ls
akiyo_cif.264  evalvid-2.7.tar.bz2  ffmpeg                               nse.tcl
akiyo_cif.yuv  evalvid.jpg          ffmpeg-lin.tar.bz2                   ping.tcl
akiyo_qcif.7z  exam.tcl             libxvidcore-dev_1.3.2-dmo1_i386.deb  script.tcl~
root@bipul-VirtualBox:~/Downloads# ffmpeg -i akiyo_cif.yuv  akiyo_cif.m4vffmpeg version 0.8.6-4:0.8.6-0ubuntu0.12.04.1, Copyright (c) 2000-2013 the Libav developers
  built on Apr  2 2013 17:00:59 with gcc 4.6.3
*** THIS PROGRAM IS DEPRECATED ***
This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
[IMGUTILS @ 0xbf8b8974] Picture size 0x0 is invalid
[IMGUTILS @ 0xbf8b88a4] Picture size 0x0 is invalid
[rawvideo @ 0x8fda240] Could not find codec parameters (Video: rawvideo, yuv420p)
[rawvideo @ 0x8fda240] Estimating duration from bitrate, this may be inaccurate
akiyo_cif.yuv: could not find codec parameters
root@bipul-VirtualBox:~/Downloads#