raspi-plex-transcode

Help for manipulating the plex-media-server transcode on the raspberry pi

Ensure hardware decoding works and your firmware is up to date

As mentioned in this forum post: https://forums.raspberrypi.com/viewtopic.php?t=262558

Hardware decoding of h264 will NOT WORK if the gpu memory is limited. I had added gpu=16 in my config.txt since I run my pi headless and thought it to be a waste of ram. Setting it to gpu=128 (the default) should be fine.

Brought to my attention by "fancybits" in the plex forums it is recommended to update the rpi kernel and firmware by running sudo rpi-update.

https://forums.plex.tv/t/hardware-transcoding-for-raspberry-pi-4-plex-media-server/538779/236

TLDR Install

cd ~
mkdir plex-backup
cp "/usr/lib/plexmediaserver/Plex Transcoder" plex-backup/
git clone https://github.com/ForsakenNGS/raspi-plex-transcode.git
cd raspi-plex-transcode
./compile.sh
./install.sh

Getting started

Log into your pi (as user pi) and cd into your home directory. (You can install this somewhere else if you update the configuration file accordingly)

Download this repository with git and cd into it using:

git clone https://github.com/ForsakenNGS/raspi-plex-transcode.git
cd raspi-plex-transcode

From this point you can continue with one of the three utility script:

compile.sh Download the source of the plex ffmpeg-fork, install the required dependencies and compile it.
install.sh Replace the original plex transcoder
uninstall.sh Restore the original plex transcoder

IMPORTANT: Backup your stuff! I'm doing my best to make the process as safe as possible, but there is always the chance that something goes wrong. Be warned!

Most important file to backup is the original plex transcoder found by default at /usr/lib/plexmediaserver/Plex Transcoder e.g.:

mkdir ~/plex-backup
cp "/usr/lib/plexmediaserver/Plex Transcoder" ~/plex-backup/

Compiling plex ffmpeg with custom options

First of all make sure you are in the directory of this projects git repository.

Now simply run ./compile.sh which will do the following:

Download the latest version of the plex-ffmpeg forks source code
Extract it
Install all required dependencies (will ask for superuser permissions)
Configure and compile the ffmpeg source code

If you want to manually adjust the configure parameters you can do so in the first few lines of the compile.sh script.

Installing the wrapper script

First of all make sure you are in the directory of this projects git repository.

Now simply run ./install.sh which will do the following:

Create a backup of the original plex transcoder script /usr/lib/plexmediaserver/Plex Transcoder as /usr/lib/plexmediaserver/Plex Transcoder Backup if not already present (will ask for superuser permissions)
Remove the original plex transcoder script /usr/lib/plexmediaserver/Plex Transcoder (will ask for superuser permissions)
Put a symlink in its place that will redirect all encoding calls to this projects wrapper script (will ask for superuser permissions)

Uninstalling the wrapper script

First of all make sure you are in the directory of this projects git repository.

Now simply run ./uninstall.sh which will do the following:

Remove the original plex transcoder script /usr/lib/plexmediaserver/Plex Transcoder (will ask for superuser permissions)
Move the backup of the original plex transcoder script /usr/lib/plexmediaserver/Plex Transcoder Backup back into its proper place at /usr/lib/plexmediaserver/Plex Transcoder (will ask for superuser permissions)

Configuration

The wrapper ffmpeg-transcode will replace the plex parameters according to the configuration file ffmpeg-transcode.yaml. An example can be found in this repository as instructed to download above. The following options are available:

executable (required)

Defines the ffmpeg executable that is invoked with the altered parameters. The default is /home/pi/plex-media-server-ffmpeg/ffmpeg

profiles (required)

A list of profiles indexed by name that are being used to adjust the plex parameters. Each profile requires an input and output key which defines overrides for the default parameters. An example as included in the default configuration:

'profiles':
  'default':
    'input':
    'output':
      '-codec:0': 'h264_v4l2m2m'
      '-crf:0': '10'
      '-minrate:0': '1M'
      '-maxrate:0': '5M'
      '-bufsize:0': '10M'
      '-seg_duration': '2'

Everything in the input section applies to the input stream (everything before the -i filename parameter).
Everything in the output section applies to the output stream (everything after the -i filename parameter).
Any valid ffmpeg parameter can be used.
Repetitions of the same parameter are currently not supported.

profile_select

Controls when certain profiles are used. The following child-keys are available:

default Defines a default profile which is used if no other rule matches. Example:

'profile_select':
  'default': 'default'

by_argument Defines conditions which will trigger a certain profile to be used.
- argSection One of either input or output. This will decide whether the script will check the given argument for the input or the output stream.
- argName The name of the argument as supplied by plex. e.g.: -codec:0 will check the video codec, -i will check the input file.
- type What kind of condition will be checked. Available are:
  - exact Matches if the given value parameter matches the value of the specified argument.
  - regex Matches if the regex supplied within the value parameter matches the value of the specified argument.
  - present Matches if the specified argument is present.
  - missing Matches if the specified argument is missing.
- ignorecase Currently only used for the regex type. Makes the regular expression case insensitive.
- value The value used for matching with the exact and regex types.
- profile The target profile as defined in the profiles section that is used if the condition matches.
- priority A priority that is used when multiple conditions match. Higher is more important. If omitted the default priority of 0 is used.

Example that will match if the path or filename contain the string anime somewhere:

'profile_select':
  'by_argument':
    -
      'argSection': 'input'
      'argName': '-i'
      'type': 'regex'
      'ignorecase': true
      'value': '.*anime.*'
      'profile': 'anime'

Research sources for configuration

Encoding options for h264_v4l2m2m: raspberrypi/firmware#1612