Black screen on video playback


After the normal video recording, when it was tried to play, only the black
screen and the sound were seen.
During counting frames by commands
ffmpeg -i 223364973906427620.mkv -vcodec copy -acodec copy -f null
/dev/null 2>&1 | grep ‘frame=’ | cut -f 2 -d ’ '
ffprobe -v error -count_frames -select_streams v:0 -show_entries
stream=nb_read_frames -of default=nokey=1:noprint_wrappers=1

Output 0 frames

uname -a
Linux altin-demo-signal 3.13.0-52-generic #86 SMP Mon May 4 04:32:59 UTC
2015 x86_64 x86_64 x86_64 GNU/Linu

What is the problem and what should be done to record and play video