[FFmpeg-user] Decklink Capture

[Reuben Martin]

On Thursday, March 12, 2015 08:01:04 PM Dave Rice wrote:
> > On Mar 12, 2015, at 7:30 PM, Reuben Martin <reuben.m at gmail.com> wrote:
> > 
> > On Wednesday, March 11, 2015 06:43:11 PM you wrote:
> >> On Wednesday, March 11, 2015 07:19:14 PM Dave Rice wrote:
> >>>> I’ve used bmdtools and piped it to ffmpeg for quite a while, and they
> >>>> work
> >>>> fine. I’m just curious about trying to access it directly.
> >>> 
> >>> Same here, though I still use bmdtools. I'm curious how you compare the
> >>> two.
> >> 
> >> I’m hoping less overhead due to the elimination of all the memory copy
> >> going on with the pipe. I won’t be able to test till tomorrow.
> > 
> > It did minor testing today and didn’t notice anything abnormal aside from
> > ffplay complaining quite verbosely about buffer overruns when opening
> > directly with ffplay.
> 
> Try -re before the input.

-re doesn’t apply to ffplay. 
 
> > Otherwise, there is a small reduction in overhead, and the video
> > is smoother when reducing the output framerate to half that of the input.
> > (60 to 30 in my case)

And by smoother, I just mean that discarding every other frame seems to flow 
smoother on the playback. I think there may be something different going on 
with how the timestamps on frames work when pulling directly from source as 
opposed to a pipe. But then again the perceived difference is subtle, so it may 
just be placebo effect.

> 
> What OS are you using?

Gentoo