[FFmpeg-devel] Blackmagic DeckLink indev

JULIAN GARDNER joolzg at btinternet.com
Thu Mar 29 02:17:47 CEST 2012

> From: Kieran Kunhya <kierank at ob-encoder.com>
>To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org> 
>Sent: Thursday, 29 March 2012, 0:56
>Subject: Re: [FFmpeg-devel] Blackmagic DeckLink indev
>I think the frame drops are because of the way the card's api works. You
>only have (for PAL) 40ms to get everything done before the next frame.
>I believe with the current ffmpeg design, all the processing is done in the
>thread that the card returns frames using and so if for whatever reason
>encoding or scaling takes more than 40ms, you drop the frame.

Thats not the problem, its working fine on the 8 core machine with 1080i but on another 8 core machine with 720p it does not, also the code stores the frames in a buffer and these are read from a callback from the decklink API, no polling. I have also checked the cpu usage and none go above 1% when encoding

What is worrying me is the 0.06 fps in the status

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