audioflinger: define MMAP HAL Stream control interface
Added definition of MmapStreamInterface used by Oboe service
to open, configure and control MMAP streams at the audio HAl.
This interface is implemented by audioflinger and abstracts the details
of interacting with audio policy manager and audio HAL from Oboe service.
A callback interface MmapStreamCallback is also defiend to communicate
volume and routing changes back to Oboe service.
Bug: 33398120
Test: build
Change-Id: If953d44903aaa4eb17ff16f1922ca16e5e0e0a87
diff --git a/include/media/MmapStreamCallback.h b/include/media/MmapStreamCallback.h
new file mode 100644
index 0000000..8098e79
--- /dev/null
+++ b/include/media/MmapStreamCallback.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2016 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_AUDIO_MMAP_STREAM_CALLBACK_H
+#define ANDROID_AUDIO_MMAP_STREAM_CALLBACK_H
+
+#include <system/audio.h>
+#include <utils/Errors.h>
+#include <utils/RefBase.h>
+
+namespace android {
+
+
+class MmapStreamCallback : public virtual RefBase {
+ public:
+
+ /**
+ * The mmap stream should be torn down because conditions that permitted its creation with
+ * the requested parameters have changed and do not allow it to operate with the requested
+ * constraints any more.
+ */
+ virtual void onTearDown() = 0;
+
+ /**
+ * The volume to be applied to the use case specified when opening the stream has changed
+ * \param[in] channels a channel mask containing all channels the volume should be applied to.
+ * \param[in] values the volume values to be applied to each channel. The size of the vector
+ * should correspond to the channel count retrieved with
+ * audio_channel_count_from_in_mask() or audio_channel_count_from_out_mask()
+ */
+ virtual void onVolumeChanged(audio_channel_mask_t channels, Vector<float> values) = 0;
+
+ /**
+ * The device the stream is routed to/from has changed
+ * \param[in] onRoutingChanged the unique device ID of the new device.
+ */
+ virtual void onRoutingChanged(audio_port_handle_t deviceId) = 0;
+
+ protected:
+ MmapStreamCallback() {}
+ virtual ~MmapStreamCallback() {}
+};
+
+
+} // namespace android
+
+#endif // ANDROID_AUDIO_MMAP_STREAM_CALLBACK_H
diff --git a/include/media/MmapStreamInterface.h b/include/media/MmapStreamInterface.h
new file mode 100644
index 0000000..9f3731e
--- /dev/null
+++ b/include/media/MmapStreamInterface.h
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2016 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_AUDIO_MMAP_STREAM_INTERFACE_H
+#define ANDROID_AUDIO_MMAP_STREAM_INTERFACE_H
+
+#include <system/audio.h>
+#include <utils/Errors.h>
+#include <utils/RefBase.h>
+
+namespace android {
+
+class MmapStreamCallback;
+
+class MmapStreamInterface : public virtual RefBase
+{
+ public:
+
+ /**
+ * Values for direction argument passed to openMmapStream()
+ */
+ typedef enum {
+ DIRECTION_OUTPUT = 0, /**< open a playback mmap stream */
+ DIRECTION_INPUT, /**< open a capture mmap stream */
+ } stream_direction_t;
+
+ class Client {
+ public:
+ uid_t clientUid;
+ pid_t clientPid;
+ String16 packageName;
+ };
+ /**
+ * Open a playback or capture stream in MMAP mode at the audio HAL.
+ *
+ * \note This method is implemented by AudioFlinger
+ *
+ * \param[in] direction open a playback or capture stream.
+ * \param[in] attr audio attributes defining the main use case for this stream
+ * \param[in,out] config audio parameters (sampling rate, format ...) for the stream.
+ * Requested parameters as input,
+ * Actual parameters as output
+ * \param[in] client a Client struct describing the first client using this stream.
+ * \param[in,out] deviceId audio device the stream should preferably be routed to/from
+ * Requested as input,
+ * Actual as output
+ * \param[in] callback the MmapStreamCallback interface used by AudioFlinger to notify
+ * condition changes affecting the stream operation
+ * \param[out] interface the MmapStreamInterface interface controlling the created stream
+ * \return OK if the stream was successfully created.
+ * NO_INIT if AudioFlinger is not properly initialized
+ * BAD_VALUE if the stream cannot be opened because of invalid arguments
+ * INVALID_OPERATION if the stream cannot be opened because of platform limitations
+ */
+ static status_t openMmapStream(stream_direction_t direction,
+ const audio_attributes_t *attr,
+ audio_config_base_t *config,
+ const Client& client,
+ audio_port_handle_t *deviceId,
+ const sp<MmapStreamCallback>& callback,
+ sp<MmapStreamInterface>& interface);
+
+ /**
+ * Retrieve information on the mmap buffer used for audio samples transfer.
+ *
+ * \param[in] min_size_frames minimum buffer size requested. The actual buffer
+ * size returned in struct audio_mmap_buffer_info can be larger.
+ * \param[out] info address at which the mmap buffer information should be returned.
+ *
+ * \return OK if the buffer was allocated.
+ * NO_INIT in case of initialization error
+ * BAD_VALUE if the requested buffer size is too large
+ * INVALID_OPERATION if called out of sequence (e.g. buffer already allocated)
+ */
+ virtual status_t createMmapBuffer(int32_t minSizeFrames,
+ struct audio_mmap_buffer_info *info) = 0;
+
+ /**
+ * Read current read/write position in the mmap buffer with associated time stamp.
+ *
+ * \param[out] position address at which the mmap read/write position should be returned.
+ *
+ * \return OK if the position is successfully returned.
+ * NOT_ENOUGH_DATA if the position cannot be retrieved
+ * INVALID_OPERATION if called before createMmapBuffer()
+ */
+ virtual status_t getMmapPosition(struct audio_mmap_position *position) = 0;
+
+ /**
+ * Start a stream operating in mmap mode.
+ * createMmapBuffer() must be called before calling start()
+ *
+ * \param[in] client a Client struct describing the client starting on this stream.
+ * \param[out] handle unique handle for this instance. Used with stop().
+ * \return OK in case of success.
+ * INVALID_OPERATION if called out of sequence
+ */
+ virtual status_t start(const Client& client, audio_port_handle_t *handle) = 0;
+
+ /**
+ * Stop a stream operating in mmap mode.
+ * Must be called after start()
+ *
+ * \param[in] handle unique handle allocated by start().
+ * \return OK in case of success.
+ * INVALID_OPERATION if called out of sequence
+ */
+ virtual status_t stop(audio_port_handle_t handle) = 0;
+
+ protected:
+ // Subclasses can not be constructed directly by clients.
+ MmapStreamInterface() {}
+
+ // The destructor automatically closes the stream.
+ virtual ~MmapStreamInterface() {}
+};
+
+} // namespace android
+
+#endif // ANDROID_AUDIO_MMAP_STREAM_INTERFACE_H