1. A method of repeat padding for hybrid video sequences by a video codec device having a processor and a memory, comprising: with the video codec device, encoding a hybrid video sequence having plural frames, the plural frames of the video sequence including both progressive frames and interlaced frames, wherein the encoding the hybrid video sequence includes: setting a maximum coded width and maximum coded height for the video sequence; for an entry point segment, determining whether to signal coded width and coded height for the entry point segment apart from signaling of the maximum coded width and the maximum coded height, respectively, for the video sequence and, if so, setting the coded width and the coded height for the entry point segment; determining an active content frame size for a first frame, wherein the active content frame size is a resolution in terms of pixels, wherein the active content frame size of the first frame is indicated by the coded width and the coded height for the entry point segment if the coded width and the coded height for the entry point segment are set, and otherwise the active content frame size is indicated by the maximum coded width and the maximum coded height for the video sequence; encoding and decoding the first frame, the first frame having a macroblock-aligned vertical size that depends at least in part on frame coding mode of the first frame, wherein the decoded first frame is used as a reference frame; if the reference frame was coded as a frame of progressive video, expanding from the active content frame size of the reference frame using a first form of repeat padding, wherein the first form of repeat padding includes repeating a last row of active content of the reference frame, the active content being pixels in an area defined by the active content frame size; if the reference frame was coded as separate fields of interlaced video or frame of interlaced video, expanding from the active content frame size of the reference frame using a second form of repeat padding, wherein the second form of repeat padding includes repeating a last row of each field of the active content of the reference frame; and for a second frame of plural frames of the entry point segment, setting a frame coding mode that indicates whether the second frame is coded as a frame of progressive video, coded as separate fields of interlaced video or coded as a frame of interlaced video, and encoding the second frame using motion compensation relative to the reference frame; and outputting, from the video codec device, encoded data for the video sequence in an output bitstream.