X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/02ba7921a8b083f421a747b89c65a87d0afd5841..c6a70f38f22abf3c46914b85ff620975f12bf027:/clients/playrtp.c diff --git a/clients/playrtp.c b/clients/playrtp.c index 81c1e8e..5b1e496 100644 --- a/clients/playrtp.c +++ b/clients/playrtp.c @@ -64,6 +64,7 @@ #include #include #include +#include #include "log.h" #include "mem.h" @@ -211,6 +212,7 @@ static const struct option options[] = { { "pause-mode", required_argument, 0, 'P' }, { "socket", required_argument, 0, 's' }, { "config", required_argument, 0, 'C' }, + { "monitor", no_argument, 0, 'M' }, { 0, 0, 0, 0 } }; @@ -322,6 +324,9 @@ static void *queue_thread(void attribute((unused)) *arg) { pthread_cond_broadcast(&cond); pthread_mutex_unlock(&lock); } +#if HAVE_STUPID_GCC44 + return NULL; +#endif } /** @brief Background thread collecting samples @@ -400,6 +405,14 @@ static void *listen_thread(void attribute((unused)) *arg) { fatal(0, "unsupported RTP payload type %d", header.mpt & 0x7F); } + /* See if packet is silent */ + const uint16_t *s = p->samples_raw; + n = p->nsamples; + for(; n > 0; --n) + if(*s++) + break; + if(!n) + p->flags |= SILENT; if(logfp) fprintf(logfp, "sequence %u timestamp %"PRIx32" length %"PRIx32" end %"PRIx32"\n", seq, timestamp, p->nsamples, timestamp + p->nsamples); @@ -503,6 +516,7 @@ static size_t playrtp_callback(void *buffer, size_t max_samples, void attribute((unused)) *userdata) { size_t samples; + int silent = 0; pthread_mutex_lock(&lock); /* Get the next packet, junking any that are now in the past */ @@ -533,6 +547,7 @@ static size_t playrtp_callback(void *buffer, *bufptr++ = (int16_t)ntohs(*ptr++); --i; } + silent = !!(p->flags & SILENT); } else { /* There is no suitable packet. We introduce 0s up to the next packet, or * to fill the buffer if there's no next packet or that's too many. The @@ -543,6 +558,7 @@ static size_t playrtp_callback(void *buffer, samples = max_samples; //info("infill by %zu", samples); memset(buffer, 0, samples * uaudio_sample_size); + silent = 1; } /* Debug dump */ if(dump_buffer) { @@ -553,6 +569,45 @@ static size_t playrtp_callback(void *buffer, } /* Advance timestamp */ next_timestamp += samples; + /* If we're getting behind then try to drop just silent packets + * + * In theory this shouldn't be necessary. The server is supposed to send + * packets at the right rate and compares the number of samples sent with the + * time in order to ensure this. + * + * However, various things could throw this off: + * + * - the server's clock could advance at the wrong rate. This would cause it + * to mis-estimate the right number of samples to have sent and + * inappropriately throttle or speed up. + * + * - playback could happen at the wrong rate. If the playback host's sound + * card has a slightly incorrect clock then eventually it will get out + * of step. + * + * So if we play back slightly slower than the server sends for either of + * these reasons then eventually our buffer, and the socket's buffer, will + * fill, and the kernel will start dropping packets. The result is audible + * and not very nice. + * + * Therefore if we're getting behind, we pre-emptively drop silent packets, + * since a change in the duration of a silence is less noticeable than a + * dropped packet from the middle of continuous music. + * + * (If things go wrong the other way then eventually we run out of packets to + * play and are forced to play silence. This doesn't seem to happen in + * practice but if it does then in the same way we can artificially extend + * silent packets to compensate.) + * + * Dropped packets are always logged; use 'disorder-playrtp --monitor' to + * track how close to target buffer occupancy we are on a once-a-minute + * basis. + */ + if(nsamples > minbuffer && silent) { + info("dropping %zu samples (%"PRIu32" > %"PRIu32")", + samples, nsamples, minbuffer); + samples = 0; + } /* Junk obsolete packets */ playrtp_next_packet(); pthread_mutex_unlock(&lock); @@ -579,6 +634,7 @@ int main(int argc, char **argv) { union any_sockaddr mgroup; const char *dumpfile = 0; pthread_t ltid; + int monitor = 0; static const int one = 1; static const struct addrinfo prefs = { @@ -594,7 +650,7 @@ int main(int argc, char **argv) { mem_init(); if(!setlocale(LC_CTYPE, "")) fatal(errno, "error calling setlocale"); backend = uaudio_apis[0]; - while((n = getopt_long(argc, argv, "hVdD:m:x:L:R:M:aocC:re:P:", options, 0)) >= 0) { + while((n = getopt_long(argc, argv, "hVdD:m:x:L:R:aocC:re:P:M", options, 0)) >= 0) { switch(n) { case 'h': help(); case 'V': version("disorder-playrtp"); @@ -618,6 +674,7 @@ int main(int argc, char **argv) { case 'r': dumpfile = optarg; break; case 'e': backend = &uaudio_command; uaudio_set("command", optarg); break; case 'P': uaudio_set("pause-mode", optarg); break; + case 'M': monitor = 1; break; default: fatal(0, "invalid option"); } } @@ -780,6 +837,7 @@ int main(int argc, char **argv) { if((err = pthread_create(<id, 0, queue_thread, 0))) fatal(err, "pthread_create queue_thread"); pthread_mutex_lock(&lock); + time_t lastlog = 0; for(;;) { /* Wait for the buffer to fill up a bit */ playrtp_fill_buffer(); @@ -802,6 +860,20 @@ int main(int argc, char **argv) { while(nsamples >= minbuffer || (nsamples > 0 && contains(pheap_first(&packets), next_timestamp))) { + if(monitor) { + time_t now = time(0); + + if(now >= lastlog + 60) { + int offset = nsamples - minbuffer; + double offtime = (double)offset / (uaudio_rate * uaudio_channels); + info("%+d samples off (%d.%02ds, %d bytes)", + offset, + (int)fabs(offtime) * (offtime < 0 ? -1 : 1), + (int)(fabs(offtime) * 100) % 100, + offset * uaudio_bits / CHAR_BIT); + lastlog = now; + } + } //fprintf(stderr, "%8u/%u (%u) PLAYING\n", nsamples, maxbuffer, minbuffer); pthread_cond_wait(&cond, &lock); }