Driver For It Works Panda 17b Webcam Hit
Birhanie Scavotto
Hacking a Sony Alpha for clean HDMI out: On my journey to find the perfect image for video conferences and lectures with a spare DSLM camera I found several solutions to use a Sony Alpha as a webcam - with varying results and obstacles.
First of all: Why a DSLM instead of a regular webcam? Simple answer: Better image quality. Nominally, you will find many webcams that have the same or even a higher resolution than a normal web conference video stream supports, but the actual image quality is limited by sharpness and noise of the small webcam sensors and optics. Even at the end of 2020 after a year of never ending video chats, people are still surprised by the image quality on my DSLM setup and no artificial depth of focus can match the natural Bokeh of a fast prime lens.
The oldest one, my first DSLM, which retired mid 2019. Since selling would not yield enough cash to justify it, I kept it for projects as I can keep using all my e-mount lenses. For example when using it to create time lapses of my 3d prints.
Interestingly, there are not two cameras for which I had the same troubles and the same ideal solution. The a6400 is the easiest as there is an official webcam software to use with an USB cable and as it has perfectly sharp clean HDMI out without any problems. The a6000 should in theory at least also have a clean HDMI out, but it suffers from a weird software bug that applies a beauty filter to your face all the time. So does the a5000, which on top does not provide clean HDMI out, meaning the user interface of the camera will always be visible in the image that is sent via HDMI. Finally, the NEX-5T also does not have a clean HDMI output, but it also is incapable of providing an image at a reasonable resolution unless you are actually recording, which has its own limitations.
The first one is the Imaging Edge Webcam software by Sony, which allows you to simply plug in your camera via USB and it should be recognized as a webcam. Unfortunately, only the a6400 and similarly new models are supported and since it is not available for Linux, I have not tried it. But if you are on Windows or MacOS and have a modern camera that you want to use, go ahead and try it - it will probably be the easiest solution.
This software is designed for video streams to various platforms like Twitch, but there are plugins to redirect its output to a virtual webcam 5. The only problem I encounter regularly is that while most web conference software (Zoom and various browser-based solutions) accepts a 1080p stream, Microsoft Teams would not accept anything beyond 720p, so I have to switch the resolution in OBS after using the best quality in Zoom and then taking a call on Teams.
The reward for this extra step is that I can set up a second camera for presentations in which I show experiments6 on my desk or when I find it nicer to have a desk scene to greet the audience before switching to a close-up cam that shows just my face as an overlay to some slides.
So, the first candidate as a webcam to free up my a6400 was my old NEX-5T, which I did not really use anymore. Unfortunately, the image from the HDMI output is horrible in every way. It has a user interface and it has a very low resolution. In contrast to the other models discussed here, it also does not have a dedicated video setting on the mode dial, but instead you are just supposed to hit a video record button in any mode. The idea is nice, but besides being thoroughly annoying when you shoot pictures in 3:2 and need to frame your 16:9 video with the 3:2 picture-preview before you hit the button, this also means that you cannot switch to video mode (which vastly improves the HDMI quality on the other cameras) without actually recording anything.
So, I tried a different approach. I had already been playing with the REST API on that camera when I used it to create time lapses of 3d prints in Octoprint and I know from the official Imaging Edge app that there is actually a live stream available from the camera which serves as a preview to frame your shots in your phone. So, after having a look at the official documentation by Sony, I realized that it is not too hard to activate the live view function and to retrieve the stream. In fact, there are two simple API calls required: startRecMode to establish the API session and startLiveviewWithSize to request the live stream.
The camera will respond with an URL that you can directly throw into OBS as a media source. Unfortunately, even though I am using the startLiveviewWithSize to explicitly request the high resolution stream (parameter L), the stream still has a rather low resolution and the frame rate suffers immediately if the Wifi connection to your camera is not 100% perfect.
