I'm attempting to create a Windows application that will allow the controls on earbuds/headphones that have them (such as the Nokia Purity earbuds) to work on Windows. I would think that there are two ways to go about doing this:
Attempt to get some kind of input from the audio output jack
Plug the earbuds into the microphone jack, and then try and play music through there (while watching the microphone's input for whatever it is that the buttons do).
So, I'm starting off by trying the first option, which leads me to my question. Is there a way to get any kind of raw input from the audio jack in Windows? Is there a better way to do this? I'd like to use C#, but if it's only possible in C/C++ or another language, that would be fine as well. Thanks!
There is no such possibility. PC audio jacks are only two channels (stereo). Headphones with additional buttons use more than two channels to handle them.
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I created a book app and used Cocos2D and physics engine (Chipmunk) to create it. I would like to add "read aloud" feature to it.
So far I found instructions/books and tutorials how to add read aloud feature when book is created with iBook Author (but I couldn't use iBook Author due to some limitations) using Epub3 and SMIL.
I also found a good tutorial from J. Shapiro how to make narrated book using AVSpeechSynthesizer. This helps, only that I would like to use recorded voice, rather than synthesized sound. I don't know if this approach can be modified to do so?
I also know how it can be done in Sprite Kit framework.
The only info that I couldn't find is how to add "read aloud" feature to the app written using Cocos2D. Could it be done within SimpleAudioEngine, or it can be combined with some other engine (possibly from Sprite Kit framework)?
I would appreciate very much if somebody can give me some references/pointers or tutorial links where to look for some answers how to add this feature.
Thanking you in advance.
I would like to use recorded voice, rather than synthesized sound
Good. Add your voice recording audio files (caf, wav or mp3 format) to the project. Play it back at the appropriate time using:
[[SimpleAudioEngine sharedEngine] playEffect:#"someVoiceRecordingFile.wav"];
Define what read aloud means to you because I find that a lot of terms, especially semi-vague ones like this, are used differently depending on who is using it.
When you say read aloud book do you essentially mean a digital storybook that reads the story to you by simply playing narration audio? I've created dozens of these and what you are asking has multiple steps depending on what features you are going for in your book. If you mean simply playing audio and that is it, then yes you could do that in cocos2d using SimpleAudioEngine (as one option) but I assume you already knew that which is why this question has a tab bit of vagueness to it. Either way you probably wouldn't want to play narration as an effect but rather stream it. To do that along with background music you'd stream background music via the left channel and narration via the right. You can easily add a method to SimpleAudioEngine to make this nice and neat. To get you started something similar to this can be used to access the right channel:
CDLongAudioSource* sound = [[CDAudioManager sharedManager] audioSourceForChannel:kASC_Right];
if ([sound isPlaying])
{
[sound stop];
}
[sound load:fileName];
Also use the proper settings and recommended formats for streaming audio such as aifc (or really all audio in general). Although I believe you can stream mp3 without it being decompressed first, the problem is with timing. If you are using highlighted text or looping audio then aifc is the better option. Personally I've never had a reason to use mp3. Wav with narration is something I'd avoid even if just for the file size increase. If the mp3 is decompressed even for streaming (which I'm not sure if it is off the top of my head) then you'd have a huge spike in memory that will be both highly unwanted and at times down right bad.
There are many other things that can go into it but those are the basic first steps. If you want to do things like highlighted text, per-word animations, etc then that will take more work of course and you'd need to be comfortable with cocos2d, SpriteKit, or whatever you decide to use. I'll be doing a tutorial series on it one day soon so I'll cover all of that stuff.
On the other hand, if you are talking about recording someone's voice and having it playback i.e. a mother recording herself reading the story so her child can hear her voice whenever they are using your app, then you'd simply record the audio like you would any other piece of audio, save it to the device, and play it back when the page is displayed in the proper reading mode (or whatever you personally call it). One place to look is the AVAudioRecorder that is part of the AVFoundation framework. Simply Google "iOS audio recording" for examples if you need them.
I'm sure this question would have been asked before but I've searched and can't find anything specific to help a solution.
I'll start out outlining the initial concerns and if more indepth technical information is needed then I can give it. Hopefully there is enough information for the initial question(s).
I'm writing an app using c++ and directshow in visual studio 2010. The main project specification is for a live preview and, at any time of choosing, record the video to mpeg2 to harddrive then to dvd to be played in a standard dvd player, all the time the live preview is not to be interrupted.
The capturing seems a pretty trivial standard straight forward thing to do with directshow.
There are a couple of custom filters that i wrote. Nothing amazing but we wanted our own custom screen overlay information - time and date etc - this must be in the preview and the recorded file. I use the avi decompressor connected to the capture card video out pin, and connect the avi decompressor to my filter to give me an rgb image that i can manipulate. The output from this filter is then split via an inftee filter, one goes to the screen, the other goes into the ms mpeg2 encoder. The audio goes from the capture card audio out into the same mpeg2 encoder. Output from the mpeg2 encoder then goes to a file. That file then gets authored for dvd and burnt to dvd.
