/* * 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 #include #include #include #include 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; /** * 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 AudioClient 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,out] sessionId audio sessionId for the stream * Requested as input, may be AUDIO_SESSION_ALLOCATE * 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 * \param[out] same unique handle as the one used for the first client stream started. * \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 AudioClient& client, audio_port_handle_t *deviceId, audio_session_t *sessionId, const sp& callback, sp& interface, audio_port_handle_t *handle); /** * Retrieve information on the mmap buffer used for audio samples transfer. * Must be called before any other method after opening the stream or entering standby. * * \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. * NO_INIT in case of initialization error * 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; /** * Get a recent count of the number of audio frames presented/received to/from an * external observer. * * \param[out] position count of presented audio frames * \param[out] timeNanos associated clock time * * \return OK if the external position is set correctly. * NO_INIT in case of initialization error * INVALID_OPERATION if the interface is not implemented */ virtual status_t getExternalPosition(uint64_t* position, int64_t* timeNanos) = 0; /** * Start a stream operating in mmap mode. * createMmapBuffer() must be called before calling start() * * \param[in] client a AudioClient struct describing the client starting on this stream. * \param[in] attr audio attributes provided by the client. * \param[out] handle unique handle for this instance. Used with stop(). * \return OK in case of success. * NO_INIT in case of initialization error * INVALID_OPERATION if called out of sequence */ virtual status_t start(const AudioClient& client, const audio_attributes_t *attr, 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. * NO_INIT in case of initialization error * INVALID_OPERATION if called out of sequence */ virtual status_t stop(audio_port_handle_t handle) = 0; /** * Put a stream operating in mmap mode into standby. * Must be called after createMmapBuffer(). Cannot be called if any client is active. * It is recommended to place a mmap stream into standby as often as possible when no client is * active to save power. * * \return OK in case of success. * NO_INIT in case of initialization error * INVALID_OPERATION if called out of sequence */ virtual status_t standby() = 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