Thank you for your answer, I really appreciate it, and I have to share with you that it was a useful example, but in the following link is explained how to use it on Windows Phone 8.1 and how to create your own implementation of MSS.
http://video.ch9.ms/sessions/build/2014/2-528.pptx
What you’re doing is impossible.
Wave files aren’t media streams. You can’t dynamically change a .wav file and expect the MediaElement to pick those changes.
If you’re trying to play audio that you’re receiving from the network, or audio that you're generating dynamically from something else, then you need to play from your custom media stream source, not from a file.
The sample code is available here. The sample plays mp3; you’ll need to change it, wave audio is supported, with some limitations.
Related
I am looking to make a sound visualizer with Unity3D (mainly for the UI and graphics), and as I get ready to export the project, I need to know how to get a live audio feed from whatever is playing on the computer and translate that to the audio samples that my program uses.
Currently, I use preset .mp3 files and apply them to audiosources, and a script updates the samples live and those translate to the bars you see in audio visualizers. I would like to move this up a step, but I don't know how to do that. I've looked into NAudio and CSCore, but I haven't been able to make anything work.
All I need is for NAudio or CSCore to record to a file, and also have me continuously play that file. That seems like it would have problems though, so if I can just get a sound card stream and use that data to pass through to the program, that would be great.
If anyone has any experience, docs, or tips that can help me out, please send them over. Appreciate the help, thank you.
I have a device that provides an H.264 video stream from a URL like:
rtsp://192.168.0.10:554/videoservice
Since this is live video I don't need to be able to control it (pause, rewind, etc), just play. Is this supported by MediaElement or another standard class, do I need something like Smooth Streaming Client SDK or is this a lot more complicated than I thought?
Update:
I downloaded Microsoft's Player Framework but this doesn't play the stream either. I can't find anything in the examples about RTSP.
Update:
I used Wireshark to compare the packets that VLC Media Player (which works) sends with MediaElement and Player Framework and neither of them seemed to use RTSP protocol. Instead they're sending WPAD packets to a different address, even though I've provided the IP address of the source. Why is this necessary? Is there any way of turning this behaviour off?
See the post here. You need to wrap your data in MPEG-4 Part 14 containers and then pass them into MediaElement.SetSource. It appears you can't do this just using the documented API. Here is the important information from the link:
We don't support RTP but rather the MPEG-4 Part 14 container format.
You will need to write our own source to be able to parse the data a
pass it directly to the Microsoft decoder. At this time we do not have
any samples on how to write a custom source and have it loaded from
your Metro style app. Unfortunately it is not possible to simply use
the documentation to figure out how to do this. I have been talking
with Stan and we are trying to figure out how and when we can make
this information available. As soon as this information is available
I will announce it on my blog http://blogs.msdn.com/mediasdkstuff/.
Here is a list of supported video formats.
There is also an example here of how to extend the media class which might have an example of how to do something similar to what you are asking.
There is a similar example here.
I am developing a windows phone 7 application and it does video recording. I would like to get the sound portion of the video file (MP4) and do some enhancements on the sound. I believe sound is saved as AAC frames in MP4. (Right?) How can I extract sound of a videa MP4 file?
Since this is a video file, it can be huge file. So uploading to cloud and processing there is not a good option. Since this WP7 application I cannot use unmaged dlls :( Is there a way to do in pure C#? Any open source tools/samples?
Thanks!
MP4 is a container format and realistically the sound portion isn't always AAC. It could be MP3 or any other number of different audio formats. You may be thinking of M4A, which I believe requires either AAC or ALAC.
On the subject of audio extraction, it should be possible to extract the audio from an MP4 using just managed code. You'll have to read up on the MP4 format (here, for example - this question is also worth reading) and then search through the file for the location of the audio and then either copy it to its own buffer or do your manipulations in chunks. Even then, you'll have to be able to recognize when it isn't an audio format that your app won't support.
It's possible that there already exists a .net library that can do all of this but I don't know of any. It's probably not very popular because managed code is definitely not the best angle to approach this from, but considering this is Windows Phone, it is, as you noted, your only avenue of approach.
Good luck!
I want to transcode a lot of audio from its source format to PCM without resampling or messing with the sample size. I figure if Windows Media Player can play the file and it doesn't use a legacy ACM codecs it must be using DirectSound to do so (this is on Windows XP and Windows Server 2k3). So is it possible to access DirectSound from C# and do so? I've tried searching the web but all the examples have been about playback which I have no interest in doing.
