I'm attempting to grab the peak level (decibal level or whatnot) from an audio stream from a Kinect using OpenNI.
I've found these:
http://openni.org/docs2/Reference/classxn_1_1_audio_meta_data.html
http://openni.org/docs2/tutorial/smpl_audio.html
But I'm having a hard time piecing it together. I just need an integer of some sort to figure out how loud the surrounding area for the kinect is.
Thanks!
I've tried using the Audio API provided by OpenNI with no luck, not even the provided sample. I had the same question a while back.
If you're on osx/linux you can use both openni/libfreenect side by side(as admin only on linux) and libfreenect has some experimental audio support.
In the mean time I've found two other projects that look interesting:
HARK
MS Kinect-OpenNI Bridge
I haven't used both, although the second looks promising, so it should be possible to access audio via MS SDK and process data using OpenNI as well.
Related
I would like to detect if my PC is playing any kind of audio (music/movie anything).
I wrote an app which notifies me of my twitter updates. Now I would like to add a speech synthesis to it but I only want to play out the messages if there is no music or movie playing.
Although I'm using C# I don't mind doing the detection using C++ and then integrating it.
So the questions are:
1) How can I detect audio output?
2) What is the best free speech synthesis library for windows?
After some time looking through the MSDN I have found the solution.
Using the loopback recording you can listen to what's being outputted to the audio output device.
http://msdn.microsoft.com/en-gb/library/windows/desktop/dd316551(v=vs.85).aspx
This link also refers to an example of how to capture the stream:
http://msdn.microsoft.com/en-gb/library/windows/desktop/dd370800(v=vs.85).aspx
In here you can get the buffer data as shown in the example by calling:
pCaptureClient->GetBuffer(...)
All you have to do then is to check the value of those bytes. If they are all 0s then there is nothing playin..
For the speech synthesis I used the SpeechSynthesizer .NET class
http://msdn.microsoft.com/en-us/library/system.speech.synthesis.speechsynthesizer.aspx
I've stumbled through some code to enumerate my microphone devices (with some help), and am able to grab the "friendly name" and "clsid" information from each device.
I've done some tinkering with GraphEd.exe to try and figure out how I can take audio from directshow and write it to a file (I'm not currently concerned about the format, wav should be fine), and can't seem to find the right combination.
One of the articles I've read linked to this Windows SDK sample, but when I examined the code, I ended up getting pretty confused at how to use that code, ie. setting the output file, or specifying which audio capture device to use.
I also came across a codeguru article that has a nicely featured audio recorder, but it does not have an interface for selecting the audio device, and I can't seem to find where it statically picks which recording device to use.
I think I'd be most interested in figuring out how to use the Windows SDK sample, but any explanation on either of the two approaches would be fantastic.
Edit: I should mention my knowledge and ability as a win32 COM programmer is very low on the scale, so if this is easy, just explain it to me like I'm five, please.
Recording audio into file with DirectShow needs you to build the right filter graph, as you should have figured out already. The parts include:
The device itself, which you instantiate via moniker (not CLSID!), it is typically PCM format
Multiplexer component that converts streams into container format
File Writer Filter that takes file-compatible stream and writes into a file
The tricky moment is #2 since there is not standard component available. Windows SDK samples however contains the missing part - WavDest Filter Sample. Building it and making it ready for use, you can build a graph that records from device into .WAV file.
Your graph will look like this, and it's built easily programmatically as well:
I noticed that I have a variation of WavDest installed with Google Earth - for the case you have troubles building it yourself and you will be looking for prebuilt binary.
You can instruct ffmpeg to record from a directshow device, and output to a file.
I need to add webcam video capture to a legacy MFC C++ application. The video needs to be saved as MP4. Did a bit of googling but didn't come across anything that looked promising. Any suggestions on the best approach?
EDIT:
Windows platform.
EDIT:
Must be compatible with XP
There are a few popular options to choose from:
DirectShow API - it does not have stock MPEG-4 compressors for video and audio, neither it has a stock multiplexor for .MP4 format, though there is an excellent free multiplexor from GDCL: http://www.gdcl.co.uk/mpeg4/. Also there is decent documentation, a lot of samples
Media Foundation API - it has everything you need (codecs, multiplexor) but only in Windows 7 (maybe even not all edtions)
FFmpeg and libavcodec/libavformat are definitely relevant, however H.264 encoder is only available under GPL license, not sure about video capture part right there, and you might have hard time looking for documentation and samples.
I'd say look at OpenCV as a library, hook into their video capture for that aspect, it can write out to mp4 but you'll need a couple of other libs for handling the output stream (on Linux I'd say ffmpeg and x264), that should get the buffer into the container with a reasonable amount of hassle.
