Merge "qcom/audio/hal: add offset to MMAP output time"
diff --git a/hal/audio_hw.c b/hal/audio_hw.c
index f8bf0c9..2807bcc 100644
--- a/hal/audio_hw.c
+++ b/hal/audio_hw.c
@@ -3789,6 +3789,17 @@
ALOGV("%s requested config.period_count = %d", __func__, config->period_count);
}
+// Read offset for the positional timestamp from a persistent vendor property.
+// This is to workaround apparent inaccuracies in the timing information that
+// is used by the AAudio timing model. The inaccuracies can cause glitches.
+static int64_t get_mmap_out_time_offset() {
+ const int32_t kDefaultOffsetMicros = 0;
+ int32_t mmap_time_offset_micros = property_get_int32(
+ "persist.audio.out_mmap_delay_micros", kDefaultOffsetMicros);
+ ALOGI("mmap_time_offset_micros = %d for output", mmap_time_offset_micros);
+ return mmap_time_offset_micros * (int64_t)1000;
+}
+
static int out_create_mmap_buffer(const struct audio_stream_out *stream,
int32_t min_size_frames,
struct audio_mmap_buffer_info *info)
@@ -3866,6 +3877,8 @@
goto exit;
}
+ out->mmap_time_offset_nanos = get_mmap_out_time_offset();
+
out->standby = false;
ret = 0;
@@ -3909,7 +3922,9 @@
ALOGE("%s: %s", __func__, pcm_get_error(out->pcm));
goto exit;
}
- position->time_nanoseconds = audio_utils_ns_from_timespec(&ts);
+ position->time_nanoseconds = audio_utils_ns_from_timespec(&ts)
+ + out->mmap_time_offset_nanos;
+
exit:
pthread_mutex_unlock(&out->lock);
return ret;
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index 7bca070..0992650 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -232,6 +232,7 @@
uint32_t supported_sample_rates[MAX_SUPPORTED_SAMPLE_RATES + 1];
bool muted;
uint64_t written; /* total frames written, not cleared when entering standby */
+ int64_t mmap_time_offset_nanos; /* fudge factor to correct inaccuracies in DSP */
audio_io_handle_t handle;
int non_blocking;