Also renames related CMake variables to match both the Find*FFmpeg* and
variables defined within the file. Fixes odd errors produced by the old
FindFFmpeg.
Citra's FindFFmpeg is slightly modified here: adds Citra's copyright at
the beginning, renames FFmpeg_INCLUDES to FFmpeg_INCLUDE_DIR, disables a
few components in _FFmpeg_ALL_COMPONENTS, and adds the missing avutil
component to the comment above.
This commit aims to implement the NVDEC (Nvidia Decoder) functionality, with video frame decoding being handled by the FFmpeg library.
The process begins with Ioctl commands being sent to the NVDEC and VIC (Video Image Composer) emulated devices. These allocate the necessary GPU buffers for the frame data, along with providing information on the incoming video data. A Submit command then signals the GPU to process and decode the frame data.
To decode the frame, the respective codec's header must be manually composed from the information provided by NVDEC, then sent with the raw frame data to the ffmpeg library.
Currently, H264 and VP9 are supported, with VP9 having some minor artifacting issues related mainly to the reference frame composition in its uncompressed header.
Async GPU is not properly implemented at the moment.
Co-Authored-By: David <25727384+ogniK5377@users.noreply.github.com>
