X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/5330d674656f13820c3426723f7c03bb54a9ef59..ceb044f4e944cd32110619d50b8ccb6dfddd3ac1:/server/speaker.c diff --git a/server/speaker.c b/server/speaker.c index 055b08a..acbc9bf 100644 --- a/server/speaker.c +++ b/server/speaker.c @@ -44,6 +44,10 @@ #include #include #include +#include +#include +#include +#include #include "configuration.h" #include "syscalls.h" @@ -52,6 +56,9 @@ #include "mem.h" #include "speaker.h" #include "user.h" +#include "addr.h" +#include "timeval.h" +#include "rtp.h" #if API_ALSA #include @@ -68,6 +75,11 @@ #define FRAMES 4096 /* Frame batch size */ +#define NETWORK_BYTES 1024 /* Bytes to send per network packet */ +/* (don't make this too big or arithmetic will start to overflow) */ + +#define RTP_AHEAD 2 /* Max RTP playahead (seconds) */ + #define NFDS 256 /* Max FDs to poll for */ /* Known tracks are kept in a linked list. We don't normally to have @@ -99,7 +111,14 @@ static snd_pcm_uframes_t last_pcm_bufsize; /* last seen buffer size */ #endif static int ready; /* ready to send audio */ static int forceplay; /* frames to force play */ -static int kidfd = -1; /* child process input */ +static int cmdfd = -1; /* child process input */ +static int bfd = -1; /* broadcast FD */ +static uint32_t rtp_time; /* RTP timestamp */ +static struct timeval rtp_time_real; /* corresponding real time */ +static uint16_t rtp_seq; /* frame sequence number */ +static uint32_t rtp_id; /* RTP SSRC */ +static int idled; /* set when idled */ +static int audio_errors; /* audio error counter */ static const struct option options[] = { { "help", no_argument, 0, 'h' }, @@ -247,7 +266,7 @@ static int formats_equal(const ao_sample_format *a, static void idle(void) { D(("idle")); #if API_ALSA - if(pcm) { + if(config->speaker_backend == BACKEND_ALSA && pcm) { int err; if((err = snd_pcm_nonblock(pcm, 0)) < 0) @@ -261,6 +280,7 @@ static void idle(void) { D(("released audio device")); } #endif + idled = 1; ready = 0; } @@ -349,7 +369,11 @@ static int activate(void) { D((" - not got format for %s", playing->id)); return -1; } - if(kidfd >= 0) { + switch(config->speaker_backend) { + case BACKEND_COMMAND: + case BACKEND_NETWORK: + /* If we pass audio on to some other agent then we enforce the configured + * sample format on the *inbound* audio data. */ if(!formats_equal(&playing->format, &config->sample_format)) { char argbuf[1024], *q = argbuf; const char *av[18], **pp = av; @@ -393,109 +417,112 @@ static int activate(void) { ready = 1; } return 0; - } + case BACKEND_ALSA: #if API_ALSA - /* If we need to change format then close the current device. */ - if(pcm && !formats_equal(&playing->format, &pcm_format)) - idle(); - if(!pcm) { - snd_pcm_hw_params_t *hwparams; - snd_pcm_sw_params_t *swparams; - snd_pcm_uframes_t pcm_bufsize; - int err; - int sample_format = 0; - unsigned rate; - - D(("snd_pcm_open")); - if((err = snd_pcm_open(&pcm, - config->device, - SND_PCM_STREAM_PLAYBACK, - SND_PCM_NONBLOCK))) { - error(0, "error from snd_pcm_open: %d", err); - goto error; - } - snd_pcm_hw_params_alloca(&hwparams); - D(("set up hw params")); - if((err = snd_pcm_hw_params_any(pcm, hwparams)) < 0) - fatal(0, "error from snd_pcm_hw_params_any: %d", err); - if((err = snd_pcm_hw_params_set_access(pcm, hwparams, - SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) - fatal(0, "error from snd_pcm_hw_params_set_access: %d", err); - switch(playing->format.bits) { - case 8: - sample_format = SND_PCM_FORMAT_S8; - break; - case 16: - switch(playing->format.byte_format) { - case AO_FMT_NATIVE: sample_format = SND_PCM_FORMAT_S16; break; - case AO_FMT_LITTLE: sample_format = SND_PCM_FORMAT_S16_LE; break; - case AO_FMT_BIG: sample_format = SND_PCM_FORMAT_S16_BE; break; - error(0, "unrecognized byte format %d", playing->format.byte_format); + /* If we need to change format then close the current device. */ + if(pcm && !formats_equal(&playing->format, &pcm_format)) + idle(); + if(!pcm) { + snd_pcm_hw_params_t *hwparams; + snd_pcm_sw_params_t *swparams; + snd_pcm_uframes_t pcm_bufsize; + int err; + int sample_format = 0; + unsigned rate; + + D(("snd_pcm_open")); + if((err = snd_pcm_open(&pcm, + config->device, + SND_PCM_STREAM_PLAYBACK, + SND_PCM_NONBLOCK))) { + error(0, "error from snd_pcm_open: %d", err); + goto error; + } + snd_pcm_hw_params_alloca(&hwparams); + D(("set up hw params")); + if((err = snd_pcm_hw_params_any(pcm, hwparams)) < 0) + fatal(0, "error from snd_pcm_hw_params_any: %d", err); + if((err = snd_pcm_hw_params_set_access(pcm, hwparams, + SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) + fatal(0, "error from snd_pcm_hw_params_set_access: %d", err); + switch(playing->format.bits) { + case 8: + sample_format = SND_PCM_FORMAT_S8; + break; + case 16: + switch(playing->format.byte_format) { + case AO_FMT_NATIVE: sample_format = SND_PCM_FORMAT_S16; break; + case AO_FMT_LITTLE: sample_format = SND_PCM_FORMAT_S16_LE; break; + case AO_FMT_BIG: sample_format = SND_PCM_FORMAT_S16_BE; break; + error(0, "unrecognized byte format %d", playing->format.byte_format); + goto fatal; + } + break; + default: + error(0, "unsupported sample size %d", playing->format.bits); goto fatal; } - break; - default: - error(0, "unsupported sample size %d", playing->format.bits); - goto fatal; - } - if((err = snd_pcm_hw_params_set_format(pcm, hwparams, - sample_format)) < 0) { - error(0, "error from snd_pcm_hw_params_set_format (%d): %d", - sample_format, err); - goto fatal; - } - rate = playing->format.rate; - if((err = snd_pcm_hw_params_set_rate_near(pcm, hwparams, &rate, 0)) < 0) { - error(0, "error from snd_pcm_hw_params_set_rate (%d): %d", - playing->format.rate, err); - goto fatal; + if((err = snd_pcm_hw_params_set_format(pcm, hwparams, + sample_format)) < 0) { + error(0, "error from snd_pcm_hw_params_set_format (%d): %d", + sample_format, err); + goto fatal; + } + rate = playing->format.rate; + if((err = snd_pcm_hw_params_set_rate_near(pcm, hwparams, &rate, 0)) < 0) { + error(0, "error from snd_pcm_hw_params_set_rate (%d): %d", + playing->format.rate, err); + goto fatal; + } + if(rate != (unsigned)playing->format.rate) + info("want rate %d, got %u", playing->format.rate, rate); + if((err = snd_pcm_hw_params_set_channels(pcm, hwparams, + playing->format.channels)) < 0) { + error(0, "error from snd_pcm_hw_params_set_channels (%d): %d", + playing->format.channels, err); + goto fatal; + } + bufsize = 3 * FRAMES; + pcm_bufsize = bufsize; + if((err = snd_pcm_hw_params_set_buffer_size_near(pcm, hwparams, + &pcm_bufsize)) < 0) + fatal(0, "error from snd_pcm_hw_params_set_buffer_size (%d): %d", + 3 * FRAMES, err); + if(pcm_bufsize != 3 * FRAMES && pcm_bufsize != last_pcm_bufsize) + info("asked for PCM buffer of %d frames, got %d", + 3 * FRAMES, (int)pcm_bufsize); + last_pcm_bufsize = pcm_bufsize; + if((err = snd_pcm_hw_params(pcm, hwparams)) < 0) + fatal(0, "error calling snd_pcm_hw_params: %d", err); + D(("set