![]() The rate control mode for older release builds of FFmpeg configured with older release versions of ffnvcodec header packages only need the rate control option modified to constant bitrate via -rc:v vbr_hq. Depending on the specific version of FFmpeg built & the version of the ffnvcodec header package in use, ie either from a release version OR from git master, the following paramerers will need to change: See this answer on why these parameters were selected. However, the maximum bitrate and buffer size(s) remain set to match your settings in libx264. The bitrate is explicitly unset via -b:v 0 to comply with the constraints of the selected rate control mode in NVENC. For the rate control in use, I've selected variable bitrate mode (set via the private codec option -rc:v vbr) with constant quality parameter rate control set to a value of 21. ![]() Note that not all video formats are supported by NVDEC, and as such, a fallback to software-based decoding will be provided. These can be verified with Philip Langdale's nv-video-info project's nvdecinfo's program, as documented in this answer, if you're on Linux. Hardware acceleration support for specific codecs are platform and driver-dependent. For their usability, please see ffmpeg -h filter=scale_npp and ffmpeg -h filter=scale_cuda respectively. The availability of these filters depends on how FFmpeg was configured, as explained below. ![]() Scaling operations are done with either scale_npp OR scale_cuda, as these run purely on the GPU. On a multi-GPU system, select a valid GPU as listed by nvidia-smi. GPU selection with NVDEC hardware acceleration is toggled via the global option -hwaccel_device 0 and for the encoder, via h264_nvenc's private codec option -gpu 0. See this for more information on NVENC capabilities, including the hardware acceleration infrastructure available to FFmpeg on capable NVIDIA hardware. ![]() The default GPU selected for NVENC is 0, and that the GPU is NVENC capable. Try these commands with the following assumptions: ![]()
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