play raw video (YUV420 in this case):
ffplay -f rawvideo -pix_fmt yuv420p -video_size 1280x720 input_video.yuv , or alternatively
ffplay -f rawvideo -pixel_format yuv420p -video_size 1280x720 input_video.yuv
play raw audio (pcm: f32le in this case)
ffplay -f f32le -ac 1 -ar 48000 input_audio
where, -f is the pcm format; -ac is the audio channels; -ar is the audio sampling rate