up sw params")); + snd_pcm_sw_params_alloca(&swparams); + if((err = snd_pcm_sw_params_current(pcm, swparams)) < 0) + fatal(0, "error calling snd_pcm_sw_params_current: %d", err); + if((err = snd_pcm_sw_params_set_avail_min(pcm, swparams, FRAMES)) < 0) + fatal(0, "error calling snd_pcm_sw_params_set_avail_min %d: %d", + FRAMES, err); + if((err = snd_pcm_sw_params(pcm, swparams)) < 0) + fatal(0, "error calling snd_pcm_sw_params: %d", err); + pcm_format = playing->format; + bpf = bytes_per_frame(&pcm_format); + D(("acquired audio device")); + log_params(hwparams, swparams); + ready = 1; } - if(rate != (unsigned)playing->format.rate) - info("want rate %d, got %u", playing->format.rate, rate); - if((err = snd_pcm_hw_params_set_channels(pcm, hwparams, - playing->format.channels)) < 0) { - error(0, "error from snd_pcm_hw_params_set_channels (%d): %d", - playing->format.channels, err); - goto fatal; + return 0; + fatal: + abandon(); + error: + /* We assume the error is temporary and that we'll retry in a bit. */ + if(pcm) { + snd_pcm_close(pcm); + pcm = 0; } - bufsize = 3 * FRAMES; - pcm_bufsize = bufsize; - if((err = snd_pcm_hw_params_set_buffer_size_near(pcm, hwparams, - &pcm_bufsize)) < 0) - fatal(0, "error from snd_pcm_hw_params_set_buffer_size (%d): %d", - 3 * FRAMES, err); - if(pcm_bufsize != 3 * FRAMES && pcm_bufsize != last_pcm_bufsize) - info("asked for PCM buffer of %d frames, got %d", - 3 * FRAMES, (int)pcm_bufsize); - last_pcm_bufsize = pcm_bufsize; - if((err = snd_pcm_hw_params(pcm, hwparams)) < 0) - fatal(0, "error calling snd_pcm_hw_params: %d", err); - D(("set up sw params")); - snd_pcm_sw_params_alloca(&swparams); - if((err = snd_pcm_sw_params_current(pcm, swparams)) < 0) - fatal(0, "error calling snd_pcm_sw_params_current: %d", err); - if((err = snd_pcm_sw_params_set_avail_min(pcm, swparams, FRAMES)) < 0) - fatal(0, "error calling snd_pcm_sw_params_set_avail_min %d: %d", - FRAMES, err); - if((err = snd_pcm_sw_params(pcm, swparams)) < 0) - fatal(0, "error calling snd_pcm_sw_params: %d", err); - pcm_format = playing->format; - bpf = bytes_per_frame(&pcm_format); - D(("acquired audio device")); - log_params(hwparams, swparams); - ready = 1; - } - return 0; -fatal: - abandon(); -error: - /* We assume the error is temporary and that we'll retry in a bit. */ - if(pcm) { - snd_pcm_close(pcm); - pcm = 0; - } + return -1; #endif - return -1; + default: + assert(!"reached"); + } } /* Check to see whether the current track has finished playing */ @@ -507,13 +534,13 @@ static void maybe_finished(void) { abandon(); } -static void fork_kid(void) { - pid_t kid; +static void fork_cmd(void) { + pid_t cmdpid; int pfd[2]; - if(kidfd != -1) close(kidfd); + if(cmdfd != -1) close(cmdfd); xpipe(pfd); - kid = xfork(); - if(!kid) { + cmdpid = xfork(); + if(!cmdpid) { xdup2(pfd[0], 0); close(pfd[0]); close(pfd[1]); @@ -521,13 +548,15 @@ static void fork_kid(void) { fatal(errno, "error execing /bin/sh"); } close(pfd[0]); - kidfd = pfd[1]; - D(("forked kid %d, fd = %d", kid, kidfd)); + cmdfd = pfd[1]; + D(("forked cmd %d, fd = %d", cmdpid, cmdfd)); } static void play(size_t frames) { - size_t avail_bytes, written_frames; + size_t avail_bytes, write_bytes, written_frames; ssize_t written_bytes; + struct rtp_header header; + struct iovec vec[2]; if(activate()) { if(playing) @@ -555,8 +584,9 @@ static void play(size_t frames) { else avail_bytes = playing->used; - if(kidfd == -1) { + switch(config->speaker_backend) { #if