Adapting content items to target delivery formats

A non-transitory machine-readable storage medium storing instructions which, when executed, cause a processing device to perform operations comprising:

• receiving, by a user device, a first bitstream comprising data corresponding to a media item, for display at a first aspect ratio, wherein the first bitstream corresponding to the first aspect ratio is received from a content platform via a network;
• receiving, by the user device, a second bitstream comprising data corresponding to the media item, for display at a second aspect ratio, wherein the second bitstream corresponding to the second aspect ratio is received from the content platform via the network;
• providing the first bitstream corresponding to the first aspect ratio to a first bitstream decoder and the second bitstream corresponding to the second aspect ratio to a second bitstream decoder, wherein operations of the first bitstream decoder in decoding the first bitstream corresponding to the first aspect ratio and operations of the second bitstream decoder in decoding the second bitstream corresponding to the second aspect ratio overlap in time;
• determining whether to display the media item at the first aspect ratio or the second aspect ratio using user selection of the first aspect ratio or the second aspect ratio;
• responsive to determining that the media item is to be displayed at the second aspect ratio, generating a composited media item based on the first bitstream corresponding to the first aspect ratio and the second bitstream corresponding to the second aspect ratio, wherein the second bitstream provides content to fill display regions outside the first aspect ratio;
• and
• displaying the composited media item.

A system for a user device, the system comprising:

• a memory;
• and
• a processing device, coupled to the memory, to perform operations comprising:
• receiving a first bitstream comprising data corresponding to a media item, for display at a first aspect ratio, wherein the first bitstream corresponding to the first aspect ratio is received at the user device from a content platform via a network;
• receiving a second bitstream comprising data corresponding to the media item, for display at a second aspect ratio, wherein the second bitstream corresponding to the second aspect ratio is received at the user device from the content platform via the network;
• providing the first bitstream corresponding to the first aspect ratio to a first bitstream decoder and the second bitstream corresponding to the second aspect ratio to a second bitstream decoder, wherein operations of the first bitstream decoder in decoding the first bitstream corresponding to the first aspect ratio and operations of the second bitstream decoder in decoding the second bitstream corresponding to the second aspect ratio overlap in time;
• determining whether to display the media item at the first aspect ratio or the second aspect ratio using user selection of the first aspect ratio or the second aspect ratio;
• responsive to determining that the media item is to be displayed at the second aspect ratio, generating a composited media item based on the first bitstream corresponding to the first aspect ratio and the second bitstream corresponding to the second aspect ratio, wherein the second bitstream provides content to fill display regions outside the first aspect ratio;
• and
• displaying the composited media item.