Create Perfect DCPs with Stunning Picture and Sound Quality!

This article provides essential guidelines for achieving optimal picture and sound quality, as well as proper subtitling, in Digital Cinema Packages (DCP).

May 26, 2024

DCP Services

KINODCP offers DCP creation starting from $5/min. Get your quote today.

A Digital Cinema Package (DCP) sets the standard for the highest picture and sound quality in digital cinema. Compared to consumer standards like DVD or Blu-ray, a DCP offers superior quality. This blog post highlights the technical aspects and provides recommendations for the optimal creation of a DCP.

Picture Quality

A DCP offers exceptional color and contrast depth. With a standard resolution of usually 2K, although 4K is also possible, the DCP provides remarkable picture quality. The color depth of 12 bits per color channel allows for 4096 contrast levels and billions of colors. This depth and the extended color space ensure outstanding visual experiences that are fully realized through high-quality digital cinema projectors. The image information is copied into the XYZ color space, with the source material being either in Rec.709 or Rec.2020 (HDR) color space.

Aspect Ratios

Choosing the right aspect ratio is crucial for optimal projection in cinemas. The most common aspect ratios for DCPs are:

  • FLAT (1.85:1): This configuration is often used and corresponds to a resolution of 1998x1080 (2K) or 3996x2160 (4K).
  • SCOPE (2.39:1): This wider configuration corresponds to a resolution of 2048x858 (2K) or 4096x1716 (4K).
  • FULL (1.9:1): This is less commonly used and corresponds to the maximum resolution of 2048x1080 (2K) or 4096x2160 (4K).

When selecting the aspect ratio, it should be noted that not all cinemas have the same screen configuration. FLAT and SCOPE aspect ratios dominate the modern cinema landscape. An incorrect aspect ratio can lead to unwanted effects such as letterboxing or pillarboxing, reducing the visible image area.

Sound Quality

On the sound side, up to 16 audio channels are possible in the standard DCP. The most commonly used format is Dolby 5.1. Advanced technologies such as Barco Auro 3D (11.1 sound) and Dolby Atmos (61.3 sound) offer expanded possibilities and a more immersive cinema experience.

Stereo Sound

While stereo mixes are technically possible in a DCP, they often cause problems in cinemas. It is recommended to use at least a 3.0 mix (three channels: left, right, and center) or ideally a 5.1 mix. The reason is that stereo sound (2.0) in cinemas is usually only played through the outer front speakers of the surround system. This creates a “gap” in the middle of the room, impairing speech intelligibility as the center front speakers are not used. Phase cancellations and other unwanted side effects can also occur.

To avoid these problems, it is advisable to hire a sound studio to create an original 3.0 or 5.1 mix based on stems or to perform a cost-effective upmix from stereo to 5.1 or 3.0.

Subtitles

The integration of subtitles in a DCP depends on the frame rate of the source material. For source material with 24 FPS, subtitles can be addable in an Interop-DCP. If the source material is in 25 FPS or higher, it is recommended to burn the subtitles into the image before creating the DCP, as addable subtitles at 25 FPS cannot be played on some cinema systems.

Recommendations for Subtitling

  • Line count and character count: A maximum of two lines with up to 42 characters per line.
  • Positioning: Centered horizontal positioning. Vertical positioning: Line 1 = 9% from the bottom edge of the image, Line 2 = 15% from the bottom edge of the image.
  • Formats: Subtitles can be delivered in the D-Cinema CineCanvas Interop 1.0 XML format or as SRT files. For SRT files, standard values for vertical positioning are used unless other information is provided.

Subtitles in XML format are displayed either with the standard font on the playback device or a font can be embedded in the resulting MXF file. However, for non-Latin languages and character sets, this can lead to large MXF files and latency when reading the file in the player. For complex subtitles, it is always advisable to burn them into the image.

If a frame rate conversion is not possible or desired, the subtitles can also be burned in. However, this leads to higher mastering costs as several versions of the film have to be processed and checked.

Conclusion

For the creation of a DCP, it is advisable to consider the specific technical requirements and recommendations for picture and sound as well as subtitling to ensure optimal playback in the cinema. A carefully crafted DCP offers viewers the best possible cinema experience and ensures that the artistic vision of the film is fully realized.