[FFmpeg-user] Decklink input buffer overrun

[Ricardo Kleemann]

On Wed, Sep 23, 2015 at 12:47 PM, Flávio Pontes <flaviocpontes at gmail.com>
wrote:

> Hi,
>
> I need to stream the 2 inputs from a DeckLink Duo card in FHD.
> So far I could compile ffmpeg with decklink support and capture one input
> at a time without problems.
>
> When I try to capture from the 2 inputs I start getting the following
> message repeatedly on both terminals:
> [decklink @ 0x32287e0] Decklink input buffer overrun!
>
> I use these commands in the terminals:
>
> /opt/ffmpeg_build/bin/ffmpeg -f decklink -re -i 'DeckLink SDI (1)@7' -g 90
> -s hd1080 -profile:v baseline -pix_fmt yuv420p -preset veryfast -c:v
> libx264 -b:v 2000k -bufsize 1400k -minrate 2000k -maxrate 2000k -c:a
> libfdk_aac -b:a 96k -threads 4 -f flv rtmp://10.12.20.62/myapp/tvines
>
> /opt/ffmpeg_build/bin/ffmpeg -f decklink -re -i 'DeckLink SDI (2)@7' -g 90
> -s hd1080 -profile:v baseline -pix_fmt yuv420p -preset veryfast -c:v
> libx264 -b:v 2000k -bufsize 1400k -minrate 2000k -maxrate 2000k -c:a
> libfdk_aac -b:a 96k -threads 4 -f flv rtmp://10.12.20.62/myapp/tvescola
>
> I tried many combinations but couldn't get it to work.
> I wonder if the input buffer is shared between the 2 inputs.
> Is there any way to set an input buffer size independently for each
> command?
>
> Thx in advance!
> Flávio.
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Hi Flávio,

I'm not sure if this directly addresses your problem, but have you tried
using the -thread_queue_size parameter? I believe having a deeper queue
might help, the default value is only 8. I've used much larger values, even
2048 for example.

Granted, I think 2048 is overkill but I don't see any problem in setting up
larger queues.

Ricardo