Applications: nrf5340_audio: Add audio struct

Add framework for transferring audio.
OCT-2690

Signed-off-by: Kristoffer Rist Skøien <kristoffer.skoien@nordicsemi.no>

include/audio_defines.h

@@ -11,6 +11,9 @@
 #ifndef _AUDIO_DEFINES_H_
 #define _AUDIO_DEFINES_H_
 
+#include <zephyr/types.h>
+#include <stdbool.h>
+
 /**
  * @brief Audio channel assignment values
  */
@@ -20,4 +23,81 @@ enum audio_channel {
  AUDIO_CH_NUM,
 };
 
+/**
+ * @brief Audio data coding.
+ */
+enum coding {
+ /* Raw PCM audio data */
+ PCM = 1,
+
+ /* LC3-coded audio data */
+ LC3
+};
+
+struct audio_metadata {
+ /* Indicates the data type/encoding. */
+ enum coding data_coding;
+
+ /* Playback length in microseconds. */
+ uint32_t data_len_us;
+
+ /* The audio sample rate.
+ * This may typically be 16000, 24000, 44100 or 48000 Hz.
+ */
+ uint32_t sample_rate_hz;
+
+ /* Number of valid bits for a sample (bit depth). Typically 16 or 24. */
+ uint8_t bits_per_sample;
+
+ /* Number of bits used to carry a sample of size bits_per_sample.
+ * For example, say we have a 24 bit sample stored in a 32 bit
+ * word (int32_t), then:
+ * bits_per_sample = 24
+ * carrier_size = 32
+ */
+ uint8_t carried_bits_pr_sample;
+
+ /* A 32 bit mask indicating which channel(s)/locations are active within
+ * the data. A bit set indicates the location is active and
+ * a count of these will give the number of locations within the
+ * audio stream.
+ * Note: This will follow the ANSI/CTA-861-G’s Table 34 codes
+ * for speaker placement (as used by Bluetooth Low Energy Audio).
+ */
+ uint32_t locations;
+
+ /* Reference time stamp (e.g. ISO timestamp reference from BLE controller). */
+ uint32_t reference_ts_us;
+
+ /* The timestamp for when the data was received. */
+ uint32_t data_rx_ts_us;
+
+ /* A Boolean flag to indicate this data has errors
+ * (true = bad, false = good).
+ * Note: Timestamps are still valid even though this flag is set.
+ */
+ bool bad_data;
+};
+
+/**
+ * @brief A unit of audio.
+ *
+ * This unit can be used anywhere, so it may be an audio block, a frame or something else.
+ * It may contain encoded or raw data, as well as a single or multiple channels.
+ */
+struct audio_data {
+ /* A pointer to the raw or coded data (e.g., PCM, LC3, etc.) buffer. */
+ void *data;
+
+ /* The size in bytes of the data buffer.
+ * To get the size of each channel, this value must be divided by the number of
+ * used channels. Metadata is not included in this figure.
+ */
+ size_t data_size;
+
+ /* Additional information describing the audio data.
+ */
+ struct audio_metadata meta;
+};
+
 #endif /* _AUDIO_DEFINES_H_ */