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Ffmpeg post-processing OBS Plugin
import obspython as obs
import subprocess
import os
import re
import datetime
# Info for potential OBS Python hackers!
# Tip 1 - Read the "OBS Studio Backend Design" documentation page. Read the documentation table of contents.
# Tip 2 - be sure to add to your script path to enable completion.
# Tip 3 - Some of the Python API is generated at runtime, so it won't show up in
# To search the full API for e.g. "frontend" functions, uncomment this line and reload your script:
# [print(i) for i in dir(obs) if i.lower().find("frontend") > -1]
# Tip 4 - Here's a set of ffmpeg flags to produce mobile-ready Telegram mp4s:
# -an -vf scale=720:-1:flags=lanczos -vprofile baseline -pix_fmt yuv420p
class OBSDataModel:
"""Interact with an obs_data more comfortably using Python type checking.
This class models a single obs_data object at a time.
This ffmpeg plugin only ever interacts with a single "properties" data object, corresponding to user input boxes
in the script settings.
There are two access methods:
1. Store config data persistently with store_data() and load_data().
2. Non-persistent access with [] syntax: useful when the obs_data object is unavailable, eg. external callbacks.
Initialized with a dict containing the names and default values of the data items.
getter_fun = {bool: obs.obs_data_get_bool, str: obs.obs_data_get_string,
int: obs.obs_data_get_int, float: obs.obs_data_get_double}
setter_fun = {bool: obs.obs_data_set_bool, str: obs.obs_data_set_string,
int: obs.obs_data_set_int, float: obs.obs_data_set_double}
default_fun = {bool: obs.obs_data_set_default_bool, str: obs.obs_data_set_default_string,
int: obs.obs_data_set_default_int, float: obs.obs_data_set_default_double}
data_dict = None
def __init__(self, default_dict):
self.data_dict = default_dict
def __getitem__(self, arg):
return self.data_dict[arg]
def __setitem__(self, arg, value):
self.data_dict[arg] = value
def store_data(self, obs_data, name, value):
self.data_dict[name] = value
self.setter_fun[type(value)](obs_data, name, value)
def load_data(self, obs_data, name):
self.data_dict[name] = self.getter_fun[type(self.data_dict[name])](obs_data, name)
return self.data_dict[name]
def set_data_defaults(self, obs_data):
"""First, default values for obs_data items according to contents of data_dict.
Then synchronizes data_dict with obs_data."""
for name, value in self.data_dict.items():
self.default_fun[type(value)](obs_data, name, value)
self.load_data(obs_data, name)
class OBSPluginFfmpeg(OBSDataModel):
""" Main class implementing OBS Ffmpeg Python Plugin."""
# Default values for script options
_defaults = ({"debug_enabled": False,
"auto_convert": True,
"src_regex": "",
"dst_regex": "",
"src_regex_validated": str(,
"dst_regex_validated": "%SCENE%_" + str(,
"record_folder": os.path.expanduser("~") + os.path.sep + "Videos",
"custom_flags": "-vf scale=-1:720:flags=lanczos"
description = "<b>Ffmpeg Auto-converter</b>" + \
"<hr>" + \
"Automatically transcode OBS output with ffmpeg. Supports renaming with Python regular expressions. " + \
"Make sure ffmpeg is in the system path!<br/><br/>" + \
"Additional renaming tokens:<br/>" + \
"%SCENE% - name of current scene <br/>" + \
"%SRC1% - input source 1 (SRC2 for source 2, etc.)" + \
"<br/><br/>" + \
"©2018 Michael Abrahams. GPLv3 license." + \
# We install a callback in this signal handler to run ffmpeg when recording is finished
recording_signal_handler = None
last_ffmpeg_output = ""
def __init__(self):
def debug(self, text):
if self['debug_enabled']:
def set_defaults(self, settings):
self.debug(f"_____ script_defaults()\n Saved settings data:\n {obs.obs_data_get_json(settings)}")
def load(self, settings):
# Initialize text fields to the last fully validated version
self.store_data(settings, "src_regex", self["src_regex_validated"])
self.store_data(settings, "dst_regex", self["dst_regex_validated"])
def save(self, settings):
"""Store any validation errors from ffmpeg_convert when we couldn't write settings."""
# XXX: We can't trigger this every time plugin is reloaded, only when the user moves around in prefs menu.
self.store_data(settings, "src_regex_validated", self["src_regex_validated"])
self.store_data(settings, "dst_regex_validated", self["dst_regex_validated"])
def update_settings(self, settings_data):
""" Read updated data when user changes input fields."""
self.debug("_____ update_settings()")
[self.load_data(settings_data, d) for d in ["debug_enabled", "auto_convert", "custom_flags",
"record_folder", "src_regex", "dst_regex"]]
def validate(self, properties, prop_id, settings_data):
""" Validate user input regex with re.compile() """
run_button = obs.obs_properties_get(properties, "run_button")
obs.obs_property_set_enabled(run_button, True)
obs.obs_property_set_description(run_button, "Run")
self.store_data(settings_data, "src_regex_validated", self["src_regex"])
self.store_data(settings_data, "dst_regex_validated", self["dst_regex"])
