Hey everyone, I am setting up a home studio to record training videos..
The goal: Record video and audio directly to the computer.
The Problem: When recording directly to the computer the video quality is much worse than when I record to a SD card and transfer the video.
Equipment I have:
Magewell capture card gen 2 and the USB 3.0 cable I have that came with it
Sony mirror less camera a6300
mini HDMI to HDMI (connects the camera to the capture card)
3 month old Alien Desk top, 32gigs of ram, NVIDIA Geforce GX 1080 display card
In summery: here is a link to a poor quality that is recorded directly to the computer and good quality video is from the SD card. https://drive.google.com/open?id=1qaFR5DYqB5RZnss864X-j-EwJc6LSVnF
What I cant figure out is why the big difference in quality in recordings. I have tried this same test with OBS and got the same thing. From what I understand the magewell shouldn't be the issue and I know my computer is not the issue.. What I am not familiar with is the more technical side of things such as settings that may be the cause and bit rates or maybe its the wires connecting it all? I dont know but I have spent a ton of time on this and need some help figuring this out so I can move on to the next step and get to creating.
+ Reply to Thread
Results 1 to 12 of 12
I suspect something in the encoding/capture software; there is an obvious frame rate problem -
not much movement in your video but you can clearly see some jerky sections as frames appear
to be dropped.
Have you checked the CPU utilization during capture? Is the software using HW acceleration
from the graphics card? If so, try turning it off
One thing that would explain the framerate drop: if you use the magewell - which has a usb 3.0 interface - with v2.0 port, it drops the available bitrate limit from 5Gbps to 480Mbps. Basically 1/10 of the capacity. Since that family of devices only supports a few kinds of stream, all of them uncompressed, what happens is your available framerate has to drop down to where the total bitrate can fit within that lower limit. This means dropping from 60p to 10 or 7 or 6p. Literally.
Recording uncompressed requires expensive hardware, and if your camcorder doesn't support uncompressed what happens is it compresses the video during shooting for storage on the media while decompressing it and outputting to HDMI, then the Magewell compresses the stream again and sends it over USB, Double loss which usually leads to incompatible framerates.
The poor quality recording looks to me like it was downscaled to standard definition interlaced video, output as composite vdieo, captured at SD resolution, deinterlaced somewhere along the way, then upscaled to HD resolution.
I dont really know what HW acceleration.. I an tell you that the Magewell does not come with and software and I can check into the vmix.. I also used OBS and the same thing has happened.. same bad quality that is..
as for the frame rate, this is a separate issue right? I can adjust the frame rate in the camera pretty easy.. I actually dont remember what this was shot on..
again Im pretty green with this kind of stuff though.
I would think not though..
ps loving this forum very helpful bunch!.
Magewell 32060 Specs
Host Interface USB 3.0, 300-350MB/s throughput
USB 2.0 40MB/s throughput
HDMI Input HDMI 1.4a standard, and support up to 1080p/60Hz 8-bit, (RGB, YUV)
Output Resolutions Resolutions: 640×480 / 720×480 / 720×576 / 768×576 / 800×600 / 1024×768 / 1280×720 / 1280×800 / 1280×960 / 1280×1024 / 1368×768 / 1440×900 / 1600×1200 / 1680×1050 / 1920×1080 / 1920×1200 / 640×360 / 856×480 / 960×540 / 1024×576
Frame-rate: 25/29.97/30/50/59.94/60 fps
Sampling Rate HDMI: 165 MHz
USB Standard Meets the standards of UVC (USB video class) and UAC（USB audio class）
Color Space YUY2, RGB24
Scaling Hardware based
Image Adjustment Brightness, contrast, hue, saturation
Operating System Windows 7 (x86 and x64 version)
Windows Server 2008 R2
Linux (Kernel version 2.6.38 and above)
OS X (10.8 and above)
Software Compatibility Windows Media Encoder (Windows) Adobe Flash Media Live Encoder(Windows, OS X) Real Producer Plus(Windows)
VLC (Windows, OS X, Linux)
QuickTime Broadcaster (OS X)
QuickTime Player (OS X)
Wirecast (Windows, OS X)
APIs DirectShow (Windows), DirectSound (Windows),V4L2 (Linux), ALSA (Linux)
Onboard Memory 64MB DDR2, 16 bits at 300 MHz
Upgradeable Firmware Yes
*** note I did a test where I unplugged the magewell (micro usb to usb) and hooked up the camera with its (micro HDMI to HDMI) and the same grainy look appeared.. I can create a video of that too..
But are you using a USB 2.0 port? Or USB 3.0?
Btw, fyi I am very familiar with that device as I recommended & support hundreds of them at a University campus. If you set it up properly, it will give you glorious looking (1080p60 or better, depending) video.
External Recording Modes: 4:2:2 8-Bit (Not sure if it's throu HDMI or USB)
UHD 4K (3840 x 2160) at 24p/25p/29.97p
Full HD (1920 x 1080)24p/50i/50p/59.94i/59.94p
Compressed Recording Modes:
UHD 4K (3840 x 2160) at 24p/25p/29.97p [60 to 100 Mb/s]
Full HD (1920 x 1080) at 100p/120p [60 to 100 Mb/s]
Full HD (1920 x 1080) at 24p/25p/29.97p/50p/59.94p [50 Mb/s]
Full HD (1920 x 1080) at 50p/59.94p [28 Mb/s]
Full HD (1920 x 1080) at 24p/25p [17 to 24 Mb/s]
Full HD (1920 x 1080) at 50i/59.94i [17 to 24 Mb/s]
Full HD (1920 x 1080) at 50p/59.94p [28 Mb/s]
Full HD (1920 x 1080) at 25p/29.97p [16 Mb/s]
HD (1280 x 720) at 25p/29.97p [6 Mb/s]
My guess is you are using the wrong output mode.