I'm trying to create a VolumeSlider widget that changes the volume of my audio output.
log.debug("Starting audio player (%s)..." % url)
mediaSource = Phonon.MediaSource(url)
mediaSource.setAutoDelete(True)
self.player = Phonon.createPlayer(Phonon.VideoCategory, mediaSource)
self.player.setTickInterval(100)
self.player.tick.connect(self.updatePlayerLength)
self.mediaSlider.setMediaObject(self.player)
audioOutput = Phonon.AudioOutput(Phonon.MusicCategory)
Phonon.createPath(self.player, audioOutput)
self.mediaVolumeSlider.setAudioOutput(audioOutput)
self.player.play()
However even though I can move the volume slider, the actual volume doesn't change. What did I miss?
I have never used Phonon.createPlayer, because the API seems totally baffling. Apparently, it is supposed to be a "convenience" function that creates a path between an media object and an audio output. But it only gives a reference to the media object. There appears to be no access to the audio output object, which would seem to make it completely useless (but I may well be missing something).
Anyway, I think it is much more convenient to create the paths explicitly, so that it is clear how all the parts are connected together.
The following code works for me on Linux and WinXP:
self.media = Phonon.MediaObject(self)
self.video = Phonon.VideoWidget(self)
self.audio = Phonon.AudioOutput(Phonon.VideoCategory, self)
Phonon.createPath(self.media, self.audio)
Phonon.createPath(self.media, self.video)
self.slider = Phonon.VolumeSlider(self)
self.slider.setAudioOutput(self.audio)
Related
So, i was making a roblox game, and i implemented a shop, but i forgot something, the way how to make it give you an item once a time.
My code is this:
local BtoolGiver = script.Parent
local player = game:GetService("Players")
local valid = game.Workspace.SoundGroup.SoundSFX
local invalid = game.Workspace.SoundGroup.Sounding
script.Parent.MouseButton1Click:Connect(function()
valid.Playing = true
local tool = BtoolGiver.F3X:Clone()
tool.Parent = game.Players.LocalPlayer.Backpack
end)
Can you find a way how to fit the code in it?
Thanks!
How do I know which kind of data is currently emitted by a physical channel?
physical_chan.ai_meas_types gives me the possible type of data (ex: CURRENT, TEMPERATURE_THERMOCOUPLE, VOLTAGE). I would like to know which one are currently emitting.
Do I try/except add_ai_current_chan to check if a current is emitted? It seems like an ugly hack. Any suggestions?
import nidaqmx.system
system = nidaqmx.system.System.local()
device = system.devices["PXI1Slot2"]
with nidaqmx.Task() as task:
for physical_chan in device.ai_physical_chans:
# physical_chan.ai_meas_types gives me the possible options.
# task.ai_channels.add_ai_current_chan(physical_chan.name)
task.ai_channels.add_ai_voltage_chan(physical_chan.name)
print(task.read())
I am trying to create a PostScript file using the Apache xml-graphics library. When I run under Java, it works fine.
But when I build for .NET using IKVM, then on a call to GlyphVector.getoutline(x, y), the code never returns.
This is happening when I:
AttributedString as = new AttributedString(buf.toString());
// call as.addAttribute() setting various TextAttribute for various ranges
FontRenderContext frc = graphics.getFontRenderContext();
LineBreakMeasurer lineMeasurer = new LineBreakMeasurer(as.getIterator(), frc);
TextLayout layout = lineMeasurer.nextLayout(Integer.MAX_VALUE);
layout.draw (graphics, left, line.getBaseline());
Any idea what can be going wrong?
thanks - dave
I implemented an encoder in 2 ways.
1) based on the SDK Transcoder example, which uses topology and transcoding profile
2) based on IMFSourceReader and IMFSinkWriter, where the Sinkwriter delivers the samples to the Sourcewriter for transcoding
I tested both implementations on Windows 8.1 with Nvidia (Quadro K2200) and Intel GPU (P4600/P4700)
But bizarrly only the topology implementation uses GPU (on both).
In 2) I both I set "MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS", which has not to be set I guess, because 1) works with GPU with and without this flag set for the container type.
Is there a trick to enable GPU with IMFSinkWriter or is this a bug in the media foundation?
I had initially ran into the same issue. You don't mention how you configured the output type of the source reader (and the input type of the sink), but I found that if you allow the system to handle it (by selecting the output type of the reader to be RGB32), the performance will be horrible and all CPU bound. (error checking omitted for brevity)
hr = videoMediaType->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Video);
hr = videoMediaType->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_RGB32);
hr = reader->SetCurrentMediaType((DWORD)MF_SOURCE_READER_FIRST_VIDEO_STREAM, nullptr, videoMediaType);
reader->SetStreamSelection((DWORD)MF_SOURCE_READER_FIRST_VIDEO_STREAM, true);
And the documentation agrees, indicating that this configuration is useful for getting a single snapshot from the video. As a result, if you configure the reader to deliver the native media type, performance is excellent, but you now have to transform the format yourself.
reader->GetNativeMediaType((DWORD)MF_SOURCE_READER_FIRST_VIDEO_STREAM, videoMode->GetIndex(), videoMediaType);
From here, if you are dealing with simple color conversion (like YUY2 or YUV from a webcam) then there are a few options. I originally tried writing my own converter, and pushing that off to the GPU using HLSL with DirectCompute. This works very well, but in your case, the format isn't as trivial.
