A method including: ingesting a video segment and a set of video features of the video segment; estimating a part size distribution for the video segment based on the set of video features and a first rendition of the video segment; calculating a maximum expected part size based on a threshold percentile in the part size distribution; at a first time, transmitting, to an video player, a manifest file indicating a set of byterange-addressable parts of the video segment in the first rendition, each byterange addressed part characterized by the maximum expected part size; at a second time, receiving, a playback request for a first byterange-addressable part; transcoding the first byterange-addressable part; in response to the maximum expected part size exceeding a size of the first byterange-addressable part in the first rendition, appending padding data to the first byterange-addressable part; and transmitting the first byterange-addressable part to the AV player.