18. The method of claim 17 , wherein the extracted video features comprise spatial and temporal features of the source video, wherein the spatial features of a frame of the source video represent the spatial activity of the frame, and the temporal features of a frame of the source video represent the amount of motion in the frame.
17. The method of claim 16 , wherein estimating video coding complexity of a source video comprises: training a video coding complexity model using a plurality of videos selected from among the plurality of different encoded videos of the video corpus; receiving the source video, the source video having a first video format; encoding the source video into an intermediate video format; extracting video features from the encoded source video; and computing a video coding complexity score based on the extracted video features and the trained video coding complexity model.