Concatrim

Concatrim is a python program to trim-and-concatenate media files. It depends on ffmpeg.

License

Concatrim is distributed as source code on this repository and PyPI under MIT license.

Features

1. Trim an input time-based media file based on given time spans and concatenate trimmed pieces into a single file.
2. Mapping between time points in the original and trimmed file.

Installation

Dependencies

System application

• ffmpeg

Python libraries

See requirements.txt.

From PyPI

Install using pip

pip install concatrim

From source

Clone this repository and run setup.py to install

python setup.py install

Usage

Caveats

At the moment;

• the package only provides Python API's for its supported operations (no command line interface).
• the program only supports audio inputs.

trim-then-concatenate

To trim a media file, use Concatrimmer class from concatrim package. Initiate an instance with the input file name and optionally configuration for padding. When you trim more than two parts of the input media, a silence padding (configured in milliseconds) will be inserted between each slice.

from concatrim import Concatrimmer

c = Concatrimmer('input-file.mp3', 1000)  # will insert 1-second silences between slices

From here, you can set which part of the input we want to trim, using add_spans method.

c.add_spans([1000, 4000], [12000, 22000])
#  configures the program to extract two parts, 1-4 second and 12-22 second. 

When you're done adding spans, call concatrim method, with a directory name you want to use to store trimmed output file.

c.concatrim('../outputs')

Additionally, we can pass prefix, suffix arguments to rename the output file (suffix will be added at before the extension name).

c.concatrim('../outputs', suffix='.trimmmed')

Timepoint conversion

Once you have all spans for trimming configured in a Concatrimmer object, you can also ask for conversion between two time points; one from the original media file, and the other from the trimmed one. This conversion will consider the padding pauses that'd be inserted between spans. Again, all input and output of the conversion is in milliseconds.

c.conv_to_trimmed(2100)  # will return 1100
c.conv_to_original(1100)  # will return 2100
c.conv_to_original(11100)  # will return None because 11100 ms is trimmed out
c.conv_to_original(12100)  # will return 4100