mirror of
https://github.com/RaySollium99/picodrive.git
synced 2025-10-27 00:29:39 -04:00
65 lines
1.5 KiB
C
65 lines
1.5 KiB
C
/*
|
|
* MP3 decoding using minimp3
|
|
* (C) kub, 2020
|
|
*
|
|
* This work is licensed under the terms of MAME license.
|
|
* See COPYING file in the top-level directory.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
|
|
#include <pico/pico_int.h>
|
|
#define MINIMP3_IMPLEMENTATION
|
|
#include "minimp3/minimp3.h"
|
|
#include "mp3.h"
|
|
|
|
static mp3dec_t mp3dec;
|
|
static unsigned char mp3_input_buffer[2 * 1024];
|
|
|
|
int mp3dec_start(FILE *f, int fpos_start)
|
|
{
|
|
mp3dec_init(&mp3dec);
|
|
return 0;
|
|
}
|
|
|
|
int mp3dec_decode(FILE *f, int *file_pos, int file_len)
|
|
{
|
|
mp3dec_frame_info_t info;
|
|
unsigned char *readPtr;
|
|
int bytesLeft;
|
|
int offset; // mp3 frame offset from readPtr
|
|
int len;
|
|
int retry = 3;
|
|
|
|
do
|
|
{
|
|
if (*file_pos >= file_len)
|
|
return 1; /* EOF, nothing to do */
|
|
|
|
fseek(f, *file_pos, SEEK_SET);
|
|
bytesLeft = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), f);
|
|
|
|
offset = mp3_find_sync_word(mp3_input_buffer, bytesLeft);
|
|
if (offset < 0) {
|
|
lprintf("find_sync_word (%i/%i) err %i\n",
|
|
*file_pos, file_len, offset);
|
|
*file_pos = file_len;
|
|
return 1; // EOF
|
|
}
|
|
*file_pos += offset;
|
|
readPtr = mp3_input_buffer + offset;
|
|
bytesLeft -= offset;
|
|
|
|
len = mp3dec_decode_frame(&mp3dec, readPtr, bytesLeft, cdda_out_buffer, &info);
|
|
if (len > 0) // retrieved decoded data
|
|
*file_pos += info.frame_bytes;
|
|
else if (info.frame_bytes > 0) // no output but input consumed?
|
|
*file_pos += 1; // try to skip frame
|
|
else if (offset == 0) // bad frame?
|
|
*file_pos += 1; // try resyncing
|
|
// else // truncated frame, try more data
|
|
}
|
|
while (len <= 0 && --retry > 0);
|
|
|
|
return len <= 0;
|
|
}
|