I can read and play the file but when I write a mp4 or even avi video its not playable . I have confirmed that ffmpeg can create the video fine so why from openCV its not working?
iam using openCV 3.1.0 and python 3.3
ffmpeg -i /tmp/kyak.mp4 -vcodec libx264 -f mp4 /tmp/a.mp4
the code below produces the file but it contains zero frame as shown by ffmpeg command .
import numpy as np
import cv2
cap = cv2.VideoCapture('/tmp/kyak.mp4')
fourcc = cv2.VideoWriter_fourcc('X','2','6','4')
out = cv2.VideoWriter('/tmp/output.mp4',fourcc, 20.0, (640,480))
while (cap.isOpened()):
ret,frame=cap.read()
if ret == True:
gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
#write the gray frame
out.write(gray)
cv2.imshow('frame',gray)
if cv2.waitKey(30) & 0xFF == ord('q'):
break
else:
break
cap.release()
out.release()
cv2.destroyAllWindows()
The video plays but I get this error from the code above :
OpenCV: FFMPEG: tag 0x34363258/'X264' is not supported with codec id 28 and format 'mp4 / MP4 (MPEG-4 Part 14)'
OpenCV: FFMPEG: fallback to use tag 0x00000021/'!???'
if I replace the "fourcc" with "0x00000021" then the error goes away but still the produced file has zero frame .
[root@hadoop1 scripts]# ffmpeg -i /tmp/output.mp4
ffmpeg version N-82533-gae514b1 Copyright (c) 2000-2016 the FFmpeg developers
built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-17)
configuration: --enable-libx264 --enable-gpl --enable-shared
libavutil 55. 40.100 / 55. 40.100
libavcodec 57. 66.105 / 57. 66.105
libavformat 57. 57.100 / 57. 57.100
libavdevice 57. 2.100 / 57. 2.100
libavfilter 6. 67.100 / 6. 67.100
libswscale 4. 3.101 / 4. 3.101
libswresample 2. 4.100 / 2. 4.100
libpostproc 54. 2.100 / 54. 2.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/output.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf57.57.100
Duration: 00:00:00.00, bitrate: N/A
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