有没有API 可以得到MP3所得能播放的时间的啊？

[prettyladys]

有没有API 可以得到MP3所得能播放的时间的啊？



我播放MP3 但我想时间跟播一起来。可没这样的API可以得到。MSDN我翻傻了。

[qrlvls]

因为涉及到具体的格式信息，没有直接可用的API函数
www.codeproject.com 上有获取MP3信息的代码

[dongfa]

可以使用IMediaDet来检测.它是基于Directshow的.

部分代码如下:


HRESULT hr = S_OK;
do
{
hr = CoCreateInstance(__uuidof(MediaDet), NULL, CLSCTX_ALL,
__uuidof(IMediaDet), (LPVOID *)&m_pMedia);
if(FAILED(hr))
break;

CComBSTR szFile(lpszFile);
hr = m_pMedia->put_Filename(szFile.m_str);
if(FAILED(hr))
break;

long lCount = 0;
hr = m_pMedia->get_OutputStreams(&lCount);
if(FAILED(hr))
break;

for(long i = 0; i < lCount; i ++)
{
hr = m_pMedia->put_CurrentStream(i);
if(FAILED(hr))
break;

AM_MEDIA_TYPE aet;
hr = m_pMedia->get_StreamMediaType(&aet);
if(FAILED(hr))
break;

if((aet.formattype == FORMAT_VideoInfo) && (aet.cbFormat >= sizeof(VIDEOINFOHEADER)) && (aet.pbFormat != NULL))
{
double dLen = 0.0f;
hr = m_pMedia->get_StreamLength(&dLen);
if(FAILED(hr))
continue ;

double dRate = 0.0f;
hr = m_pMedia->get_FrameRate(&dRate);
if(FAILED(hr))
continue ;

m_bHasVideo = TRUE;
m_dVideoLen = dLen;
m_dVideoFrameRate = dRate;
m_lVideoLen = (DWORD)(m_dVideoLen*m_dVideoFrameRate);

VIDEOINFOHEADER *pVIH = (VIDEOINFOHEADER*)aet.pbFormat;
m_lVideoWidth = pVIH->bmiHeader.biWidth;
m_lVideoHeight = pVIH->bmiHeader.biHeight;
m_sVideoBitCount = pVIH->bmiHeader.biBitCount;
}

if((aet.formattype == FORMAT_WaveFormatEx) && (aet.cbFormat >= sizeof(WAVEFORMATEX)) && (aet.pbFormat != NULL))
{
double dLen = 0.0f;
hr = m_pMedia->get_StreamLength(&dLen);
if(FAILED(hr))
continue ;

m_bHasAudio = TRUE;
m_dAudioLen = dLen;
double dRate = m_dVideoFrameRate;
if(dRate <= 0.1f)
dRate = 25.0f;
m_lAudioLen = (DWORD)(m_dAudioLen*dRate);
WAVEFORMATEX *pWFE = (WAVEFORMATEX *)aet.pbFormat;
m_sAudioNumChannels = pWFE->nChannels;
m_sAudioBitsPerSample = pWFE->wBitsPerSample;
m_lAudioSamplesPerSecond = pWFE->nSamplesPerSec;
}
}
}while(0);