We have an "MC1362 Camera" and an "Inspecta-5" frame grabber in our lab. There is program in LABVIEW11 which gets the data from a frame grabber, however as the Labview is slow my supervisor has told me to write a program in c++ to get the data from the frame grabber. I have no idea how to write a c++ program to connect to a frame grabber and do the data acquisition. I know how to write software in c++, but have never tried programming to connect to hardware and read data from it. Is there any specific library or framework which can help me, or any tutorial?
Please, if anybody knows, help me in this matter.
Update:just to add, we are doing medical image analysis, and a laser illuminate a subject, so camera will take pictures and pass it to the computer. I need to grab the pictures and analysis them.
You basically have a couple of options,
1 see if there is an SDK for the grabber card, if there is this is usually easier then option 2 but is of course restricted to work with that grabber or familly of grabber cards, we do it this way with the eurysys grabber cards.
2 assuming you are running on a windows platform, implement a DirectShow filtergraph and write your own ouput filter to get the data, the SDK for DirectShow is quiet good and has many examples. This approach is far more flexible and you should be able to use a number of grabber but its also alot more complex, we do it this way for USB / some other inbuilt grabbers.
Our software is done in Delphi 7 but its just importing DLLs, for C++ should be no problem and most SDK's are written round C++ anyway.
I know its not much but its a place to start.
Update
Just done a quick Google search and there is an SDK for that Grabber and on first looks its seams fairly straight forward.
I'm looking for a free, portable C or C++ library which allows me to play mono sound samples on specific channels in a 5.1 setup. For example the sound should be played with the left front speaker whereby all other speakers remain silent. Is there any library capable of doing this?
I had a look at OpenAL. However, I can only specify the position from which the sound should come, but it seems to me that I cannot say something like "use only the front left channel to play this sound".
Any hints are welcome!
I had a look at OpenAL. However, I can only specify the position from which the sound should come, but it seems to me that I cannot say something like "use only the front left channel to play this sound".
I don't think this is quite true. I think you can do it with OpenAL, although it's not trivial. OpenAL only does the positional stuff if you feed it mono format data. If you give it stereo or higher, it plays the data the way it was provided. However, you're only guaranteed stereo support. You'll need to check to see if the 5.1 channel format extension is available on your system (AL_FORMAT_51CHN16). If so, then, I think that you feed your sound to the channel you want and feed zeroes to all the others channels when you buffer the samples. Note that you need hardware support for this on the sound card. A "generic software" device won't cut it.
See this discussion from the OpenAL mailing list.
Alternatively, I think that PortAudio is Open, cross-platform, and supports multiple channel output. You do still have to interleave the data so that if you're sending a sound to a single channel, you have to send zeroes to all the others. You'll also still need to do some checking when opening a stream on a device to make sure the device supports 6 channels of output.
A long time ago I used RTAudio. But I cannot say if this lib can do what you want to archive, but maybe it helps.
http://fmod.org could do the trick too
I use the BASS Audio Library http://www.un4seen.com for all my audio, sound and music projects. I am very happy with it.
BASS is an audio library to provide developers with powerful and efficient sample, stream (MP3, MP2, MP1, OGG, WAV, AIFF, custom generated, and more via add-ons), MOD music (XM, IT, S3M, MOD, MTM, UMX), MO3 music (MP3/OGG compressed MODs), and recording functions. All in a tiny DLL, under 100KB* in size. C/C++, Delphi, Visual Basic, MASM, .Net and other APIs are available. BASS is available for the Windows, Mac, Win64, WinCE, Linux, and iOS platforms.
I have never used it to play different samples in a 5.1 configuration. But, according their own documentation, it should be possible.
Main features
Samples Support for WAV/AIFF/MP3/MP2/MP1/OGG and custom generated samples
Sample streams Stream any sample data in 8/16/32 bit, with both "push" and "pull" systems. File streams MP3/MP2/MP1/OGG/WAV/AIFF file streaming. Internet file streaming. Stream data from HTTP and FTP servers (inc. Shoutcast, Icecast & Icecast2), with IDN and proxy server support and adjustable buffering. ** Custom file streaming ** Stream data from anywhere using any delivery method, with both "push" and "pull" systems
Multi-channel Support for more than plain stereo, including multi-channel OGG/WAV/AIFF files
...
Multiple outputs Simultaneously use multiple soundcards, and move channels between them
Speaker assignment Assign streams and MOD musics to specific speakers to take advantage of hardware capable of more than plain stereo (up to 4 separate stereo outputs with a 7.1 soundcard)
3D sound Play samples/streams/musics in any 3D position
Licensing
BASS is free for non-commercial use. If you are a non-commercial entity (eg. an individual) and you are not making any money from your product (through sales, advertising, etc), then you can use BASS in it for free. Otherwise, one of the following licences will be required.