Converting MIDI byte array to MP3 byte array - c#

Does someone know how to convert a MIDI file (average playback time of 30 seconds) which is represented in a byte array to an MP3 byte array?
So, ideally I need to have a C# function which accepts a MIDI byte array and returns a MP3 byte array.
The conversion should not take more than 2 - 3 seconds.
Are there any frameworks / tools / 3rd-party DLLs to perform this easily?
Please let me know.
Thanks,
Vijay

MIDI file is not audio, it is audio instructions. This has to be "rendered/played" to audio (using various MIDI players depending on the capability of your sound card) and then compressed to MP3.
I do not know a DLL that can do all of that. Lame MP3 DLL is a free open source DLL that can do the compression for you.
http://lame.sourceforge.net/

Over at CodeProject there's a C# MIDI Toolkit which could help you. You'll probably have write the code to record the output stream yourself though.

Related

converting Rtsp stream to .wav and parallel y to bytes while stream is running

Thanks in advance ,I am converting rtsp live stream to .wav file using ffmpeg.Its converting good but i want to convert .wav file to byte stream parallely at the time of converting rtsp to .wav file
1)Launch ffmpeg as a Proceas with the option to decode to standard output in the Arguments (usually a '-' at the end of the arguments)
2) Read the standard output from that Process in accordance with the output format being written.
This keeps the output in memory and allows you to consume it just after its been provided to stdout.
See this question for an example commanf of how to get raw audio from ffmpeg.
Can ffmpeg convert audio to raw PCM? If so, how?
You can't expect a player to understand the datastrucutes without the wav headers because the sample size and rate are not defined in a raw pcm stream.
Finally I think you'll see that it's better to output wav format and read the wav format which will contain everything a player needs to playback the audio.
You would them provide wav audio instead of pcm which will work in naudio as well as many other players quite easily.

WP 8.1 Trimming MP3 FILES

Is there a way to trim a mp3 file?
I did some research and every search was leading me to NAudio.
However NAudio doesn't support WP8.1. Actually I don't think it support any version of windows phone.
Is there any other way to trim a mp3 file? MP3s are made of frames and ID3 tags.
Is there a helper that could read mp3 frames and then copy them into a new file?
An MP3 file is a collection of MPEG frames that you can manipulate fairly easily. If you read the NAudio source code (specifically the Mp3Frame class) you'll find a fairly good set of C# code for reading the individual frames. From there you can index the frames, figure out their positions in time and copy out only the ones you're interested in to the output file.
It may be a bit more complex than that, but have a look at Mark's code in and around the Mp3Frame class for some more information on how it works.
Oh, and don't forget to credit him if you use his code.

How to convert AMR sound stream to PCM uncompressed stream in .NET

I need to convert an AMR (Adaptive Multi-Rate) audio file recorded in a phone (as a Stream object) to a PCM uncompressed wav audio Stream so it can be processed afterwards for speech recognition. The Speech Recognition doesn't like the AMR format. This is going to be a server application using the Microsoft Speech Platform. I am not sure about using the ffdshow or similar libraries in a .
Right now I am researching NAudio and DirectShowNet to see if they can help me accomplish this but was hoping someone can point in the right direction.
After a lot of searching for a solution for this, I am going to use ffmpeg. It provides the AMR-NB (NB=Narrow Band) decoder. There are a lot of c# wrappers for ffmpeg around; most of them abandoned efforts and one that is up to date but is not free. Just running ffmpeg with the basic parameters provides what I need, plus it is really fast.
I don't like the idea of calling an external process to do the conversion, plus I need to save the AMR stream as a file so it can be converted to a wav file but I believe I can make it work efficiently.

Audio Conversion C#

What is the best way to convert various audio formats to PCM?
For example: mp3, evrc, ogg vox.
Is there a library out there that will allow me to implement this relatively easily?
EDIT:
I guess my initial question wasn't really what I needed. Most of the libs I have found are file converters. What I need is a block converter, where I pass in a 1Kb block of vox data and it returns its converted PCM block. Of course I’ll have to tell the converter what type of data it is and various pieces of codec information.
The solution I am going for is to save and VOIP formats into a common wav format and to play that conformed file in real time. I thought there should be an easy way to do this because all audio is eventually turned into PCM before it is outputted anyways.
You can use NAudio to pass blocks of compressed audio into any ACM codecs you have installed on your machine. You do need to know how to create the appropriate WAVEFORMAT structure to describe the compressed audio type correctly though.
Check out AVBlocks SDK for .NET. It supports several audio formats, and audio transforms like Multi-channel audio to Stereo audio, resampling and bitrate conversion.
Try modified code from http://alvas.net/alvas.audio,tips.aspx#tip91
static void AnyToWav(string fileName)
{
DsReader dr = new DsReader(fileName);
IntPtr formatPcm = dr.ReadFormat();
byte[] dataPcm = dr.ReadData();
dr.Close();
WaveWriter ww = new WaveWriter(File.Create(fileName + ".wav"), AudioCompressionManager.FormatBytes(formatPcm));
ww.WriteData(formatPcm);
ww.Close();
}
Don't know any lib that does it all but we do mp3->wav using madxlib.
It's free but I suggest paying the $10 for the sdk as it comes with documentation and examples.
There is a c# tutorial on youtube that might be helpful to you. It shows how to use a specific audio library called alvas.audio that really does some neat things with audio. I found the video to be very educational. The audio library is completely written in c#. Watch the video for more details: http://www.youtube.com/watch?v=2DIQECXFPeU

Converting mp3 bitrates using lame_enc.dll or similar

I need to programatically convert mp3's of any bitrate to a standard bitrate for streaming audio using c#.
Currently a buffer is populated with mp3 data from disk and then send out to the "listeners" at what should be a constant speed (the broadcast), but the mp3's could be of any bitrate. This makes timing extremely difficult and should rather be streamed at a standard bitrate instead of a bitrate dictated by the mp3 itself.
Lame seems to be the right encoder for the job, but any documentation or sample code only seems to be concerned with converting from wav samples to mp3. Not mp3 to mp3. The exe wrapper can do the bitrate conversion, but completely without any clue as to what gets passed to beEncodeChunk().
Has anyone had any experience in doing this kind of thing with lame or any similar encoder?
Do i need to decode to wav then encode back to mp3 to achieve what i'm after?
I welcome any links or advice with open arms.
Thanks
you have to decode the mp3 to wav, then re-encode it to the new bitrate

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