I am trying to make an application for listening to podcasts. Each podcast is an mp3 file, around 50MB in size. After reviewing the Using Audio chapter of the Multimedia Programming Guide, I decided to use AVPlayer, as the other options did not seem appropriate. However, the more I work with AVFoundation, the more complicated it seems and I have a feeling that simply streaming an mp3 file should be easier. Plus on the top of this document, there is a note stating:
Important: This document contains
information that used to be in iOS
Application Programming Guide. The
information in this document has not
been updated specifically for iOS 4.0
Does that mean that I have some other options, or that AVFoundation is maybe an overkill for what I need to do? I would really appreciate it if someone could clear things out a bit and let me know if I'm making something wrong here.
Thanks in advance!
You should explore Cocos Denshion.
http://www.cocos2d-iphone.org/wiki/doku.php/cocosdenshion:cookbook
The audio engine comes with cocos2d, and it is just 5 classes you can include with your project.
It's very simple to use, as you can see from the above link. It's basically just a wrapper for some AVFoundation classes.
The only trick will be to stream your mp3, but it looks like you can simply update the Cocos Denshion CDAudioManager to hand a URL to the AVAudioPlayer, as a start. Whether or not that satisfies your streaming requirement, I don't know.
At the very least, it will give you some AVFoundation code to study.
I just found a pdf with a nice overview of some possible options from this course blog. Together with Julian's suggestion this is all I could find so far.
Related
Here is what i like to achieve:
I like to play around in creating "new" software / hardware instruments.
Sound processing and creation is always managed by software. But one could play the instrument via ultrasonic distance sensor for example. Another idea is to start playback when someone interrupts the light of a photoelectric barrier and so on....
So the instrument would play common sounds, but has to be used in an unusal way. For example, the ultrasonic instrument would play a sound if it detects something in a certain distance. The sound could be manipiulated in pitch for example if the distance gets smaller.
Basically i like to playback a sound sample and manipualte this in realtime.
I guess i have to use WAV samples for this, right? And which programming language do you think fits best for this task?
Edited after kevins hint: please kick me into the right direction - give me a hint where to start.
Thanks in advance
Since you're using the the Processing tag, you can try Processing.
It comes with a sound library like Minim or you can install beads which is great. There's actually a nice book on it: Sonifying Processing
You might find SuperColider fun as well.
The main thing is what are you comfortable with at the moment ?
If Processing syntax looks intimidating, you can actually try a different programming paradigm like data flow. In which case you can use PureData(free, opensource) or MaxMSP(very similar, but commercial). The idea is rather than typing instructions, you connect boxes with wires which is fun and the examples are great too.
If you're into c++ there are plenty of libraries. On the creative side, there's a nice set of libraries called OpenFrameworks that's easy and fun to use. If this is your cup of tea, have a peek at Maximilian.
Bottomline is: there are multiple options to achieve the same task. Choose the best tool for your (based on your background) or try each and see what you like best.
You asked "And which programming language do you think fits best for this task?" - I would also suggest using Processing. I have been used Processing to work with sounds previously. And in all cases I used Minim. It has many UgenS to generate sounds programmatically.
Also, you wants to integrate with some sensors. I'm not sure what types of sensors you will use, but Processing goes pretty well with different Arduino modules and sensors. Check this link for more direction.
Furthermore, you can export your project as .exe or executable .jar files. And their JS version (P5.js) works almost the same as the Java version.
I'm toying around with constructing a basic music composition system for fun. I can represent music in memory, but I'd (obviously) like to be able to output actual sounds! I don't really care what the format is (MIDI, mp3, ogg, whatever). I just want to be able to load samples into the program and play them in the simplest way possible. I've searched around for a solution but everything I'm seeing is either a) too complex (overhead-wise) for my needs, b) not actively supported, or c) not well-documented. I would love to see an example of sound output or otherwise, some direction on the simplest way to do so.
You might like Euterpea, which isn't on Hackage but was a breeze to install and has quite verbose documentation (it seems it forms the core of an introductory Haskell course at Yale). Hover over the word "Euterpea" in the menu at the top to find more links/instructions.
I ended up using MIDI and sending events to SimpleSynth, on Mac OSX. This was achieved using the hmidi package and the bindings to OSX's CoreMIDI by bkomuves. I had to install a fork of the hmidi package from here to get it working with the latest GHC. I then installed SimpleSynth and enabled an IAC Driver using the Audio MIDI Setup utility on OSX. I then set SimpleSynth to listen from the IAC Driver I set up and was able to use the enumerateDestinations function from bkomuvres' bindings to CoreMIDI to grab the first available Destination and send MidiEvents from hmidi using send. It works like a charm!
With Haskell, you may wish to get a handle on the language fully by utilising other libraries/applications from your code, however the following link is a link to libraries for music and sound.
http://www.haskell.org/haskellwiki/Applications_and_libraries/Music_and_sound
Another idea is to gain familiarity with OpenAL with C/C++ and then from there you will have some familiarity with the structure of HOpenAL (Haskell binding of OpenAL which indeed calls the OpenAL DLL/SO).
Link with straightforward tutorial for OpenAL ago!
http://enigma-dev.org/forums/index.php?topic=730.0;wap2
I hope this helps...
