How to get ffprobe metadata as variable to parse in python

Question

When I run ffprobe <video>, I get the standard metadata as below:

ffprobe version 4.3.1 Copyright (c) 2007-2020 the FFmpeg developers
  built with Apple clang version 11.0.3 (clang-1103.0.32.62)
  configuration: --prefix=/opt/local --enable-swscale --enable-avfilter --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-libopus --enable-librsvg --enable-libtheora --enable-libopenjpeg --enable-libmodplug --enable-libvpx --enable-libsoxr --enable-libspeex --enable-libass --enable-libbluray --enable-lzma --enable-gnutls --enable-fontconfig --enable-libfreetype --enable-libfribidi --disable-libjack --disable-libopencore-amrnb --disable-libopencore-amrwb --disable-libxcb --disable-libxcb-shm --disable-libxcb-xfixes --disable-indev=jack --enable-opencl --disable-outdev=xv --enable-audiotoolbox --enable-videotoolbox --enable-sdl2 --disable-securetransport --mandir=/opt/local/share/man --enable-shared --enable-pthreads --cc=/usr/bin/clang --enable-libdav1d --arch=x86_64 --enable-x86asm --enable-libx265 --enable-gpl --enable-postproc --enable-libx264 --enable-libxvid
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '../directConversion/200mbs105_55.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
  Duration: 00:01:12.43, start: 0.000000, bitrate: 213963 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1080x1920 [SAR 1:1 DAR 9:16], 213828 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : Core Media Video
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : Core Media Audio

I want to get this information from python so I can parse this output and use some of it in my code. However, I can't get this to work.

I have tried the following:

data = subprocess.call(f'ffprobe {video}', shell=True)
data = subprocess.check_output(f'ffprobe {vid}', shell=True)
data = subprocess.Popen(f'ffprobe {vid}', shell=True)
data = subprocess. Popen(f'ffprobe {vid}', stdout=subprocess.PIPE ).communicate()[0]
data = run(f'ffprobe {vid}', capture_output=True).stdout

If I include shell=True, then the proper information prints in the terminal but I get an empty string for data. For commands without shell=True I get file not found error and it breaks. What should I do? I got all of these solutions from SO and they seem to work for others.

`ffprobe` is in your shell path, but not in the path of Python context. As an ad hock solution, you can use full path. The default path in Linux is `/usr/bin/ffprobe`. If it isn't there, use `which ffprobe` in your shell. Note: for easy parsing, you may ask FFprobe to return the data in JSON format, and convert the string to Python dictionary. — Rotem, Apr 29 '21 at 13:45
When I run `which ffprobe` I get `/opt/local/bin/ffprobe`. What should I do with this info? Also, how do I get the JSON as you recommend? — connor449, Apr 29 '21 at 13:50
Changing my command to `f'/opt/local/bin/ffprobe {vid}` results in no change — connor449, Apr 29 '21 at 13:51
Are you using Mac or Linux? I don't think I can help you with the path. For JSON format, use `ffprobe -print_format json`. Then use `dict = json.loads(data)`. — Rotem, Apr 29 '21 at 14:11
I am using a mac. I also don't understand your ffprobe -print_format json recommendation. Is this a terminal command, a python command? — connor449, Apr 29 '21 at 14:14
I think I know the problem: You should use `shlex.split`: `data = run(shlex.split(f'ffprobe {vid} -print_format json'), capture_output=True).stdout` — Rotem, Apr 29 '21 at 14:21

score 3 · Accepted Answer · answered Apr 29 '21 at 15:13

You may use shlex.split or put the arguments to FFprobe in a list.

In Windows OS, you can use sp.run(f'ffprobe {video}' ...
In Linux and Mac, Python tries to execute the command as file name with spaces.
For example: 'ffprobe vid.mp4' is considered a single executable command (file name with space).

You may use an arguments list:
sp.run(['ffprobe', f'{video}']...

Or use shlex.split for splitting the shell command to a list:
sp.run(shlex.split(f'ffprobe {video}'))...

For simple parsing FFprobe output in Python:

Execute ffprobe with -of json argument, and get the output in JSON format.
Convert the output string to dictionary using json.loads.

Here is a code sample that reads the output of FFprobe into a dictionary:

import subprocess as sp
import shlex
import json

video = 'vid.mkv'

# Execute ffprobe (to show streams), and get the output in JSON format
data = sp.run(shlex.split(f'ffprobe -loglevel error -show_streams -of json {video}'), capture_output=True).stdout

# Same - using a list of arguments:
# data = sp.run(['ffprobe', '-loglevel', 'error', '-show_streams', '-of', 'json', f'{video}'], capture_output=True).stdout

# Convert data from JSON string to dictionary
d = json.loads(data)

print(d)  # Print the dictionary for testing

Notes:

I used -show_streams argument as an example.
In case there is missing (or too much) information, look for the relevant set of arguments.
The example assumes that ffprobe is in the execution path.

How to get ffprobe metadata as variable to parse in python

1 Answers1