Ultimately, creating and configuring an instance of the color converter (as an IMFTransform) works perfectly.
Microsoft::WRL::ComPtr<IMFMediaType> mediaTransform;
hr = ::CoCreateInstance(CLSID_CColorConvertDMO, nullptr, CLSCTX_INPROC_SERVER, __uuidof(IMFTransform), reinterpret_cast<void**>(mediaTransform.GetAddressOf());
// set the input type of the transform to the NATIVE output type of the reader
hr = mediaTransform->SetInputType(0u, videoMediaType.Get(), 0u);
Create and configure a separate sample and buffer.
IMFSample* transformSample;
hr = ::MFCreateSample(&transformSample);
hr = ::MFCreateMemoryBuffer(RGB_MFT_OUTPUT_BUFFER_SIZE, &_transformBuffer);
hr = transformSample->AddBuffer(transformBuffer);
MFT_OUTPUT_DATA_BUFFER* transformDataBuffer;
transformDataBuffer = new MFT_OUTPUT_DATA_BUFFER();
transformDataBuffer->pSample = _transformSample;
transformDataBuffer->dwStreamID = 0u;
transformDataBuffer->dwStatus = 0u;
transformDataBuffer->pEvents = nullptr;
When receiving samples from the source, hand them off to the transform to be converted.
hr = mediaTransform->ProcessInput(0u, sample, 0u));
hr = mediaTransform->ProcessOutput(0u, 1u, transformDataBuffer, &outStatus));
hr = transformDataBuffer->pSample->GetBufferByIndex(0, &mediaBuffer);
Then of course, finally hand off the transformed sample to the sink just as you do today. I am confident that this will work, and you will be a very happy person. For me, I went from 20% CPU utilization (originally implementation) down to 2% (I am concurrently displaying the video). Good luck. I hope you enjoy your project.
I have some code creating a QTabWidget from Python using PyQt4. I want to get a 'throbber' animated gif in the tab. The /only way/ I have found how to do this is the following convoluted method.
tabBar = self.tabReports.tabBar()
lbl = QtGui.QLabel(self.tabReports)
movie = QtGui.QMovie(os.path.join(self.basedir, "images\\throbber.gif"))
lbl.setMovie(movie)
QtCore.QObject.connect(movie, QtCore.SIGNAL("frameChanged(int)"), lambda i: movie.jumpToFrame(i))
movie.start()
log.debug("valid = %s"%(movie.isValid()))
tabBar.setTabButton(idxtab, QtGui.QTabBar.LeftSide, lbl)
The debugging call always returns true, but the throbber sometimes works, sometimes is blank, and sometimes has a large ugly delay between frames. In particular, I can't help but think connecting the frameChanged signal from the movie to a function that simply calls jumpToFrame on the same movie is not correct.
Even more distressing, if I simply drop the lambda (That is, make the line say QtCore.QObject.connect(movie, QtCore.SIGNAL("frameChanged(int)"), movie.jumpToFrame) it never renders even the first frame.
So, what am I doing wrong?
PS: I realize .tabBar() is a protected member, but I assumed (apparently correctly) that PyQt unprotects protected members :). I'm new to Qt, and i'd rather not subclass QTabWidget if I can help it.
I believe the problem with the code I initially posted was that the QMovie didn't have a parent, and thus scoping issues allowed the underlying C++ issue to be destroyed. It is also possible I had had threading issues - threading.thread and QThread do not play nice together. The working code I have now is below - no messing with signals nor slots needed.
def animateTab(self, tab_widget, enable):
tw = tab_widget
tabBar = tw.tabBar()
if enable:
lbl = QtGui.QLabel(tw)
movie = QtGui.QMovie("images\\throbber.gif"), parent=lbl)
movie.setScaledSize(QtCore.QSize(16, 16))
lbl.setMovie(movie)
movie.start()
else:
lbl = QtGui.QLabel(tw)
lbl.setMinimumSize(QtCore.QSize(16, 16))
tabBar.setTabButton(tab_section.index, QtGui.QTabBar.LeftSide, lbl)
I faced the same problem and this posting helped to make it work:
http://www.daniweb.com/forums/printthread.php?t=191210&pp=40
For me this seems to make the difference: QMovie("image.gif", QByteArray(), self)