I have OpenCV 4.4 on my Raspberry Pi Model 4B. I can play the video directly from camera. When I am recording the video and looking to play the file then I am not able to play the video. I am using VLC player. Here is the code I am using to record the video
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
if (cap.isOpened()==False) :
print("error in opening video stream")
exit()
fourcc = cv2.VideoWriter_fourcc(*'mp4v')
out = cv2.VideoWriter('video.mp4',fourcc,20.0,(160,120),True)
while(cap.isOpened()):
ret,frame = cap.read()
if ret == True:
frame = cv2.flip(frame,0)
out.write(frame)
cv2.imshow('frame',frame)
# Press 'q' to quit
if cv2.waitKey(25) & 0xFF == ord('q'):
break
else:
break
cap.release()
out.release()
cv2.destroyAllWindows()
On running the above script, I am getting following warning
[ WARN:0] global /home/pi/opencv/modules/videoio/src/cap_gstreamer.cpp (935) open OpenCV | GStreamer warning: Cannot query video position: status=0, value=-1, duration=-1
When I tried to convert the recorded video using ffmpeg, I am getting error. Code I am using for conversion
ffmpeg -i video.mp4 -vcodec libx264 demo.mp4
Error details
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2mp41
encoder : Lavf58.20.100
Duration: 00:00:00.00, bitrate: N/A
Output #0, mp4, to 'demo.mp4':
Output file #0 does not contain any stream
It seems the file is created but it has missing video codec. Looking for help.
Thank you
Thank you everyone !
I am able to solve it. It seems there was an issue with the frame and height that I was providing to VideoWriter with respect to default VideoCapture resolution. Below-mentioned is the modified script