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.
Related
So I'm trying to get a basic tool to output video/audio(s) to Twitch. I'm new to this side (AV) of programming so I'm not even sure what to look for. I'm trying to use mainly Windows infrastructure and third party where not available.
What are the steps of getting raw bitmap and wave data into a codec and then into a rtsp client and finally showing up on Twitch? I'm not looking for code. I'm looking for concepts so I can search for as I'm not absolutely sure what to search for. I'd rather not go through OBS source code to figure it out and use that as last resort.
So I capture the monitor via Output Duplication and also the Sound on the system as a wave and the microphone as another wave. I'm trying to push this to Twitch. I know that there's Media Foundation on Windows but I don't know how far to streaming it can get as I assume there no netcode integrated in it? And also the libav* collection in FFMPEG.
What are the basic steps of sending bitmap/wave to Twitch via any of thee above libraries or even others as long as they work on Windows. Please don't add code, I just need a not very long conceptual explanation and I'll take it from there. Try to cover also how bitrate and framerate gets regulated (do I have do it or the codec does it)?
Assume absolute noob level in this area (concept-wise not code-wise).
I am currently creating a game. My game will use music from an mp3 file that the user sends in in order to make decisions on where to place things, how fast the level moves, etc. I am fairly new at this, I have been reading information about mp3. Currently I have found all the frames in the mp3 file that I am using. I don't really know where to go from here. What I want to do is measure the frequencies of the sound wave of the music at certain times (like every sec) and then based on that frequency, do what I need to for the game. I don't know whether I should decode the mp3, that looks like a lot of work and I don't want to do that if I don't have 2 or if I can just read the bytes in the frame and convert them without decoding anything. I am developing this in c#, using the game engine FlatRedBall. I am not using any libraries. I am also planning on selling this game so I would like to avoid using other people's code if I can avoid it. Please someone help me, I just need a direction to go from here. I know how to parse the header and calculate the framelength, I just don't know the next step in what I want to do...
Convert your music to .ogg format which is free and use free library to play it.
Note: I was going to post this as a comment but it quickly grew too big. :)
Writing your own MP3 enconder/decoder is probably going to take a good ammount of effort; effort which would probably be better spent on your game itself. Therefore, is possible, I would be all means try to use an open source library.
That said, most good MP3 libraries are LGPL/GPL licensed. This means you can use it in a commercial setting, as long as you dynamically link to it. Also the SDL Mixer library, as of version 1.2.12, supports MP3s and is under a more permissive zlib license, but since you mention C# I don't know if stable and up-to-date bindings are available. Also since your project isn't written in SDL to begin with, it might be hard to integrate it.
Also, as #pro_metedor hinted, perhaps using a more open format could help in licensing issues. In general, OGG achieves better compression than MP3, which is a plus for things like download size, bandwidth/resource usage, etc.
Just shop around for a while, and try to be a little flexible. I'm sure you'll find something nice! :)
I want to write a simple sound editor with a very specific purpose: cutting and re-gluing an audio file (which will contain spoken prose) in such a way that each sentence is repeated N times. (This is for foreign language learning.)
I don't want to use an existing sound editor because I would like to tailor the GUI specifically for this narrow task, reducing the amount of motions and clicks to a minimum.
Unfortunately I don't have any experience whatsoever in working with sound. I was wondering about recommendations for C++ libraries/APIs on Windows that would enable me to:
read in an audio file (mp3 or wav)
select a portion from "here" to "here"
listen to it
append it to a new file
write the whole thing out as mp3 (or at least wav)
Also any general thoughts are very welcome (this is completely unknown territory for me so if you have had any stumbling blocks and mistakes you don't want others to repeat, please do share).
I have previously been quite happy about http://www.portaudio.com/, which is a nice platform independent wrapper to the sound hardware (low latency recording and playback).
For reading / writing mp3s I have used LAME http://lame.sourceforge.net which is also supported support on pretty much all popular platforms.
You might also want to check out the source code of Audacity http://audacity.sourceforge.net/, which does what you want and a lot more.
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.
This question has been in my mind for a few years and I never actually found the answer for this.
What I would like to do is extract the actual waveform/PCM of an MP3 file, so that I can play it using the soundcard (of course).
Ideally I would be experimenting some DSP effects.
My first step was to look into LAME, but I didn't find anything relevant about MP3 decoding in a program or stuff like that.
So I'm asking where I could find something like this.
What language should I use? I was thinking C, but maybe there are programming languages out there that would do the job more efficiently.
Thanks!
Guillaume.
The question boils down to: what are you trying to accomplish?
From the description of your question of decoding an MP3 and playing it on the sound card makes it sounds as if you are trying to make a media player.
However, if your intent is to play around with DSP effects, then it sounds like the question is more about processing the sound rather than decoding MP3s. if that's the case, probably looking into writing plug-ins for existing media players (such as Windows Media Player and Winamp) would be easiest path to what you're trying to accomplish.
Frankly, learning to write your own decoder from scratch is not just a programming problem but a mathematical one, so using existing libraries are the way to go. Talking to the operating system or libraries like DirectSound to output audio seems like unnecessary work if anything. I feel that working on plug-ins for existing players would be the way to go, unless your goal is to make your own media player.
If what you really want to accomplish is playing with audio data, then probably decoding an MP3 to uncompressed PCM using any MP3 decoder, then manipulating it in the language of your choice would accomplish your goal of dealing with effects with sound.
The language choice is going to depend on whether you are going to interact directly with MP3 decoding libraries, or whether you can just use raw audio input, which would allow you to use pretty much any language of your choice.
There was a similar question a while back, Getting started with programmatic audio, where I posted an answer on some basic ways to manipulate audio, such as amplification, changing playback speed, and doing some work with FFT.
libmpg123 should do the trick.
I have been using the Windows Media SDK, not for this purpose, but I am pretty sure there are hooks let that let you intercept the audio stream, or convert MP4 to uncompressed WAV. I used C++.
Lots:
http://www.mp3-tech.org/programmer/decoding.html
Pick your poison...
Also, LAME does decode MP3s (check out --decode option), so you might find something interesting in that source.
-Adam
It really depends what platform you are programming on and what you want to do with the code. If you are on Windows you should look at the windows media format sdk or DirectShow. They should both have the ability to decode mp3 files into the raw waveform. On the Mac, I would expect Quicktime to have this same ability. Others have already suggested source for Linux/open source code.
I would recommend looking at Cubase and Wavelab as both will convert MP3 to WAV etc and allow you to play around with the waveform