Crop, Resize & Stream DirectShow

[Tom_S]

All,

I am a newbie to VLC (but not to video editing) so please excuse my ignorance. I have spent the last few days scouring the internet for information regarding cropping and resizing a stream. I am using Windows XP SP3 and VLC 0.9.8a and my source is Microsoft DV being captured via DirectShow. My source video has a black border all the way around it, which I need to remove. The source video size is 720x480 which I need to resize to 320x240. The optimal solution would be to crop the black border first then resize the resulting video and stream over RTP/UDP. I have tried several solutions and came up with the following code to test with.

Code: Select all

vlc file://"dump.ts" :sout=#transcode{cropleft=26,cropright=26,croptop=17,cropbottom=17,width=320,height=240,vcodec=mp2v,vb=1024,scale=1,acodec=mp2a,ab=192,channels=2}:duplicate{dst=std{access=file,mux=ts,dst="test.ts"}}

It resizes the video ok, but it doesn't crop it. Please help with this. I know I'm not the only one looking for this solution.

Thank you in advance,

Tom_S

[Tom_S]

*bump*

[VLC_help]

Leave scale=1 out if you force resolution.

[Tom_S]

Thank you for your suggestion. I was able to resize even with "scale=1" in my string mentioned earlier... However, I modified my execution string to:

Code: Select all

vlc file://"dump.ts" :sout=#transcode{cropleft=100 ,cropright=100,croptop=100,cropbottom=100,width=320,height=240,vcodec=mp2v,vb=10 24,acodec=mp2a,ab=192,channels=2}:duplicate{dst=std{access=file,mux=ts,dst="test .ts"}}

VLC responded the same way as before (ie. resizing but not cropping) with the output video. Any more help is greatly appreciated. I do not care about the resulting aspect ratio being 100% accurate as long as the "borders" can be cropped out.

[Tom_S]

*bump*

[VLC_help]

Sorry, it seems that the rest of my post was left out.

The :crop-geometry is one option that should work

--crop-geometry=<string> Crop geometry (pixels)
Set the geometry of the zone to crop. This is set as <width> x
<height> + <left offset> + <top offset>.

You can also set it from GUI via Tools -> Preferences... (Show settings: All) and Video -> Filters then tick Crop video filter from under Video filter module and go to Video -> Filters -> Crop.

[Tom_S]

Thank you for your response. I tried using both methods that you mentioned above. They do not seem to affect the output video (ie. borders still exist & video is not resized). Here is my latest execution string:

Code: Select all

vlc file://"dump.ts" :crop-geometry="320x480+10+10" :sout=#transcode{vcodec=mp2v,vb=1024,acodec=mp2a,ab=192,channels=2}:duplicate{dst=std{access=file,mux=ts,dst="test.ts"}}

In the 'Tools' -> 'Messages' window I see 2 errors...

main error: Failed to create video filter2 'chain'
main error: Failed while trying to append 'chain' to filter chain

Am I missing something? Please submit a 'working' code sample for me to try.

[VLC_help]

For command-line usage, I think you need --filter crop before crop-geometry, so

Code: Select all

vlc file://"dump.ts" --filter crop --crop-geometry="320x480+10+10" :sout=#transcode{vcodec=mp2v,vb=1024,acodec=mp2a,ab=192,channels=2}:duplicate{dst=std{access=file,mux=ts,dst="test.ts"}}

EDIT:
I also found that croppadd might work
vfilter=croppadd{cropttop=20,cropbottom=30,paddleft=100}
so
transcode{vcodec=mp2v,vfilter=croppadd{cropttop=20,cropbottom=30,paddleft=100}}

[Tom_S]

Again, THANK YOU for your help! I finally was able to make it work!

I tried using the 'croppadd' filter before but couldn't figure out how to use it. Here is my final code:

Code: Select all

vlc file://"dump.ts" :sout=#transcode{vcodec=mp2v,vb=800,vfilter=croppadd{croptop=40,cropbottom=38,cropleft=56,cropright=47},width=320,height=240,acodec=mp2a,ab=192,channels=2}:duplicate{dst=std{access=file,mux=ts,dst="test.ts"}}

It works for both 'converting' files and 'streaming' (at least for me).

NOTE: I used the 'Show Extended Settings' -> 'Video Effects' -> 'Crop' window to figure out how many pixels to crop from the original video. It worked great!