Trim 5 frames starting from 160-th frame and write to png sequence
ffmpeg -pix_fmt yuv420p -s 1920x1088 -r 1 -i input_video.yuv -r 1 -ss 160 -frames 5 output_sequence_%d.png
size of input video is 1920x1088, format YUV420 progressive.
UPD: ffmpeg is renamed to avconv. Using it for trimming AVI video:
avconv -ss 00:58:00 -t 00:59:30 -i ./video.avi frame_%05d.png
UPD2: it seems ffmpeg is back.