except Exception:
self.debug("Invalid regex!")
obs.obs_property_set_enabled(run_button, False)
obs.obs_property_set_description(run_button, "Invalid regular expression!")
self.debug(f"src validated: {self['src_regex_validated']} dst validated: {self['dst_regex_validated']}")
def recording_finished(self, stop_code):
""" Implements post-recording callback. """
self.debug(f"Recording finished with stop_code: {stop_code}")
if self['auto_convert'] is True and stop_code is 0:
def find_latest_obs_capture(self, capture_dir):
# TODO: handle this better.
def new_video_sort_key(f):
if[-3:] in ['flv', 'mp4', 'mov', 'mkv'] and is not self.last_ffmpeg_output:
return f.stat().st_mtime
return 0
newest_video_file = sorted(os.scandir(capture_dir), key=new_video_sort_key, reverse=True)[0]
if new_video_sort_key(newest_video_file) is 0:
print("Could not find any video files!")
return None
def ffmpeg_convert(self):
"""Search $HOME/videos for most recently created file. Convert using custom ffmpeg command. """
# XXX: We can get an object of type config_t but no Python methods are set up to access it.
# Instead we have to prompt user to specify their video folder.
# cfg = obs.obs_frontend_get_profile_config()
print("Converting ")
capture_dir = self['record_folder'] + os.path.sep
obs_capture_file_name = self.find_latest_obs_capture(capture_dir)
if obs_capture_file_name is None:
return False
# Get current scene and source name for %SUBSTITUTION%
current_scene = obs.obs_frontend_get_current_scene() # Note - returns an "obs_source" object
scene_name = obs.obs_source_get_name(current_scene)
current_scene = obs.obs_scene_from_source(current_scene)
scene_items = obs.obs_scene_enum_items(current_scene)
source_names = [obs.obs_source_get_name(obs.obs_sceneitem_get_source(i)) for i in scene_items]
# Do regexp and token substitutions
out_file_name = obs_capture_file_name[0:-4]
if self["src_regex_validated"] is not None:
dst_regex_out = self["dst_regex_validated"].replace("%SCENE%", scene_name)
for n, src in enumerate(source_names):
repl_str = f"%SOURCE{n + 1}%"
dst_regex_out = dst_regex_out.replace(repl_str, src)
out_file_name = re.sub(self["src_regex_validated"], dst_regex_out, out_file_name)
except Exception:
### XXX: Should invalidate src_regex and dst_regex if this happens
print("Regular expression replacement failed!")
out_file_name = out_file_name + ".mp4"
# Run ffmpeg
ffmpeg_command = f'ffmpeg -i "{capture_dir + obs_capture_file_name}" {self["custom_flags"]} "{capture_dir + out_file_name}"'
self.debug(f"ffmpeg command: {ffmpeg_command}")
res =, check=True, universal_newlines=True,
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
self.last_ffmpeg_output = out_file_name
except subprocess.CalledProcessError as e:
# Todo: send a louder message if this happens (and for failure of regex above)
print(f"Ffmpeg failed! Command was: \n{ffmpeg_command}\n\nOutput was:")
# Instance plugin
ffplug = OBSPluginFfmpeg()
# Define global callbacks
def cb_button_pressed(properties, button):
# XXX: unlike in search_str_callback, editing the button text in this callback doesn't work.
return True
def cb_search_text_changed(*args):
def cb_recording_finished(callback_data):
stop_code = obs.calldata_int(callback_data, "code")
return True
def update_recording_callback(reconnect = True):
if ffplug.recording_signal_handler is not None:
obs.signal_handler_disconnect(ffplug.recording_signal_handler, "stop", cb_recording_finished)
if reconnect:
ffplug.recording_signal_handler = obs.obs_output_get_signal_handler(obs.obs_frontend_get_recording_output())
obs.signal_handler_connect(ffplug.recording_signal_handler, "stop", cb_recording_finished)
# OBS API Hooks Start Below
def script_defaults(settings):
# obs.obs_data_clear(settings) # Clear saved plugin data. Useful for debugging.
def script_load(settings):
# XXX: there's no good way to trigger callbacks when profiles are changed.
def script_description():
return ffplug.description
def script_update(settings):
def script_unload():
ffplug.debug("_____ script_unload()")
def script_save(settings):
def script_properties():
ffplug.debug("_____ script_properties()")
p = obs.obs_properties_create()
obs.obs_properties_add_bool(p, "auto_convert", "Autorun after recording")
obs.obs_properties_add_bool(p, "debug_enabled", "Debug Mode")
search_area = obs.obs_properties_add_text(p, "src_regex", "Find (regex)", 0)
obs.obs_property_set_modified_callback(search_area, cb_search_text_changed)
replace_area = obs.obs_properties_add_text(p, "dst_regex", "Replace (regex)", 0)
obs.obs_property_set_modified_callback(replace_area, cb_search_text_changed)
obs.obs_properties_add_path(p, "record_folder", "Recording folder",
obs.OBS_PATH_DIRECTORY, "", os.path.expanduser("~"))
obs.obs_properties_add_text(p, "custom_flags", "Ffmpeg flags:", 0)
obs.obs_properties_add_button(p, "run_button", "Run", cb_button_pressed)
return p
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gitalexhubuser commented Jul 11, 2018

