Programming :: Custom Progress Bar Of Video Conversion Script (FLV To XVID)

i have written a bash script to convert flv files (e.g. videos) to xvid to be played on my dvd player. the conversion is not really the issue, as it works. what i am dealing with now are 2 problems i have not found a good workarouond:
1. surpressing the shell output of mencoder completely ( i do not want to see all the mencoder messages). this i have only solved to a certain extend.
2. i want to create a progress bar. this one i have not yet cracked.

the script:
code:
#!/bin/bash
## settings
v_bitrate=768
video_opts="-ovc xvid -xvidencopts bitrate=$v_bitrate:autoaspect"
audio_opts="-oac mp3lame -lameopts fast:preset=standard"
store_dir=./converted_files .....

#start the script
main_menu
1. mencoder output: using /dev/null works more or less. for example: if mencoder detects a double frame while converting, a message is still printed on the bash screen
2. progressbar: i have no clue yet on how to do this. any link or tip is welcome.
my goal is something like this:
[56%] [time in progress] [timeleft]