We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you a podcast all about Citrix Workspace, moving to the cloud, and analytics & intelligence. Episode 2 coming soon!Listen Now

x

How to use Audio Compression Manager under C++

Duebel
Duebel asked
on
Medium Priority
1,250 Views
Last Modified: 2013-12-03
I have serious problems with the Win32 ACM. I have to do the following tasks:
* record audio (PCM 11kHz, Mono, 8bit),
* compress this into TrueSpeech 1k/s (lowest format),
* send it over a netwotk,
* decompress it back to the original format,
* play sample.
The recording works. But how can I compress it using the Windows ACM functions into the TrueSpeech format? I achieved it to convert the sample to another PCM format but not to another audio codec. If you have some sample code that shows how to implement such a compression using C++ please send it to me.
Thanks in advance
Gregor Fleissner
Comment
Watch Question

Commented:
Video for Windows 1.1 DK comes with a sample: ACMApp. It can be used to convert between any format that ACM supports. Let me know your email address so that I can send it to you.

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts

Author

Commented:
Thanks a lot for your answer. After you mentinoed ACMApp I found this sample by my self inside the VC5 help.

Author

Commented:
The ACMAPP sample is not that easy to read. Maybe you can help me.
I recorded sound in PCM 8kHz Mono 8bit format. Now I want to convert it into TrueSpeech (8kHz, 1bit, mono) format. Here is the code I I wrote but which didn't work:

++++++++++++++++++++++++++++++++
HACMSTREAM hACMStream;
WAVEFORMATEX wfx;
ACMSTREAMHEADER acmHeader;
DWORD dwSource, dwDest;
BYTE* pDestData;
      
wfx.nChannels=1;
wfx.wFormatTag=34;
wfx.wBitsPerSample=1;
wfx.nSamplesPerSec=8000;
wfx.nAvgBytesPerSec=1067;
wfx.nBlockAlign=32;
wfx.cbSize=32;
      
m_hr=acmStreamOpen(&hACMStream, NULL, &m_wfx, &wfx, NULL, 0, 0, 0);
dwSource=dwDest=GetLength();
m_hr=acmStreamSize(hACMStream, dwSource, &dwDest, ACM_STREAMSIZEF_SOURCE);

pDestData=(BYTE*)malloc(dwDest);

ZeroMemory(&acmHeader, sizeof(acmHeader));
acmHeader.cbStruct=sizeof(acmHeader);
acmHeader.pbSrc=(BYTE*)m_pData;
acmHeader.cbSrcLength=dwSource;
acmHeader.cbSrcLengthUsed=dwSource;
acmHeader.pbDst=pDestData;
acmHeader.cbDstLength=dwDest;
      
m_hr=acmStreamPrepareHeader(hACMStream, &acmHeader, 0);
m_hr=acmStreamConvert(hACMStream, &acmHeader, 0);
++++++++++++++++++++++++++++++++

The acmOpenStream function fails with error 512 (ACMERR_NOTPOSSIBLE). What is not correct here?
Please help me.
Thanks

Commented:
First, use ACMApp to convert a PCM 8kHz Mono 8bit format file to a TrueSpeech 8kHz 1bit mono format file so as to make sure ACM supports this sort of conversion. Second, make sure the two formats (WAVEFORMATEX) are correct. (Since wfx.cbSize=32, you should define WAVEFORMATEX + 32 bytes variable BYTE wavefmt[sizeof(WAVEFORMATEX) + 32], I think.) Third, try applying the flags ACM_STREAMOPENF_NONREALTIME and ACM_STREAMOPENF_ASYNC with a callback function.

Author

Commented:
Thank you very very much. The problem was the size and the not specified ACM_STREAMOPENF_NONREALTIME flag. Now it works great.

Commented:
Can you sent me a sample code?I want to
built a VioceEmail progame,need your help!
Thank you!
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.