CODEWITHSUNDEEP
c#windows-phone-8
Tinoy Jameson
Tinoy Jameson

Reputation: 413

AMR-NB audio support in Windows Phone 8

Does windows phone 8 supports amr-nb audio format? Can we convert the amr-nb to pcm in windows phone 8?

Upvotes: 1

Views: 313

Answers (1)

AlexisXu
AlexisXu

Reputation: 126

yes...we can do that. In Windows Phone 8 you can use c++ code now.

I have done this correctly.You can following these steps:

  1. create c++ runtime project

  2. intergate amr-nb code to the c++ runtime project

  3. in your c# project, call the function to do the matters.

and the code 

int DecodeAMRFileToWAVEFile(const char* pchAMRFileName, const char* pchWAVEFilename)
{
    FILE* fpamr = NULL;
FILE* fpwave = NULL;
char magic[8];
void * destate;
int nFrameCount = 0;
int stdFrameSize;
unsigned char stdFrameHeader;

unsigned char amrFrame[MAX_AMR_FRAME_SIZE];
short pcmFrame[PCM_FRAME_SIZE];

fpamr = fopen(pchAMRFileName, "rb");
if ( fpamr==NULL ) return 0;

// 检查amr文件头
fread(magic, sizeof(char), strlen(AMR_MAGIC_NUMBER), fpamr);
if (strncmp(magic, AMR_MAGIC_NUMBER, strlen(AMR_MAGIC_NUMBER)))
{
    fclose(fpamr);
    return 0;
}

// 创建并初始化WAVE文件
fpwave = fopen(pchWAVEFilename, "wb");
WriteWAVEFileHeader(fpwave, nFrameCount);

/* init decoder */
destate = Decoder_Interface_init();

// 读第一帧 - 作为参考帧
memset(amrFrame, 0, sizeof(amrFrame));
memset(pcmFrame, 0, sizeof(pcmFrame));
ReadAMRFrameFirst(fpamr, amrFrame, &stdFrameSize, &stdFrameHeader);

// 解码一个AMR音频帧成PCM数据
Decoder_Interface_Decode(destate, amrFrame, pcmFrame, 0);
nFrameCount++;
fwrite(pcmFrame, sizeof(short), PCM_FRAME_SIZE, fpwave);

// 逐帧解码AMR并写到WAVE文件里
while(1)
{
    memset(amrFrame, 0, sizeof(amrFrame));
    memset(pcmFrame, 0, sizeof(pcmFrame));
    if (!ReadAMRFrame(fpamr, amrFrame, stdFrameSize, stdFrameHeader)) break;

    // 解码一个AMR音频帧成PCM数据 (8k-16b-单声道)
    Decoder_Interface_Decode(destate, amrFrame, pcmFrame, 0);
    nFrameCount++;
    fwrite(pcmFrame, sizeof(short), PCM_FRAME_SIZE, fpwave);
}

Decoder_Interface_exit(destate);

fclose(fpamr);
fclose(fpwave);

// 重写WAVE文件头
fpwave = fopen(pchWAVEFilename, "r+");
WriteWAVEFileHeader(fpwave, nFrameCount);
fclose(fpwave);

return nFrameCount;
}

the comments are writen in Chinese :D

Upvotes: 2

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