FAQ - showmewebcam/showmewebcam GitHub Wiki

What is the minimum size SD card required?

The showmewebcam image is about 50mb uncompressed. Hence any SD card with more than 64mb should be fine.

What housings/mounting plates can I use?

Have a look at our Overview here

Are there any lenses you can recommend?

Depending on where you set up your webcam, we recommend any focal length between 4 and 9mm. You can certainly also use a 16mm lens, however that would require you to set it up a few meters away from your face.

Have a look at our Overview here

Do I need to shut down the Pi before disconnecting it?

In our experiences, no. Showmewebcam does not use a writable root filesystem so it almost never writes to the SD card. You can, in fact, disconnect the power at any time and not worrying about SD card corruption.

We have seen reports in other forums that if the Pi is up, you shouldn't cut the power down abruptly or the SD card will be bricked. However, we haven't actually encountered that situation from our users.

Fun fact: Most of the times, the camera doesn't even crash when you remove the SD card while it is powered up!

My Raspberry Pi doesn't work!

This could have many reasons, but in most cases the culprit is either the camera cable or the USB cable. Try to check if they are connected, or even try different cables. Many USB cables can only carry power, so check for that as well.

If you're sure they both work fine, here's what most people had issues with:

  • Try attaching it directly to your computer, ie. not via a USB hub
  • Try changing the cable, as they break more often than one would believe
  • Try to use a different SD Card
  • Look at the LED pattern, it should blink once when loading the kernel and three times when it is ready
  • Try to remove initial_turbo=10 from /boot/config.txt -- If this works for you, please comment in this thread.

How can I record the MJPEG stream into a video file on Linux?

To be answered in more detail..

On Linux with /dev/video0 being the showmewebcam device:

First: Get information about the capabilities with

ffmpeg -f video4linux2 -list_formats all -i /dev/video0

or

v4l2-ctl --list-formats-ext

Command line:

ffmpeg -f v4l2 -input_format mjpeg -i /dev/video0 -c:v copy video.mkv

GUI:

On Window:

My video picture is pixelated!

After the showmewebcam is connected to the host PC via USB, different combinations of resolutions are advertized. The problem with the pixelated video could be that a low resolutions is picked by the program (e.g. it has been observed sometimes on Windows 10 using MS Teams). You can check that by using the camera-ctl tool after logging into the camera via a serial connection.

To fix this, first check that Video Bitrate is set to its max. If that does not bring any results, the low resolutions can be removed from the advertized set, as shown in the README