Recording Tests using vMix 15.0.0.73 x64bit

I thought I would do some recording tests using the different codec's in vMix, I have had some bad and good results. Each test was around 6 minutes long using 1 camera a virtual set and 2 MP4 videos.


PC specks:
MOBO: Asus P6X58D-E
CPU: Processor Intel Core i7 950 @ 3.07GHz, 3068 Mhz, 4 Core(s), 8 Logical Processor(s)
RAM: Patriot 8GB 1600MHz DDR3 X2 = 16GB
GPU: Asus NVIDIA GeForce GTX 760 2GB GDDR5 256Bit
BlackMagic Design Intensity Pro PCIe card
YUAN SC510N4-HDMI Capture card 4-Channel HDMI
PSU: EZ Cool PS-1000 800W Infinity
AUDIO: Behringer X32 Producer X-USB card
HD: 1 x 1TB, 1 X 2TB

Hardware Used:
Blackmagic Design ATEM Television Studio
Behringer X32 Producer
MacBook Pro Retina

Setup in vMix:
Input 1 is 1 Camera 1920X1080-50i input into a virtual set with a screen in the background with the shows ident in it.
Input 2 has the same 1 Camera 1920X1080-50i input into the same virtual set with a screen in the background, this time the screen in the background has a video in it.
Input 4 and 5 has videos.
Input 6 has a title with the presenters name.

vMix setup for recording a show:
External Output going to the Intensity Pro card that comes out via a HDMI cable to a ATEM TVS input and then comes out to the Macbook Pro Retina via the USB cable and is recorded using BlackMagic Media Express.
Fullscreen output is also used too goto a monitor for the presenter.

For recording via vMix I am recording to a 2TB 7500 speed Hard Drive (note this is not my C: drive).

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Before I start the show:
1. I press the Fullscreen button.
2. I press the record button in vmix, then I start recording on the Macbook.

This is what I did when recording with different formats:
I would fade from black to the presenter, the presenter would introduce the video, I switch from input 1 too input 2 and the video starts playing, then I zoom into show the video in full screen, once the video is finished playing I fade back to input 1 with the presenter, he talks about the next video while I load the next video into input 2 screen then I fade to input 2 and zoom to full screen and so on.
Sometimes I would insert the title with the presenters name.

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Problems with recordings and getting dropped frames

RECORDING TESTS WITH DIFERENT FORMATS

Test 1 recording MPEG-2
size: 1920X1080, frame rate: PAL 50i, bit rate: 28Mbps, file format: TS + Audio box ticked.
Record New File Every: 5 Minutes.
No dropped frames on recording via vMix and the video is very smooth, no dropped frames on recording via the Intensity Pro card via the ATEM TVS to my Macbook, the MAX CPU reading is about 22% in vmix.

Test 2 recording MP4
size: 1920X1080, frame rate: PAL 50i, bit rate: 28Mbps + Use Hardware Encoder + Audio box ticked.
Record New File Every: 5 Minutes.
Dropped frames on recording via vMix, jumpy video, and dropped frames on recording via the Intensity Pro card via the ATEM TVS to my Macbook, jumpy video, the MAX CPU reading is about 85% in vmix.

Test 3 recording AVI
size: 1920X1080, frame rate: PAL 50i, bit rate: 28Mbps, Codec: GoPro CineForm Codec (x64) v9.0.5 + Audio box ticked.
Record New File Every: 5 Minutes.
Dropped frames on recording via vMix and the video is jumpy, no dropped frames on recording via the Intensity Pro card via the ATEM TVS to my Macbook, the MAX CPU reading is about 30% in vmix.

Test 4 recording AVI
size: 1920X1080, frame rate: PAL 50i, bit rate: 28Mbps, Codec: Magic YUV lossless video codec v 1.0 (64bit) + Audio box ticked.
Record New File Every: 5 Minutes.
No dropped frames on recording via vMix and the video is very smooth, no dropped frames on recording via the Intensity Pro card via the ATEM TVS to my Macbook, the MAX CPU reading is about 20% in vmix.

Test 5 recording AVI
size: 1920X1080, frame rate: PAL 50i, bit rate: 28Mbps, Codec: YUV 4:2:2 Uncompressed + Audio box ticked.
Record New File Every: 5 Minutes.
No dropped frames on recording via vMix and the video is very smooth, no dropped frames on recording via the Intensity Pro card via the ATEM TVS to my Macbook, the MAX CPU reading is about 12% in vmix. But the recorded video files were very, very big for 6 minutes.

In conclusion all video codec's worked very well except for the AVI GoPro CineForm Codec (x64) v9.0.5 and MP4 codec it had dropped frames, was very jumpy and high CPU readings. All Codec's were in there original format, no changes made to them.

This one is for Martin, could you in the next version of vMix add a bar or timings to show how far a video has progressed on a video input, this would be very useful as there is no way of knowing when a video is going to finish when you are setting up your next shot in the preview window, this way you can look down to the video input to see how it is progressing. it would be like when you right click on a video input and see the show/hide playback speed.

See below a screen capture of my setup in vMix.

Hi J,

I think the person to answer that question would be Martin.

Perhaps because we never use such high bit rates for mp4 recordings, we have never had those problems you describe.

It would be helpful if Martin could clarify what "Use Hardware Encoder" in the settings for Recording mp4 implies. This feature is not documented in the vMix documentation. The Help states "Due to the complexity of H264 compression, this option requires a faster processor for optimal performance". But what that means if the CPU has built in video encoding support or not is unclear.

Slightly off topic, but related, are similar questions for streaming (which is mp4). And how things like CUDA, NVENC, and graphics cards hardware encoder come into play...

Hi Guys,

MP4 recording in vMix takes advantage of the Media Foundation encoder installed as a part of Windows.

Under Windows 7 this tends to use a lot of CPU and is not recommended for 1080 recordings.
Microsoft has substantially improved the CPU efficiency of this in Windows 8.1 so you can reliable record 1080p MP4s with less than
30% CPU usage on a modern quad core i7 processor.

Microsoft provides the option for graphics card makers to replace the software encoder with a hardware encoder option.
This is what the "Use Hardware Encoder" checkbox activates.
At the moment only Intel supports this option, so unless you are using Intel graphics as the primary
graphics in the system, this checkbox will have no effect.

In summary:

* MP4 recording under Windows 8.1 uses significantly less CPU than Windows 7. Upgrading is recommended.
* Hardware acceleration is only available on Intel Graphics where it is connected to the primary monitor.

Regards,

Martin
vMix