Recovering corrupted video files from Tello

[raulvolador]

Hello,

Lately I got some corrupted video files from my Tello. At the end of a successful flight I realized saved video file at my mobile phone was not playable.

I supose video file corruption occurs when Wi-Fi connection between aircraft and phone is unexpectly lost, for example if you shut down Tello before exits flight app.

Searching the web I found a video reaparing method that works right with Tello H264 video stream. you just have to follow steps explained here:

recover_mp4 1.92 Free / 2.65 Premium Service Download - VideoHelp

In summary:

First, you have to open a Windows Command window and use repairing tool called recover_mp4_x86. The way it works is curious, it needs a right, playable, sample Tello video file and uses the header info extracted to correct corrupt video file.

After that, you have to encode repaired .H264 stream into an mp4 playable file with ffmpeg tool.

It worked for me. If you need more help I can write a detailed tutorial here.

Cheers

Raul
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[Tuba]

That's great. Any chance you can upload the corrupted and fixed videos to Youtube so people can see the fix?

 

[raulvolador]

That's great. Any chance you can upload the corrupted and fixed videos to Youtube so people can see the fix?

That not possible becouse corrupted file is not playable.

Raul

 

[Tuba]

That not possible becouse corrupted file is not playable.

Raul

Ah, understood.

 

[Stas_T]

Here is a more detailed guide for this tool: How to Fix Corrupted MP4 Files – The Definitive Guide

 

[anbalck]

I use ATelloPilot app and it have the option to write raw video stream from tello in h264.
This files can't be opened by Windows media player and many other programs up to the DaVinci studio.
But it can normally played by PotPlayer (KMPlayer, GOM Player - all have the same engine).
Try to change broken file extension to .h264 and use one of this player.

 

[Stas_T]

So far as I know, h264 is actually a video compression codec that requires a video container to host the encoded video. Therefore, a file with the ".h264" extension may be a misnamed .MP4 file.

Simply changing file extension to ".h264" won't do anything if the file is corrupted.

The most powerful player for Widows users is Media Player Classic. You can download it along with K-Lite Codec Pack. Both are free. This media player sometimes can play video files that have damaged headers.

BTW, you shouldn't install more than one codec pack on you system, since they may have conflicts. This is like having two antivirus apps installed at a time.

 

[anbalck]

Yes, you are right.
h264 - codec (format) of streaming.
mp4 - container for part of stream and consists of header and video and audio streams.
Simple renaming to mp4 will not work of course.
But i suppose that all apps for Tello cache the video stream, and this stream is in h264. Broken files are videocache, which is normally processed by app to obtain mp4 after stop writing. If app or Tello fails, this process failed too.
And KMplayer family of pleers can work with stream without any containers.
But i can fails too It needs to be checked.

 

[volate!lo]

the h264 file of TeloFpv is just that. A h264 elemntary stream containing the NALUs that make up the stream. ffmpeg should be abkle to play these but I never tried.

The MP4 files OTOH are already a container file with H264 content in the process of writing. They are just missing a valid header.