 26 additions and 32 deletions
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58
lib/raop_rtp.c
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@@ -425,8 +425,9 @@ raop_rtp_thread_udp(void *arg)
struct sockaddr_storage saddr;
socklen_t saddrlen;
bool have_synced = false;
bool no_data_yet = true;
char no_data[] = {0x00, 0x34, 0x68, 0x00};
bool audio_stream_started = false;
unsigned char empty_packet_marker[] = {0x00, 0x34, 0x68, 0x00};
const int resend_offset = 4;
/* the 44.1 kHZ rtp_time epoch is about 27 hours */
bool have_rtp_time = false;
int64_t rtp_time; /* will only change by small amounts to track rtp epoch changes */
@@ -478,33 +479,28 @@ raop_rtp_thread_udp(void *arg)
raop_rtp->control_saddr_len = saddrlen;
int type_c = packet[1] & ~0x80;
logger_log(raop_rtp->logger, LOGGER_DEBUG, "\nraop_rtp type_c 0x%02x, packetlen = %d", type_c, packetlen);
if (type_c == 0x56) {
if (type_c == 0x56 && packetlen >= resend_offset + 4) {
/* Handle resent data packet */
const int offset = 4;
if (packetlen > offset + 12) {
unsigned short seqnum = byteutils_get_short_be(packet + offset, 2);
if (packetlen == offset + 16 && !memcmp(&packet[offset + 12], no_data, 4)) {
/* skip packet */
} else {
logger_log(raop_rtp->logger, LOGGER_DEBUG, "raop_rtp audio resent: seqnum=%u", seqnum);
int result = raop_buffer_enqueue(raop_rtp->buffer, packet + offset, packetlen - offset, 1);
assert(result >= 0);
}
unsigned short seqnum = byteutils_get_short_be(packet, resend_offset + 2);
if (packetlen > resend_offset + 12) {
logger_log(raop_rtp->logger, LOGGER_DEBUG, "raop_rtp audio resent: seqnum=%u", seqnum);
int result = raop_buffer_enqueue(raop_rtp->buffer, packet + resend_offset, packetlen - resend_offset, 1);
assert(result >= 0);
} else {
/* unrecognized type_c = 0x56 packets with length 8 have been reported */
/* type_c = 0x56 packets with length 8 have been reported */
char *str = utils_data_to_string(packet, packetlen, 16);
logger_log(raop_rtp->logger, LOGGER_INFO, "Received short type_c = 0x%2x packet with length %d:\n%s", type_c, packetlen, str);
logger_log(raop_rtp->logger, LOGGER_INFO, "Received empty resent packet with length %d, seqnum=%u:\n%s", packetlen, seqnum, str);
free (str);
}
} else if (type_c == 0x54 && packetlen >= 20) {
/* packet[0] = 0x90 (first sync ?) or 0x80 (subsequent ones) *
* packet[1:3] = 0xd4, 0xd4 && ~0x80 = type 54 *
* packet[2:3] = 0x00 0x04 *
* packet[4:7] : sync_rtp big-endian uint32_t) *
* packet[8:15]: remote ntp timestamp (uint64 big-endian) *
* packet[16:20]: next_rtp big-endian uint32_t) *
* next_rtp = sync_rtp + 7497 = 441 * 17 (0.17 sec) for AAC-ELD *
* next_rtp = sync_rtp + 77175 = 441 * 175 (1.75 sec) for ALAC */
/* packet[0] = 0x90 (first sync ?) or 0x80 (subsequent ones)
* packet[1] = 0xd4, (0xd4 && ~0x80 = type 0x54)
* packet[2:3] = 0x00 0x04
* packet[4:7] : sync_rtp (big-endian uint32_t)
* packet[8:15]: remote ntp timestamp (big-endian uint64_t)
* packet[16:20]: next_rtp (big-endian uint32_t)
* next_rtp = sync_rtp + 7497 = 441 * 17 (0.17 sec) for AAC-ELD
* next_rtp = sync_rtp + 77175 = 441 * 175 (1.75 sec) for ALAC */
// The unit for the rtp clock is 1 / sample rate = 1 / 44100
uint32_t sync_rtp = byteutils_get_int_be(packet, 4);
@@ -561,20 +557,18 @@ raop_rtp_thread_udp(void *arg)
packetlen = recvfrom(raop_rtp->dsock, (char *)packet, sizeof(packet), 0,
(struct sockaddr *)&saddr, &saddrlen);
// rtp payload type
int type_d = packet[1] & ~0x80;
//int type_d = packet[1] & ~0x80;
//logger_log(raop_rtp->logger, LOGGER_DEBUG, "raop_rtp_thread_udp type_d 0x%02x, packetlen = %d", type_d, packetlen);
// Len = 16 appears if there is no time
if (packetlen >= 12) {
int no_resend = (raop_rtp->control_rport == 0); /* true when control_rport is not set */
uint32_t rtp_timestamp = byteutils_get_int_be(packet, 4);
if (packetlen == 16 && !memcmp(&packet[12], no_data, 4)) {
/* skip packet */
if (packetlen == 16 && !memcmp(&packet[12], empty_packet_marker, 4)) {
/* skip packet: these marked empty packets occur before first time syncronization */
} else {
if (no_data_yet) {
no_data_yet = false;
if (!audio_stream_started) {
audio_stream_started = true;
if (have_synced == false) {
/* until the first rtp sync occurs, we don't know the exact client ntp timestamp that matches the client rtp timesamp */
uint32_t rtp_timestamp = byteutils_get_int_be(packet, 4);
int64_t ntp_now = (int64_t) raop_ntp_get_local_time(raop_rtp->ntp);
int64_t ntp_time = ((int64_t) ntp_now) - ntp_start_time;
int64_t latency = 0;
@@ -648,7 +642,7 @@ raop_rtp_thread_udp(void *arg)
}
} else {
char *str = utils_data_to_string(packet, packetlen, 16);
logger_log(raop_rtp->logger, LOGGER_INFO, "Received short type_d = 0x%2x packet with length %d:\n%s", type_d, packetlen, str);
logger_log(raop_rtp->logger, LOGGER_INFO, "Received short type_d = 0x%2x packet with length %d:\n%s", packet[1] & ~0x80, packetlen, str);
free (str);
}
}