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).
Related
I´m doing a "Whatsapp" like app and I need to send user videos (from camera/gallery).
I need to send video from ios to android and from android to ios (windows phone in the future).
First thing I thought is to use camera params to record the video in low resolution, but that won´t help with recorded videos stored in the phone already.
Second thought was to zip the video file, but I guess this is not enough for very large files.
Third: actually compressing the video file generating a new file, and then zip it before sending it through the network.
So this is what I need before actually sending the video:
Compress the video file, generating a new file that will play nicely in
both platforms (ios and android)
Make the compressing process aysnc(as I don´t want to block the UI
thread for a really long time)
Zip it (this is the easy part, just for the record)
Any ideas or help are appreciated
You would best need to use your platforms framework to also leverage existing hardware support for encoding (mainly h.264 hardware encoding). A PCL solution would eat to much battery as it would need to run on CPU only giving you bad performance and even worst battery live.
This ties in with 1. Just use your platforms native method to execute the frameworks methods async.
Skip this part. It will increase overhead and disallow video streaming There are virtually 0 benefits from using a zip algorithm on top of an already compressed video stream.
Just make sure that you end up with a cross platform compatible video format like H264.
I am looking to develop an app in C# WinRt, but was wondering what libraries are available for playback and for complicated manipulation. I am looking for a free library that allows for an extensive list of audio formats to be played (for example mp3, wma, wav, ogg, etc.) and also to be analyzed. Thats pretty much the basic functionality I would need. But if I could get picky, a library that can convert audio files between the formats would be handy. Doing a google search I came across the Naudio library, but it was not so greatly compatible with WinRt.Thanks for any tips or advice on this.
The current alpha build of NAudio 1.7 (available via NuGet) does contain a Windows RT assembly and the source code includes a simple demo of playback and recording as a Windows Store app. Since it uses Media Foundation, you'll be able to play most of the file types you suggested (although ogg won't be supported out of the box), and you can construct your audio pipeline to access the audio as floating point samples for analysis.
Things that aren't currently supported are using the Media Foundation encoders to encode, and the various reader/writer classes need to be re-written to use the WinRT asynchronous streams and File I/O APIs instead of the regular .NET ones. Hopefully these features will be added to the library soon.
I have a video analytics program that processes assorted frames from a video. (Several hours long)
The video is likely going to be an MP4 but may be other formats going forwards.
At the moment, I have a C# wrapper around an ffmpeg call to extract an individual frame at the requested time. (I'm using the ffmpeg.exe binary. Not the libraries directly)
At the moment, this all works. But it's slow. Very slow.
I've found ways to improve the speed by storing the extracted frames in a ramdisk while they're being processed. Changing the stored image format etc...
I just wanted to check if anyone could think of any way to pull individual frames out. At split-second accuracy.
I know this is probably possible with DShow etc... I went straight to FFMPEG as I've used it before. But if DShow is likely to be faster I'll gladly change!
In Windows you have native APIs to process, and in particular read from, media files:
DirectShow
Media Foundation
Both provide support for MP4 (H.264 video), DirectShow as a framework extended by third party MP4 Demultiplexer and H.264 decoder (of needed, also Windows 7 provides build it), and Media Foundation - natively or extended by third party extensions depending on OS version.
Both can be interfaced from .NET via open source wrappers DirectShow.NET and Media Foundation .NET respectively. This works out way faster then FFmpeg CLI for individual frames. Also note that you would be able to obtain frames incrementally without need to locate specific time and do excessive duplicated work, not even to mention process startup/initialization overhead. Alternatively you could use FFmpeg/Libav binaries through wrapper into C# and get similar performance.
You can change the position of the offset parameters. The order matters for the speed if the video contains valid meta data you can seek through the video faster.
If you put the offset before the input file the offset will be calculated with the bit rate with is not every time exactly (in case of a variable bit rate), but it is much faster. The correct way is to walk through the video (offset parameter is after the input file) but this takes time.
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