Transcoding optical media in Linux
Obstacle Course
On Linux
Linux uses the libdvdcss program library to decrypt DVDs whose use is restricted by the CSS system. The program library is available from the software repositories of numerous distributions and can be installed with the help of appropriate package management tools. The common ripping programs on Linux will then play and transcode commercial video DVDs without any further adjustments.
The MakeMKV [5] program available for Linux transcodes Blu-ray media restricted by AACS and Blu-ray+ – without a manual installation, according to the ads. The programmers of the software indicate on their website that they always support the latest versions of these encryption mechanisms.
However, the VLC media player is all you need for simple Blu-ray playback. The HandBrake transcoding software can also handle Blu-ray with the libbluray2 package. If you want to consider menus implemented in Java on the original data carriers, as well, you need the libbluray-bdj package.
If you then install the files libbdplus
and libaacs0
on your system, you are still legal, because according to the VLC website, the software does not contain any certificates or keys. The libaacs0
package only provides the encryption framework, not the actual keys and certificates.
You need these keys to play encrypted Blu-ray discs. How you can get these keys and integrate them into a Linux system is now an open secret. Various websites describe the configuration in detail and provide links to the key files, which are also regularly updated by third parties. Effective copy protection this might not be, but those in the US and European Union are nevertheless entering legally dubious territory. The VLC media player can also cope with protected Blu-ray discs, thanks to the keys, and you can use the menu in many cases.
HandBrake
For many years, the continuously updated HandBrake [6] has been regarded as a comprehensive solution for transcoding videos. The software can be found in the repositories of almost all common Linux distributions and is quickly installed without any additional overhead. HandBrake is also available as a command-line program; however, it requires some training to master the many parameters. The GUI is launched from the Multimedia menu.
The program window looks a bit confusing, with a horizontal menubar at the top and a buttonbar below it with important controls. Transcoding actions are set up in the fields below.
To begin, you have to open the source drive by selecting Open Source
from the buttonbar. If you want to transcode a video DVD, the drive will normally be /dev/dvd
or a data carrier already identified by the system's file manager. Blu-ray drives are usually mounted on Linux as /dev/sr0
or /dev/sr1
.
Once the source has been clarified, the routine parses the individual tracks on the data carrier and automatically locates the movie. If problems occur and the application reports, for example, that it cannot find any content, check whether you have installed all the required libraries and other components for your system and whether they are up to date.
The longest track appears with a preview image in the main window. HandBrake does not automatically transcode shorter tracks, such as menu views or bonus tracks. If necessary, you can select these manually in the Title drop-down.
In the next step, you need to set up transcoding. HandBrake uses either MP4 or Matroska containers as the target format and offers numerous settings for both (Figure 2). You can choose UHD resolutions for Blu-ray source media for playback on high-resolution 3K or 4K monitors.
Here, you also set the refresh rate and define the compression formats you want to use (e.g., H.264 or H.265, but also VP8 or VP9). These formats can be combined with different resolutions and frame rates, if required, and you can shrink high-resolution Blu-ray media to the old PAL TV format.
Once the settings are correct, you need to identify the audio and subtitle tracks in the next step. Most movies on DVD or Blu-ray come with multilingual audio tracks and additional subtitles. In HandBrake, you select the desired audio tracks and the required subtitle tracks under the Audio and Subtitle tabs. VLC and other front ends, such as SMPlayer, let you select an audio track in different languages when playing the films. The players also show subtitle tracks at the push of a button.
From the Dimensions , Filters , and Video tabs, you can tweak further options. The choices range from modifying the image size and selecting an encoder to options for image enhancement, and you can adjust the bit and frame rates retroactively in these dialogs.
A Question of Format
HandBrake offers an impressive number of predefined settings that are used for special playback devices such as smartphones or gaming consoles. The Preset selection field opens a submenu at the side with the possibilities (Figure 3).
The most important configurations for universal transcoding are hidden in the Matroska and General presets. The Matroska preset offers various compression formats, such as H.264, H.265, VP8, or VP9. You can choose various resolutions from the PAL TV format to HQ, as well as different frame rates. The General preset has the same nominal resolutions and frame rates but additionally offers special audio settings (e.g., for Dolby Surround). However, this dialog is defined for saving the files in MP4 containers.
The Web group has presets optimized for web applications such as Gmail and YouTube. The Devices and Legacy groups provide device-specific settings, including default settings for older devices. The range of presets in the Legacy group ranges from Apple's iPad and iPod mobile systems via Android tablets, to modern Sony PlayStation consoles, to the Xbox or Chromecast systems.
Of course, individual parameters can be changed for presets in the settings groups. However, you should be aware that higher resolutions and frame rates can have a significant effect on transcoding speed: With longer movies, it can take several hours to save them in the target format on your storage device.
Buy this article as PDF
(incl. VAT)