DirectSound is an audio playback API, you mean DirectShow. Windows Media player does use DirectShow to play audio files. In theory, all you need to do is build the same playback graph that media player uses, but replace the audio driver on the end with a .WAV writer filter.
This is somewhat easier to do in C++ code, since the DirectShow graph object is really designed to be called from C++, but with a good set of interop definitions, you can do this in C#.
There's http://directshownet.sourceforge.net/ for serious hacking with DirectShow in .NET, but that's probably overkill for your problem.
I would suggest getting a copy of GraphEdit if you don't already have one. You can use it to "prototype" direct show graphs interactively. drop a file into graphedit. then delete the filter on the end and replace it with a file writer filter.
One problem you will have is that there is no .WAV file writer filter in the default set of o DirectShow filters, you will have to find or write one.
If you just want to get the files converted, and could care less about learning how to write code using DirectShow, I would suggest that you just get a copy of Sound Forge (possibly even a demo version). It has a scripting language (C#,vb) that can be used to easily batch process most audio file formats.
Conversion to WAV can be done from the Windows command line using SoX (Sound eXchange, http://sox.sourceforge.net/). You could write a batch file or a C# application that calls SoX with the proper attributes. I'm not sure how WinAMP's feature works specifically, but it has a file writer output option built in as well. You can stream the entire playlist to wave files.
Have a look at this article on CodeProject about audio conversion here and here.
I'm looking to develop a Silverlight application which will take a stream of data (not an audio stream as such) from a web server.
The data stream would then be manipulated to give audio of a certain format (G.711 a-Law for example) which would then be converted into PCM so that additional effects can be applied (such as boosting the volume).
I'm OK up to this point. I've got my data, converted the G.711 into PCM but my problem is being able to output this PCM audio to the sound card.
I basing a solution on some C# code intended for a .Net application but in Silverlight there is a problem with trying to take a copy of a delegate (function pointer) which will be the topic of a separate question once I've produced a simple code sample.
So, the question is... How can I output the PCM audio that I have held in a data structure (currently an array) in my Silverlight to the user? (Please don't say write the byte values to a text box)
If it were a MP3 or WMA file I would play it using a MediaElement but I don't want to have to make it into a file as this would put a crimp on applying dynamic effects to the audio.
I've seen a few posts from people saying low level audio support is poor/non-existant in Silverlight so I'm open to any suggestions/ideas people may have.
The simple answer is that there is no support for PCM playback from Silverlight in version 2. So unless you want to write a fully managed PCM to MP3 converter you are stuck. Even then I'm not sure you could get the MediaElement to play from isolated storage.
Is there any chance you could use a web service to perform the conversion?
See also this question:
Where's the sound API in Silverlight? Or, how do I write a music app to run in the browser?
Update: Silverlight 3 supports your custom audio sources. However, it won't let you intercept samples to perform effects on WMA or MP3, presumably for DRM reasons, so you would still potentially need to write your own decoder.
Short answer is use a MediaElement + a MediaStreamSource
Check out these:
http://blogs.msdn.com/gillesk/archive/2009/03/23/playing-back-wave-files-in-silverlight.aspx
http://code.msdn.microsoft.com/wavmss/Release/ProjectReleases.aspx?ReleaseId=2417
Basically, write a decoder in managed code to convert G.711 a-Law to PCM, then do whatever modifications you want to the raw values, then pass those into a MediaStreamSource.
Looks like Silverlight 3 supports direct PCM output now, or will when released. I don't see anything in the docs about the raw AV pipeline yet.
Mark Heath's answer is correct - only certain formats are supported - mp3 and certain flavours of WMA (unfortunately not WMA lossless which would be 'closer' to PCM).
To play PCM data in Silverlight, you could do the following:
* Convert the PCM into mp3 data, and store it in memory.
* Play the mp3 data using the technique presented at ManagedMediaHelpers. The idea here involves a class called Mp3MediaStreamSource (derived from System.Windows.Media.MediaStreamSource) that provides mp3 chunks to a MediaElement to play. The chunks will need to be in a stream, but of course a memory stream will do.
I initially thought you might be able to provide PCM chunks via MediaStreamSource, but this does not work. It's a real shame as it would solve your problem (and the one I was facing - making a Speex audio file player) really easily!