Use explicit nvenc capability checks instead to determine usable devices
instead of SM versions.
Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>
There is no point in separate structures as they have 1:1 relationship,
they are always used together and they have same lifetime.
Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>
Functions names and scopes are from libav. This commit basically moves
code around without changing it; it shouldn't change any functionality
except some small leak fixes on error paths.
Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>
For reasons we are not privy to, nvidia decided that the nvenc encoder
should apply aspect ratio compensation to 'DVD like' content, assuming that
the content is not BT.601 compliant, but needs to be BT.601 compliant. In
this context, that means that they make the following, questionable,
assumptions:
1) If the input dimensions are 720x480 or 720x576, assume the content has
an active area of 704x480 or 704x576.
2) Assume that whatever the input sample aspect ratio is, it does not account
for the difference between 'physical' and 'active' dimensions.
From these assumptions, they then conclude that they can 'help', by adjusting
the sample aspect ratio by a factor of 45/44. And indeed, if you wanted to
display only the 704 wide active area with the same aspect ratio as the full
720 wide image - this would be the correct adjustment factor, but what if you
don't? And more importantly, what if you're used to lavc not making this kind
of adjustment at encode time - because none of the other encoders do this!
And, what if you had already accounted for BT.601 and your input had the
correct attributes? Well, it's going to apply the compensation anyway!
So, if you take some content, and feed it through nvenc repeatedly, it
will keep scaling the aspect ratio every time, stretching your video out
more and more and more.
So, clearly, regardless of whether you want to apply bt.601 aspect ratio
adjustments or not, this is not the way to do it. With any other lavc
encoder, you would do it as part of defining your input parameters or do
the adjustment at playback time, and there's no reason by nvenc should
be any different.
This change adds some logic to undo the compensation that nvenc would
otherwise do.
nvidia engineers have told us that they will work to make this
compensation mechanism optional in a future release of the nvenc
SDK. At that point, we can adapt accordingly.
Signed-off-by: Philip Langdale <philipl@overt.org>
Reviewed-by: Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
The code needs only a few definitions from cuda.h, so define them
directly when CUDA is not enabled. CUDA is still required for accepting
HW frames as input.
Based on the code by Timo Rothenpieler <timo@rothenpieler.org>.
For some unknown reason enabling these causes proper CBR padding,
so as there are no known downsides just always enable them in CBR mode.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
When there is a non-zero decoding delay due to reordering, the first dts
should be lower than the first pts (since the first packet fed to the
decoder does not produce any output).
Use the same scheme used in mpegvideo_enc (which comes from x264
originally) -- wait for first two timestamps and extrapolate linearly to
the past to produce the first dts value.
Timo Rothenpieler
Andrey Turkin
Anton Khirnov
Philip Langdale
Vittorio Giovara
Lucas Cooper
Agatha Hu