logo or Marquee text: do I need to transcode?

About encoding, codec settings, muxers and filter usage
maitrepiet
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logo or Marquee text: do I need to transcode?

Postby maitrepiet » 17 Jan 2010 20:26

Hi there,
here's what I would like to do:
capture a live stream from my DV camera (it's mpeg2 full HD), dynamically add some text or logo to it, and record to file.
here's what I tried
vlc.exe dshow:// --dshow-vdev="Sony HDR-HC5E" --dshow-adev=none --sout-keep --sout "#transcode{vcodec=mp2v,sfilter=marq{marquee='Railway Station',position=10}}:std{access=file,dst=C:\Users\Piet\vlc-1.1.0-git\video.mpg }"

Allthough it more or less works, the quality is not acceptable.

Basically, I don't want to transcode, I just want to add the text. Also, since I'm only recording small fragments, the resulting size of the file is also not that important. So Fixed bit-rate would be OK.

However, I have no clue how to tell vlc to do this.

IS transcoding really needed to add text or images?

Rémi Denis-Courmont
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Re: logo or Marquee text: do I need to transcode?

Postby Rémi Denis-Courmont » 17 Jan 2010 21:12

If you want to modify the picture, you have to transcode. There is no way around it, at least not with current VLC versions.
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maitrepiet
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Logo crashing VLC

Postby maitrepiet » 24 Jan 2010 20:43

Hi,
I succeeded in recording an input video stream and dynamically add logo's to the recorded output.

So far so good.

However, when I try to position the logo at the upper right corner, it is positioned somewhere slightly right from center, as if VLC does not correctly recognize the resolution of the stream.
When I increase the horizontal size of my logo to 750 pixels, VLC simply crashes.

The input video stream is High Def DV (1440 x1080)

I start vlc with:
vlc.exe --extraintf oldrc --rc-host 127.0.0.1:12345 --logo-file rood.png dshow:// --dshow-vdev="Sony HDR-HC5E" --dshow-adev=none --sout "#transcode{vcodec=mp2v,vb=12000,sfilter=logo}:std{access=file,mux=ps,dst=C:\Users\Piet\vlc-1.1.0-git\video.mpg }"

Any idea what is causing this, and how I can solve it.
I have compiled the latest branch I get with GIT.

Piet

jahanzeb
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Re: logo or Marquee text: do I need to transcode?

Postby jahanzeb » 04 Apr 2012 06:34

If you want to modify the picture, you have to transcode. There is no way around it, at least not with current VLC versions.
I wanted to know if this has become possible in the latest version of VLC 2.X. I want to display Marquee on my sout streams withought transcoding.

Rémi Denis-Courmont
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Re: logo or Marquee text: do I need to transcode?

Postby Rémi Denis-Courmont » 04 Apr 2012 07:51

I don't think it's even logically possible to do marquee without decoding.
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jahanzeb
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Re: logo or Marquee text: do I need to transcode?

Postby jahanzeb » 04 Apr 2012 08:28

I am able to add logo and marquee on the display withought transcoding. So thats why I was wondering if same thing is possible with sout.

Code: Select all

cvlc --sub-filter "logo{file=logo.png,position=6,y=40}:marq{marquee=%H:%M:%S,position=5}" Movie.mp4

Rémi Denis-Courmont
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Re: logo or Marquee text: do I need to transcode?

Postby Rémi Denis-Courmont » 04 Apr 2012 08:40

You do realize that you have to decode before you can show video locally, don't you?
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jahanzeb
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Re: logo or Marquee text: do I need to transcode?

Postby jahanzeb » 04 Apr 2012 09:31

Sorry for my lack of understanding in this area. I do know that video needs to be decoded before displaying. From you answer I gather that overlay of image or text is only possible on a decoded video.


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