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主控：STM32F103ZET6
文件系统：FATFS R0.07c
SDIO 4bit DMA
软解码：helix mp3
功能：上电从SD卡读取MP3文件，调用helix 库解码MP3，将解码后的数据传到I2S2 codec上播放
问题：解码没问题，播放可以听到完整歌曲，但有吱吱的杂音，不知道是不是I2S2 Master的问题，看论坛上stm32 radio好象有说过这个问题
以下是播放程序代码：
/**
******************************************************************************
* @file Project/play.c
* @author baiweijishu
* @version V1.0.0
* @date 28/09/2011
* @brief this file provides all audio play relevant function
******************************************************************************
* @copy
*
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
* TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
* DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
* FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
* CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*
* <h2>© COPYRIGHT 2011 baiweijishu</h2>
*/
/* Includes ------------------------------------------------------------------*/
#include "stm3210e_eval_lcd.h"
#include "i2s_codec.h"
#include "sdcard.h"
#include "ff.h"
#include <string.h>
#include "mp3dec.h"
#include "mp3common.h"
/* Audio file location */
#define AUDIO_FILE_ADDRESS 0x64060000
extern __IO uint32_t AudioDataIndex;
s16 outbuf[4608]; // Playback buffer - Value must be 4608 to hold 2xMp3decoded frames.
// MP3
#define READBUF_SIZE 4000 // Value must min be 2xMAINBUF_SIZE = 2x1940 = 3880bytes
MP3FrameInfo mp3FrameInfo; // Content is the output from MP3GetLastFrameInfo,
// we only read this once, and conclude it will be the same in all frames
// Maybe this needs to be changed, for different requirements.
static HMP3Decoder hMP3Decoder; // Content is the pointers to all buffers and information for the MP3 Library
u32 Old_Pll; // Saves the PLL setting before we change it to Very high speed in MP3 section
volatile u32 bytesLeft; // Saves how many bytes left in readbuf
volatile u32 outOfData; // Used to set when out of data to quit playback
u8 readBuf[READBUF_SIZE]; // Read buffer where data from SD card is read to
u8 *readPtr; // Pointer to the next new data
u32 offset; // Used to save the offset to the next frame
u32 err=0; // Return value from MP3decoder
// MP3 END
void play_mp3(void)
{
FRESULT fsresult;
FATFS fs;
FILINFO finfo;
DIR dir;
FIL file;
UINT cnt;
/* Initilizes the MP3 Library */
hMP3Decoder = MP3InitDecoder();
/*open mp3 file*/
fsresult = f_mount(0, &fs);
fsresult = f_opendir(&dir,"");
fsresult = f_open(&file, "a.mp3", FA_READ);
/* Reset counters */
bytesLeft = 0;
outOfData = 0;
readPtr = readBuf;
/* Initialize the application environment(I2S, I2C, codec,memory) */
printf("I2S_CODEC_Init \n\r");
I2S_CODEC_Init(OutputDevice_HEADPHONE, AUDIO_FILE_ADDRESS);
printf("I2S_CODEC_Init finish\n\r");
/* Enable Playing the audio file */
I2S_CODEC_Play(GetVar_DataStartAddr());
fsresult = f_read(&file,readBuf,READBUF_SIZE,&cnt);
bytesLeft += cnt;
while(1)
{
/* find start of next MP3 frame - assume EOF if no sync found */
offset = MP3FindSyncWord(readPtr, bytesLeft);
if (offset < 0) {
outOfData = 1;
return;
}
else
{
readPtr += offset; //data start point
bytesLeft -= offset; //in buffer
err = MP3Decode(hMP3Decoder, &readPtr, &bytesLeft, outbuf, 0);
if (bytesLeft < READBUF_SIZE)
{
memmove(readBuf,readPtr,bytesLeft);
fsresult = f_read(&file, readBuf + bytesLeft, READBUF_SIZE - bytesLeft, &cnt);
if (cnt < READBUF_SIZE - bytesLeft)
memset(readBuf + bytesLeft + cnt, 0, READBUF_SIZE - bytesLeft - cnt);
bytesLeft=READBUF_SIZE;
readPtr=readBuf;
}
MP3GetLastFrameInfo(hMP3Decoder, &mp3FrameInfo);
// printf("mp3FrameInfo.samprate=%d\n\r",mp3FrameInfo.samprate);
// printf("mp3FrameInfo.nChans=%d\n\r",mp3FrameInfo.nChans);
// printf("mp3FrameInfo.samprate=%d\n\r",mp3FrameInfo.samprate);
// printf("mp3FrameInfo.outputSamps=%d\n\r",mp3FrameInfo.outputSamps);
// printf("mp3FrameInfo.layer=%d\n\r",mp3FrameInfo.layer);
// printf("mp3FrameInfo.version=%d\n\r",mp3FrameInfo.version);
// printf("mp3FrameInfo.bitrate=%d\n\r",mp3FrameInfo.bitrate/1000);
//
// for(cnt=0;cnt<mp3FrameInfo.outputSamps;cnt++)
// printf("%d ",outbuf[cnt]);
// LCD_DisplayStringLine(Line3, "debug by zhangxl");
printf("debug by zhangxl \n\r");
while (AudioDataIndex < mp3FrameInfo.outputSamps)
printf("I2S_CODEC_Play \n\r");
AudioDataIndex=0;
}
}
}
/******************* (C) COPYRIGHT 2011 baiweijishu *****END OF FILE****/ |
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发表于 2011-10-1 23:28:27
楼主
可惜东西不全
楼主能否上传点资料？？？？
。看来我找资料的能力还很欠缺
