migrate ffprobe command to ffmpeg-python - ffmpeg-python

Question

I currently am trying to migrate the following command from ffprobe to ffmpeg-python
ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 input.mp4
I tried the following and it did not work
ffmpeg.probe(file_path, v='error', select_streams='v:0', count_packets=True, show_entries=True, stream='nb_read_packets', of=True, csv='p=0')
I have tried this inputting it as a dictionary as well
ffmpeg.probe(file_path, **{'v':'error', 'select_streams':'v:0', 'count_packets':1, 'show_entries':1, 'stream':'nb_read_packets', 'of':'csv=p=0'})
But none of these seem to work, any help would be appreciated

Answer 1

TL;DR Answer
With the way the parameters for the python bindings for ffmpeg-python work, the format of the command you are inputting is incorrect. Instead the following should work for you
import ffmpeg, json
out = ffmpeg.probe("input.mp4", cmd='ffprobe', v='error', select_streams='v:0', count_packets=None, show_entries='stream=nb_read_packets')
out["streams"][0]["nb_read_packets"]
Complete Answer
Digging through the API reference for the ffmpeg-python module, the python binding ffmpeg.probe, states that it will
Run ffprobe on the specified file and return a JSON representation of
the output.
Debugging through the module/source code, this python binding for ffprobe will always add the command line options -show_format, -show_streams, -of json to your command that you pass in as defined in the
_probe.py file.
So for the ffprobe command you provided:
ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 input.mp4
will essentially be this command line options after passing through ffmpeg.fprobe:
ffprobe -show_format -show_streams -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 -of json input.mp4
I downloaded an mp4 video that was probably a chromecast commercial based on the description. Here's the gist link that I found it from, and look for the title "For Bigger Escape". I downloaded the file and renamed it input.mp4 to match the example you provided.
After running
>ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 input.mp4
361
>
I get 361.
Now running the command:
ffprobe -show_format -show_streams -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 -of json input.mp4
I get the output
{
"programs": [
],
"streams": [
{
"nb_read_packets": "361",
"disposition": {
"default": 1,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0,
"timed_thumbnails": 0
},
"tags": {
"language": "und",
"handler_name": "VideoHandler"
}
}
],
"format": {
"filename": "input.mp4",
"nb_streams": 2,
"nb_programs": 0,
"format_name": "mov,mp4,m4a,3gp,3g2,mj2",
"format_long_name": "QuickTime / MOV",
"start_time": "0.000000",
"duration": "15.045000",
"size": "2299653",
"bit_rate": "1222813",
"probe_score": 100,
"tags": {
"major_brand": "mp42",
"minor_version": "0",
"compatible_brands": "isommp42",
"creation_time": "2013-11-12T06:38:58.000000Z"
}
}
}
That value of 361 is now in key value of nb_read_packets
I tried exactly replicating the command line
out= ffmpeg.probe("input.mp4", cmd='ffprobe', v='error', select_streams='v:0', count_packets=None, show_entries='stream=nb_read_packets', of='csv=p=0')
in ffmpeg-python, but I keep getting a JSONDecodeError:
The value of s from the debugger showed this string value:
s
'361,1,0,0,0,0,0,0,0,0,0,0,0,und,VideoHandler\r\ninput.mp4,2,0,"mov,mp4,m4a,3gp,3g2,mj2",QuickTime / MOV,0.000000,15.045000,2299653,1222813,100,mp42,0,isommp42,2013-11-12T06:38:58.000000Z\r\n'
My only assumption is with the -of or -print_format option, some characters were stripped or modified and that is giving the json decoder issues to decode it.
I finally decided to take out the -of csv=p=0 flag and the following was able to run with no errors
import ffmpeg, json
out = ffmpeg.probe("input.mp4", cmd='ffprobe', v='error', select_streams='v:0', count_packets=None, show_entries='stream=nb_read_packets')
value = out["streams"][0]["nb_read_packets"]
print(value)
361
Side Note
Some of the options that do not have direct parameters following them are defined as None because they do not have any parameters. This has been brought up several times in open issues from the github repo, and I have previously commented on it. It is not stated in the documents, and as far as I know, no PRs are out to update the docs to explicitly state it.