For HD (high-definition) screenings, some festivals are already using digital files in containers such as MOV, MP4 and MKV, but many others are choosing to use Blu-ray discs, and many cinemas and screening rooms are even equipping themselves with these players. However, despite what it may seem, Blu-ray is not the best option for HD screenings and, of course, it is not the standard for this type of file. Let’s see why.
Blu-ray is a video medium; that is, it is not a format (container) or a video codec. The codec used by Blu-ray is MPEG-4 Part 10, i.e. h.264; the audio can be uncompressed in separate tracks (for 5.1, for example) or compressed in .ac3. The h.264 video and audio are stored on the disc in the .M2TS container along with subtitle information, the menu, etc.
Therefore, the quality of a Blu-ray is determined by the source files: if I compress to h264 starting from a .dpx or .tiff sequence, I will obtain a high-quality h264, whereas if I start from other intermediate files, the quality will be somewhat lower. In other words, the quality of a digital file is determined by the source files and the encoding, not by the container or the medium.
The limitations of the Blu-ray disc, as a medium, are several:
- A Blu-ray disc can only be played on a Blu-ray player.
- The disc medium is unstable and can cause read errors. What’s more, physical formats are gradually disappearing; even digital cinema (DCP) is not based on a medium, but on digital files.
- It is expensive to produce and copy.
- It depends on one company (Sony).
Now let’s look at .MKV (Matroska). It is an open container that supports various video codecs, such as h264, Dvix, MPEG2, etc., and supports multiple audio tracks, allowing you to have the 5.1 version (in .ac3) and stereo sound in the same file. It also has great subtitle capacity, allowing multiple tracks in the same file, and it is possible to create chapters.
This container was created in 2005 with the intention of becoming the standard for video, and after several years it has achieved this, thanks to being an open-source project that is part of the community and is serving as the basis for many other projects (such as Google’s Webm and Dvix 7, to the detriment of AVI).
In addition—and this is the part that interests us most for screenings—all player manufacturers have incorporated it into their devices. Currently, we can play MKV files on:
- Multimedia hard drives
- Blu-ray players, from USB or disc (since 2009)
- Smart TVs with a USB input
- Computers with any operating system (Windows, Mac or Linux) and with any player (such as VLC)
- And any device that may appear in the future, since being open source, there are no limitations on its use and development.
So…, if I can have a video encoded in h264 (remember: quality will depend on the encoding process), in Full HD 1080p with 5.1 sound (in .ac3 format), with multiple subtitle tracks, in a .MKV container, which I can play on a Blu-ray player, multimedia disc, or computer…
why would I want a Blu-ray disc?
For nothing, unless I want to sell films and need a disc to apply DRM to; but we are talking about screenings at film festivals. Unfortunately, one of the problems .MKV currently has is its success for Blu-ray rips and illegal downloads on the internet, but this use cannot, and must not, lead to its rejection.
With the .MKV container, we have a great opportunity for independent cinema, short films and, of course, festivals, as it allows us to create and distribute our content in HD freely, and reduces the cost of all shipping and high-definition screening processes.