[FFmpeg-devel] adding RGBA and BGRA to nvenc.c

Sven C. Dack sven.c.dack at sky.com
Thu Sep 8 17:52:48 EEST 2016

On 08/09/16 15:17, Andy Furniss wrote:
> Carl Eugen Hoyos wrote:
>> 2016-09-08 12:01 GMT+02:00 Andy Furniss <adf.lists at gmail.com>:
>>> I don't know what it is about x11grab/CSC with ffmpeg, but
>>> on my old CPU gstreamer is twice as fast.
>> x11grab or xcb?
> I guess xcb as I don't --enable anything related with configure.

In case it got mistaken...

The following is what gives the 100 fp/s (with a GTX 960):
$ ffmpeg -f x11grab -framerate 200 -s hd1080 -i :0.0 -c:v hevc_nvenc -y test.mkv

The mentioned 100 fp/s refers to the HEVS/H.265 hardware encoder (nvenc). 
X11grab is here only the input device.

Without the encoder does it give me 160 fp/s:
$ ffmpeg -f x11grab -s hd1080 -framerate 500 -i :0.0 -f null -

Different sizes then give different results:

- For hd720 is it 200 fp/s (with nvenc) and 420 fp/s (without nvenc).
- For hd480 is it 460 fp/s (with nvenc) and 890 fp/s (without nvenc).

Can you compare gstreamer to those numbers?

Is anyone also capable of running this in a true 4K display with a Pascal card? 
There the speed matters the most.


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