circuitpython/shared-module/audiomp3/MP3File.h
Jeff Epler 1cdac3f16a MP3File: Fix stereo playback on samd AudioOut
There were several problems with the way this worked -- the read_count
approach was too complicated and I made a mistake "simplifying" it from
WaveFile.  And when the right channel was returned, it was off by 1 byte,
making it into static.

Instead, directly track which is the "other" channel that has data
available, and by using the right data type make the "+ channel"
arithmetic give the right result.

This requires a double cast (int16_t*)(void*) due to an alignment warning;
the alignment is now ensured manually, but the compiler doesn't make the
necessary inference that the low address bit must be clear.
2019-12-12 08:44:15 -06:00

71 lines
2.9 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2018 Scott Shawcroft
* Copyright (c) 2019 Jeff Epler for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef MICROPY_INCLUDED_SHARED_MODULE_AUDIOIO_MP3FILE_H
#define MICROPY_INCLUDED_SHARED_MODULE_AUDIOIO_MP3FILE_H
#include "extmod/vfs_fat.h"
#include "py/obj.h"
#include "shared-module/audiocore/__init__.h"
typedef struct {
mp_obj_base_t base;
struct _MP3DecInfo *decoder;
uint8_t* inbuf;
uint32_t inbuf_length;
uint32_t inbuf_offset;
int16_t* buffers[2];
uint32_t len;
uint32_t frame_buffer_size;
uint32_t sample_rate;
pyb_file_obj_t* file;
uint8_t buffer_index;
uint8_t channel_count;
bool eof;
int8_t other_channel;
int8_t other_buffer_index;
} audiomp3_mp3file_obj_t;
// These are not available from Python because it may be called in an interrupt.
void audiomp3_mp3file_reset_buffer(audiomp3_mp3file_obj_t* self,
bool single_channel,
uint8_t channel);
audioio_get_buffer_result_t audiomp3_mp3file_get_buffer(audiomp3_mp3file_obj_t* self,
bool single_channel,
uint8_t channel,
uint8_t** buffer,
uint32_t* buffer_length); // length in bytes
void audiomp3_mp3file_get_buffer_structure(audiomp3_mp3file_obj_t* self, bool single_channel,
bool* single_buffer, bool* samples_signed,
uint32_t* max_buffer_length, uint8_t* spacing);
#endif // MICROPY_INCLUDED_SHARED_MODULE_AUDIOIO_MP3FILE_H