For an application I'm creating, I need to be able to read AAC and MP3 files and get the waveform data (not play it directly, I need to manipulate the data before playing).
Ideally, I should be able to read any MP3/AAC file out there (VBR, different bitrates, etc), or at least anything that could potentially show up in iTunes.
This last point is very important, as Chuck commented. I assumed iTunes would be MP3s, I didn't know they used AAC. In essence, I must be able to read anything that is in iTunes.
What approach do you recommend me to use?
What kind of libraries are out there?
This is for a commercial application that will run on Windows, written in C# 3.0. I can use Open Source libraries, but nothing with a license that will make me release my source code later.
Any pointers are greatly appreciated!
Take a look at mpg123 which is LGPL licenced.
There's also MAD, which is GPL but a commercial license can be negotiated.
For AAC there's FAAD2, but it is GPL. Not sure if other terms are available. Another source of enquiry might be checking the sources and licences used in this list of AAC software on wikipedia.
Related
recently i have started workin on project of my own which is capturing a camera output using DirectShow .Net. There are few problems that i don't know how ot solve
1) How can i encode the captured stream into H.264 format.I understand i should some how add filter in the filter graph. But i wasn't able to find where and how . Also i was not able to find if there is standart H.264 filter or should i download it form some where? If i need to download it can it just be a dll to wich i add reference or should it be installer?
2) Is there a way to save the captured output into a memory object, some kind of stream or it can only be written to file?
Best Regards,
Iordan
You're can use commercial software from VisioForge or Viscomsoft.
AForge potencial problem - no audio during capture, only video. Also output formats is a very limited. But - it's free and open source, if you're have any DirectShow experiense you can add audio support.
You will need to use something like FFMpeg or Handbrake. Check out http://vidcoder.codeplex.com/.
AForge also has some video editing abilities and you can also pass filters to it. There are also several FFMpeg C# wrappers you could use such as https://github.com/crazyender/FFMPEG.net
You should use AForge.net. All of the hard work is done for you already. Use VideoFileWriter http://www.aforgenet.com/framework/docs/html/4ee1742c-44d3-b250-d6aa-90cd2d606611.htm. I appears that the AForge framework uses FFMpeg under the hood as well (See AForge.Video.FFMPEG namespace). You just create a writer and pass it the bitmap/frame writer.WriteVideoFrame(bitmap);
You should fully investigate the video abstractions in AForge. You could save yourself considerable amounts of time.
Example: http://www.aforgenet.com/framework/samples/video.html
1) Yes, You should download encoder filter library. Most of decoders are supplied with free. But encoder is not. If you don't want to pay, you have to find open source Encoder.
And To use at the graphedit program, you should do dll register with that dll file. Or the installer program do this instead. And you also need to check container type like mp4, mkv... In other words you need mux filter to save that in a file. I think someone will link available urls. Sorry I don't have urls now.
2)What is that the means of capture? Is that Movie? or Image?
In case of Image, There are many sample projects and SampleGrabbers. You can save it to both of a file and memory.
In case of Movie, I'm sure your pc memory is not enougth to them with out encoding. Make memory stream and pass it to capture manager.
You can also make a filter in order to customize filter to your needs. All of information are included in Windows SDK samples.
Where I can found something suitable (library) for .NET 4.0 (C#) capable for following features:
+ Reading mp3/wav samples with direct access to samplebuffer of loaded samples? (for example I want to load mp3 sample and programatically add reverb, chorus, and more custom effects implemented by me)
+ Playing directly audio buffers (arrays of floats)
+ Saving audio buffers to disk as mp3 or wav
Some time ago i found ASIO for .NET and this only works with .NET 3.5, is there something for .NET 4.0? Thank's a lot for your help.
ASIO for .NET won't help you in the cracking of mp3 or wav files. The most modern API in Windows for doing this is Microsoft Media Foundation. These are all COM APIs though, so you're either going to be doing (perhaps painful) COM interop from .NET or (easier) writing a C++/CLI wrapper. If you go the C++/CLI wrapper, you will need to be aware of performance issues (especially with how critical latency is to audio programming).
I'm skeptical that you will get the audio latency you need when programming in .NET. A good audio driver (like ASIO) will get you down to <3ms of latency. So if you are targetting "live audio", you will need to be generating audio buffers quicker than that (unless you are fine with longer latencies). To put it this way, the "time intervals" that the Windows APIs deal with are in 100 nanosecond intervals :).
You likely don't want to have to crack the files yourself. It becomes tedious as it's not only just mp3 and wav. You also have to be aware of how the wav is formatted as well (to account for different bit rates, number of channels, etc.). Using Media Foundation, it will automatically load the write decoder for you, you just give it the file path. Check out this tutorial that shows opening an existing WAV file and writing a new WAV file. I just recently went down this path for a drum sequencer I'm creating, and it's not very painful at all (if you're familiar with COM programming).
The central component in MF that makes this possible is the MFSourceReader.
