157 lines
5.1 KiB
C
157 lines
5.1 KiB
C
/****************************************************************************
|
|
* include/nuttx/audio/pcm.h
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you 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 __INCLUDE_NUTTX_AUDIO_PCM_H
|
|
#define __INCLUDE_NUTTX_AUDIO_PCM_H
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <stdint.h>
|
|
#include <stdbool.h>
|
|
|
|
#include <nuttx/irq.h>
|
|
|
|
#ifdef CONFIG_AUDIO_FORMAT_PCM
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/* Configuration ************************************************************
|
|
*
|
|
* CONFIG_AUDIO_FORMAT_PCM - Enabled PCM support
|
|
*/
|
|
|
|
/* Pre-requisites */
|
|
|
|
#ifndef CONFIG_AUDIO
|
|
# error CONFIG_AUDIO is required for PCM support
|
|
#endif
|
|
|
|
/* Default configuration values */
|
|
|
|
/* WAVE Header Definitions **************************************************/
|
|
|
|
/* All values are little 32-bit or 16-bit endian */
|
|
|
|
#define WAV_HDR_CHUNKID 0x46464952 /* "RIFF" */
|
|
#define WAV_HDR_FORMAT 0x45564157 /* "WAVE" */
|
|
#define WAV_FMT_CHUNKID 0x20746d66 /* "fmt " */
|
|
#define WAV_FMT_CHUNKLEN 16 /* Size of a PCM subchunk */
|
|
#define WAV_FMT_FORMAT 1 /* Linear quantization */
|
|
#define WAV_FMT_MONO 1 /* nchannels=1 */
|
|
#define WAV_FMT_STEREO 2 /* nchannels=2 */
|
|
#define WAV_DATA_CHUNKID 0x61746164 /* "data" */
|
|
|
|
/****************************************************************************
|
|
* Public Types
|
|
****************************************************************************/
|
|
|
|
/* The standard WAV header consist of three chunks
|
|
*
|
|
* 1. A WAV header chunk,
|
|
* 2. A format chunk, and
|
|
* 3. A data chunk.
|
|
*/
|
|
|
|
struct wav_hdrchunk_s
|
|
{
|
|
uint32_t chunkid; /* Contains the letters "RIFF" in ASCII form. */
|
|
uint32_t chunklen; /* Size of the rest of the following chunk */
|
|
uint32_t format; /* Contains the letters "WAVE" */
|
|
};
|
|
|
|
struct wav_formatchunk_s
|
|
{
|
|
uint32_t chunkid; /* Contains the letters "fmt " */
|
|
uint32_t chunklen; /* Size of the following chunk (16 for PCM) */
|
|
uint16_t format; /* PCM=1 (i.e. Linear quantization) */
|
|
uint16_t nchannels; /* Mono=1, Stereo=2 */
|
|
uint32_t samprate; /* 8000, 44100, ... */
|
|
uint32_t byterate; /* samprate * nchannels * bpsamp / 8 */
|
|
uint16_t align; /* nchannels * bpsamp / 8 */
|
|
uint16_t bpsamp; /* Bits per sample: 8 bits = 8, 16 bits = 16 */
|
|
};
|
|
|
|
struct wav_datachunk_s
|
|
{
|
|
uint32_t chunkid; /* Contains the letters "data" */
|
|
uint32_t chunklen; /* Number of bytes in the data */
|
|
};
|
|
|
|
/* The standard WAV file header format is then these three chunks */
|
|
|
|
struct wav_header_s
|
|
{
|
|
struct wav_hdrchunk_s hdr;
|
|
struct wav_formatchunk_s fmt;
|
|
struct wav_datachunk_s data;
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Public Data
|
|
****************************************************************************/
|
|
|
|
#ifdef __cplusplus
|
|
#define EXTERN extern "C"
|
|
extern "C"
|
|
{
|
|
#else
|
|
#define EXTERN extern
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: pcm_decode_initialize
|
|
*
|
|
* Description:
|
|
* Initialize the PCM device. The PCM device accepts and contains a
|
|
* low-level audio DAC-type device. It then returns a new audio lower
|
|
* half interface at adds a PCM decoding from end to the low-level
|
|
* audio device
|
|
*
|
|
* Input Parameters:
|
|
* dev - A reference to the low-level audio DAC-type device to contain.
|
|
*
|
|
* Returned Value:
|
|
* On success, a new audio device instance is returned that wraps the
|
|
* low-level device and provides a PCM decoding front end. NULL is
|
|
* returned on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
FAR struct audio_lowerhalf_s *
|
|
pcm_decode_initialize(FAR struct audio_lowerhalf_s *dev);
|
|
|
|
#undef EXTERN
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* CONFIG_AUDIO_FORMAT_PCM */
|
|
#endif /* __INCLUDE_NUTTX_AUDIO_PCM_H */
|