Raspberry Pi 4 saving corrupt h264 files?

Question

I've been able to record .h264 files without a problem, both using raspivid and through Python, but whatever I try, I can't convert them to a .mp4, .mkv or .avi file.

I've tried converting using MP4box (suggested in several places) and mkvmerge, but to no avail.

When I use MP4box (MP4box -add <source.h264> <dest.mp4>), I get :

AVC-H264 import - frame size 1920 x 1080 at 25.000 FPS
WARNING: NAL Unit type 0 not handled - adding5/100)
AVC Import results: 44 samples - Slices: 3 I 41 P 0 B - 0 SEI - 3 IDR
Saving video.mp4: 0.500 secs Interleaving

Then I try to play this file using VLC, it doesn't give an error, but shows garbled data.

To be clear, the camera works fine (shows perfect video using Python code and raspistill outputs a perfect jpg file). I tried a different camera as well.

An attempt with mkvmerge :

pi@raspberrypi:~/cam $ raspivid -o test.h264 -fps 30 -t 15000 -w 1920 -h 1080
pi@raspberrypi:~/cam $ mkvmerge --default-duration 0:30p -o video.mkv test.h264
mkvmerge v31.0.0 ('Dolores In A Shoestand') 32-bit
'test.h264': Using the demultiplexer for the format 'AVC/h.264'.
'test.h264' track 0: Using the output module for the format 'AVC/h.264 (unframed)'.
The file 'video.mkv' has been opened for writing.
Error: 'test.h264' track 0: mkvmerge encountered broken or unparsable data in this AVC/h.264 video track. Either your file is damaged (which mkvmerge cannot cope with yet) or this is a bug in mkvmerge itself. The error message was:
Success
pi@raspberrypi:~/cam $

This is on a Raspberry Pi 4.

A sample file can be found here : https://filebin.net/c40usz0crhgggadf Created with : raspivid -t 30000 -w 640 -h 480 -fps 25 -b 1200000 -p 0,0,640,480 -o pivideo.h264

Answer 1

I'm going to respond to this myself. After doing an 'apt-get upgrade', the problem is gone.

If anyone wants to figure this out to find the root cause, this is what apt-get did :

The following packages will be upgraded:
  bind9-host bluez-firmware firmware-atheros firmware-brcm80211 firmware-libertas firmware-misc-nonfree firmware-realtek libbind9-161 libdns-export1104 libdns1104 libgs9 libgs9-common libisc-export1100 libisc1100 libisccc161
  libisccfg163 liblwres161 libraspberrypi-bin libraspberrypi-dev libraspberrypi-doc libraspberrypi0 pi-bluetooth raspberrypi-bootloader raspberrypi-kernel raspberrypi-kernel-headers raspi-config rpd-plym-splash
The following packages will be DOWNGRADED:
  python3-pgzero
27 upgraded, 0 newly installed, 1 downgraded, 0 to remove and 0 not upgraded.