Hi all.
Here are my experiences and observations of vMix behavoir. Hope it serves someone.
We have installed vMix on a i7-4770K system with an Asrock extreme9/ac M/B charged with 32Gb-2400 RAM, and a RAID-0 SSHD 4x250Mbps 2Tb. disks, a MINE HD400 FullHD HDMI acquisition card (http://www.mine.com.cn/en/acquisition-card.asp?classid=140), and a GTX-580 nVidia graphics card. It's configured with integrated video as primary graphics card and iGPU and multimonitor activated. We have three 1080p monitors attached. 2 on GTX outputs and one on the iGPU output. The computer boots on this last.
When in windows, that is monitor #1, the first connected to the GTX becomes #2 (that is selected as main) and the second conected becomes #3. Curiosly, in the configuration of vMix, i can see 4 monitors, where #1 is inexistent (may be the second integrated iGPU output?), the #2 coresponds to windows #1, the #3 is the windows #2 and so...
On the vMix configuration, I select 1080p25, PAL settings, widescreen (why I must choose that if 1080p ever implies 16:9?, IMHO, it should be by default)
I allways get note of the ms when it has been stabilished, after 30 seconds
If I open vMix on the monitor attached to GTX, 4ms
If I open vMix on the monitor attached to iGPU, 0ms
After I opened vMix on GTX I import a preconfigured config, restarted, and then i get also 0-1ms on the GTX
I want to have:
- A full screen with mutiview, as studio-plató return monitor.
- A 1080p25 record (.ts, or better .mp4)
- As vMix cannot stream at same time that records, I need a external output to be captured from VLC to stream in http to have a on-air output via another PC
When I open a first camera, 0-1ms
When open a second camera (from the same driver), 15-18ms
When open a third camera, 15-18ms
When open the fourth camera , 0-1ms (here I get crazy)
Then I close the last camera, 0-1ms
Then I close the third camera, 0-1ms
Then I open the third camera, 0-1ms
Then I open the fourth camera, 0-1ms
When I open the fifth and sixth cameras from a cheap USB capture device, I get also 0-1ms
When I open the seventh camera from Creative C920 FullHD camera, I get 22-24ms
When I open the eighth camera, also a C920, I get also 22-44ms
Disperated, I closed the two last cameras.
If I open the fullscreen monitor, setted as monitor 3 (the second attched to GTX), it remains instable, 2-3 seconds at 15-17ms, and then one second over 30-33ms.
With fullscreen opened, if I close the three last cameras, 0-1ms, If then I open a second camera, same instable behavoir.
If I set the fullscreen (output, preview or multiview monitor) to the monitor 2 (the attached to iGPU), then the numbers are worse, 2-3 seconds at 22-24ms, and then one second over 38-40ms
If I set the dual oputput display, the situation becomes even worse, 2-3 seconds at 37-41ms, and then 1 seconds at 51-56ms
When I set off the fullscreen, it returns to 0-1ms
If then I init the recording, setted as MPEG2 .ts (16Mbps), 2-3ms (I found that If I set it to mp4, the CPU comes to 35-45%, but is a non fault tolerant recording)
If I stop recording, 0-1ms
If I init external output, 2-3ms
If then I init simultaneously recording and external output (virtual camera), 2-3ms, may be 5-7ms every 3 seconds...
Then, I closed recording and external output and added a ticker to the preset. When played, I get 2-4ms
Then, I activate recording and external output. I get 2-4ms, but with some irregular instability, that gets over 7ms not too often...
Then, I open a mp4 video. Just when I opened the video, I get 12ms, then it returns to 2-4ms. When playing the video, the first tick is also 12ms, then it goes to 3-6ms
Then, I open a XML animated title. I see no impact when configuring it to be launched on mouse click action over overlay 2, wich is configured to a duration of 4000ms. This way, I can dispose the titles in minimal (collapsed) fingertip.
Then, I opened a ticker, where I configure the crew (camera operators, editors, reporters, sound, musics, lights, presentator...). When playing, I also see no impact.
My preset contains the 4 FullHD cameras from the same driver, 2 C920 FullHD USB cameras, 2 USB Conexant capture device (PAL video 720x576 coming from cheap wireless conections), the live sound input (from Realtech HD microphone, with very low level, only 5, and no boost, as it comes from a old Yamaha 01v mixer) 1 presentation video, 1 transition video, 6 videos ready to play, 3 static images (jpg), 3 composed scenes (from three-four live sources plus 1 video and 1 image), 1 final video, 6 animated titles, and a ticker (where is presented the crew). The presentation video trigger the start of record and chains to the first video, then we play with the videos, the 8 live inputs and the compositions and titles, as needed. The final video triggers the ticker and stops the recording. The external output is also needed for on-air shows.
Observations:
- As it's a unexpected behavoir when opening vMix until you load a configuration file (4ms vs. 0-1ms), the session must begin loading a config file and resetting.
- As it's a unexpected behavoir with fullscreen output, worse when setting the output to a screen connected to different graphics card, that manifests only when I have more than one video cameras from the same drive, but not all of them, all cameras must be opened. I also noted some strange behavoir when playing a ticker or some animated title, so I prefer to set the dual output and gets multiview on secondary monitor playing a simple VLC capture configuration. So, I have a VLC ionstance with http streaming over vMix stabdar output and a second VLC instance with vMix Video External 2 output.
- As it's a unexpected behavoir when triggering a record from a TransitionIn event of a video player, as the firsts frames recorded comes from the program (whatever it contains) prior to cut, not from the video itself, a full black input should be configured to be on the program window prior to begin the show.
