Audio feedback for gtkmm application - linux

I am developing a gtkmm application. I am using linux.
I was wondering if there is a way to provide audio feedback to the user when he/she executes some action?
I found a related post on audio feedback for gtkmm here. But it does not provide a proper solution.

There is libcanberra for triggering event sounds from the system's sound theme. I don't know if it is available from gtkmm.
If you want more flexibility to play music, etc., then you'll want gstreamermm.

Related

Embedded audio conference API

I really don't have knowledge about this area (WebRTC, video conference, audio conference, etc).
I want to add to my system (web application) a client support using audio conference.
I was looking for Twilio, it seems a good solution, but I think it doesn't fit my case, because it always need a virtual phone number to get works and I don't need it at my system.
What I need is something like Facebook calls, Google Hangouts (without video).
Is there any solution/library/API for it? It's no necessary be a free solution.

In which language is www.audiotool.com programmed?

Im learning to code web stuff. ruby,javascript...
I would like to do something that makes noise like www.audiotool.com
The app is basically a DAW, digital audio workstation, is fast and sounds good... you can eveb use samples and save projects in the cloud.
But my main question is which languages or tools can make an app like this ?
but i don't know which languages make this kind of apps posible ?
is it creating the sound in the browser, or in a server and sending it back ?
any guesses?
Audiotool.com uses flash to synthesize audio. Their FAQ says that you should update your flash player if you're having trouble, so that seems like a pretty strong indication that they use flash.
However, if you want to make music apps, I would advise against using flash. Newer devices and operating systems will drop support for flash (iPhones/iPads already don't support flash, I believe).
If you want a future-proofed music-making solution, you can do that all client-side in javascript with the web-audio api.
I have authored, and actively maintain a javascript library that aims to simplify the process of building complex apps with the web audio api. If you're just getting started with making music on the web, you might want to check it out. The web audio api is not terribly beginner-friendly, in my opinion. https://github.com/rserota/wad

How to redirect audio stream from microphone to headphone instantly

I need to open the incoming audio stream from the microphone and address it instantly to the headphones so you hear what is being acquired by the microphone.
it is not possible to do this using xna microphone, because it is necessary to pass through a buffer that slows down the headphone listening. I think needs to use Windows.Phone.Media.Capture as AudioDevice and perhaps AudioSink but do not understand how. Do you have any suggestions?
thanks
It looks you've got tighter latency requirements than the a previous question in this area. For phone 8 the best latency result is probably going to be to use the DirectX audio APIs from C++.
The documentation on MSDN will tell you which APIs you can use from the phone, but if I know MSDN I expect you will need to go digging to find examples of how to use them - and when you find them you'll need to be familiar with C/C++, and how to set up a "hybrid" C#/C++ project in Visual Studio.
Even then you'll have to try and it out on a real phone to see if the latency performance is good enough for your purposes.

Audio modification or synthesis in phonegap

Is it posible to do something else with audio in phonegap than playing or recording it?
I'm developing an app that needs to be able to change sound's pitch, modify it with effects or at least synthesize it. I like how fast is to develop simple applications for multiple mobile plataforms with Phonegap, it'll be really useful to know if some kind of audio manipulation can be done with it in any way.
Thank you.

Record audio from various internal devices in Android (via undocumented API)

I was wondering whether it is possible to capture audio data from other sources like the system out, FM radio, bluetooth headset, etc. I'm particularly interested in capturing audio from the FM radio and already investigated all possibilities including trying to sniff the raw bluetooth communication between the phone and the radio device with no luck. It's too bad Android only allows recording audio from the MIC.
I've looked at the Android source code and couldn't find a backdoor to allow me to do that without rooting the device. Do you, at least, have any idea how to use other devices (maybe access somehow /dev/audio) say via NDK or even better - Java (maybe Reflection?) to trick the system to capture the audio stream from say, the FM radio. (in my case I'm trying to develop the app for the HTC Desire)
PS. And for those of you who are against using undocumented APIs, please don't post here - I'm writing an app that will be for my personal use or even if I ever publish it I will warn the user of possible incompatibilities.
I've spent quite some time deciphering the audio stack, and I think you may try to hijack libaudio. You'll have trouble speaking directly to the hardware (/dev/*) because many devices use proprietary audio drivers. There's no rule in this regard.
However, the audio hardware abstraction layer (HAL) provided by /system/lib/libaudio.so should expose the API described at http://source.android.com/porting/audio.html
The Android system, and especially audioflinger, uses this libaudio HAL to find available devices, deal with routing, and of course to read/write PCM data.
So, you could hijack the interaction between audioflinger and libaudio, by renaming the later, and providing your own libaudio which decorates the real one. Doing so, you should be able to log what happens and very possibly intercept FM radio output, provided that this is not directly handled by the hardware.
Of course, all this requires rooting. Please comment if you manage to do this, that interests me.

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