In a computing device that implements an encoder, a method comprises receiving an encoded video sequence with a file container, receiving input to execute a trimming operation to create a frame accurate target segment of one or more desired pictures from the encoded video sequence and trimming to frame accuracy. Trimming to frame accuracy is accomplished by changing the parameter identifications of leading and trailing portions, if supported, or changing the parameters, and using the changed parameters or parameter identifications in re-encoding the leading and trailing portions, while an untouched middle portion between the leading and trailing portions is re-muxed without re-encoding.