So my questions are...
Where and how would be the best place to allow starting and stopping of only mpeg2 file output, to be done via user action?
I have tried using smart tee filters - 1 for video and 1 for audio as the last filter BEFORE the mpeg2 encoder, then using the iamstreamcontrol interface to turn off the pins at the appropriate time. Should this cause any timing issues with the final mpeg2? as the output file will play via mplayer and vlc etc but doesnt get converted to be mpeg2 dvd compliant ( for testing - via any dvd authoring software - complaints of a broken file and somteimes gives time references ) - is it possible that time stamps in the file are a problem and giving an error? If the file is captured from the first moment that capture commences ( as opposed to say after 5 mins of streaming ) then everything is ok.
I did think of using the streambuffer route - http://msdn.microsoft.com/en-gb/library/windows/desktop/dd693041(v=vs.85).aspx - but I'm not sure on the best direction to takes things. It seems that are possibly a few choices for the best direction.
Any help and tips would be greatly appreciated. Especially if theres websites/books/information of DirectShow filters,pins,graphs and how they all flow together.
EDIT: I was thinking of making my own copy of the 'Smart Tee' filter that in that I would have 2 pins coming in - audio and video - and 4 out pins - 2 video ( 1 preview and 1 capture ) and 2 of the same for audio, but would I end up with the same issue? And what is the correct way to handle 'switching off' the capture pins of that custom filter. Would I be wasting my time to work on something like this? Is it a simple case of overriding the Active/Inactive methods of the output pin(s) and either send or not send the sample? I feel its not that easy?
Many thanks!
Where and how would be the best place to allow starting and stopping of only mpeg2 file output, to be done via user action?
For this kind of action I would recommend GMFBridge. Creating your own filter is not easy. GMFBridge allows you to use two separate graphs with a dynamic connection. Use the first graph for the preview and the second graph for the file output. And only connect the graphs after a user action.
I am just starting to learn DirectShow with C++. I need to use DirectShow to record the audio and write it to a WAV file on the disk. I heard from other people that Win 7 does not allow for rendering audio using DirectShow.
In addition, I would like to know how should I start with recoding audio using DirectShow with C++? If there is sample source, it would be great.
Thanks in advance.
I think you may have misunderstood these other people. Windows Media Foundation is aimed to be the successor of DirectShow, but DirectShow is still a very valid technology on Windows 7.
The easiest thing to accomplish what you want to do, is to get it right using the GraphEdit tool first ( I assume you want to do this programmatically).
Create a graph that contains your audio device, a WavDestFilter, and a file writer.
Source -> WavDest -> File Writer
Play the graph. Stop the graph and you should have created a .wav file with the recorded audio. If you can get this right, then you need to do the whole thing programmatically.
There are a couple of samples in the SDK that show you how to programmatically add filters to a graph and connect them, that should enable you to get started.
WRT the WavDestFilter, IIRC it might not be in all versions of the SDK, you'll have to find an appropriate one. You also need to build it, and regsvr32 it, so that it will show up in your list of available filters in GraphEdit.
If this all seems a bit much, I would read through the DirectShow documentation on MSDN to at least get an overview of DirectShow.
I want to make an application that can split an mp3 into pieces. Ex: if I give t a 3 minute song, and want 3 parts, I would expect 3 new mp3s at 1 minute each.
Thanks
I'd try this: http://mp3splt.sourceforge.net/mp3splt_page/about.php
It claims to have a GUI, and command-line interface, and even a library. I'd probably start with the GUI or CLI and see how it goes.
Lame should be able to do any basic encoding and decoding you would need.
http://lame.sourceforge.net/
I need to find a video filter in order to mix multiple video streams (let's say, maximum 4).
I've found a video mixer filter from MediaLooks and is ok, but the problem is that i'm trying to use it in a school project (for the entire semester) and so the 30 days trial is kind of unacceptable.
So my question to you is that: are you aware of a free direct show filter that could help. If this is not working then it means i must write one. The problem here is that i don't know from where to start.
If you need output to the display, you can use the VMR. If you need output to file, then I think you will need to write something. The standard solution to this is to write an allocator/presenter plugin for the VMR that allows you to get back the mixed video and then save it somewhere. This is more efficient that a fully software-only mixer filter.
G
I finally ended up by implementing my own filter.
The VideoMixerRender9 (and 7) will do the trick for you. You can set the opacity and area each video going into the VMR9. I suggest playing with it from within graphedit.
I would also like to suggest skipping that all together. If you use WPF, you will get far more media capabilities, much easier.
If you want low level DirectShow support, you can try my project, WPF Mediakit. I have a control called MediaUriElement that is similar to WPF's MediaElement.