Hi there!
try to use it on 21.1.2 obs x64 and it dont works( help me plz.

Am i understand right? that i record any video in *.mkv. And after i press stop recording my file automatically reencode to mp4?
i have *same 2 files.

it very useful for sony vegas. it doesnt use mkv and avi. only mp4. it s so hard to reencode every file again and again.

i found it here
i dont have settings like this

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TrinityDiy commented Aug 28, 2018

Hello there,
Long time reader first time poster.
OK i had the same problem above. I found Python 6 works with OBS. Now i can see the settings and change them but i get errors.

Script log:
[] ffmpeg command: ffmpeg -i "C:\Users\TrinityDiy\Videos\2018-08-28 16-37-56.flv" -vf scale=-1:720:flags=lanczos "C:\Users\TrinityDiy\Videos\Scene_2018-08-28 16-37-56.mp4"
[] Traceback (most recent call last):
[] File "C:/Program Files/obs-studio/data/obs-plugins/frontend-tools/scripts\", line 215, in cb_recording_finished
[] File "C:/Program Files/obs-studio/data/obs-plugins/frontend-tools/scripts\", line 138, in recording_finished
[] self.ffmpeg_convert()
[] File "C:/Program Files/obs-studio/data/obs-plugins/frontend-tools/scripts\", line 189, in ffmpeg_convert
[] stdout=subprocess.PIPE, stderr=subprocess.PIPE)
[] File "C:\Users\TrinityDiy\AppData\Local\Programs\Python\Python36\lib\", line 403, in run
[] with Popen(*popenargs, **kwargs) as process:
[] File "C:\Users\TrinityDiy\AppData\Local\Programs\Python\Python36\lib\", line 709, in init
[] restore_signals, start_new_session)
[] File "C:\Users\TrinityDiy\AppData\Local\Programs\Python\Python36\lib\", line 997, in _execute_child
[] startupinfo)
[] FileNotFoundError: [WinError 2] The system cannot find the file specified
[] Recording finished with stop_code: 0
[] ffmpeg command: ffmpeg -i "C:\Users\TrinityDiy\Videos\2018-08-28 16-37-56.flv" -vf scale=-1:720:flags=lanczos "C:\Users\TrinityDiy\Videos\Scene_2018-08-28 16-37-56.mp4"

Thank you in advance

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jatracy commented Dec 19, 2019

SOLVED - A reboot fixed my issue. Gotta love Windows!

Any help would be greatly appreciated.

I am also having issues running the subprocess command within OBS. I can run it fine (with a basic ffmpeg command) from the command line (within Idle).
Here is the Script Log output:

[] Recording finished with stop_code: 0
[] Converting
[] ffmpeg command: ffmpeg -i "C:/Users/jeffa/Dropbox/Golf_Stuff/Golf Swing Videos/Captures\2019-12-19 17-05-39.mp4" -an -vf scale=720👎flags=lanczos -vprofile baseline -pix_fmt yuv420p "C:/Users/jeffa/Dropbox/Golf_Stuff/Golf Swing Videos/Captures\2019-12-19 17-05-39.mp4"
[] DEBUG 1 ffmpeg -i "C:/Users/jeffa/Dropbox/Golf_Stuff/Golf Swing Videos/Captures\2019-12-19 17-05-39.mp4" -an -vf scale=720👎flags=lanczos -vprofile baseline -pix_fmt yuv420p "C:/Users/jeffa/Dropbox/Golf_Stuff/Golf Swing Videos/Captures\2019-12-19 17-05-39.mp4"
[] Traceback (most recent call last):
[] File "C:/Program Files/obs-studio/data/obs-plugins/frontend-tools/scripts\", line 221, in cb_recording_finished
[] ffplug.recording_finished(stop_code)
[] File "C:/Program Files/obs-studio/data/obs-plugins/frontend-tools/scripts\", line 139, in recording_finished
[] self.ffmpeg_convert()
[] File "C:/Program Files/obs-studio/data/obs-plugins/frontend-tools/scripts\", line 194, in ffmpeg_convert
[] res =, universal_newlines=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
[] File "C:\Program Files\Python36\lib\", line 403, in run
[] with Popen(*popenargs, **kwargs) as process:
[] File "C:\Program Files\Python36\lib\", line 709, in init
[] restore_signals, start_new_session)
[] File "C:\Program Files\Python36\lib\", line 997, in _execute_child
[] startupinfo)
[] FileNotFoundError: [WinError 2] The system cannot find the file specified

