gaudio_driver_play.h

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/*
 * This file is subject to the terms of the GFX License. If a copy of
 * the license was not distributed with this file, you can obtain one at:
 *
 *              http://ugfx.io/license.html
 */
 
/**
 * @file    src/gaudio/gaudio_driver_play.h
 * @brief   GAUDIO - Audio play driver header file.
 *
 * @defgroup GAUDIO_Driver_Playback Driver Playback
 * @ingroup GAUDIO
 *
 * @brief Playback driver interface for the GAUDIO module.
 *
 * @{
 */
 
#ifndef _GAUDIO_PLAY_LLD_H
#define _GAUDIO_PLAY_LLD_H
 
#include "../../gfx.h"
 
#if (GFX_USE_GAUDIO && GAUDIO_NEED_PLAY) || defined(__DOXYGEN__)
 
/*===========================================================================*/
/* Type definitions                                                          */
/*===========================================================================*/
 
/*===========================================================================*/
/* External declarations.                                                    */
/*===========================================================================*/
 
#ifdef __cplusplus
extern "C" {
#endif
 
/**
 * @brief               Get a block of audio data to play
 * @return              A pointer to the GAaudioData structure or NULL if none is currently available
 *
 * @note                Defined in the high level GAUDIO code for use by the GAUDIO play drivers.
 *
 * @iclass
 * @notapi
 */
GDataBuffer *gaudioPlayGetDataBlockI(void);
 
/**
 * @brief               Release a block of audio data to the free list
 *
 * @param[in] paud      The GDataBuffer block to be released.
 *
 * @note                Defined in the high level GAUDIO code for use by the GAUDIO play drivers.
 *
 * @iclass
 * @notapi
 */
void gaudioPlayReleaseDataBlockI(GDataBuffer *paud);
 
/**
 * @brief               Signal that all playing has now stopped
 *
 * @note                Defined in the high level GAUDIO code for use by the GAUDIO play drivers.
 *
 * @iclass
 * @notapi
 */
void gaudioPlayDoneI(void);
 
/**
 * @brief               Initialise the play driver
 * @return              gTrue if the channel, frequency and format are valid.
 *
 * @param[in] channel   The channel to use (see the driver for the available channels provided)
 * @param[in] frequency The sample frequency to use
 * @param[in] format    The sample format
 *
 * @note                The driver will always have been stopped and de-init before this is called.
 *
 * @api
 */
gBool gaudio_play_lld_init(gU16 channel, gU32 frequency, ArrayDataFormat format);
 
/**
 * @brief               Start the audio output playing
 *
 * @note                This may be called at any stage including while the driver
 *                      is already playing. The driver should check for data blocks
 *                      to play using @p gaudioPlayGetDataBlockI().
 *
 * @api
 */
void gaudio_play_lld_start(void);
 
/**
 * @brief               Stop the audio output playing.
 *
 * @note                Some drivers may only stop playing at a data block boundary.
 * @note                It is possible but unlikely for it to be called when playing has already stopped.
 * @note                It should not return until all active buffers (currently in use by the driver)
 *                      have been returned to the free-list and @p gaudioPlayDoneI() has been called.
 *
 * @api
 */
void gaudio_play_lld_stop(void);
 
/**
 * @brief               Set the output volume.
 * @return              gTrue if successful.
 *
 * @param[in] vol       0->255 (0 = muted)
 *
 * @note                Some drivers may not support this. They will return gFalse.
 * @note                For stereo devices, both channels are set to the same volume.
 *
 * @api
 */
gBool gaudio_play_lld_set_volume(gU8 vol);
 
#ifdef __cplusplus
}
#endif
 
#endif /* GFX_USE_GAUDIO && GAUDIO_NEED_PLAY */
 
#endif /* _GAUDIO_PLAY_LLD_H */
/** @} */