A method of encoding a video frame is disclosed in which video slices of the video frame are initially encoded in parallel using both interframe encoding and intraframe encoding. Then, after a first predetermined minimum amount of the video frame has been encoded, the method includes periodically determining whether the amount of intraframe encoded information for the frame achieves a first threshold, and when the first threshold is achieved, encoding the remainder of the video frame using only intraframe encoding. The method may include determining whether a lower second threshold is achieved based on relative complexity of the frame and quantization. The method may include performing similar comparisons on a slice by slice basis in which any one or more of the processing devices skips motion estimation and interframe encoding for corresponding video slices. A video encoder is disclosed which includes multiple processing devices and a shared memory.