set SampleRateConversionQuality as Medium by default (#2024)

google · Jun 5, 2024 · 88f9c11 · 88f9c11
1 parent 854e0d4
commit 88f9c11
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Showing 3 changed files with 3 additions and 5 deletions.
diff --git a/docs/FullGuide.md b/docs/FullGuide.md
@@ -491,10 +491,6 @@ builder.setDataCallback(myCallback);
 builder.setPerformanceMode(PerformanceMode::LowLatency);
 ```
 
-### Setting the Sample Rate Conversion Quality
-
-If your streams use different sample rates to the hardware device sample rates then you may experience additional latency in your streams. This is due to the fact the audio buffer must be resampled to/from the the hardware format to your desired software format. This latency can be particularly large if the Sample Rate Conversion Quality is left to the default setting of `oboe::SampleRateConversionQuality::None` as system level APIs (or the hardware itself) will handle the resampling which is MUCH slower and will not be reported as part of the `calculateLatencyMillis()` value. To rectify this (particularly important for the input stream), you should set the following when constructing your stream - `setSampleRateConversionQuality(oboe::SampleRateConversionQuality::Fastest)`.
-
 ## Thread safety
 
 The Oboe API is not completely [thread safe](https://en.wikipedia.org/wiki/Thread_safety).

diff --git a/include/oboe/AudioStreamBase.h b/include/oboe/AudioStreamBase.h
@@ -307,7 +307,7 @@ class AudioStreamBase {
     // Control whether Oboe can convert data formats to achieve optimal results.
     bool                            mFormatConversionAllowed = false;
     // Control whether and how Oboe can convert sample rates to achieve optimal results.
-    SampleRateConversionQuality     mSampleRateConversionQuality = SampleRateConversionQuality::None;
+    SampleRateConversionQuality     mSampleRateConversionQuality = SampleRateConversionQuality::Medium;
 
     /** Validate stream parameters that might not be checked in lower layers */
     virtual Result isValidConfig() {

diff --git a/tests/testStreamOpen.cpp b/tests/testStreamOpen.cpp
@@ -145,6 +145,7 @@ TEST_F(StreamOpenOutput, ForOpenSLESDefaultChannelCountIsUsed){
 TEST_F(StreamOpenOutput, OutputForOpenSLESPerformanceModeShouldBeNone){
     // We will not get a LowLatency stream if we request 16000 Hz.
     mBuilder.setSampleRate(16000);
+    mBuilder.setSampleRateConversionQuality(SampleRateConversionQuality::None);
     mBuilder.setPerformanceMode(PerformanceMode::LowLatency);
     mBuilder.setDirection(Direction::Output);
     mBuilder.setAudioApi(AudioApi::OpenSLES);
@@ -156,6 +157,7 @@ TEST_F(StreamOpenOutput, OutputForOpenSLESPerformanceModeShouldBeNone){
 TEST_F(StreamOpenInput, InputForOpenSLESPerformanceModeShouldBeNone){
     // We will not get a LowLatency stream if we request 16000 Hz.
     mBuilder.setSampleRate(16000);
+    mBuilder.setSampleRateConversionQuality(SampleRateConversionQuality::None);
     mBuilder.setPerformanceMode(PerformanceMode::LowLatency);
     mBuilder.setDirection(Direction::Input);
     mBuilder.setAudioApi(AudioApi::OpenSLES);