[FFmpeg-user] RES: A question on the Quadro P6000 and maximum simultaneous NVENC encodes in FFmpeg

[Dennis Mungai]

So, to clarify:

If you were to disable hwaccel decode (and rely solely on software-based
decoding) BUT utilize NVENC on a system with a beefy processor and adequate
RAM, you should be able to eliminate the bottleneck, correct?

Because what you're implying (by the bottleneck at decode side) would be a
limitation in how FFmpeg handles filter performance (hwupload, to be
exact), an issue that can be circumvented by eliminating hwaccel in decode.



On Fri, 24 Aug 2018 at 00:57, Yang Zhang <yzfedora at gmail.com> wrote:

> The problem is even you using the Tesla P100, and you can see it has 3
> NVENC chips inside it. but it has only 1 NVDEC chip, this is very very
> important. the bottleneck is at decoding side. this is why you got freezing
> or stutter problem. basically, perhaps you can use Tesla P100 encoding 75
> hd1080p channels, but you can not decoding more than 25 hd1080p channels on
> it.
>
> On Fri, Aug 24, 2018 at 5:51 AM Dennis Mungai <dmngaie at gmail.com> wrote:
>
> > No.
> >
> > This is as tested on the Tesla P100.
> >
> > On Fri, 24 Aug 2018 at 00:26, Pedro Daniel Costa <
> > portalnet2 at outlook.com.br>
> > wrote:
> >
> > > Ok
> > >
> > > But with the TESLA models, did you have any issues over 40 streams?
> > >
> > > I am planning on budge project to run minimum 100channels
> > >
> > > -----Mensagem original-----
> > > De: ffmpeg-user [mailto:ffmpeg-user-bounces at ffmpeg.org] Em nome de
> > Dennis
> > > Mungai
> > > Enviada em: quinta-feira, 23 de agosto de 2018 13:54
> > > Para: FFmpeg user questions
> > > Assunto: [FFmpeg-user] A question on the Quadro P6000 and maximum
> > > simultaneous NVENC encodes in FFmpeg
> > >
> > > Hello there,
> > >
> > > For users with this specific card (and FFmpeg installed), kindly
> clarify
> > > on the following:
> > >
> > > (a). How many simultaneous encoder sessions can you run on this card?
> > >
> > > (b). Have you ran into any issues, such as stuttering and dropping
> > streams
> > > with multiple concurrent encodes?
> > >
> > > I ask because of a recent case where adding more than ~40 concurrent
> > > encodes would make the output "drop" and stutter massively, as if
> FFmpeg
> > > itself was hanging, despite the GPU having more than enough VRAM
> (24GB?)
> > > and resources (under ~11% utilization according to nvidia-smi),
> implying
> > > some sort of artificial limitation in effect despite the GPU support
> > matrix
> > > specifying otherwise:
> > > https://developer.nvidia.com/video-encode-decode-gpu-support-matrix
> > >
> > > Your feedback on this is appreciated.
> > > _______________________________________________
> > > ffmpeg-user mailing list
> > > ffmpeg-user at ffmpeg.org
> > > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> > >
> > > To unsubscribe, visit link above, or email
> > ffmpeg-user-request at ffmpeg.org
> > > with subject "unsubscribe".
> > > _______________________________________________
> > > ffmpeg-user mailing list
> > > ffmpeg-user at ffmpeg.org
> > > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> > >
> > > To unsubscribe, visit link above, or email
> > > ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
> > _______________________________________________
> > ffmpeg-user mailing list
> > ffmpeg-user at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
> To unsubscribe, visit link above, or email
> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".