ffmpeg transmission problem

test.sh

#! /bin/bash

ls x/* | sort |
    while read name; do
        echo "IN $name" >&2
        cat $name;
        sleep 1;
    done |
    ffmpeg -framerate 1 -f image2pipe -vcodec mjpeg -s 640x480 -pix_fmt yuvj420p -i - -vcodec libx265 -f matroska - |
    ffmpeg -f matroska -i - -r 1/1 out.%07d.jpg