I am using the timestamps that FFmpeg outputs to get information about the video integrity. So far I have tested this on about 50 videos and only had one "Unusual time skip" false positive.
Is this method of checking a valid way to do this, could there be legitimate reasons why the time skip would significantly increase and is there a more accurate way to determine an invalid time skip than $dif*2?
ffmpegIntegrityCheck() { local frame=0 local prevFrame=0 local duration=0 local timestamp=0 local seconds=0 local prevSeconds=0 local dif=0 local line="" ffmpeg -v debug -progress - -nostats -i "$1" -f null - 2>&1 \ | while read -r line; do # Get the video duration if [[ "$duration" = 0 && "$line" =~ "Duration: " ]]; then duration=${line#* } duration=${duration%, start*} duration=${duration%.*} echo "Duration $duration" # Check if the frame number stops increasing elif [[ "$line" =~ "frame=" ]]; then frame=${line#*=} if [ "$frame" = "$prevFrame" ]; then echo "No frame change at $timestamp frame $frame" fi prevFrame="$frame" # Check the increase in seconds between each timestamp, elif [[ "$line" =~ "out_time=" ]]; then timestamp=${line#*=} timestamp=${timestamp%.*} seconds=$(echo "$timestamp" \ | awk -F: '{ print ($1 * 3600) + ($2 * 60) + $3 }') if [ "$dif" != 0 ] && (( $seconds-$prevSeconds > $dif*2 )); then echo "Unusual time skip at $timestamp" else dif=$(($seconds-$prevSeconds)) fi prevSeconds="$seconds" # Check if the last timestamp matches the duration elif [[ "$line" = "progress=end" ]]; then if [ "$duration" != "$timestamp" ]; then duration=$(echo "$duration" \ | awk -F: '{ print ($1 * 3600) + ($2 * 60) + $3 }') if (( $seconds < $duration-1 || $seconds > $duration+1 )); then echo "End time mismatch at $timestamp" fi fi fi done } The reason I am trying to check with more than just ffmpeg -v error is because I have found corrupted files where ffmpeg has reported no errors. I have also found files where FFmpeg reports errors but when I watch the video there are no problems so I would like to try and check whether there are any playback problems without watching it.
The logic behind looking at the timestamp jumps was that if the file all of a sudden starts processing significantly faster, I assume it is having errors and skipping some processing. This assumption does seem to match my results with files where ffmpeg -v error is reporting errors but it does produce some false positives
The log from a file producing errors in FFmpeg:
Duration 01:36:32 No frame change at 00:48:29 frame 69673 Unusual time skip at 00:49:42 No frame change at 00:49:42 frame 69673 Unusual time skip at 00:50:58 No frame change at 00:50:58 frame 69673 Unusual time skip at 00:51:44 No frame change at 00:51:44 frame 69673 Unusual time skip at 00:53:09 No frame change at 00:53:09 frame 69673 Unusual time skip at 00:54:04 No frame change at 00:54:04 frame 69673 Unusual time skip at 00:55:25 No frame change at 00:55:25 frame 69673 Unusual time skip at 00:56:32 No frame change at 00:56:32 frame 69673 Unusual time skip at 00:57:30 No frame change at 00:57:30 frame 69673 Unusual time skip at 00:58:08 No frame change at 00:58:08 frame 69673 Unusual time skip at 00:59:37 No frame change at 00:59:37 frame 69673 No frame change at 01:00:02 frame 69673 Unusual time skip at 01:01:19 No frame change at 01:01:19 frame 69673 Unusual time skip at 01:02:33 No frame change at 01:02:33 frame 69673 Unusual time skip at 01:03:39 No frame change at 01:03:39 frame 69673 No frame change at 01:03:39 frame 69673 No frame change at 01:06:02 frame 69673 No frame change at 01:06:25 frame 69673 Unusual time skip at 01:08:18 No frame change at 01:08:18 frame 69673 Unusual time skip at 01:09:19 No frame change at 01:09:19 frame 69673 Unusual time skip at 01:10:19 No frame change at 01:10:19 frame 69673 Unusual time skip at 01:11:26 No frame change at 01:11:26 frame 69673 Unusual time skip at 01:12:39 No frame change at 01:12:39 frame 69673 Unusual time skip at 01:13:53 No frame change at 01:13:53 frame 69673 Unusual time skip at 01:14:55 No frame change at 01:14:55 frame 69673 No frame change at 01:14:59 frame 69673 Unusual time skip at 01:17:04 No frame change at 01:17:04 frame 69673 No frame change at 01:17:04 frame 69673 No frame change at 01:19:01 frame 69673 No frame change at 01:19:25 frame 69673 Unusual time skip at 01:21:07 No frame change at 01:21:07 frame 69673 No frame change at 01:21:40 frame 69673 Unusual time skip at 01:23:34 No frame change at 01:23:34 frame 69673 No frame change at 01:24:18 frame 69673 No frame change at 01:25:34 frame 69673 No frame change at 01:26:41 frame 69673 No frame change at 01:27:48 frame 69673 No frame change at 01:28:06 frame 69673 Unusual time skip at 01:29:01 No frame change at 01:29:01 frame 69673 Unusual time skip at 01:30:38 No frame change at 01:30:38 frame 69673 No frame change at 01:30:38 frame 69673 No frame change at 01:33:15 frame 69673 No frame change at 01:33:51 frame 69673 Unusual time skip at 01:35:24 No frame change at 01:35:24 frame 69673 End time mismatch at 01:36:16 
while readloop to an awk script, and then you could just declare a function that creates thesecondsvalue for you. I almost think that could be done inbashwithout calling awk, but allf of this is off topic and would take some experimenting. Add that sample output , at least, and others with more experience in video may be able to help. Good luck!ffmpeg -h full. Way over my pay grade, but may give you some better terms to search the interweb for. Good luck!