In my Windows Store application I want to make resampling with audio files.
It seems, what good solution for this problem is using Resampler object from Media Foundation Transforms. To get this object I should enumerate media transforms with function MFTEnumEx, as described here:
Enumerating MFTs.
But while certification I get such error:
API MFTEnumEx in mfplat.dll is not supported for this application type.
Is there any other way to get avaiable on Windows 8 Transforms, or another way to resample audio files?
Thanks!
Be aware that outside of native transforms which comes out of the box Windows store apps transforms (such as codecs) are sandboxed for your application.
If you setup a custom MFT with a traditional codec pack it won't be available to your windows store app. You'll have to package the MFT with your app and make it Activatable by WinRT (and also implement IMediaExtension). Remember that MediaExtensions are COM/WinRT mixes.
You have a list of supported formats here and I guess your best option is hardcoding it in your application :
http://msdn.microsoft.com/en-us/library/windows/apps/hh986969.aspx
Related
I have a lot of experience with libusb, libudev, and SetupAPI for writing Windows drivers, but it's totally unclear to me what CfgMgr32 offers over SetupAPI for Windows USB applications. Microsoft outlines how one would port from SetupAPI to CfgMgr32, but, I don't really understand the trade-offs or if there are gotchas.
Specifically, most of the time my work involves communicating to bespoke devices with isochronous endpoints, devices with bulk endpoints and HID devices. Is there any clear reason to do one or the other?
One reason is stated at the top of the Microsoft page describing how to port from SetupApi to CfgMgr32 found here https://learn.microsoft.com/en-us/windows-hardware/drivers/install/porting-from-setupapi-to-cfgmgr32.
Excerpt with pertinent part in bold:
This topic provides code examples that show how to port code that uses Setupapi.dll functionality to use Cfgmgr32.dll instead. Porting your code allows you to run your code on the Universal Windows Platform (UWP), which does not support SetupApi. A subset of CfgMgr32 is supported on UWP, specifically functionality exposed through the api-ms-win-devices-config-l1-1-0.dll API set (Windows 8 and later) or the api-ms-win-devices-config-l1-1-1.dll API set (Windows 8.1 and later). In Windows 10 and later, simply link to onecore.lib.
Another reason is that the CfgMgr API provides a specific return status code for operations whereas SetupApi returns a value to indicate success/error but a further call is required to GetLastError to get the specific error code of the last operation.
I am trying to add a continuous speech to text recognizer in a mobile application during a webrtc audio-only call.
I'm using react native on the mobile side, with the react-native-webrtc module and a custom web api for the signaling part. I've got the hand of the web api, so I am able to add the feature on it's side if it's the only solution, but I prefer to perform it on the client side to avoid consuming bandwidth if there is no need.
First, I have worked and tested some ideas with my laptop browser. My first idea, was to use the SpeechRecognition interface from the webspeechapi : https://developer.mozilla.org/en-US/docs/Web/API/SpeechRecognition
I have merged the audio only webrtc demo with the audiovisualiser demonstration in one page but there, I did not find how to connect a mediaElementSourceNode (created via AudioContext.createMediaElementSource(remoteStream) at line 44 of streamvisualizer.js) to a web_speech_api SpeechRecognition class. In the Mozilla documentation, the audio stream seems to came with the constructor of the class, which may call the getUserMedia() api.
Second, during my researches I have found two open source speech to text engine : cmusphinx and mozilla's deep-speech. The first one have a js binding and seems great with the audioRecoder that I can feed with my own mediaElementSourceNode from the first try. However, how to embed this in my react native application?
There are also Android and iOS natives webrtc modules, which I may be able to connect with cmusphinx platform specific bindings (iOS, Android) but I don't know about native classes inter-operability. Can you help me with that?
I haven't already created any "grammar" or define "hot-words" because I am not sure of technologies involved, but I can do it latter if I am able to connect a speech recognition engine to my audio stream.
You need to stream the audio to the ASR server by either adding another webrtc party on the call or by some other protocol (TCP/Websocket/etc). On the server you perform recognition and send results back.
First, I have worked and tested some ideas with my laptop browser. My first idea, was to use the SpeechRecognition interface from the webspeechapi : https://developer.mozilla.org/en-US/docs/Web/API/SpeechRecognition
This is experimental and does not really work in Firefox. In Chrome it only takes microphone input directly, not dual stream from caller and callee.
The first one have a js binding and seems great with the audioRecoder that I can feed with my own mediaElementSourceNode from the first try.
You will not be able to run this as local recognition inside your react native app
I'm creating a Store app using C# and XAML. I wanted to show the user the progress of file operations such as file copy. The API I'm using is StorageFile.CopyAsync.
It returns a task which is await-able. So I can tell my app to wait for the operation to finish. But if the file is too large I won't be able to tell how much of it, the app has copied.
Since CopyAsync returns IAsyncOperation<StorageFile> instead of IAsyncOperationWithProgress<StorageFile>, you're out of luck with this API. I don't think there's any built in API for copying that would implement progress reporting (Stream.CopyAsync doesn't implement it either).
You could always implement your own version which copies bytes from one stream to another in chunks and reports progress while doing it. It might be less performant than the built in APIs, though.
How to get System model /system type information programmatically using C# in Windows 8 application?
The GetNativeSystemInfo function is allowed API in store apps. Just use PInvoke as usual and you'll have all information in a SYSTEM_INFO struct.
I'm interested in grabbing the EPG data from DVB-T streams. Does anyone know of any C libraries or an alternative means of getting the data?
tv_grab_dvb can do this. See the subversion repository for sources.
tv_grab_dvb is made to work with the stream grabbed from the DVB-T card using dvbtools on Linux, but it may be portable to other platforms - I think it just works with the raw data from the stream.
...a new answer to an old question:
I wrote a utility called dvbtee that can be used as a c++ library, a cross-platform command line utility, or a node.js module.
(despite it being a c++ library, one could still link to it from c code)
The command line utility will parse your streams and output the EPG, depending on the arguments you specify, it can generate plain text or a JSON block of data.
dvbtee: a digital television streamer / parser / service information aggregator supporting various interfaces including telnet CLI & http control
The node.js module will emit events containing the PSIP table data (along with EPG info)
node-dvbtee: MPEG2 transport stream parser for Node.js with support for television broadcast PSIP tables