Hardware accelerated decoding generally uses AVHWFramesContext for pool
allocation of hardware surfaces. These are setup to allocate surfaces
aligned to hardware and hwaccel API requirements. Due to the
architecture, av_hwframe_get_buffer() will return AVFrames with
the dimensions set to the aligned sizes.
This causes some decoders (like hevc) return these aligned size as
final frame size, instead of cropping them to the video's actual
dimensions. To make sure this doesn't happen, crop the frame to the
size the decoder expects when ff_get_buffer() is called.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
So a hwaccel can access avctx->hwaccel in init for whatever reason. This
is for the new d3d hwaccel API. We could create separate entrypoints for
each of the 3 hwaccel types (dxva2, d3d11va, new d3d11va), but this
seems nicer.
Signed-off-by: Diego Biurrun <diego@biurrun.de>
Currently, the new decoding API is pretty much just a wrapper around the
old deprecated one. This is problematic, since it interferes with making
full use of the flexibility added by the new API. The old API should
also be removed at some future point.
Reorganize the code so that the new send_packet/receive_frame functions
call the actual decoding directly and change the old deprecated
avcodec_decode_* functions into wrappers around the new API.
The new internal API for decoders is now changing as well. Before this
commit, it mirrors the public API, so the decoders need to implement
send_packet() and receive_frame() callbacks. This turns out to require
awkward constructs in both the decoders and the generic code. After this
commit, the decoders only implement the receive_frame() callback and
call a new internal function, ff_decode_get_packet() to obtain input
data, in the same manner to how the bitstream filters now work.
avcodec will now always make a reference to the input packet, which means
that non-refcounted input packets will be copied. Keeping the previous
behaviour, where this copy could sometimes be avoided, would make the
code significantly more complex and fragile for only dubious gains,
since packets are typically small and everyone who cares about
performance should use refcounted packets anyway.
The current code stores a pointer to the packet passed to the decoder,
which is then used during get_buffer() for timestamps and side data
passthrough. However, since this is a pointer to user data which we do
not own, storing it is potentially dangerous. It is also ill defined for
the new decoding API with split input/output.
Fix this problem by making an explicit internally owned copy of the
packet properties.
Anton Khirnov
wm4
Vittorio Giovara