So, Today, Spark fell on the ground as battery popped out itself - The distance was just 8/10 feet so there wasn't any damage done.
Next flight was great. A flight for 10 minutes and I made some footage. But the shutter button didn't respond well to the touch.
Now I have inserted memory card to my MacBook and saw that the footage is just MP4 files with no information in it.
I just turned it on and made 2 new videos.

Camera/Shutter button worked fine.
The first video is the same like before. Unable to play MP4 file
And another video works fine.
The camera seems fine. There is no visible damage.
Need Help.

Hello and good day Faysal9. I am sorry to know what happened to your previous flight with your DJI Spark. Since this issue is happening after the crash I would recommend you contact our support team to start up a ticket for the said drone at https://www.dji.com/support?site=brandsite&from=nav . We have the professional team who would do their best to fix and find out the reason of the incident and then the corresponding resolution would be provided. Please note that DJI will not perform data analysis for cases occurring after the expiry of the warranty period; otherwise, valid charges will apply. Thank for your support.

format the SD card and try the recording again. The card may have shifted during the fall.

Is it an 0 kb file?
Or is it a file size accordingly to the time you did video, but it can't be opened?

(" saw that the footage is just MP4 files with no information in it.")

If the second, probably the file didn't get closed?
Like described in here
http://live555.com/drones/DJI-Phantom-2-Vision+-video-fix/

To your second test, was the first file ok, but the second  not?
Do some test video again, do one long one, another long one, and just another one for a sec, to close the last one before?
Just a possible workaround, but worth a try, methinks

Strangely: Try putting your SD card back in the Spark. Turn on the spark and leave it sit a minute or so. I've seen this fix broken video files, though I really don't have a theory about how. Maybe it sees the unfinished mp4 file and ties up the loose ends. I sometimes get a broken video file when I forget to stop recording before turning off the spark.

Hi,I am sorry to hear that your Spark fell on the ground,may be you can try to convert your video,With the help of a professional MP4 to MOV video converter you can convert M4V video to all other popular video, like convert M4V to MOV, and HD MP4, HD AVI, HD MOV. The Dumpmedia Video Converter lt is also very easy to use and provide great quality of output.