# Recording Talks for BSDCan

## Intended Audience
This document describes techniques for BSDCan 2020 speakers to prerecord their talks, to be streamed during the conference.

It is anticipated that recordings will either be slides with video of the speaker superimposed over the corner, or just slides, with the speaker's audio.

# Equipment

## Desktop / Laptop

This guide is written with the assumption that speakers will use a single PC to present. Slides are recorded via screen capture, along with audio and video.

## Microphone
It is possible to record with the built-in microphone on your laptop or webcam, but results will be much better when using a good quality external microphone, or a headset. A suitable microphone might cost from $50 CAD to several hundred dollars.

Some suggestions (lower to higher price):
- [Logitech Headset](https://www.amazon.com/Logitech-ClearChat-Comfort-Headset-981-000014/dp/B000UXZQ42/?pldnSite=1)
- [Blue Snowball](https://www.bluedesigns.com/products/snowball/)
- [RØDE NT-USB](http://www.rode.com/microphones/nt-usb)
- [RØDE Podcaster](http://www.rode.com/microphones/podcaster)

TODO: Add links to additional microphone suggestions.

## Webcam

External webcams are likely to be better quality than the built-in one in most laptops, but either will be fine.

# Software - OBS Studio
[OBS Studio](https://obsproject.com/) is a free, open source software application for recording and livestreaming. It is well suited to recording talks. It has a lot of advanced functionality, but we'll only require the basics.

## Installation

### FreeBSD
OBS Studio is available in the package collection and requires just `pkg install obs-studio`.

## Setup

We will use non-studio mode for recording. OBS Studio should have a single black rectangle in the top half of the window. If there are two, click on the **Studio Mode** button on the bottom right of the window to turn it off. It should look like this:


### Settings
Next we'll set the recording format. Click on the **Settings** button, then apply the following settings in the specified panes:

#### Output
Video Bitrate: Approx 3Mbps
Encoder: Software (x264)
Recording Format: mkv (or mp4)

#### Video
Base (Canvas) Resolution: 1920x1080
Output (Scaled) Resolution: 1920x1080
*(If you find that your machine cannot handle the higher resolution, use 1280x720 instead.)*
Common FPS Values: 30

Exit the settings dialog.

### Scene
Next we will set up the video and audio sources in a scene. Start the software that you are using for your slides, and enter presentation mode.

The Scene collection in OBS Studio is at the bottom left of the window. If there is are no entries in the "Scenes" list, click the **+** and add a scene.

Next, click the **+** below the Sources list, and choose **Window Capture (XComposite)**. Select **Create New** from the window that appears, name the source "Presentation", and click **OK**.

Then, select your presentation from the **Window** dropdown in the Window Capture settings.

Turn off the **☐ Capture Cursor** option.

Depending on your video card red and blue channels may be reversed; if so, check **☑ Swap red and blue**.


Click **OK**. By default your captured window should fill the canvas; if not, move and adust the size to make it so.

Click the **+** below the sources list again, and choose **Video Capture Device (V4L2)**. Select **Create New** from the next window, and name the source "Cam".

Choose your camera device from the **Device** dropdown. You may find that **Video Format** BGR3 (Emulated) gives the best results for framerate and resolution. Click **OK**


Click **+** below Sources, and choose **Audio Input Capture (PulseAudio)**. Name the new source "Mic" and click **OK**.

Choose the appropriate device, and click **OK**.

From the main OBS Studio screen resize and drag the camera video to an appropriate location.


You may want to click the lock icons beside the sources so that they don't get accidentally moved or changed.

## Recording

Click **Start Recording**. Switch to your presentation window, and record your talk. When finished, switch back to OBS Studio, and click **Stop Recording**.

# Software - using ffmpeg

It is (should be?) possible to record a screencast, without an inset webcam but with speaker audio, using only ffmpeg.

TODO: add details

# Links
- [How to film your lectures using OBS](https://bioceed.uib.no/dropfolder/bioCEED/How%20to%20film%20your%20lectures%20using%20OBS%20studio.pdf) from Universitetet i Bergen

## Tech notes from Matt
- Ethernet
- Wired headset
- Week before pre-meeting
- e.g. "there's a really bright light behind you"
- deliver talk standing up
- (maybe 1/2 did)