video-capture

问题 There is a very good solution how to use WebCam via MS Expression Encoder SDK. So this code Dim vidDevices = EncoderDevices.FindDevices(EncoderDeviceType.Video) returns the list of the installed video devices. My question is: how to get WebCam as device by default. Is it possible to return /filter only first installed WebCam and no more? I mean I don't care how many video devices installed I just need get one of the WebCam and that's it. Is it possible to automate it somehow or we have to

问题 I have Mp4 Capture Application in direct show. In my application i need to capture 30 min(or say some dynamic value) video continuously for the I made one WaitableTimer Routine , after 30 minutes i want to stop the capture and then start again ... but after i stop capture on next sample in start capture the stream not get added to the file. to start next capture , i have to release all the capture variables again get devices and build graph and then i can start capture. Cant i simply stop

问题 I have created a simple GUI to preview webcam stream and to get snapshot from it. For this I have created on axes to show video, one push button(pushbutton1) to start preview, one push button(pushbutton2) to get snapshot. Following is the code for these two push buttons. function pushbutton1_Callback(hObject, eventdata, handles) % hObject handle to pushbutton1 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see

问题 I am trying to capture a single frame per second from a RTSP stream with following command ffmpeg -i rtsp://XXX -q:v 1 -vf fps=fps=1 -strftime 1 ZZZZ\%H_%M_%S.jpg But some of the frames are smeared ,pixeled and corrupted - this effect is drastically increases if rtsp resolution is increased (if the resolution is decreased for example to 720P most of the frames are OK) I have to say that playing same rtsp stream in VLC or FFPLAY is flowless. How I can fix it to grab better quality Thanks in

问题 I use the Python (2.7) package VideoCapture. When I try to instantiate the Device, I get an Exception: Error: Capture Graph could not be created. I use cam = Device() , so nothing special there. I have one laptop where this works without a problem, and another where I get the Exception. They are different, but both have internal USB-Webcams. One week ago it worked, but now I only get the exception. Both use Windows 7. Does anybody have an idea how to resolve this, or how I could get more

问题 Apple has a sample code called Rosy Writer that shows how to capture video and apply effects to it. During this section of the code, on the outputPreviewPixelBuffer part, Apple supposedly shows how they keep preview latency low by dropping stale frames. - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { CMFormatDescriptionRef formatDescription = CMSampleBufferGetFormatDescription(

问题 I worked with OpenCV 3.2 with Python3 and SBC OXU4. I have a true 5MPx web-camera connected to SBC. I want to take from this camera 2592x1944 resolution picture. If I use Cheese I can take picture with this resolution. I can save pictures with command line program streamer -t 4 -r 4 -s 2592x1944 -o b0.jpeg But when I take picture with OpenCV3.2 like this: #!/usr/bin/env python3 import cv2 import os import time capture1 = cv2.VideoCapture(2) if capture1.isOpened(): capture1.set(3, 2592)

问题 I have been trying to access my analog camera via a EasyCap video capture device. Any code I try only picks the usb webcam or internal webcam. I guess that since video capture device is a video controller, opencv doesnt recognize it as a imaging device. Can anyone conform if you cannot access analog cameras with opencv via a video capture device. If so, then what other method can be used. 回答1: i struggled with the same problem (in my case within python instead of C++, although I am certain it

问题 enter code here When I try to recording video from camera at version Android 2.2. It has some errors.No one could find the solution. İs there any bug Android MediaRecorder API. How can I solve this. I got more errors.You can see some of them in picture. And an error like that: Camera Preview -13 Thanks a lot. http://i.stack.imgur.com/72lp7.png recorder.prepare() fails and throws Java.lang.illegalexeption Here is Code: package app.raceway.com; import java.io.File; import java.io.IOException;

问题 enter code here When I try to recording video from camera at version Android 2.2. It has some errors.No one could find the solution. İs there any bug Android MediaRecorder API. How can I solve this. I got more errors.You can see some of them in picture. And an error like that: Camera Preview -13 Thanks a lot. http://i.stack.imgur.com/72lp7.png recorder.prepare() fails and throws Java.lang.illegalexeption Here is Code: package app.raceway.com; import java.io.File; import java.io.IOException;