From f8f5cce977bc327604b1d3185875cbc956b55909 Mon Sep 17 00:00:00 2001 From: "Steinar H. Gunderson" Date: Tue, 8 Nov 2016 09:36:52 +0100 Subject: [PATCH] Clarify a bit about the digital intermediate. --- hardware.rst | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/hardware.rst b/hardware.rst index d116734..9d6af9d 100644 --- a/hardware.rst +++ b/hardware.rst @@ -39,7 +39,7 @@ output as a sort of “digital intermediate” that can much easier be stored to (for future editing or re-streaming) or sent to an encoder on another machine for final streaming. -Currently, only VA-API is supported for H.264 encoding, although Nageru might +Currently, only VA-API is supported for encoding the digital intermediate, although Nageru might support NVIDIA's NVENC at some point in the future. In particular, this means that Intel Quick Sync Video (QSV), the hardware H.264 encoder present on all modern Intel GPUs, is supported. QSV is more than fast enough to keep up with 720p60 in @@ -52,13 +52,14 @@ constant bitrate, which means the bitrate will vary strongly with content. further editing or transcoding without strong generational loss.) Thus, the QSV stream is not intended for streaming to end users of the Internet; it will need to be reencoded by some external means, or you can use Nageru's x264 -support (see `:doc:Streaming`). +support to produce a user-facing stream in addition to the digital intermediate +(see :doc:`streaming`). By default, Nageru uses zerocopy from the GPU to the VA-API buffers in order to reduce memory transfer bandwidth, but this depends on EGL support (as opposed to the older GLX standard), and also that the GPU you are rendering to also supports VA-API. NVIDIA's proprietary drivers do not support either. Unfortunately, -this is somewhat cumbersoe to automatically detect before it's too late to do anything +this is somewhat cumbersome to automatically detect before it's too late to do anything about it (Qt has already initialized using EGL), so on NVIDIA systems, Nageru will exit with an error message asking you to set *--va-display* to your Intel GPU manually. Simply follow the instructions printed to the terminal -- 2.39.2