Apple wants to make it easier for content producers to combine dialogue, music and special effects and, especially, improve the intelligibility of dialog on TV sets. The company has been granted a patent (number 20170126343) for “audio stem delivery and control.”
It involves a system and method for playing back content that includes a video stream and a final audio mix that represents sounds for the video stream. An interface receives the video stream and the final audio mix. The final audio mix includes a dialogue stem and a music and effects stem that together represent an entirety of sounds for the video stream.
In the patent filing, Apple notes that sound program content, including movies and television shows, are often composed of several distinct audio components, including dialogue of characters/actors, music, and sound effects. Each of these component parts called stems may include multiple spatial channels and are mixed together prior to delivery to a consumer or a distribution company. For example, a production company may mix a 5.1 channel dialogue stem, a 5.1 music stem, and a 5.1 effects stem into a single master 5.1 audio mix or stream. This master stream/mix may afterwards be delivered to a consumer through a recordable medium (e.g., DVD or Blu-ray) or through an online streaming service.
Although mixing dialogue, music, and effects to form a single master mix or stream is convenient for purposes of distribution, this process often results in poor audio reproduction for the consumer, Apple says. For example, intelligibility of dialogue may become an issue during playback because the dialogue stem for a piece of sound program content must be played back using the same settings as music and effects stems since each of these components are unified in a single master stream/mix.
Apple says that dialogue intelligibility has become a growing and widely perceived problem, especially among movies played through television sets where dialogue may be easily lost amongst music and effects. The company says an approach is needed that improves intelligibility of dialogue content.
Of course, Apple files for — and is granted — lots of patents by the U.S. Patent & Trademark Office. Many are for inventions that never see the light of day. However, you never can tell which ones will materialize in a real product.