Improve metadata output -- maybe it works reliably now. Add call to g…

…et audio parameters from back ends, to be able to give volume metadata.

audio.h

@@ -3,6 +3,16 @@
 
 #include <stdint.h>
 
+typedef struct {
+ double airplay_volume;
+ double current_volume_dB;
+ int minimum_volume_dB;
+ int maximum_volume_dB;
+ int has_true_mute;
+ int is_muted;
+ int valid;
+} audio_parameters;
+
 typedef struct {
  void (*help)(void);
  char *name;
@@ -28,6 +38,9 @@ typedef struct {
 
  // may be NULL, in which case soft volume is applied
  void (*volume)(double vol);
+
+ // may be NULL, in which case soft volume parameters are used
+ void (*parameters)(audio_parameters* info);
 } audio_output;
 
 audio_output *audio_get_output(char *name);

audio_alsa.c

@@ -43,6 +43,7 @@ static void stop(void);
 static void flush(void);
 static uint32_t delay(void);
 static void volume(double vol);
+static void parameters(audio_parameters* info);
 static int has_mute=0;
 static int has_db_vol=0;
 static double set_volume;
@@ -57,7 +58,8 @@ audio_output audio_alsa = {
  .flush = &flush,
  .delay = &delay,
  .play = &play,
- .volume = NULL
+ .volume = NULL, // to be set later on...
+ .parameters = NULL // to be set later on...
 };
 
 static pthread_mutex_t alsa_mutex = PTHREAD_MUTEX_INITIALIZER;
@@ -158,6 +160,7 @@ static int init(int argc, char **argv) {
  (snd_mixer_selem_ask_playback_vol_dB(alsa_mix_elem,alsa_mix_maxv,&alsa_mix_maxdb)==0)) {
  has_db_vol=1;
  audio_alsa.volume = &volume; // insert the volume function now we know it can do dB stuff
+ audio_alsa.parameters = &parameters; // likewise the parameters stuff
  if (alsa_mix_mindb==-9999999) {
  // trying to say that the lowest vol is mute, maybe? Raspberry Pi does this
  if (snd_mixer_selem_ask_playback_vol_dB(alsa_mix_elem,alsa_mix_minv+1,&alsa_mix_mindb)==0)
@@ -314,6 +317,15 @@ static void stop(void) {
  // close_alsa_device();
 }
 
+static void parameters(audio_parameters* info) {
+ info->has_true_mute=has_mute;
+ info->is_muted = ((has_mute) && (set_volume == -144.0));
+ info->minimum_volume_dB=alsa_mix_mindb;
+ info->maximum_volume_dB=alsa_mix_maxdb;
+ info->airplay_volume=set_volume;
+ info->current_volume_dB=vol2attn(set_volume,alsa_mix_maxdb,alsa_mix_mindb);
+}
+
 static void volume(double vol) {
  set_volume=vol;
  double vol_setting = vol2attn(vol,alsa_mix_maxdb,alsa_mix_mindb);

audio_ao.c

@@ -127,5 +127,6 @@ audio_output audio_ao = {
  .flush = NULL,
  .delay = NULL,
  .play = &play,
- .volume = NULL
+ .volume = NULL,
+ .parameters = NULL
 };

audio_dummy.c

@@ -81,5 +81,6 @@ audio_output audio_dummy = {
  .flush = NULL,
  .delay = NULL,
  .play = &play,
- .volume = NULL
+ .volume = NULL,
+ .parameters = NULL
 };

audio_pipe.c

@@ -86,5 +86,6 @@ audio_output audio_pipe = {
  .flush = NULL,
  .delay = NULL,
  .play = &play,
- .volume = NULL
+ .volume = NULL,
+ .parameters = NULL
 };

audio_pulse.c

@@ -148,5 +148,6 @@ audio_output audio_pulse = {
  .flush = NULL,
  .delay = NULL,
  .play = &play,
- .volume = NULL
+ .volume = NULL,
+ .parameters = NULL
 };

audio_sndio.c

@@ -82,5 +82,6 @@ audio_output audio_sndio = {
  .flush = NULL,
  .delay = NULL,
  .play = &play,
- .volume = &volume
+ .volume = &volume,
+ .parameters = NULL
 };

common.c

@@ -399,6 +399,8 @@ void command_stop(void) {
 // See http:https://tangentsoft.net/audio/atten.html for data on good attenuators.
 // We want a smooth attenuation function, like, for example, the ALPS RK27 Potentiometer transfer functions referred to at the link above.
 