I want to start on a hobby project that focuses on displaying audio files in a folder in a certain fashion and has the ability to play such an audio file and shows basic control options for playing. However, i'm struggling to find a fit programming language for this.
The displaying part shouldn't be too hard and can probably be done in most of the programming languages. The audio part is what concerns me the most since it's not the main focus of the project and should only do limited things (so it shouldn't be too hard) and i do not know anything about sound support in the programming languages i currently know. (Java, C and C++)
Specifically i would like to be able to do these things:
Play a sound file
Stop/pause a playing song
Adjust volume
Show a bar that displays the current position in the song
Most files will be .mp3 files but being able to process other formats is certainly a plus. Since this is just a small project it's ok if it runs just on Windows. Scalabilty would be nice but not required.
It would be nice to have a small overview of audio support/audio libraries of programming languages (i'm always up for something new) that can accomplish these simple things, in a not too complicated way, aswell as personal experiences.
In this way i hope to create a better understanding of which programming language fits my project best. (i would very much like to not have to change language mid-way the project)
--
Edit:
This is only for a later stage of the project if the first part was successfull: i will want to change the file names of the audio files that are displayed. (to make them follow a specific format)
I haven't written audio processing programs much, but I know a lot of them exist for C and C++. For Java perhaps, too, but I don't know Java. I had used audio with SDL in a game, but that doesn't have that many features and I don't recommend it.
There's this question asking for a library in C, and there are a couple of similar questions that SO brings up on the side. You may want to take a look at those.
You would also need to look for a library that loads different file types. SDL at least, only opens .wav files, which I believe most of the playback libraries would support. For MP3, you will most likely need an additional library. I know Audacity uses LAME Mp3 so I'm guessing that should be good.
Some of the functionalities you want is also doable by yourself. For example, knowing the length of the music and the amount you have already read, you will know how far in the audio you are. Adjusting the volume is also a multiplication (in the simplest case) that you can do on the audio data if the library doesn't provide it.
A very good choice seems to be PortAudio which is used by Audacity, and also recommended in the accepted answer of the question I mentioned above.
I've done audio apps in both Java and C++. Java development goes way faster because it's a more powerful language and has garbage collection, but JavaSound is a pretty awful solution for audio. Of course, there are wrappers for FFMPEG and other stuff, so you can get a lot of things working. Here's an example of a Java audio app: http://www.indabamusic.com/help/mantis
OTOH, C++ gives you lots of control, low latency and wealth of libraries. (another answer mentioned Portaudio, which is, indeed, great.) But you will definitely find it also has a much longer development cycle.
You can certainly do everything you want to do with either language.
I have a bunch of video files that I want to process. I want to write a program that can find the audio peaks in each file and return the times where those peaks occurred.
I've looked for a lot of different APIs in different languages but couldn't get any of them to work. I am partial to php and java, so if anyone knows any good audio processing libraries in those languages that would be great! But really I don't care too much about the language. I will need to run this program on a cron.
Also, is it possible to use system calls to ffmpeg from within a script to accomplish this? Thanks in advance.
While I've only used this to work directly with audio files, the python wrapper around theechonest's audio analysis service can slurp in the audio from various video files. It uses ffmpegs shared libs to do this, though I find this wrapper much easier to work with via python then the command line.
Of particular interest within the api is echonest.video which is, to quote the docs:
Framework that turns video into silly putty.
I'd add a couple other helpful urls but apparently I can only add one since I don't have a reputation...
anyway, hopefully that's a helpful lead.
I've tried looking up how I might go about this for a while now, and maybe I am using the wrong terminology in my searches or it's way too advanced for me. I basically want to be able to analyze audio files in real-time. I know hardly anything about audio processing so I should probably start small and work my way up. Eventually I'd like to be able to display a power (or frequency?) spectrum correlating to audio playing in real time. Basically like the WinAmp spectogram (terminology?)
Any online tutorials with perhaps an API suggestion or two would be greatly appreciated. I've found some vague explanations (mostly dealing with calculating FFT's then converting them to something...) Like I said, I know little of audio processing, so knowing where to start would be great.
Language of choice: C++
You could look into VST plugins as a starting point for the theory behind audio processing. There's a blog with some tutorials in c++ here.
You can also check out other SO questions on VST plugins for more info.
I believe audacity can run VST plugins, I'll look at that.
EDIT: Audacity doesn't support them out of the box, but you can enable it. You could download a trial of something like ableton live too.
I'd recommend using a graphical tool to begin with to prototype some ideas. Try Puredata or something similar.
http://puredata.info/
Juce is a fantastic way to get to grips with C++ with an Audio slant.
http://www.rawmaterialsoftware.com/juce.php
I've also stumbled across UGen which might help you get up and running without having to understand too much of the sample-by-sample processing theory. I've not looked at this much yet but it looks interesting at the outset.
http://code.google.com/p/ugen/
The KVR forums are full of knowledgable people who will help and direct newcomers to audio and plugin development.
http://www.kvraudio.com/
If you're feeling brave the dive in to a good book. I've heard a lot of good things about the following:
http://www.amazon.com/DAFX-Digital-Udo-246-lzer/dp/0471490784
Good luck! This is not an easy area to get going in!
(PS, the blog linked in the above answer is mine -> it's out of date and wont help you actually do any signal processing)