API_ALSA + case BACKEND_ALSA: { snd_pcm_sframes_t pcm_written_frames; size_t avail_frames; int err; @@ -587,28 +617,121 @@ static void play(size_t frames) { } written_frames = pcm_written_frames; written_bytes = written_frames * bpf; -#else - assert(!"reached"); + break; + } #endif - } else { + case BACKEND_COMMAND: if(avail_bytes > frames * bpf) avail_bytes = frames * bpf; - written_bytes = write(kidfd, playing->buffer + playing->start, + written_bytes = write(cmdfd, playing->buffer + playing->start, avail_bytes); D(("actually play %zu bytes, wrote %d", avail_bytes, (int)written_bytes)); if(written_bytes < 0) { switch(errno) { case EPIPE: - error(0, "hmm, kid died; trying another"); - fork_kid(); + error(0, "hmm, command died; trying another"); + fork_cmd(); return; case EAGAIN: return; } } written_frames = written_bytes / bpf; /* good enough */ + break; + case BACKEND_NETWORK: + /* We transmit using RTP (RFC3550) and attempt to conform to the internet + * AVT profile (RFC3551). */ + if(rtp_time_real.tv_sec == 0) + xgettimeofday(&rtp_time_real, 0); + if(idled) { + struct timeval now; + xgettimeofday(&now, 0); + /* There's been a gap. Fix up the RTP time accordingly. */ + const long offset = (((now.tv_sec + now.tv_usec /1000000.0) + - (rtp_time_real.tv_sec + rtp_time_real.tv_usec / 1000000.0)) + * playing->format.rate * playing->format.channels); + if(offset >= 0) { + info("offset RTP timestamp by %ld", offset); + rtp_time += offset; + } + rtp_time_real = now; + } + header.vpxcc = 2 << 6; /* V=2, P=0, X=0, CC=0 */ + header.seq = htons(rtp_seq++); + header.timestamp = htonl(rtp_time); + header.ssrc = rtp_id; + header.mpt = (idled ? 0x80 : 0x00) | 10; + /* 10 = L16 = 16-bit x 2 x 44100KHz. We ought to deduce this value from + * the sample rate (in a library somewhere so that configuration.c can rule + * out invalid rates). + */ + idled = 0; + if(avail_bytes > NETWORK_BYTES - sizeof header) { + avail_bytes = NETWORK_BYTES - sizeof header; + avail_bytes -= avail_bytes % bpf; + } + /* "The RTP clock rate used for generating the RTP timestamp is independent + * of the number of channels and the encoding; it equals the number of + * sampling periods per second. For N-channel encodings, each sampling + * period (say, 1/8000 of a second) generates N samples. (This terminology + * is standard, but somewhat confusing, as the total number of samples + * generated per second is then the sampling rate times the channel + * count.)" + */ + write_bytes = avail_bytes; +#if 0 + while(write_bytes > 0 && (uint32_t)(playing->buffer + playing->start + write_bytes - 4) == 0) + write_bytes -= 4; +#endif + if(write_bytes) { + vec[0].iov_base = (void *)&header; + vec[0].iov_len = sizeof header; + vec[1].iov_base = playing->buffer + playing->start; + vec[1].iov_len = avail_bytes; +#if 0 + { + char buffer[3 * sizeof header + 1]; + size_t n; + const uint8_t *ptr = (void *)&header; + + for(n = 0; n < sizeof header; ++n) + sprintf(&buffer[3 * n], "%02x ", *ptr++); + info(buffer); + } +#endif + do { + written_bytes = writev(bfd, + vec, + 2); + } while(written_bytes < 0 && errno == EINTR); + if(written_bytes < 0) { + error(errno, "error transmitting audio data"); + ++audio_errors; + if(audio_errors == 10) + fatal(0, "too many audio errors"); + return; + } + } else + audio_errors /= 2; + written_bytes = avail_bytes; + written_frames = written_bytes / bpf; + /* Advance RTP's notion of the time */ + rtp_time += written_frames * playing->format.channels; + /* Advance