As the core facet of the media transformation support, RadiantGrid offers program assembly of media content. Encompassed in program assembly is the stitching together of multiple media assets, without using intermediate files. Whole or partial media assets can be stitched together. One common scenario is to stitch a black slug (few seconds of all black video with silent audio), with a promotional interstitial, with the master asset (movie, TV show, etc.), with a trailing interstitial, and finally with a trailing black slug.
In program assembly, assets are assembled end-to-end with the audio and video tracks stitched together. Source assets are not required to have identical formats, frame rates, or frame sizes. During transcode, the source video frames are rescaled and/or cropped into the output video stream, and the source video is adapted to the output frame rate by dropping or duplicating frames.
Other customers have master assets that contain black segments where advertisements would be inserted during broadcast. The RadiantGrid black-detection parser can be used during ingestion to locate these segments of black video, and the list of non-black video ranges will be used to create virtual clips that reference the master asset. This list of virtual clips will be stored as metadata with the master asset. These virtual clips can be assembled into the transcoded output file, which would no longer contain these black interstitial segments.
In addition, during program assembly, 32-bit (alpha-channel) static images or motion video can be overlaid on the source media during transcoding. These overlays can occur at specific times during the video, or repeatedly on a regular period. The overlay functionality is often used for overlaying logos, ratings graphics, or titles.