Modern digital cinema projection technology is subject to precise standards, dictated by the DCI consortium (Digital Cinema Initiatives, LCC).
This in order to obtain a quality not found in common home systems and to maintain a sort of compatibility with the cinematic standards of the past.
Encoding of your content in this particular format takes place in the background as soon as the content is deemed suitable by us for screening and is coupled to a show.
Below is some information and some tricks to get the best result.
On Cinestream it is possible to upload videos with the following extensions:
For some formats (eg: .avi .wmv and .mkv) the preview in the browser may not be available.
Individual files can have a maximum size of 250 MB.
From the very beginning, the cinema projection standard was to project 24 frames per second onto the screen.
Most smartphones output images at 25 or 30 fps which are the television standard for Europe (EBU) and the United States (SMPTE) respectively.
When loading contents with a different frame rate it is necessary to take into account that the original movie will be automatically converted to 24 fps.
This kind of conversion, especially when there is a musical soundtrack, sometimes leads to unwanted effects. It also results in a significant performance degradation in rendering the final images.
Our advice is to produce and upload material shot or already converted and tested at 24 fps.
The resolution of a digital cinema projection varies according to the most common projection formats. The one used during film pre-shows is usually defined as 2K FLAT format which corresponds to 1998x1080, therefore a slightly larger image than a more homely Full HD format.
Consequently, when projecting a Full HD movie with a native resolution of 1920x1080, black bands 34 pixels wide each will appear on both the right and left sides of a cinema projection screen. This will not cause problems for most users but for those wishing to exploit the entire projection format the only solution is to scale the images to the desired resolution with special tools.
A higher quality result is obtained by scaling down content higher than 2K resolution such as UHD or 4K video files.
The Cinestream system automatically scales down video content or images loaded with a resolution higher than 2K until it reaches a vertical resolution of 1080 pixels, or horizontal resolution of 1998 pixels.
It is important to remember that the cinematographic format, like the television one, contrary to what is happening now on social media, is of the landscape or horizontal type. Uploading portrait or vertical content, be it a video or a photograph, involves the exploitation of only the central part of the cinema projection screen.
Another important consideration in publishing your content on Cinestream is to understand that a movie that initially may seem well done on a smartphone display, projected in the cinema on a screen that can be even 20m wide could even be annoying because it is poorly stabilized or because the poor image quality is exposed.
It is therefore good practice, if not to carry out all the processing of the work with a PC, to use it at least for a final quality control.
Using a PC, in addition to being able to produce content with exact specifications, make possible to obtain superior quality control of the finished product, a fundamental prerequisite for both Cinestream and its Broadcasters.