Monday, March 27, 2023

Convert a sequence of JPG images into a MP4 video using FFMPEG

If you have a sequence of images like the screen shot below, it is quite straightforward to use ffmpeg to concatenate them into a single video file. 

Obviously, you need to specify the image file name and sequence pattern, the frame rate to show each image as shown in the example ffmpeg command below.

$ ffmpeg -hide_banner \
-f image2 \
-framerate 1 \
-start_number 1 \
-i %02d.jpeg \
-vcodec mpeg4  \

where -f specifies the input format as image,

-framerate specifies the rate in Hz at which to display each image frame,

-start_number specifies the starting number of the image frame sequence,

-i specifies the file name and sequence pattern, e.g. %02d means a pattern of 2 digits with a prefix character '0' for single digit numbers,

-vcodec tells ffmpeg to output mpeg4 format.

 Running the command will display the following output and generate the output video file output.mp4.

Monday, January 30, 2023

Fixing a kernel panic error when installing Ubuntu 20.04 in VirtualBox

I was trying to create an Ubuntu 20.04 virtual machine using Oracle VirtualBox but I kept encountering this error with the message "...end kernel panic - not syncing: Attempted to kill the idle task!..." The screenshot below shows the error in VirtualBox.

Eventually, I found out the error was caused by inadequate alllocated CPU resources in VirtualBox. By default, the number of CPU allocated for the VM is 1, as shown in the screen shot below.

Simply increasing the number of CPU to at least 2 helped to solve the kernel panic error in this case.