About the pain of 4K60P. .

Hey, everyone:
I am still happy during this time that Adobe can generate ProRes in Windows. . . . .
However, I have tried many versions of CasparCG, and it seems that the video with Alpha Channel is not smooth when playing in 4K60P environment. Although the configuration of the computer is already very high, is it a coding problem?
My configuration:
Motherboard: ASRock Z390 ITX
Memory: DDR4 2666 16G *2
Graphics Card: NVIDIA Quadro P4000 8GB
IO card: Decklink 8k pro
CPU: Intel 8700K
Plus a curious and passionate heart.
Oh, yes, video file I tried prores444 and QuickTime Animation.

Can you make sure, that the Decklink 8K gets the 8 PCIe lanes, that it needs to perform well? For instance SiSoftware Sandra is able to show the PCIe configuration and how much lanes are assigned to the different devices. There is also a free version.

I’m sure 8KPRO works fine in M2’s PCI-E 4Xgen3, because I used the VMIX test to broadcast the 4K60P FILL+KEY. I played the same on the P5000+E5 of the X299, and it was not smooth. very much. . . . . .
In fact, I think it is not good enough for the hardware decoding support of the 4K60P on the server side?
I want to know if someone has successfully applied 4K60P?

AFAIK it should have a 8x slot…

CasparCG uses the CPU to decode video (FFMPEG) so that could be a reason why it does not work ok. Can you play the same files with VLC player smoothly?

I have consulted BMD about PCI-E. They said that 8K PRO uses 8X gen3 because there is Quad LINK 12G-SDI. If only FILL+KEY is used, it is 12GX2=24G and M2 is PCI-e 4x gen3. 40GB of bandwidth is sufficient.

I can’t broadcast it with VLC. But with Premiere it is possible to play. Vmix is also possible.

The question was not, if you could broadcast with VLC, but simply play these videos on the desktop with it. VLC also uses FFMPEG. If it does not play smoothly with VLC it will not with Caspar also.


ProRes is one of the worst formats you can use in regards to performance, it is a struggle for any CPU to unpack each frame.
ProRes is made mainly for postproduction not real-time.


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2.2.0-stable-windows version
ProRes can play smoothly in Premiere, isn’t it?
However, it is very bad that I play in the CasparCG Server using the QuickTime Animation format.

That is possible. But please understand that Premiere uses it’s own play-out engine, that has nothing to do with Caspar’s engine. Caspar uses FFMPEG and that is the same engine that VLC player uses. So, if you can play a file in VLC smoothly chances are high, that Caspar can play it.

Yes, QuickTime Animation is also available.

What do you mean? Do you understand what I am talking about?

Both the QuickTime Animation format and the QuickTime ProRes format can be played smoothly in Premiere.

Can you just read and try to understand? What is your native language and how long did you learned English?

Thank you very much didikunz, you are very patient to explain to me.
I understand what you mean, this is limited by the decoding ability of FFMPEG.
I am just curious, why Premiere can, and FFMPEG does not work.
In the near future, we all need 4K60P, isn’t it?

That future is not so near. I think in Europe it will take quite a while until a broad start of 4K50P will happen. Probably the high end sports production will use this format, but it will take a few years until all TV stations will go 4K, Some smaller stations here in Switzerland just finished going from SD to HD.

As i said, Premiere has a completely different output pipeline, so this discussion is useless. Caspar will be ready for 4K50/60p when it is needed, I am quite sure.

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Yes, I agree with you and hope that this day will come soon.
But it seems that right now I have to study FFMPEG,
See if FFMPEG supports GPU decoding like OBS supports NVENC.H264

By the way, my live streaming is 4K60P50Mbps with OBS+NVENC.H264, which is really great. I hope FFMPEG and CasparCG also have this day.

Feel free to contribute to FFMPEG’s codebase, if you are a c++ programmer.

FFMPEG used in CasparCG 2.2

ffmpeg version 3.4.2 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7.3.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libmfx --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
  libpostproc    54.  7.100 / 54.  7.100

FFMPEG used in Caspar uses HW acceleration
FFMPEG supprts hardware-accelerated decoding of H.264, HEVC, VP9, VP8, MPEG2, and MPEG4

…so ProRes decoding is not HW accelerated in FFMPEG, but can be in other software like Premiere.

However, these formats do not have an alpha channel.
Maybe there is a better way for Caspar to smoothly play 4K60P video with Alpha channel?