the corresponding real time */ + assert(NETWORK_BYTES <= 2000); /* else risk overflowing 32 bits */ + rtp_time_real.tv_usec += written_frames * 1000000 / playing->format.rate; + if(rtp_time_real.tv_usec >= 1000000) { + ++rtp_time_real.tv_sec; + rtp_time_real.tv_usec -= 1000000; + } + assert(rtp_time_real.tv_usec < 1000000); + break; + default: + assert(!"reached"); } + /* written_bytes and written_frames had better both be set and correct by + * this point */ playing->start += written_bytes; playing->used -= written_bytes; playing->played += written_frames; @@ -634,12 +757,12 @@ static void report(void) { } static void reap(int __attribute__((unused)) sig) { - pid_t kid; + pid_t cmdpid; int st; do - kid = waitpid(-1, &st, WNOHANG); - while(kid > 0); + cmdpid = waitpid(-1, &st, WNOHANG); + while(cmdpid > 0); signal(SIGCHLD, reap); } @@ -653,15 +776,38 @@ static int addfd(int fd, int events) { } int main(int argc, char **argv) { - int n, fd, stdin_slot, alsa_slots, kid_slot; + int n, fd, stdin_slot, alsa_slots, cmdfd_slot, bfd_slot, poke, timeout; + struct timeval now, delta; struct track *t; struct speaker_message sm; + struct addrinfo *res, *sres; + static const struct addrinfo pref = { + 0, + PF_INET, + SOCK_DGRAM, + IPPROTO_UDP, + 0, + 0, + 0, + 0 + }; + static const struct addrinfo prefbind = { + AI_PASSIVE, + PF_INET, + SOCK_DGRAM, + IPPROTO_UDP, + 0, + 0, + 0, + 0 + }; + static const int one = 1; + char *sockname, *ssockname; #if API_ALSA int alsa_nslots = -1, err; #endif set_progname(argv); - mem_init(0); if(!setlocale(LC_CTYPE, "")) fatal(errno, "error calling setlocale"); while((n = getopt_long(argc, argv, "hVc:dD", options, 0)) >= 0) { switch(n) { @@ -690,15 +836,43 @@ int main(int argc, char **argv) { become_mortal(); /* make sure we're not root, whatever the config says */ if(getuid() == 0 || geteuid() == 0) fatal(0, "do not run as root"); - info("started"); - if(config->speaker_command) - fork_kid(); - else { -#if API_ALSA - /* ok */ -#else - fatal(0, "invoked speaker but no speaker_command and no known sound API"); - #endif + switch(config->speaker_backend) { + case BACKEND_ALSA: + info("selected ALSA backend"); + case BACKEND_COMMAND: + info("selected command backend"); + fork_cmd(); + break; + case BACKEND_NETWORK: + res = get_address(&config->broadcast, &pref, &sockname); + if(!res) return -1; + if(config->broadcast_from.n) { + sres = get_address(&config->broadcast_from, &prefbind, &ssockname); + if(!sres) return -1; + } else + sres = 0; + if((bfd = socket(res->ai_family, + res->ai_socktype, + res->ai_protocol)) < 0) + fatal(errno, "error creating broadcast socket"); + if(setsockopt(bfd, SOL_SOCKET, SO_BROADCAST, &one, sizeof one) < 0) + fatal(errno, "error settting SO_BROADCAST on broadcast socket"); + /* We might well want to set additional broadcast- or multicast-related + * options here */ + if(sres && bind(bfd, sres->ai_addr, sres->ai_addrlen) < 0) + fatal(errno, "error binding broadcast socket to %s", ssockname); + if(connect(bfd, res->ai_addr, res->ai_addrlen) < 0) + fatal(errno, "error connecting broadcast socket to %s", sockname); + /* Select an SSRC */ + gcry_randomize(&rtp_id, sizeof rtp_id, GCRY_STRONG_RANDOM); + info("selected network backend, sending to %s", sockname); + if(config->sample_format.byte_format != AO_FMT_BIG) { + info("forcing big-endian sample format"); + config->sample_format.byte_format = AO_FMT_BIG; + } + break; + default: + fatal(0, "unknown