From 8e5bc40e2e6563c7d7da1f171bad2a84207b617d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristoffer=20Rist=20Sk=C3=B8ien?=
 <kristoffer.skoien@nordicsemi.no>
Date: Mon, 14 Aug 2023 12:09:03 +0200
Subject: [PATCH] Applications: nrf5340_audio: Add audio struct
MIME-Version: 1.0
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Add framework for transferring audio.
OCT-2690

Signed-off-by: Kristoffer Rist Skøien <kristoffer.skoien@nordicsemi.no>
---
 include/audio_defines.h | 80 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/include/audio_defines.h b/include/audio_defines.h
index f765f2d37c4..f5c11e94931 100644
--- a/include/audio_defines.h
+++ b/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_ */