Ensure that the frames you are writing match the resolution designated in your VideoWriter object constructor (e.g.,
To create an MP4 file, you need to use cv2.VideoWriter . Ensure that you have ffmpeg support. Using the MJPG FourCC code with an .avi container is a reliable alternative if mp4v/mp4 fails. 258 mp4
For in-memory MP4 creation, use PyAV to open a BytesIO file, add an H.264 stream, and set parameters such as pixel format ( yuv444p ) and quality ( crf : '17'). Ensure that the frames you are writing match