backend %d", config->speaker_backend); } while(getppid() != 1) { fdno = 0; @@ -713,12 +887,40 @@ int main(int argc, char **argv) { /* If forceplay is set then wait until it succeeds before waiting on the * sound device. */ alsa_slots = -1; - kid_slot = -1; + cmdfd_slot = -1; + bfd_slot = -1; + /* By default we will wait up to a second before thinking about current + * state. */ + timeout = 1000; if(ready && !forceplay) { - if(kidfd >= 0) - kid_slot = addfd(kidfd, POLLOUT); - else { + switch(config->speaker_backend) { + case BACKEND_COMMAND: + /* We send sample data to the subprocess as fast as it can accept it. + * This isn't ideal as pause latency can be very high as a result. */ + if(cmdfd >= 0) + cmdfd_slot = addfd(cmdfd, POLLOUT); + break; + case BACKEND_NETWORK: + /* We want to keep the notional playing point somewhere in the near + * future. If it's too near then clients that attempt even the + * slightest amount of read-ahead will never catch up, and those that + * don't will skip whenever there's a trivial network delay. If it's + * too far ahead then pause latency will be too high. + */ + xgettimeofday(&now, 0); + delta = tvsub(rtp_time_real, now); + if(delta.tv_sec < RTP_AHEAD) { + D(("delta = %ld.%06ld", (long)delta.tv_sec, (long)delta.tv_usec)); + bfd_slot = addfd(bfd, POLLOUT); + if(delta.tv_sec < 0) + rtp_time_real = now; /* catch up */ + } + break; #if API_ALSA + case BACKEND_ALSA: { + /* We send sample data to ALSA as fast as it can accept it, relying on + * the fact that it has a relatively small buffer to minimize pause + * latency. */ int retry = 3; alsa_slots = fdno; @@ -736,7 +938,11 @@ int main(int argc, char **argv) { } while(retry-- > 0); if(alsa_nslots >= 0) fdno += alsa_nslots; + break; + } #endif + default: + assert(!"unknown backend"); } } /* If any other tracks don't have a full buffer, try to read sample data @@ -748,29 +954,47 @@ int main(int argc, char **argv) { } else t->slot = -1; } - /* Wait up to a second before thinking about current state */ - n = poll(fds, fdno, 1000); + /* Wait for something interesting to happen */ + n = poll(fds, fdno, timeout); if(n < 0) { if(errno == EINTR) continue; fatal(errno, "error calling poll"); } /* Play some sound before doing anything else */ - if(alsa_slots != -1) { + poke = 0; + switch(config->speaker_backend) { #if API_ALSA - unsigned short alsa_revents; - - if((err = snd_pcm_poll_descriptors_revents(pcm, - &fds[alsa_slots], - alsa_nslots, - &alsa_revents)) < 0) - fatal(0, "error calling snd_pcm_poll_descriptors_revents: %d", err); - if(alsa_revents & (POLLOUT | POLLERR)) - play(3 * FRAMES); + case BACKEND_ALSA: + if(alsa_slots != -1) { + unsigned short alsa_revents; + + if((err = snd_pcm_poll_descriptors_revents(pcm, + &fds[alsa_slots], + alsa_nslots, + &alsa_revents)) < 0) + fatal(0, "error calling snd_pcm_poll_descriptors_revents: %d", err); + if(alsa_revents & (POLLOUT | POLLERR)) + play(3 * FRAMES); + } else + poke = 1; + break; #endif - } else if(kid_slot != -1) { - if(fds[kid_slot].revents & (POLLOUT | POLLERR)) - play(3 * FRAMES); - } else { + case BACKEND_COMMAND: + if(cmdfd_slot != -1) { + if(fds[cmdfd_slot].revents & (POLLOUT | POLLERR)) + play(3 * FRAMES); + } else + poke = 1; + break; + case BACKEND_NETWORK: + if(bfd_slot != -1) { + if(fds[bfd_slot].revents & (POLLOUT | POLLERR)) + play(3 * FRAMES); + } else + poke = 1; + break; + } + if(poke) { /* Some attempt to play must have failed */ if(playing && !paused) play(forceplay);