How to fix invalid bitrate with ffmpeg

Question

I tried to download 3-hour long video (now unavailable) with YoutubeDL and ended up with a 2GB file of 14 seconds with the correct frame size but an insane bitrate:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.20.100
  Duration: 00:00:14.08, start: 0.000000, bitrate: 1194942 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 1396506 kb/s, 49893.76 fps, 60 tbr, 90k tbn, 120 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 82853 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

I'm guessing all the data is here, but I don't know how to handle ffmpeg to give me the correct output. What should be the correct parameters to use here?

EDIT : The video is unavailable, but Youtube shows information nonetheless. The video is 9532 seconds long which means a speed factor of 676.99. Since the audio real bitrate should be 128 Kb/s, another factor of 647.29 can be calculated.

EDIT #2 : Tried to apply a slowdown filter with:

ffmpeg -i video.mp4 -filter:v "setpts=647.289*PTS" video_fixed.mp4

But I only got a still image.

The 4 first seconds seem to be fine then VLC fail to read and displays

avcodec info: Using D3D11VA (Intel(R) HD Graphics Family, vendor 8086(Intel), device a16, revision 9) for hardware decoding
main error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 300 ms)
main error: Timestamp conversion failed for 5250012: no reference clock
main error: Could not convert timestamp 0 for FFmpeg
main error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 1222 ms)
main error: Timestamp conversion failed for 6250012: no reference clock
main error: Could not convert timestamp 0 for FFmpeg
main error: ES_OUT_SET_(GROUP_)PCR is called too late (pts_delay increased to 3115 ms)
main error: Timestamp conversion failed for 8000012: no reference clock
main error: Could not convert timestamp 0 for FFmpeg
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?)
direct3d11 error: SetThumbNailClip failed: 0x800706f4

Answer 1

Here is what i would be doing to try to resolve this:

Check the video with fprobe -show_streams note how many frames there are. From that and the knowledge of the total duration it can be possible to figure out the correct framerate.

Try to reencode with:

ffmpeg -i broken.mp4 -c copy -r (what you have calculated above) try1.mp4

If this doesn't work, try reencoding rather than copying.

If that doesn't work still, maybe it would work to dump all the frames as image files and then reencode them into video with a calculated framerate.