So, the most obvious problem is not the user interface but the terrible resolution of the image, which is similar to what you get from the NEX-5T from its HDMI out. However, the a5000 has a massively underrated feature: There is a video mode on its (virtual) mode dial. Not only does it switch to the correct aspect ratio without the need to change the aspect of still images, but more importantly the HDMI output suddenly supplies a perfectly nice image:
Actually, step 6 and 8 are optional. They just read the location in memory, so you can verify that it starts with the default of 01 and that you then successfully changed it to 00. Step 7 is where you actually change something, but tt is nice to have this verification.
The thing is that the Sony cameras from that generation (I think some A7s are affected as well) have a feature to apply a beauty filter to your skin. Of course, there is a setting to disable such a stupid feature, but unfortunately this setting does not do much. If you disable it, the effect is still applied in your video recording, which is why you find several discussions about it on the web. Luckily, there is a solution that is good for most users. As demonstrated here, if you disable face detection the effect is gone in your video recordings.
Unfortunately, this did not help me. For one thing, this only works in the recording, but the problem is still there if you are not recording. So it would be pretty much the same situation as with the NEX-5T where I need to record to get a good image. But also, it means that you lose face detection, which is pretty helpful if you want to shoot your face with a shallow depth of field.
Also, if you are looking into buying a new camera just for video conferences, the a5000 is a very interesting cheap option, especially as its non-official clean HDMI means that only few people are looking at this camera during the ongoing pandemic. But remember, that this price was for a heavily used body without a lens, so if you are not already in the Sony ecosystem and do not plan on using one of your existing lenses, this option becomes less attractive as you also need to plan for buying a lens that is worthy of using a DSLM over a regular webcam.
Oh, and speaking of the improved look of the DSLM: Do not think that the image is only determined by the camera itself. Lighting is extremely important and while framing may be not too relevant in a frontal headshot for a web conference your background still counts. In my examples I am using a large umbrella as a key light and a smaller LED panel to even out the dark side of my face (not interested in a cinematic look in my work context). So, if your coworker is in a nice bright room with a subtly professional backdrop, his cheap webcam will easily outperform your DSLM in a badly lit basement with a glaring red backdrop. On the other hand, if you only get it remotely right (I could certainly learn a lot from a professional photographer/videographer), the image will stand out so clearly that people will ask you about it.
The USB Device Class Definition for Video Devices, or USB Video Class, defines video streaming functionality on the Universal Serial Bus. Much like nearly all mass storage devices (USB flash disks, external SATA disk enclosures, ...) can be managed by a single driver because they conform to the USB Mass Storage specification, UVC compliant peripherals only need a generic driver.
The UVC specification covers webcams, digital camcorders, analog video converters, analog and digital television tuners, and still-image cameras that support video streaming for both video input and output.
Due to the limited available man power and the broad scope of the UVC specification, the Linux UVC project will concentrate the development efforts on video input devices, especially webcams. Video output devices are supported in bulk mode only.
The Linux UVC projects is currently focussing on kernel support for UVC devices. The driver implements the Video4Linux 2 (V4L2) API. Support for the deprecated V4L1 API will not be added.
The table below lists known UVC devices. Other UVC compliant video input devices are very likely to be supported. If your UVC device is not listed below, please report it to the Linux media development mailing list.
1 First and second generation Logitech webcams suffer from firmware bug which make the camera somehow unstable. As the issue is timing-related, the exact impact of the bug on a particular user can't be predicted. If you plan to buy a Logitech webcam, consider getting one of the models not affected by the bug. More information about the issue, including possible workarounds, are available on the QuickCam Team website.
2 Starting at version 2.6.22, the Linux kernel includes a USB audio bug fix which triggers a (possibly identical to the above) bug in first and second generation Logitech webcams. See the Linux UVC wiki for a workaround.
3 This camera module is known to be mounted upside-down in some notebooks. Applications that use the libv4l library should display the video correctly, as libv4l detects upside-down cameras and rotates the image automatically. See Hans de Goede's post on the linux-uvc-devel mailing list for more information. For applications that don't use libv4l, try holding your computer upside-down.
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