| /* |
| * 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 <media/AudioClient.h> |
| #include <utils/Errors.h> |
| #include <utils/RefBase.h> |
| |
| #include <time.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; |
| |
| /** |
| * 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<MmapStreamCallback>& callback, |
| sp<MmapStreamInterface>& 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 |