+// Note that the max_db and min_db are given as dB*100
+
 double vol2attn(double vol, long max_db, long min_db) { 
 
 // We use a little coordinate geometry to build a transfer function from the volume passed in to the device's dynamic range.

player.c

@@ -95,7 +95,7 @@ static int32_t last_seqno_read;
 
 
 // interthread variables
-static double volume = 1.0;
+static double software_mixer_volume = 1.0;
 static int fix_volume = 0x10000;
 static pthread_mutex_t vol_mutex = PTHREAD_MUTEX_INITIALIZER;
 
@@ -133,6 +133,8 @@ static pthread_cond_t flowcontrol;
 
 static int64_t first_packet_time_to_play; // nanoseconds
 
+static audio_parameters audio_information;
+
 // stats
 static uint64_t missing_packets,late_packets,too_late_packets,resend_requests; 
 
@@ -740,7 +742,7 @@ static int stuff_buffer_soxr(short *inptr, short *outptr, int stuff) {
  }
 
  // finally, adjust the volume, if necessary
- if (volume!=1.0) {
+ if (software_mixer_volume!=1.0) {
  // pthread_mutex_lock(&vol_mutex);
  op=outptr;
  for (i=0; i<frame_size+stuff; i++) {
@@ -780,6 +782,7 @@ static void *player_thread_func(void *arg) {
  int64_t minimum_dac_queue_size = 1000000;
  int32_t minimum_buffer_occupancy = BUFFER_FRAMES;
  int32_t maximum_buffer_occupancy = 0;
+ audio_information.valid=0;
 
  int play_samples;
  int64_t current_delay;
@@ -1031,25 +1034,42 @@ void player_volume(double f) {
 // Here, we ask for an attenuation we will apply in software. The dB range of a value from 1 to 65536 is about 48.1 dB (log10 of 65536 is 4.8164).
 // Thus, we ask our vol2attn function for an appropriate dB between -48.1 and 0 dB and translate it back to a number.
 
- double linear_volume = pow(10,vol2attn(f,0,-4810)/1000);
+ double scaled_volume = vol2attn(f,0,-4810);
+ double linear_volume = pow(10,scaled_volume/1000);
 
  if(f == -144.0)
  linear_volume = 0.0;
 
  if (config.output->volume) {
- config.output->volume(f);
- linear_volume=1.0; // no attenuation needed
- } 
+ config.output->volume(f); // volume will be sent as metadata by the config.output device
+ linear_volume=1.0; // no attenuation needed -- this value is used as a flag to avoid calculations
+ }
+
+
+ if (config.output->parameters)
+ config.output->parameters(&audio_information);
+ else {
+ audio_information.airplay_volume = f;
+ audio_information.minimum_volume_dB = -4810;
+ audio_information.maximum_volume_dB = 0;
+ audio_information.current_volume_dB = scaled_volume;
+ audio_information.has_true_mute = 0;
+ audio_information.is_muted = 0;
+ }
+ audio_information.valid=1;
  pthread_mutex_lock(&vol_mutex);
- volume = linear_volume;
- fix_volume = 65536.0 * volume;
+ software_mixer_volume = linear_volume; 
+ fix_volume = 65536.0 * software_mixer_volume; 
  pthread_mutex_unlock(&vol_mutex);
+
  char *dv = malloc(64); // will be freed in the metadata thread
  if (dv) {
  memset(dv,0,64);
- snprintf(dv,63,"%.2f",f);
+ snprintf(dv,63,"%.2f,%.2f,%.2f,%.2f",audio_information.airplay_volume,audio_information.current_volume_dB/100.0,audio_information.minimum_volume_dB/100.0,audio_information.maximum_volume_dB/100.0);
  send_ssnc_metadata('pvol',dv,strlen(dv),1);
  }
+
+
 }
 
