Bash: Getting a var from txt file, after certain exp + keep a command open while cont

[kwaanens]

I'm making a small script for myself, converting video, based on ffmpeg.

I'm using idvid from Tovid, shich shows output like this:

Analyzing file: '/media/arkiv/video/musikk/el_caco/el_caco_-_a_nice_day.wmv'. This may take several minutes...
=========================================================
               File: /media/arkiv/video/musikk/el_caco/el_caco_-_a_nice_day.wmv
              Width: 640 pixels
             Height: 480 pixels
       Aspect ratio: 1.33:1
             Frames: 0
           Duration: 00:03:33 hours/mins/secs
          Framerate: 1000.000 frames per second
       Video format: WMV1
      Video bitrate: 0 bits per second
---------------------------
Audio track 1 (Stream 0.0, AID 0):
---------------------------
              Codec: wmav2
            Bitrate: 192000 bits per second
      Sampling rate: 48000 Hz

The output from idvid is a little more filled with useless crap, so I grep the relevant info, and put it into a file, zenity outputs this file like so:

zenity --text-info --filename=/home/ketil/.wmvtoavi/log/out --width=600 --height=400

Now, I'd like to be able to pick out e.g. "640" after "Width" and "480" after "Height", and mash them up so that the default $aspect_ratio for this file is 640x480. Does anyone know how I can manage that?

----

Also, I'd like to keep having the zenity command given above open, while the next dialogs come up, and end it before the actual command is run. I tried with a while/do loop, but seems I don't really understand how it works. I've been scanning the abs-guide, but need some assistance in this (I guess, pretty easy) regard.

Thanks!

- Ketil

[ghostdog74]

awk '{gsub("--height=","",$NF);gsub("--width=","",$(NF-1));print $NF,$(NF-1) }' file

[kwaanens]

I might be very dim, but do not understand this. Running the command on my file gets me:

awk '{gsub("--height=","",$NF);gsub("--width=","",$(NF-1));print $NF,$(NF-1) }' .wmvtoavi/log/out 
/media/arkiv/funnyvideos/bikerack.wmv File:
pixels 320
pixels 240
1.33:1 ratio:
0 Frames:
hours/mins/secs 00:00:29
second per
WMV2 format:
second per
0): AID
wmav2 Codec:
second per
Hz 32000

The file looks like:
File: /media/arkiv/funnyvideos/bikerack.wmv
Width: 320 pixels
Height: 240 pixels
Aspect ratio: 1.33:1
Frames: 0
Duration: 00:00:29 hours/mins/secs
Framerate: 30.000 frames per second
Video format: WMV2
Video bitrate: 0 bits per second
Audio track 1 (Stream 0.0, AID 0):
Codec: wmav2
Bitrate: 40000 bits per second
Sampling rate: 32000 Hz

So basically, it stripped "height" and "width", and for the others, it removed e.g. "Sampling rate" and moved "hz" in front of "32000".

So unless I don't understand anything, it looks like it doesn't do what I need.

- Ketil

[duff]

# WIDTH=$(grep 'Width:' .wmvtoavi/log/out | awk '{print $2}')

[kwaanens]

# WIDTH=$(grep 'Width:' .wmvtoavi/log/out | awk '{print $2}')

That one did the trick. I ended up doing:

WIDTH=$(grep 'Width:' .wmvtoavi/log/out | awk '{print $2}')
HEIGHT=$(grep 'Height:' .wmvtoavi/log/out | awk '{print $2}')
DEFAULT_FRAMESIZE="$WIDTH"x"$HEIGHT"
FRAMESIZE=`zenity --entry --text="Enter frame size. Default value has been read from input file. Change at will." --entry-text="$DEFAULT_FRAMESIZE"`

Probably could have been done smoother, but at least it works.

Now, my other problem, how do I keep the script from waiting at:

zenity --text-info --filename=/home/ketil/.wmvtoavi/log/out --width=600 --height=400

until I close it? It's nice to have the file information open while I go through the rest of the process.

- Ketil

[Chaotic Thought]

Now, I'd like to be able to pick out e.g. "640" after "Width" and "480" after "Height", and mash them up so that the default $aspect_ratio for this file is 640x480. Does anyone know how I can manage that?

If you want to save just the numbers for height and width, the trick I like to use is bash's parameter expansion to strip off the section before the number and then the section after the number. Suppose you save your command's output in a file "idvid.out", then we can use grep to save a line into a variable that looks like this (including the whitespace):

"          Width: 640 pixels"

We'll save this line into a variable, then strip off the beginning (from the beginning of the line up to and including the "Width: " part, then strip off the end (from the " pixels" part to the end of the line), then save the result in a new variable called $width, and then do the same thing for the height.

str=$(grep "Width" idvid.out)
str=${str##*Width: }
str=${str%% pixels*}
width=$str

str=$(grep "Height" idvid.out)
str=${str##*Height: }
str=${str%% pixels*}
height=$str

echo "${width}x${height}"

Sample output:

640x480


To find out more about bash's parameter expansion, do a search for "Parameter Expansion" in the bash(1) manpage.




----

Also, I'd like to keep having the zenity command given above open, while the next dialogs come up, and end it before the actual command is run. I tried with a while/do loop, but seems I don't really understand how it works. I've been scanning the abs-guide, but need some assistance in this (I guess, pretty easy) regard.

Thanks!

- Ketil

If you add & to the end of your zenity command, then your script will not wait for zenity to finish. Otherwise, bash waits for zenity to return. Not sure if that's what you were asking, but give ampersand a try--it is one of the most powerful bash operators.