Factor out buffer provider code from AudioMixer
In preparation for playback rate support and timestretching.
Bug: 19196501
Change-Id: I435accb852d32110dd0b3a9917488522c567ba80
diff --git a/services/audioflinger/BufferProviders.h b/services/audioflinger/BufferProviders.h
new file mode 100644
index 0000000..7145b80
--- /dev/null
+++ b/services/audioflinger/BufferProviders.h
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_BUFFER_PROVIDERS_H
+#define ANDROID_BUFFER_PROVIDERS_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <hardware/audio_effect.h>
+#include <media/AudioBufferProvider.h>
+#include <system/audio.h>
+
+namespace android {
+
+// ----------------------------------------------------------------------------
+
+class PassthruBufferProvider : public AudioBufferProvider {
+public:
+ PassthruBufferProvider() : mTrackBufferProvider(NULL) { }
+
+ virtual ~PassthruBufferProvider() { }
+
+ // call this to release the buffer to the upstream provider.
+ // treat it as an audio discontinuity for future samples.
+ virtual void reset() { }
+
+ // set the upstream buffer provider. Consider calling "reset" before this function.
+ virtual void setBufferProvider(AudioBufferProvider *p) {
+ mTrackBufferProvider = p;
+ }
+
+protected:
+ AudioBufferProvider *mTrackBufferProvider;
+};
+
+// Base AudioBufferProvider class used for DownMixerBufferProvider, RemixBufferProvider,
+// and ReformatBufferProvider.
+// It handles a private buffer for use in converting format or channel masks from the
+// input data to a form acceptable by the mixer.
+// TODO: Make a ResamplerBufferProvider when integers are entirely removed from the
+// processing pipeline.
+class CopyBufferProvider : public PassthruBufferProvider {
+public:
+ // Use a private buffer of bufferFrameCount frames (each frame is outputFrameSize bytes).
+ // If bufferFrameCount is 0, no private buffer is created and in-place modification of
+ // the upstream buffer provider's buffers is performed by copyFrames().
+ CopyBufferProvider(size_t inputFrameSize, size_t outputFrameSize,
+ size_t bufferFrameCount);
+ virtual ~CopyBufferProvider();
+
+ // Overrides AudioBufferProvider methods
+ virtual status_t getNextBuffer(Buffer *buffer, int64_t pts);
+ virtual void releaseBuffer(Buffer *buffer);
+
+ // Overrides PassthruBufferProvider
+ virtual void reset();
+
+ // this function should be supplied by the derived class. It converts
+ // #frames in the *src pointer to the *dst pointer. It is public because
+ // some providers will allow this to work on arbitrary buffers outside
+ // of the internal buffers.
+ virtual void copyFrames(void *dst, const void *src, size_t frames) = 0;
+
+protected:
+ const size_t mInputFrameSize;
+ const size_t mOutputFrameSize;
+private:
+ AudioBufferProvider::Buffer mBuffer;
+ const size_t mLocalBufferFrameCount;
+ void *mLocalBufferData;
+ size_t mConsumed;
+};
+
+// DownmixerBufferProvider derives from CopyBufferProvider to provide
+// position dependent downmixing by an Audio Effect.
+class DownmixerBufferProvider : public CopyBufferProvider {
+public:
+ DownmixerBufferProvider(audio_channel_mask_t inputChannelMask,
+ audio_channel_mask_t outputChannelMask, audio_format_t format,
+ uint32_t sampleRate, int32_t sessionId, size_t bufferFrameCount);
+ virtual ~DownmixerBufferProvider();
+ //Overrides
+ virtual void copyFrames(void *dst, const void *src, size_t frames);
+
+ bool isValid() const { return mDownmixHandle != NULL; }
+ static status_t init();
+ static bool isMultichannelCapable() { return sIsMultichannelCapable; }
+
+protected:
+ effect_handle_t mDownmixHandle;
+ effect_config_t mDownmixConfig;
+
+ // effect descriptor for the downmixer used by the mixer
+ static effect_descriptor_t sDwnmFxDesc;
+ // indicates whether a downmix effect has been found and is usable by this mixer
+ static bool sIsMultichannelCapable;
+ // FIXME: should we allow effects outside of the framework?
+ // We need to here. A special ioId that must be <= -2 so it does not map to a session.
+ static const int32_t SESSION_ID_INVALID_AND_IGNORED = -2;
+};
+
+// RemixBufferProvider derives from CopyBufferProvider to perform an
+// upmix or downmix to the proper channel count and mask.
+class RemixBufferProvider : public CopyBufferProvider {
+public:
+ RemixBufferProvider(audio_channel_mask_t inputChannelMask,
+ audio_channel_mask_t outputChannelMask, audio_format_t format,
+ size_t bufferFrameCount);
+ //Overrides
+ virtual void copyFrames(void *dst, const void *src, size_t frames);
+
+protected:
+ const audio_format_t mFormat;
+ const size_t mSampleSize;
+ const size_t mInputChannels;
+ const size_t mOutputChannels;
+ int8_t mIdxAry[sizeof(uint32_t) * 8]; // 32 bits => channel indices
+};
+
+// ReformatBufferProvider derives from CopyBufferProvider to convert the input data
+// to an acceptable mixer input format type.
+class ReformatBufferProvider : public CopyBufferProvider {
+public:
+ ReformatBufferProvider(int32_t channelCount,
+ audio_format_t inputFormat, audio_format_t outputFormat,
+ size_t bufferFrameCount);
+ virtual void copyFrames(void *dst, const void *src, size_t frames);
+
+protected:
+ const uint32_t mChannelCount;
+ const audio_format_t mInputFormat;
+ const audio_format_t mOutputFormat;
+};
+
+// ----------------------------------------------------------------------------
+} // namespace android
+
+#endif // ANDROID_BUFFER_PROVIDERS_H