bdab6c12d4
Before this, the mp3 file would be read into the in-memory buffer only when new samples were actually needed. This meant that the time to read mp3 content always counted against the ~22ms audio buffer length. Now, when there's at least 1 full disk block of free space in the input buffer, we can request that the buffer be filled _after_ returning from audiomp3_mp3file_get_buffer and actually filling the DMA pointers. In this way, the time taken for reading MP3 data from flash/SD is less likely to cause an underrun of audio DMA. The existing calls to fill the inbuf remain, but in most cases during streaming these become no-ops because the buffer will be over half full.
75 lines
3.0 KiB
C
75 lines
3.0 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2018 Scott Shawcroft
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* Copyright (c) 2019 Jeff Epler for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#ifndef MICROPY_INCLUDED_SHARED_MODULE_AUDIOIO_MP3FILE_H
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#define MICROPY_INCLUDED_SHARED_MODULE_AUDIOIO_MP3FILE_H
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#include "supervisor/background_callback.h"
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#include "extmod/vfs_fat.h"
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#include "py/obj.h"
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#include "shared-module/audiocore/__init__.h"
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typedef struct {
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mp_obj_base_t base;
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struct _MP3DecInfo *decoder;
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background_callback_t inbuf_fill_cb;
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uint8_t* inbuf;
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uint32_t inbuf_length;
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uint32_t inbuf_offset;
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int16_t* buffers[2];
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uint32_t len;
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uint32_t frame_buffer_size;
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uint32_t sample_rate;
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pyb_file_obj_t* file;
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uint8_t buffer_index;
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uint8_t channel_count;
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bool eof;
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int8_t other_channel;
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int8_t other_buffer_index;
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} audiomp3_mp3file_obj_t;
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// These are not available from Python because it may be called in an interrupt.
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void audiomp3_mp3file_reset_buffer(audiomp3_mp3file_obj_t* self,
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bool single_channel,
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uint8_t channel);
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audioio_get_buffer_result_t audiomp3_mp3file_get_buffer(audiomp3_mp3file_obj_t* self,
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bool single_channel,
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uint8_t channel,
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uint8_t** buffer,
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uint32_t* buffer_length); // length in bytes
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void audiomp3_mp3file_get_buffer_structure(audiomp3_mp3file_obj_t* self, bool single_channel,
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bool* single_buffer, bool* samples_signed,
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uint32_t* max_buffer_length, uint8_t* spacing);
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float audiomp3_mp3file_get_rms_level(audiomp3_mp3file_obj_t* self);
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#endif // MICROPY_INCLUDED_SHARED_MODULE_AUDIOIO_MP3FILE_H
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