If you're wanting to play the audio after you modify it, you can look at the sample "RenderExclusiveEventDriven" in the Windows SDK (under "audio" I believe). That's what I did for the drum sequencer as well. Latency won't be an issue and you're just dealing with byte arrays, so manipulating the raw data becomes very easy. Though at this point, you can probably stick with the ASIO .NET route and just use that to play the raw data you get from MFSourceReader.
I don't think there are .NET wrappers around Media Foundation yet (though if somebody has done that work already, feel free to post here as it would be awesome to know).
I want to make a program which takes video and audio and merges them. Video type or audio type is not important for me. How can I make this? Does any library exist for this? I know there are many programs about this topic but I want to learn how to implement such a program.
The technical term for what you are trying to do is 'multiplexing', and commonly referred to as 'muxing'.
FFmpeg is a multiplatform command line tool that does this, and arguable the industry standard. Many projects wrap FFmpeg into libraries and GUIs.
FFmpeg is also open source, so you can download the code and see how they have done it. That siad, it is very big and complex.
If you are interested in the actual mechanics of muxing separate audio and video files together into a destination file, then you will need to learn much about container formats and Codecs.
Look at some sort of FFMPEG wrapper in C#.
An easy way to multiplex audio and video on linux is to use gstreamer. Here's a A/V pipeline that you can create using gst-launch on a shell prompt.
filesrc location=file1.vid ! queue ! mux. filesrc location=file2.aud ! queue ! mux. avimux name=mux ! filesink location=output.avi
Replace file1.vid with the name of your encoded video file and file2.aud with the name of your encoded audio file. output.avi is the container file that you need.
I want to make a program that takes an MP3 file and breaks it into many smaller mp3 files based on 1-2 seconds of no sound (silence).
What is the easiest way to do this in c#?
Bass library. Bass has everything you need. It can access, record and edit media streams like mp3s, allowing you to sample the volume at different time points. It has a .net api, so you can use it in c#. Unfortunately it does cost money if you are using it for a commercial application, but they do provide a free non-commercial license.
Sox is a command-line tool which has an option to split an mp3 on n seconds of silence. You could always use the system command to call sox from c#.
Other related links.
Ripping a CD to mp3 in C# - third party component or api out there?
Audio Libraries for MP3 editing
How do I merge/join mp3 files with c#
This code shows a way to make a CD
ripper in C#. There are APIs from some
vendors that allow reading audio CD
tracks but it is also possible to do
it using APIs that allow low level
access to CD drives such as ASPI from
Adaptec or IOCTL control codes. The
latter method is used in this case,
because there is no need to install
any third party software, it is
completely covered by Win32 API
functions.
http://www.codeproject.com/KB/cs/csharpripper.aspx
Splitting the MP3 stream will be difficult to do with any degree of precision. The compressed MP3 data exists as sequential chunks of audio data comprised of many samples. The easiest way to perform this would be to decode the stream either progressively or in its entirety, perform your manipulation, then re-encode it (which as I understand is how most jukebox software does it)
Having a solid knowledge of the file's binary format would be a good place to start. That done, you'll know what silence looks like in the file. You may have to define exactly what silence is. Presuming that, like most audio, it started from an analog source, there's almost certainly some noise buried in the "silence". What will your tolerance for ambient/background noise be?
Once you know what you're looking for, just scan through the file, looking for "it".
Simple ...
A program to do this already exists:
http://mp3splt.sourceforge.net/mp3splt_page/home.php
I'm looking at options for adding streaming video to a social web site written in ASP.NET/C#. I have a great deal of experience with Flash too, so I'm comfortable using FLV players, but I'd definitely go Silverlight if the right library is available.
The library would need to be able to encode user uploaded video in a web format.
I imagine playback will be Flash or Silverlight based.
It would need to create thumbnails of the video.
It would need to have server software for streaming the video or have some 3rd party way of doing so.
I don't mind paying a licensing fee for the software, so it does not have to be open source or free.
The license must allow use on a commercial web site.
The closest thing I have found is MediaSoft's offering. But I never heard of this company before starting my search and don't know anyone using their software. They seem to be using FFMPEG to perform encoding, which I heard can spawn legal issues for commercial web sites. Though I'm not very familiar with the licensing of FFMPEG myself so please correct me if I heard wrong.
Has anyone used MediaSoft? Any other video libraries that you have used that worked well? Did you just end up writing your own video encoding and serving library?
Not sure about Silverlight, but Flash will render both h.264 and FLV videos. FFMPEG can convert into both via liblame for FLV and x264 for h.264. It can also generate thumbnails.
It and the corresponding modules are licensed under the LGPL/GPL which means you can use FFMPEG to generate videos/thumbnails without restriction as long as you have the rights to the original movies that you're transcoding. The GPL/LGPL license restrictions only apply to the FFMPEG code/binaries which won't matter until you decide to distribute those binaries to other people.
In addition to the above answer, you can look at red5 as a streaming solution
http://osflash.org/red5