Shrinkr Batch Transcode (Python Edition)

This Python script batch transcodes a source set of video files to a target set of proxy video files at a lower resolution.

usage: Shrinkr.py [-h] [--go] [--jobfile JOBFILE] [-v V]

Transcode a bunch of videos into smaller proxy video files
for easier viewing and editing, without redoing files unnecessarily.

Safety first:
Pass the --go option to actually run the generated transcoder commands!

optional arguments:
  -h, --help         show this help message and exit
  --go               actually run the transcoder commands (default: False)
  --jobfile JOBFILE  specify other jobfile (default: ShrinkrJob.json)
  -v V               set the debug output level (0 = INFO, 1 = DEBUG)
                     (default: 0)

This script will not repeat the transcode if the output video file exists and matches the duration of the source video file. You can run this script over and over again on a folder and only the new files that need conversion will be processed.

5 Steps

1. Read ShrinkrOutputProfiles.json, add new ffmpeg commands if needed
2. Edit ShrinkrJob.json
3. Run python Shrinkr.py to see which files it will transcode (dry run)
4. Run python Shrinkr.py --go to transcode those files
5. Add files to the video folders, rinse and repeat.

Prerequisites

1. Python 3
2. ffmpeg in the PATH — Windows, macOS, Ubuntu

How It Works

The files can be selected for transcoding based on the following characteristics:

• Source Folder(s)
• Codec (HEVC, H.264, etc.)
• Resolution (2160p, 1440p, 1080p, etc.)

Using a config file, the script will seek out and select all of the files in the specified Folder(s) that match the supplied Codec(s) and Resolution(s).

The script will set the Last Modified time of each transcoded video file to the timestamp from the source video file, so that sorting by Date Modified in Windows Explorer, macOS Finder, or GNOME Files will also show the two files next to one another.

(Windows Explorer has odd behavior, though. The default "Date" column adds in Daylight Savings Time, which makes for a confusing and inconsistent view of the world. I seriously don't know what Microsoft is telling me here, because the actual mtime value is the same. The "Date modified" column shows things correctly, though.)

Job File

The default job file ShrinkrJob.json looks like this and the fields should be pretty self-explanatory:

{
    "input_folders": ["~/Downloads/Vid", "~/Videos/FirstOne"],
    "input_exts": ["*.mp4", "*.mov", "*.mkv"],

    "select_codecs": ["hevc"],
    "select_heights": [2160],

    "output_profiles": ["x264-mp4-360p", "utvideo-mkv-360p"]
}

input_folders: The list of folders containing files to transcode. The ~ symbol will automatically be replaced with the User's Home Folder path on both Windows, Linux, and macOS.

input_exts: The list of file types to transcode.

select_codecs: The list of input video codecs to transcode.

select_heights: The list of input video heights to transcode.

output_profiles: The list of target transcoding profiles defined in the ShrinkrOutputProfiles.json file.

To tell Shrinkr to load a custom Job File, use the command-line option --jobfile YourCustomJob.json.

Sample Output

By default, Shrinkr.py will load ShrinkrJob.json and process its specified files.

C:\Shrinkr>\Python37\python.exe Shrinkr.py --go

Shrinkr -------------------------------------------------------------
Find all input files specified via the 'ShrinkrJob.json' jobfile
with folders    ['~/Downloads/Vid', '~/Videos/FirstOne']
with extensions ['*.mp4', '*.mov', '*.mkv']
---------------------------------------------------------------------

Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-1080p-24mbps-1-color-correction.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-1080p-24mbps-1.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-1080p.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-1440p-80mbps.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-2160p.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-540p-4mbps.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-720p-8mbps-1-color-correction.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-720p-8mbps-1.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-720p-8mbps-2.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-720p-8mbps-3.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-720p-8mbps-4-brightness.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-720p-8mbps-4-gamma.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-720p-8mbps-4-nofilter.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\2160p-to-720p-8mbps-4.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184142.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184213.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184234.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184335.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184418.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184906.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\h264-1080p30-24mbps.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\hevc-1080p24-33mbps.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\hevc-2160p24-40mbps.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\hevc-2160p30-80mbps.mp4"
Getting file info for "C:\Users\Max\Videos\FirstOne\FirstOne.mp4"
Getting file info for "C:\Users\Max\Videos\FirstOne\VID_20190713_184142 - Converted.mkv"
Getting file info for "C:\Users\Max\Videos\FirstOne\VID_20190721_130806 - Converted.mov"

Shrinkr -------------------------------------------------------------
Generate transcode commands, check which output files already exist

Obviously we won't need to transcode those files again if they match
the input file duration
---------------------------------------------------------------------

Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184142.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184142-shrinkr-x264-mp4-360p.mp4"
File "C:\Users\Max\Downloads\Vid\VID_20190713_184142.mp4" has already been transcoded to x264-mp4-360p
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184142.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184142-shrinkr-utvideo-mkv-360p.mkv"
File "C:\Users\Max\Downloads\Vid\VID_20190713_184142.mp4" has already been transcoded to utvideo-mkv-360p
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184213.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184213-shrinkr-x264-mp4-360p.mp4"
File "C:\Users\Max\Downloads\Vid\VID_20190713_184213.mp4" has already been transcoded to x264-mp4-360p
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184213.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184213-shrinkr-utvideo-mkv-360p.mkv"
File "C:\Users\Max\Downloads\Vid\VID_20190713_184213.mp4" has already been transcoded to utvideo-mkv-360p
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184234.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184234-shrinkr-x264-mp4-360p.mp4"
File "C:\Users\Max\Downloads\Vid\VID_20190713_184234.mp4" has already been transcoded to x264-mp4-360p
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184234.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184234-shrinkr-utvideo-mkv-360p.mkv"
File "C:\Users\Max\Downloads\Vid\VID_20190713_184234.mp4" has already been transcoded to utvideo-mkv-360p
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184335.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184335.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184418.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184418.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184906.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\VID_20190713_184906.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\hevc-2160p24-40mbps.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\hevc-2160p24-40mbps.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\hevc-2160p30-80mbps.mp4"
Getting file info for "C:\Users\Max\Downloads\Vid\hevc-2160p30-80mbps.mp4"

Shrinkr -------------------------------------------------------------
Execute -- these are the transcoding commands that will be executed:
---------------------------------------------------------------------

ffmpeg -y -i C:\Users\Max\Downloads\Vid\VID_20190713_184335.mp4 -c:v libx264 -profile:v main -filter:v scale=-2:360 -b:v 4M -c:a copy C:\Users\Max\Downloads\Vid\VID_20190713_184335-shrinkr-x264-mp4-360p.mp4
ffmpeg -y -i C:\Users\Max\Downloads\Vid\VID_20190713_184335.mp4 -c:v utvideo -filter:v scale=-2:360 -c:a copy C:\Users\Max\Downloads\Vid\VID_20190713_184335-shrinkr-utvideo-mkv-360p.mkv
ffmpeg -y -i C:\Users\Max\Downloads\Vid\VID_20190713_184418.mp4 -c:v libx264 -profile:v main -filter:v scale=-2:360 -b:v 4M -c:a copy C:\Users\Max\Downloads\Vid\VID_20190713_184418-shrinkr-x264-mp4-360p.mp4
ffmpeg -y -i C:\Users\Max\Downloads\Vid\VID_20190713_184418.mp4 -c:v utvideo -filter:v scale=-2:360 -c:a copy C:\Users\Max\Downloads\Vid\VID_20190713_184418-shrinkr-utvideo-mkv-360p.mkv
ffmpeg -y -i C:\Users\Max\Downloads\Vid\VID_20190713_18