Originally written for PureMPV, with this utility it is possible to encode webms from a given input, according to a restricted file size or a default CRF (Constant Rate Factor). If the utility is called whilst encoding, additional webm parameters will be put in a queue using Unix sockets.
To encode a quick webm with the defaults:
$ purewebm -ss 00:00:02.268 -to 00:00:10.310 -i "/tmp/Videos/nijinosaki.mkv"
Encoding 1 of 1: 100%Only the video stream will be mapped (no audio) with a size limit of 3MB, and saved under $HOME/Videos/PureWebM.
To encode a webm with size limit of 6MB, burned subtitles, and opus audio:
$ purewebm -i "/tmp/Videos/nijinosaki.mkv" --size_limit 6 -subs --extra_params '-map 0:a -c:a libopus -b:a 128k'
Encoding 1 of 1: 100%It is possible to request usage instructions through the --help or -h option flags:
$ purewebm --help
usage: purewebm [-h] [--version] (--status | --kill | --input INPUT) [--name_type {unix,md5}]
[--subtitles] [--encoder ENCODER] [--start_time START_TIME] [--stop_time STOP_TIME]
[--lavfi LAVFI] [--size_limit SIZE_LIMIT] [--crf CRF] [--cpu-used {0,1,2,3,4,5}]
[--deadline {good,best}] [--extra_params EXTRA_PARAMS]
[output]
Utility to encode quick webms with ffmpeg
positional arguments:
output the output file, if not set, the filename will be generated according to
--name_type and saved in $HOME/Videos/PureWebM
options:
-h, --help show this help message and exit
--version, -v show program's version number and exit
--status queries the main process and prints the current status
--kill sends the kill command to the main process; this will terminate all
encodings immediately, with no cleanups
--input INPUT, -i INPUT
the input file to encode (NOTE: several files can be selected adding more
-i flags just like with ffmpeg, these will be only for a single output
file; to encode different files run this program multiple times, the files
will be queued in the main process using Unix sockets)
--name_type {unix,md5}, -nt {unix,md5}
the filename type to be generated if the output file is not set: unix uses
the current time in microseconds since Epoch, md5 uses the filename of the
input file with a short MD5 hash attached (default is unix)
--subtitles, -subs burn the subtitles onto the output file; this flag will automatically use
the subtitles found in the first input file, to use a different file use
the -lavfi flag with the subtitles filter directly
--encoder ENCODER, -c:v ENCODER
the encoder to use (default is libvpx-vp9)
--start_time START_TIME, -ss START_TIME
the start time offset (same as ffmpeg's -ss)
--stop_time STOP_TIME, -to STOP_TIME
the stop time (same as ffmpeg's -to)
--lavfi LAVFI, -lavfi LAVFI
the set of filters to pass to ffmpeg
--size_limit SIZE_LIMIT, -sl SIZE_LIMIT
the size limit of the output file in megabytes, use 0 for no limit (default
is 3)
--crf CRF, -crf CRF the crf to use (default is 24)
--cpu-used {0,1,2,3,4,5}, -cpu-used {0,1,2,3,4,5}
the cpu-used for libvpx-vp9; a number between 0 and 5 inclusive, the higher
the number the faster the encoding will be with a quality trade-off
(default is 0)
--deadline {good,best}, -deadline {good,best}
the deadline for libvpx-vp9; good is the recommended one, best has the best
compression efficiency but takes the most time (default is good)
--extra_params EXTRA_PARAMS, -ep EXTRA_PARAMS
the extra parameters to pass to ffmpeg, these will be appended making it
possible to override some defaultsLogs are saved under $HOME/.config/PureWebM/PureWebM.log
Some of the default options can be changed using a configuration file named PureWebM.conf in the configuration folder. Changeable options are size_limit, crf, and deadline. The following is an example of a configuration file:
# ~/.config/PureWebM/PureWebM.conf
size_limit=4
crf=28
deadline=goodIt can be installed using pip:
$ pip install purewebmor
$ git clone https://github.com/4ndrs/PureWebM.git
$ cd PureWebM
$ pip install .Alternatively, pipx can be used if PEP 668 is enforced:
$ pipx install purewebm