Merge pull request #75 from martinellimarco/master

Ported @Pagten's target latency patch to pulseaudio IVSHMEM

Marco Martinelli committed 6 years ago

Commit 0f61a672 parents a7c3f9c 8b76c2e2 files · +40 −5Browse files

Unified · Split

2 files

Receivers/pulseaudio-ivshmem/Makefile +1 −1
Receivers/pulseaudio-ivshmem/scream-ivshmem-pulse.c +39 −4

Receivers/pulseaudio-ivshmem/Makefile+1−1

@@ -1,5 +1,5 @@
1	CC=gcc	1	CC=gcc
2	CFLAGS = -Wall	2	CFLAGS = -Wall -O2
3		3
4	scream-pulse: scream-ivshmem-pulse.c	4	scream-pulse: scream-ivshmem-pulse.c
5	$(CC) $(CFLAGS) -o scream-ivshmem-pulse scream-ivshmem-pulse.c -lpulse-simple -lpulse	5	$(CC) $(CFLAGS) -o scream-ivshmem-pulse scream-ivshmem-pulse.c -lpulse-simple -lpulse

Receivers/pulseaudio-ivshmem/scream-ivshmem-pulse.c+39−4

 static void show_usage(const char *arg0)
 {
   fprintf(stderr, "\n");
-  fprintf(stderr, "Usage: %s <ivshmem device path>\n", arg0);
+  fprintf(stderr, "Usage: %s <ivshmem device path> [-t <latency>]\n", arg0);
+  fprintf(stderr, "\n");
+  fprintf(stderr, "         All command line options are optional.\n");
+  fprintf(stderr, "         -t <latency>: Target latency in milliseconds. Defaults to 50ms.\n");
   fprintf(stderr, "\n");
   exit(1);
 }
 };
 int main(int argc, char*argv[]) {
-  if (argc != 2) {
+  if (argc < 2) {
     show_usage(argv[0]);
   }
   pa_simple *s;
   pa_sample_spec ss;
   pa_channel_map channel_map;
+  pa_buffer_attr buffer_attr;
   unsigned char cur_sample_rate = 0;
   unsigned char cur_sample_size = 0;
   unsigned char cur_channels = 2;
   uint16_t cur_channel_map = 0x0003;
+  int target_latency_ms = 50;
+  int opt;
+  while ((opt = getopt(argc, argv, "t:h")) != -1) {
+    switch (opt) {
+    case 't':
+      target_latency_ms = atoi(optarg);
+      if (target_latency_ms < 0) show_usage(argv[0]);
+      break;
+    default:
+      show_usage(argv[0]);
+    }
+  }
+  if (1+optind < argc) {
+    fprintf(stderr, "Expected argument after options\n");
+    show_usage(argv[0]);
+  }
   // Opportunistic call to renice us, so we can keep up under
   // higher load conditions. This may fail when run as non-root.
   setpriority(PRIO_PROCESS, 0, -11);
   ss.format = PA_SAMPLE_S16LE;
   ss.rate = 44100;
   ss.channels = cur_channels;
+  // set buffer size for requested latency
+  buffer_attr.maxlength = (uint32_t)-1;
+  buffer_attr.tlength = pa_usec_to_bytes((pa_usec_t)target_latency_ms * 1000u, &ss);
+  buffer_attr.prebuf = (uint32_t)-1;
+  buffer_attr.minreq = (uint32_t)-1;
+  buffer_attr.fragsize = (uint32_t)-1;
   s = pa_simple_new(NULL,
     "Scream",
     PA_STREAM_PLAYBACK,
     "Audio",
     &ss,
     &channel_map,
-    NULL,
+    &buffer_attr,
     &error
   );
   if (!s) {
       }
       if (ss.rate > 0) {
+        // sample spec has changed, so the playback buffer size for the requested latency must be recalculated as well
+        buffer_attr.tlength = pa_usec_to_bytes((pa_usec_t)target_latency_ms * 1000, &ss);
         if (s) pa_simple_free(s);
         s = pa_simple_new(NULL,
           "Scream",
           PA_STREAM_PLAYBACK,
           "Audio",
           &ss,
           &channel_map,
-          NULL,
+          &buffer_attr,
           NULL
         );
         if (s) {

Merge pull request #75 from martinellimarco/master

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