diff options
Diffstat (limited to 'examples/sound/cdstream/stream.h')
| -rw-r--r-- | examples/sound/cdstream/stream.h | 67 |
1 files changed, 48 insertions, 19 deletions
diff --git a/examples/sound/cdstream/stream.h b/examples/sound/cdstream/stream.h index aa384ed..ab28f50 100644 --- a/examples/sound/cdstream/stream.h +++ b/examples/sound/cdstream/stream.h @@ -32,7 +32,9 @@ /* Type definitions */ -typedef uint32_t *(*Stream_Callback)(void); +typedef uint32_t Stream_Time; +typedef void (*Stream_Callback)(void); +typedef Stream_Time (*Stream_TimerFunction)(void); /** * @brief Stream initialization settings structure. @@ -45,20 +47,24 @@ typedef uint32_t *(*Stream_Callback)(void); * cannot be used. The channel mask is a bitfield whose bits represent which SPU * channels the stream is going to use: for instance, a value of 0b1101 will * assign the first channel of the stream to SPU channel 0, the second channel - * to SPU channel 2 and the third channel to SPU channel 3. The sample rate is - * in Hertz, while the interleave and buffer size are in bytes. - * - * The refill threshold, refill callback and underrun callback are optional. If - * provided, the callbacks will be invoked by the SPU IRQ handler once the - * FIFO's length goes below the specified threshold and once it reaches zero, - * respectively. + * to SPU channel 2 and the third channel to SPU channel 3. The sample rate and + * optional timer rate are in Hertz, while the interleave and buffer size are in + * bytes. + * + * The refill threshold, refill callback, underrun callback and timer function + * are optional. If provided, the callbacks will be invoked by the SPU IRQ + * handler once the FIFO's length goes below the specified threshold and once it + * reaches zero, respectively. The timer function will be used to improve the + * accuracy of Stream_GetSamplesPlayed(); if not provided, VSync(-1) will be + * used by default. */ typedef struct { uint32_t spu_address, channel_mask; size_t interleave, buffer_size, refill_threshold; - int sample_rate; + int sample_rate, timer_rate; - Stream_Callback refill_callback, underrun_callback; + Stream_Callback refill_callback, underrun_callback; + Stream_TimerFunction timer_function; } Stream_Config; typedef struct { @@ -71,20 +77,20 @@ typedef struct { * * @details This structure represents a single audio stream. An arbitrary number * of streams may be created concurrently, however only one can be active at a - * time (as the SPU only provides a single interrupt). With the exception of the - * chunk counter, most fields are only used internally and shall not be accessed - * directly. + * time (as the SPU only provides a single interrupt). All fields are only used + * internally and shall not be accessed directly. */ typedef struct { Stream_Config config; volatile Stream_Buffer buffer; void *old_irq_handler, *old_dma_handler; - size_t chunk_size; + size_t chunk_size, samples_per_chunk; uint8_t num_channels; - volatile uint8_t db_active, buffering, callback_issued; - volatile uint32_t chunk_counter; + volatile uint8_t db_active, buffering, callback_issued; + volatile Stream_Time last_updated, last_stopped, play_time; + volatile int new_sample_rate; } Stream_Context; /* Public API */ @@ -146,9 +152,9 @@ bool Stream_Stop(void); /** * @brief Changes the sampling rate of a stream. * - * @details If the stream is currently active the pitch of the SPU channels - * assigned to it is changed to match the new value, otherwise the new sampling - * rate will be applied once the stream is started. + * @details If the stream is currently active the change will apply on the next + * FIFO data pull, otherwise the new sampling rate will be applied once the + * stream is started or resumed. * * @param ctx * @param value @@ -164,6 +170,29 @@ void Stream_SetSampleRate(Stream_Context *ctx, int value); bool Stream_IsActive(const Stream_Context *ctx); /** + * @brief Returns an estimate of how many audio samples have been played so far. + * + * @details The returned value can be divided by the stream's sampling rate to + * obtain the total playback time in seconds. The value is interpolated over + * time using VSync(-1) as a time reference by default. If greater accuracy is + * required, a custom timer function can be provided instead by setting the + * appropriate fields in the configuration object before calling Stream_Init(). + * + * @param ctx + * @return Number of audio samples + * + * @see Stream_ResetSamplesPlayed() + */ +uint32_t Stream_GetSamplesPlayed(const Stream_Context *ctx); + +/** + * @brief Resets the audio sample counter returned by Stream_GetSamplesPlayed(). + * + * @param ctx + */ +void Stream_ResetSamplesPlayed(Stream_Context *ctx); + +/** * @brief Returns how many bytes in a stream's FIFO are currently empty and can * be filled. * |