Here is the output from Idle:

import subprocess
res =["ffmpeg", "-h"], check=True, universal_newlines=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
print (res.stdout)

Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

Getting help:
-h -- print basic options
-h long -- print more options
-h full -- print all options (including all format and codec specific options, very long)
-h type=name -- print all options for the named decoder/encoder/demuxer/muxer/filter/bsf
See man ffmpeg for detailed description of the options.

Print help / information / capabilities:
-L show license
-h topic show help
-? topic show help
-help topic show help
--help topic show help
-version show version
-buildconf show build configuration
-formats show available formats
-muxers show available muxers
-demuxers show available demuxers
-devices show available devices
-codecs show available codecs
-decoders show available decoders
-encoders show available encoders
-bsfs show available bit stream filters
-protocols show available protocols
-filters show available filters
-pix_fmts show available pixel formats
-layouts show standard channel layouts
-sample_fmts show available audio sample formats
-colors show available color names
-sources device list sources of the input device
-sinks device list sinks of the output device
-hwaccels show available HW acceleration methods

Global options (affect whole program instead of just one file:
-loglevel loglevel set logging level
-v loglevel set logging level
-report generate a report
-max_alloc bytes set maximum size of a single allocated block
-y overwrite output files
-n never overwrite output files
-ignore_unknown Ignore unknown stream types
-filter_threads number of non-complex filter threads
-filter_complex_threads number of threads for -filter_complex
-stats print progress report during encoding
-max_error_rate maximum error rate ratio of errors (0.0: no errors, 1.0: 100% errors) above which ffmpeg returns an error instead of success.
-bits_per_raw_sample number set the number of bits per raw sample
-vol volume change audio volume (256=normal)

Per-file main options:
-f fmt force format
-c codec codec name
-codec codec codec name
-pre preset preset name
-map_metadata outfile[,metadata]:infile[,metadata] set metadata information of outfile from infile
-t duration record or transcode "duration" seconds of audio/video
-to time_stop record or transcode stop time
-fs limit_size set the limit file size in bytes
-ss time_off set the start time offset
-sseof time_off set the start time offset relative to EOF
-seek_timestamp enable/disable seeking by timestamp with -ss
-timestamp time set the recording timestamp ('now' to set the current time)
-metadata string=string add metadata
-program title=string:st=number... add program with specified streams
-target type specify target file type ("vcd", "svcd", "dvd", "dv" or "dv50" with optional prefixes "pal-", "ntsc-" or "film-")
-apad audio pad
-frames number set the number of frames to output
-filter filter_graph set stream filtergraph
-filter_script filename read stream filtergraph description from a file
-reinit_filter reinit filtergraph on input parameter changes
-discard discard
-disposition disposition

Video options:
-vframes number set the number of video frames to output
-r rate set frame rate (Hz value, fraction or abbreviation)
-s size set frame size (WxH or abbreviation)
-aspect aspect set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
-bits_per_raw_sample number set the number of bits per raw sample
-vn disable video
-vcodec codec force video codec ('copy' to copy stream)
-timecode hh:mm:ss[:;.]ff set initial TimeCode value.
-pass n select the pass number (1 to 3)
-vf filter_graph set video filters
-ab bitrate audio bitrate (please use -b:a)
-b bitrate video bitrate (please use -b:v)
-dn disable data

Audio options:
-aframes number set the number of audio frames to output
-aq quality set audio quality (codec-specific)
-ar rate set audio sampling rate (in Hz)
-ac channels set number of audio channels
-an disable audio
-acodec codec force audio codec ('copy' to copy stream)
-vol volume change audio volume (256=normal)
-af filter_graph set audio filters

Subtitle options:
-s size set frame size (WxH or abbreviation)
-sn disable subtitle
-scodec codec force subtitle codec ('copy' to copy stream)
-stag fourcc/tag force subtitle tag/fourcc
-fix_sub_duration fix subtitles duration
-canvas_size size set canvas size (WxH or abbreviation)
-spre preset set the subtitle options to the indicated preset

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