The framework will allocate a buffer and copy the data to it,
that takes time. But it avoids constently creating and
destroyng the shared memory segment, and that saves more time.
On my setup,
from ~200 to ~300 FPS at full screen (1920×1200),
from ~1400 to ~3300 at smaller size (640×480),
similar to legacy x11grab and confirmed by others.
Plus, shared memory segments are a scarce resource,
allocating potentially many is a bad idea.
Note: if the application were to drop all references to the
buffer before the next call to av_read_frame(), then passing
the shared memory segment as a refcounted buffer would be
even more efficient, but it is hard to guarantee, and it does
not happen with the ffmpeg command-line tool. Using a small
number of preallocated buffers and resorting to a copy when
the pool is exhausted would be a solution to get the better
of both worlds.
When finding a video mode based on frame size and frame rate,
use AVRational methods instead of simple comparison. Add debug information.
Signed-off-by: Matthias Hunstock <atze@fem.tu-ilmenau.de>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Provide the stream with the correct fps information when capturing.
Signed-off-by: Matthias Hunstock <atze@fem.tu-ilmenau.de>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This patch also makes BlackMagic drivers v10.6.1 a hard requirement.
Reviewed-by: Deti Fliegl <deti@fliegl.de>
Signed-off-by: Marton Balint <cus@passwd.hu>
Not all v4l2 devices implement the VIDIOC_G_PARM ioctl. This patch allow
ffmpeg to open such device and treat it the same as devices that do
implement the ioctl but returns that it do not implement the
V4L2_CAP_TIMEPERFRAME capability.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Benoit Fouet <benoit.fouet@free.fr>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Split version files into one line per symbol/directive to allow compatibility
with the Solaris linker without preprocessing and eliminate $ from version file
templates to simplify the postprocessing shell command.
There are still a couple of deprecated calls that I’m not sure what to do with.
They are both related to some logic around AVCodecContext.coded_frame.
I couldn’t find anywhere that really documented what that was, or where it was intended to move to.
I left the warnings on.
Reviewed-by: Deti Fliegl <deti@fliegl.de>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Restore alphabetical order in lists, break overly long lines, do some
prettyprinting, add some explanatory section comments, group parts
together that belong together logically.
Nicolas George
Michael Niedermayer
Marton Balint
Josh de Kock
Carl Eugen Hoyos
Lukasz Marek
Roger Pack
Matthias Hunstock
Patrick Felt
Timothy Gu
James Almer
rogerdpack
Niklas Söderlund
Diego Biurrun
Rick Kern
Vittorio Giovara