output/sles: support floating point samples

NEWS

 ver 0.21.26 (not yet released)
+* output
+  - sles: support floating point samples
 
 ver 0.21.25 (2020/07/06)
 * protocol:

src/output/plugins/sles/SlesOutputPlugin.cxx

@@ -173,12 +173,12 @@ SlesOutput::Open(AudioFormat &audio_format)
 	if (audio_format.channels > 2)
 		audio_format.channels = 1;
 
-	SLDataFormat_PCM format_pcm;
+	SLAndroidDataFormat_PCM_EX format_pcm;
 	format_pcm.formatType = SL_DATAFORMAT_PCM;
 	format_pcm.numChannels = audio_format.channels;
 	/* from the Android NDK docs: "Note that the field samplesPerSec is
 	   actually in units of milliHz, despite the misleading name." */
-	format_pcm.samplesPerSec = audio_format.sample_rate * 1000u;
+	format_pcm.sampleRate = audio_format.sample_rate * 1000u;
 	format_pcm.bitsPerSample = SL_PCMSAMPLEFORMAT_FIXED_16;
 	format_pcm.containerSize = SL_PCMSAMPLEFORMAT_FIXED_16;
 	format_pcm.channelMask = audio_format.channels == 1
@@ -187,6 +187,7 @@ SlesOutput::Open(AudioFormat &audio_format)
 	format_pcm.endianness = IsLittleEndian()
 		? SL_BYTEORDER_LITTLEENDIAN
 		: SL_BYTEORDER_BIGENDIAN;
+	format_pcm.representation = SL_ANDROID_PCM_REPRESENTATION_SIGNED_INT;
 
 	switch (audio_format.format) {
 		/* note: Android doesn't support
@@ -201,6 +202,16 @@ SlesOutput::Open(AudioFormat &audio_format)
 		   bit */
 		break;
 
+	case SampleFormat::FLOAT:
+		/* Android has an OpenSLES extension for floating
+		   point samples:
+		   https://developer.android.com/ndk/guides/audio/opensl/android-extensions */
+		format_pcm.formatType = SL_ANDROID_DATAFORMAT_PCM_EX;
+		format_pcm.bitsPerSample = format_pcm.containerSize =
+			SL_PCMSAMPLEFORMAT_FIXED_32;
+		format_pcm.representation = SL_ANDROID_PCM_REPRESENTATION_FLOAT;
+		break;
+
 	default:
 		/* fall back to 16 bit */
 		audio_format.format = SampleFormat::S16;