The repaired MP4 opens, but its timeline ends much earlier than the session you remember recording. A playable beginning is useful; it is not proof that the ending survived. Keep both the damaged original and the repaired file while you work out whether the missing time is in another segment, hidden by a playback problem, or absent from the recovered result.
Start with the original and nearby files
Save copies of the original, the repaired output and any reference clip under different names. Check the camera or recording app for additional files created at about the same time, as well as any backup or interrupted transfer. Some recorders split long sessions into separate files; a short clip may be one segment rather than the entire session. If the source was copied from a card or drive, compare the source and copy sizes and, when it is safe to do so, copy the source again to a new name.
A large damaged file is a reason to keep looking, not proof that all the missing footage is inside it. If the card or drive itself is failing, avoid writing to it or repeatedly attempting repairs on it; seek appropriate data-recovery help.
Compare the result with what you remember
Note the expected length and why you expect it: a second camera, a separate audio recording, session notes or the recorder’s file list may provide a better comparison than memory alone. Open the result in a compatible player, then try another if it stops unexpectedly. Watch and listen at the beginning, middle and end. A timeline that looks long but freezes at one point is a different observation from a video that plays normally and ends early.
Check the downloaded full result, not just a short preview. MendVid’s paid video preview covers at most the first 12 seconds, so it cannot establish whether the end of a longer recording is present. Keep your evidence separate: a player’s duration display, the last visible scene and the length of another recording each answer a different question.
Compare the reported video and audio durations
If you have FFmpeg’s ffprobe installed, run this read-only command in the folder containing a copy called repaired.mp4. Replace the name with the path to your result; keep the quotes if the path contains spaces.
ffprobe -v error -show_entries format=duration:stream=index,codec_type,start_time,duration:stream_disposition=attached_pic -of json "repaired.mp4"The output lists the streams it finds and may report a container duration and a duration for each video or audio stream, in seconds. There may be more than one video stream. Check its index and type before comparing; an attached_pic value of 1 identifies cover art, not the recording. A stream may have no duration listed, and a damaged original may not open in ffprobe at all. If audio reports 600 seconds but video reports 480 seconds, inspect whether the sound continues after the picture and whether the two streams start at different times. The difference is a clue, not proof that video frames were lost during repair or that the longer stream contains the missing scene.
To check the first video stream that is not an attached picture, you can run the next command. It reads the copy and sends decoded video to a null output; it creates no output video. It may take time on a long file and does not check audio. If the recording is a different video stream, select the appropriate stream after inspecting the list above.
ffmpeg -v warning -i "repaired.mp4" -map 0:V:0 -f null -Save any warnings. A shortened file may decode without warnings even if it contains only the recovered beginning; a clean run does not prove the original ending is present or that sound is synchronized. Errors, a frozen picture or an early stop are reasons to inspect that point; they do not identify the cause by themselves. In a discussion of one repaired recording, participants considered how assumed frame rate and variable timing could affect duration. That example does not diagnose your file.
Choose the next attempt carefully
If the original is readable and contains the missing ending, compare the repair or export settings and any selected time range before making another copy. If it is unreadable, check whether a healthy reference came from the same device or application and recording settings. Our guide to matching a reference video explains what to compare. A matching reference can supply structural clues for some reconstruction attempts. It cannot provide frames that were never written or were overwritten.
If you have already used MendVid’s video repair, a required reference and eligible retry stay on the same paid job; follow that job’s instructions to see whether a retry is available before starting another purchase. A repair attempt costs US$9.99 per file, with payment confirmed before upload and repair and no result preview before payment. An unsuccessful or incomplete attempt is not refunded, subject to non-waivable rights and applicable payment-processor rules. Recovery is not guaranteed; see the current price and repair terms before a new attempt.
If a different copy or segment contains the missing scene, preserve it alongside the result. If no copy does, neither a longer duration label nor a matching reference establishes that the missing frames can be recovered.