add support for querying the actual stream latency.

(this imports changes from BMO 904617.)

1 files changed, 17 insertions, 1 deletions

diff --git a/src/cubeb_audiotrack.c b/src/cubeb_audiotrack.c
index 5287381..0df7b03 100644
--- a/src/cubeb_audiotrack.c
+++ b/src/cubeb_audiotrack.c
@@ -5,7 +5,9 @@
  * accompanying file LICENSE for details.
  */
 
+#if !defined(NDEBUG)
 #define NDEBUG
+#endif
 #include <assert.h>
 #include <pthread.h>
 #include <stdlib.h>
@@ -424,6 +426,19 @@ audiotrack_stream_get_position(cubeb_stream * stream, uint64_t * position)
   return CUBEB_OK;
 }
 
+int
+audiotrack_stream_get_latency(cubeb_stream * stream, uint32_t * latency)
+{
+  assert(stream->instance && latency);
+
+  /* Android returns the latency in ms, we want it in frames. */
+  *latency = stream->context->klass.latency(stream->instance);
+  /* with rate <= 96000, we won't overflow until 44.739 seconds of latency */
+  *latency = (*latency * stream->params.rate) / 1000;
+
+  return 0;
+}
+
 static struct cubeb_ops const audiotrack_ops = {
   .init = audiotrack_init,
   .get_backend_id = audiotrack_get_backend_id,
@@ -433,5 +448,6 @@ static struct cubeb_ops const audiotrack_ops = {
   .stream_destroy = audiotrack_stream_destroy,
   .stream_start = audiotrack_stream_start,
   .stream_stop = audiotrack_stream_stop,
-  .stream_get_position = audiotrack_stream_get_position
+  .stream_get_position = audiotrack_stream_get_position,
+  .stream_get_latency = audiotrack_stream_get_latency
 };