Microsoft provide Audio DSP function by CLSID_CWMAudioAEC DMO Object.The only document is https://learn.microsoft.com/en-us/previous-versions/dd443455(v=vs.85).
My program need record voice from speaker and clip voice by my program.
So if I want implment AEC(Audio echo cancellation),I can't use default source mode,I must use filter mode.
Windows SDK samples contain a AEC sample,but it's source mode.
My program Use ProcessInput twice and ProcessOutput,but voice sounds bad.
Where is Windows DMO AEC filter mode sample or blog
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 developing an Android app that gets data from Movesense using the GATT profile from the sample app GATT Sensor Data App here.
I followed the tutorial available here. Building the app and getting the DFU worked fine. I can get IMU, HR and temperature data with no issues.
Now I'd like add a tap detection feature to my app. I understand that I have to subscribe to 'System/States', but first I need to be able to receive the system state data.
I understand that I need a modified DFU for that, but I don't understand what changes I should make in which files of the gatt_sensordata_app before rebuilding and generating the new DFU.
What changes should I make in order to broadcast /System/State data?
(I usually just deal with Android so apologies for the very basic question.)
I tried adding #include "system_states/resources.h" to GATTSensorDataClient.cpp but I don't know how to continue.
The normal data straming in the gatt_sensordata_app uses the sbem-encoding code that the build process generates when building the firmware. However /System/States is not among the paths that the code can serialize. Therefore the only possibility is to implement the States-support to the firmware.
Easiest way is to do as follows:
In your python app call data subscription with "/System/States/3" (3 == DOUBLE_TAP)
Add a special case to the switch in onNotify which matches the localResourceId to the WB_RES::LOCAL::SYSTEM_STATES_STATEID::LID
In that handler, return the data the way you want. Easiest is to copy paste the "default" handler but replace the code between getSbemLength() & writeToSbemBuffer(...) calls with your own serialization code
Full disclosure: I work for the Movesense team
I'm using DDA for capturing the desktop image frames and sending them to the server, where these frames should be used to create video with MMF. I want to understand, what needs to be done with MMF, if i will use Source Reader and Sink Writer to render video from captured frames.
There are two questions:
1) Well, first of all, i can't fully understand is there, actually, need for the Source Reader with Media Source, if i already receive the video frames from DDA? Can i just send them to the Sink Writer and render the video?
2) As far as i understand, first thing to do, if there is still a need for Source Reader and Media Source, is write my own Media Source, which will understand the DXGI_FORMAT_B8G8R8A8_UNORM frames, that captured with DDA. Then i should use Souce Reader and Sink Writer with suitable Decoders\Encoders and send the media data to the Media Sinks. Could you, please, explain in more detail what needs to be done in this case?
Implementing SourceReader is not necessary in your case, but you can go ahead and implement it, it will work.
Instead, you can also directly feed your input buffer captured through Desktop Duplication to SinkWriter. Just as below,
CComPtr<IMFAttributes> attribs;
CComPtr<IMFMediaSink> m_media_sink;
IMFSinkWriterPtr m_sink_writer;
MFCreateAttributes(&attribs, 0);
attribs->SetUINT32(MF_LOW_LATENCY, TRUE);
attribs->SetUINT32(MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS, TRUE);
IMFMediaTypePtr mediaTypeOut = MediaTypeutput(fps, bit_rate);
MFCreateFMPEG4MediaSink(stream, mediaTypeOut, nullptr, &m_media_sink));
MFCreateSinkWriterFromMediaSink(m_media_sink, attribs, &m_sink_writer);
//Set input media type
mediaTypeIn->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_RGB32);
//Set output media type
mediaTypeOut->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_H264);
IMFSamplePtr sample;
MFCreateSample(&sample);
sample->AddBuffer(m_buffer); // m_buffer is source buffer in R8G8B8A8 format
sample->SetSampleTime(m_time_stamp);
sample->SetSampleDuration(m_frame_duration);
m_sink_writer->WriteSample(m_stream_index, sample);
Here is a perfectly working sample based on SinkWriter. It supports both network and file sink. It actually captures the desktop through GDI approach though. DDA is almost the same, you can indeed obtain better performance using DDA.
I have also uploaded one more sample here which is in fact based on Desktop duplication, and directly uses IMFTransform instead, and streams the output video as RTP stream using Live555. I'm able to achieve up to 100FPS through this approach.
If you decide to follow the SinkWriter approach, you don't have to worry about the color conversion part as it is taken care by SinkWriter under the hood. And with IMFTransform, you will have to deal with color conversion part, but you will have a fine grained control over the encoder.
Here are some more reference links for you.
https://github.com/ashumeow/webrtc4all/blob/master/gotham/MFT_WebRTC4All/test/test_encoder.cc
DXGI Desktop Duplication: encoding frames to send them over the network
Getting green screen in ffplay: Streaming desktop (DirectX surface) as H264 video over RTP stream using Live555
Intel graphics hardware H264 MFT ProcessInput call fails after feeding few input samples, the same works fine with Nvidia hardware MFT
Color conversion from DXGI_FORMAT_B8G8R8A8_UNORM to NV12 in GPU using DirectX11 pixel shaders
GOP setting is not honored by Intel H264 hardware MFT
Encoding a D3D Surface obtained through Desktop Duplication using Media Foundation
I am developing VOIP Application on OSX and iOS and will be using AudioQueue for Audio flow, what want to Know is, by default does AudioQueue support acoustic echo cancellation or do we need to add support for it,
If we need to implement, i believe some open source library has to be implemented like Speex are there any Example available shows integration of AudioQueue with Speex or any other library
As far as I can find, you have to use Audio Units to access the system's echo cancellation. You do that by using kAudioUnitSubType_VoiceProcessingIO instead of kAudioUnitSubType_RemoteIO.
You probably want to use Audio Units anyway, in order to control your latency.
You can use a render callback function to get data from an Audio Queue and pass it to your I/O unit. For outgoing, use AudioUnitRender.
Thanks to David and This post, I have realized following changes are required for Echo Cancellation on iOS:
desc.componentSubType = kAudioUnitSubType_VoiceProcessingIO
This will enable hardware Echo suppression according to apple documentation. However, you still need to use specific flags for AudioStream description:
audioFormat.mFormatFlags = kAudioFormatFlagsCanonical;
The tiny question is:
How to start (realplayer ?) playing given online resourse (e.g. http://example.com/file.mp3)
PyS60, C++ or C# via RedFiveLabs would do.
EDIT1: Title changed from "Start RealPlayer on symbian" to the more appropriate.
I think the title is a little misleading if you just want to play back media content and not use a particular application for it.
In C++ there is CMdaAudioPlayerUtility::OpenUrlL() but it's not widely implemented. For example in S60 it will complete with KErrNotSupported status. To play files you can use other open functions in CMdaAudioPlayerUtility such as OpenFileL() or OpenDesL() but you need a separate mechanism for retrieving the files or at least the bytes onto the device.
There is also CVideoPlayerUtility::OpenUrlL() which supports rtsp audio streams but not http.