Solved

getting length of  a  wav file

Posted on 1998-05-31
2
294 Views
Last Modified: 2010-08-05
I know it is possible to get the length of a wav file (in milleseconds or seconds) but have not been able to do it.  Below is a function that is supposed to return the length of a wave file (IT DOESN'T WORK... IT RETURNS 0.0 EVERY TIME).  The code uses MCI_WAVE_OPEN_PARMS and mciSendCommand() to open a file (which it does with out error) but the dwBufferSeconds member of MCI_WAVE_OPEN_PARMS is always 0.0 after opening the wav.  Am I wrong in assuming that dwBufferSeconds should hold the length of the wav file opened or am I missing a needed flag or something?  Does somebody know what I am doing wrong or know of another way to get the length of a wav file?  Thanks.

// Function takes LPSTR pointer to string containing the
// path to a wave file, returns length of wave file
long CPlaywaveDlg::GetWavLengthSeconds(LPSTR wavPath)
{       // wavPath points to string containing wave file path
      MCI_WAVE_OPEN_PARMS mciOpenParms;
      
      DWORD mciError, mciFlags;
      int wDeviceID;
#define BUF_LEN 256
      char mciErrorString[BUF_LEN];

      //Initialize data structures...
      mciOpenParms.dwCallback = 0;  // no callback
      mciOpenParms.wDeviceID = 0;  
      mciOpenParms.lpstrDeviceType = "waveaudio";
      mciOpenParms.lpstrElementName = wavPath;
      mciOpenParms.lpstrAlias= NULL;       // no alias
      mciOpenParms.dwBufferSeconds = 0L;  
      mciFlags = MCI_OPEN_TYPE | MCI_OPEN_ELEMENT

      // Send the open command
      mciError = mciSendCommand(0, MCI_OPEN, mciFlags, (DWORD)&mciOpenParms);
      if (!mciError)
      {

            // if open was successful, retrieve the length
            double secs = mciOpenParms.dwBufferSeconds;
               
            mciError = mciSendCommand(wDeviceID, MCI_CLOSE, 0, 0L); // close the file
            }
      

            return secs;  // return the length

      }
      else
      {
            int dummy = mciGetErrorString(mciError, mciErrorString, BUF_LEN);
            
            CString errorMsg = "Media Control Interface Error ";
            errorMsg += mciErrorString;
            MessageBox(errorMsg, "Error", MB_ICONSTOP);
      }
      return -999;  // error

}

0
Comment
Question by:cww1
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 

Author Comment

by:cww1
ID: 1164999
Edited text of question
0
 
LVL 3

Accepted Solution

by:
tma050898 earned 100 total points
ID: 1165000
cww1,

I only have a minute to post this so I'm tryig to copy & paste this out of my code very quickly. Try this and if it doesn't work I'll take a little more time when I get back home...

// Get Minutes...
MCI_STATUS_PARMS StatusParms;
StatusParms.dwItem = MCI_STATUS_POSITION;
mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms);

iMinutes = ((int)((StatusParms.dwReturn / 1000) / 60 ));


// Get seconds...
MCI_STATUS_PARMS StatusParms;
StatusParms.dwItem = MCI_STATUS_POSITION;
mciSendCommand( m_wDeviceID, MCI_STATUS, MCI_WAIT | MCI_STATUS_ITEM, (DWORD)(LPVOID) &StatusParms);

iSeconds = (int)((StatusParms.dwReturn / 1000 ) % 60 ));

Tom
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

When writing generic code, using template meta-programming techniques, it is sometimes useful to know if a type is convertible to another type. A good example of when this might be is if you are writing diagnostic instrumentation for code to generat…
Article by: SunnyDark
This article's goal is to present you with an easy to use XML wrapper for C++ and also present some interesting techniques that you might use with MS C++. The reason I built this class is to ease the pain of using XML files with C++, since there is…
The goal of the tutorial is to teach the user how to use functions in C++. The video will cover how to define functions, how to call functions and how to create functions prototypes. Microsoft Visual C++ 2010 Express will be used as a text editor an…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.

717 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question