[FFmpeg-devel] DVB Subtitles - "Hard Subtitles"

JULIAN GARDNER joolzg at btinternet.com
Tue Apr 19 00:08:32 CEST 2011



--- On Mon, 18/4/11, Stefano Sabatini <stefano.sabatini-lala at poste.it> wrote:

> From: Stefano Sabatini <stefano.sabatini-lala at poste.it>
> Subject: Re: [FFmpeg-devel] DVB Subtitles - "Hard Subtitles"
> To: "FFmpeg development discussions and patches" <ffmpeg-devel at ffmpeg.org>
> Date: Monday, 18 April, 2011, 21:58
> On date Monday 2011-04-18 21:48:10
> +0100, JULIAN GARDNER encoded:
> > --- On Thu, 14/4/11, JULIAN GARDNER <joolzg at btinternet.com>
> wrote:
> > 
> > > From: JULIAN GARDNER <joolzg at btinternet.com>
> > > Subject: Re: [FFmpeg-devel] DVB Subtitles - "Hard
> Subtitles"
> > > To: "FFmpeg development discussions and patches"
> <ffmpeg-devel at ffmpeg.org>
> > > Date: Thursday, 14 April, 2011, 9:27
> > 
> > Following on from the suggestion to use a filter I
> have a question if anyone can help.
> > 
> > In my test im looking at the drawbox filter as a
> refernece but ive got this problem.
> > 
> > ffmpeg -i test.ts -vf drawbox:10:10:710:100:red -f
> mpegts -y a.ts
> > 
> > Works as it should
> > 
> > ffmpeg -i test.ts -vf drawbox:10:10:710:100:red -s
> 352x288 -f mpegts -y a.ts
> > 
> > Works but the box is drawn off screen, so my question
> is
> > 
> 
> > 1. How do i get the filter to work BEFORE the resize?
> is there a filter that does this?
> 
> -s WxH will cause ffmpeg to apply a scale filter *at the
> begin* of the
> filterchain, so before the drawbox filter is applied.
> 
> So what you want is:
> -vf drawbox:10:10:710:100:red,scale=352:288
> 
> and you don't have to specify the -s option.
> 
> BTW this list is for FFmpeg development, user questions
> should be
> posted to ffmpeg-user.
> -- 
> FFmpeg = Free & F*c*ing Majestic Power Enhanced
> Generator
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> 

So the fact that i am trying to develop code, the -devel list is not applicable but the -user list is? dont understand the logic.

As i said before i am trying to draw on the raw video frame BEFORE scaling as i want to keep the subtitles int the correct position and size, and I dont want to have to scale the subtitles before drawing onto the screen, seems silly to have 2 scalings going on.

If this is the wrong list, im sorry and i wont bother you again

joolz



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