Answers.Body: <p>I think I found the issue. One of the device is USB 1.1, and this causes the whole hub to fall down to USB 1.1 to accommodate it. I saw it using <code>lsusb -v</code>.</p>
  
  <p>USB 1.1 has a max bandwidth of 12Mbps, hence the reading I get with <code>lsusb -t</code>. I'll need to either replace the USB 1.1 device for a USB 2.0 device, or plug in a second USB card directly in the motherboard. </p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-04-20T23:13:32.630Z
Answers.LastActivityDate: 2020-04-20T23:13:32.630Z
Answers.UserDisplayName: leftcursor
Body: <p>I have two USB devices: a webcam and a microphone.  I can play the webcam's video into VLC and GUVCView. However, I want to use the microphone for another application. The issue is that launching media capture with VLC or GUVCView blocks the microphone.</p>
  
  <p>For instance, running the following before launching VLC/GUVCView:</p>
  
  <pre><code>arecord -vvv -f dat /dev/null
  </code></pre>
  
  <p>Shows what the microphone picks up. If I launch VLC first with the following command (webcam is on video0):</p>
  
  <pre><code>vlc v4l2:///dev/video0
  </code></pre>
  
  <p>And then monitor the microphone with the previously shown <code>arecord</code> command, I get nothing. It is the same behavior with GUVCView.</p>
  
  <p>Doing the opposite, launching <code>arecord</code> before VLC, however shows the issue. I only get part of the webcam's image (like the few first lines of the image). Dropping the camera resolution shows more lines in the webcam's image.</p>
  
  <p>It looks like I don't have enough USB bandwidth for both the webcam and the microphone. However, typing <code>lsusb -t</code> show that I have USB 2.0, which supports 480Mbps, and that the webcam only pulls 12Mbps.</p>
  
Tags: <video-capture><linux><microphone><usb>
Title: USB Webcam not working with USB Microphone
UserDisplayName: leftcursor
ThreadText: # USB Webcam not working with USB Microphone
  
  (Asked by: username_0 on 2020-04-14)
  
  I have two USB devices: a webcam and a microphone. I can play the webcam's video into VLC and GUVCView. However, I want to use the microphone for another application. The issue is that launching media capture with VLC or GUVCView blocks the microphone.
  
  For instance, running the following before launching VLC/GUVCView:
  
  ```
  arecord -vvv -f dat /dev/null
  
  ```
  
  Shows what the microphone picks up. If I launch VLC first with the following command (webcam is on video0):
  
  ```
  vlc v4l2:///dev/video0
  
  ```
  
  And then monitor the microphone with the previously shown `arecord` command, I get nothing. It is the same behavior with GUVCView.
  
  Doing the opposite, launching `arecord` before VLC, however shows the issue. I only get part of the webcam's image (like the few first lines of the image). Dropping the camera resolution shows more lines in the webcam's image.
  
  It looks like I don't have enough USB bandwidth for both the webcam and the microphone. However, typing `lsusb -t` show that I have USB 2.0, which supports 480Mbps, and that the webcam only pulls 12Mbps.
  
  **Tags:** video-capture, linux, microphone, usb
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2020-04-20. Score: 0 | Accepted answer
  
  I think I found the issue. One of the device is USB 1.1, and this causes the whole hub to fall down to USB 1.1 to accommodate it. I saw it using `lsusb -v`.
  
  USB 1.1 has a max bandwidth of 12Mbps, hence the reading I get with `lsusb -t`. I'll need to either replace the USB 1.1 device for a USB 2.0 device, or plug in a second USB card directly in the motherboard.
  
  
  ---
  
  