 void player_flush(uint32_t timestamp) {

rtsp.c

@@ -797,7 +797,12 @@ static void handle_set_parameter_parameter(rtsp_conn_info *conn,
 // 'pend' -- play stream end. No arguments
 // 'pfls' -- play stream flush. No arguments
 // 'prsm' -- play stream resume. No arguments
-// 'pvol' -- play volume. The volume is sent as a string.
+// 'pvol' -- play volume. The volume is sent as a string -- "airplay_volume,volume,lowest_volume,highest_volume,has_true_mute,is_muted"
+// volume, lowest_volume and highest_volume are given in dB
+// is_muted is 1 if [true] mute is enabled, 0 otherwise. 
+// The "airplay_volume" is what's sent to the player, and is from 0.00 down to -30.00, with -144.00 meaning mute.
+// This is linear on the volume control slider of iTunes or iOS AirPLay
+//
 // 'mdst' -- a sequence of metadata is about to start
 // 'mden' -- a sequence of metadata has ended
 // 'snam' -- the name of the originator -- e.g. "Joe's iPhone" or "iTunes...".
@@ -894,7 +899,7 @@ void metadata_open(void) {
  char* path = malloc(pl+1);
  snprintf(path, pl+1, "%s/%s", config.meta_dir, fn);
 
- fd = open(path, O_WRONLY);
+ fd = open(path, O_WRONLY | O_NONBLOCK);
  //if (fd < 0)
  // debug(1, "Could not open metadata FIFO %s. Will try again later.", path);
 
@@ -907,18 +912,19 @@ static void metadata_close(void) {
 }
 
 ssize_t non_blocking_write(int fd, const void *buf, size_t count) {
-//  debug(1,"writing %u to pipe...",count);
+ // debug(1,"writing %u to pipe...",count);
  // we are assuming that the count is always smaller than the FIFO's buffer
  struct pollfd ufds[1];
  ssize_t reply; 
  do {
  ufds[0].fd=fd;
  ufds[0].events = POLLOUT;
- int rv = poll(ufds,1,1000);
+ int rv = poll(ufds,1,5000);
  if (rv==-1)
  debug(1,"error waiting for pipe to unblock...");
  if (rv==0)
  debug(1,"timeout waiting for pipe to unblock");
+ reply=write(fd,buf,count);
  if ((reply==-1) && ((errno == EAGAIN) || (errno == EWOULDBLOCK)))
  debug(1,"writing to pipe will block...");
 // else
@@ -940,12 +946,12 @@ void metadata_process(uint32_t type,uint32_t code,char *data,uint32_t length) {
  return;
  char thestring[1024];
  snprintf(thestring,1024,"<type>%x</type><code>%x</code><length>%u</length>\n",type,code,length);
- ret = write(fd, thestring, strlen(thestring));
+ ret = non_blocking_write(fd, thestring, strlen(thestring));
  if (ret < 1)
  return;
  if ((data!=NULL) && (length>0)) {
  snprintf(thestring,1024,"<data encoding=\"base64\">\n");
- ret = write(fd, thestring, strlen(thestring));
+ ret = non_blocking_write(fd, thestring, strlen(thestring));
  if (ret < 1) // no reader
  return;
  // here, we write the data in base64 form using our nice base64 encoder
@@ -963,7 +969,7 @@ void metadata_process(uint32_t type,uint32_t code,char *data,uint32_t length) {
  if (base64_encode_so(remaining_data, towrite_count, outbuf, &outbuf_size)==NULL)
  debug(1,"Error encoding base64 data.");
  //debug(1,"Remaining count: %d ret: %d, outbuf_size: %d.",remaining_count,ret,outbuf_size); 
- ret = write(fd,outbuf,outbuf_size);
+ ret = non_blocking_write(fd,outbuf,outbuf_size);
  if (ret<0)
  return;
  remaining_data+=towrite_count;
@@ -973,7 +979,7 @@ void metadata_process(uint32_t type,uint32_t code,char *data,uint32_t length) {
  // return;
  }
  snprintf(thestring,1024,"</data>\n");
- ret = write(fd, thestring, strlen(thestring));
+ ret = non_blocking_write(fd, thestring, strlen(thestring));
  if (ret < 1) // no reader
  return;
  }
@@ -1070,8 +1076,8 @@ static void handle_set_parameter_metadata(rtsp_conn_info *conn,
 
 static void handle_set_parameter(rtsp_conn_info *conn,
  rtsp_message *req, rtsp_message *resp) {
- if (!req->contentlength)
- debug(1, "received empty SET_PARAMETER request.");
+ //if (!req->contentlength)
+ // debug(1, "received empty SET_PARAMETER request.");
 
  char *ct = msg_get_header(req, "Content-Type");