GRADnet Videoconference Lectures

Transcription

1 GRADnet Videoconference Lectures Recording Presenting & Editing Guidelines Curated by Sean Cooper

2 Contents Lecture Set- Up.. Page 3 Stopping a Recording.. Page 6 Advice for Lecturers. Page 7 Installing Audacity Page 8 Advice for Editors... Page 10 Author s Note: There are two main goals for this document. The first is to explain a new procedure involving the used of a digital audio editing program that will improve the lecture recordings sound quality no end. The audio feeds from VisiMeet are optimised for streaming, which means a decrease of quality. Crackles, clicks and other artefacts are also introduced into the mix. This can make the lecturer very difficult to understand, my hope is that by using Audacity these problems will be averted. The second goal is to promote a level of consistency across all of the broadcasting sites. During my time at GRADnet I have been working full time sifting through these videos. Whilst I have been able to work fulltime on these videos, it is unlikely that anyone else will be able to in the future. If the procedures mentioned here are kept to with some consistency, then cataloguing and editing these videos will become a much quicker task. N.B. I apologise in advance to any readers of this document that have a working knowledge of the software mentioned. Some of the instructions may come across tedious so I ve made sure to embolden key points. 2

3 Lecture Set- Up: Note: This section explains how to prepare a system for a commencing lecture. If this is the first time that this procedure had been used, or if Audacity is not installed, then the Installing Audacity section (page 8) should be consulted. 1. Open Audacity: If there is not a desktop icon for Audacity then it should be accessible from the Start Menu under Program Files. Once Audacity opens you should be greeted with a window looking something like that of Figure 1. If a tutorial window pops up then just dismiss it. Figure 1: Audacity s default layout. 2. Recording Settings: The recording settings are highlighted by the red box in Figure 1. From left to right these should read: MME Microphone (Realtek High Definition) 2 (Stereo) Recording Channels Speakers (Realtek High Definition) These settings will likely already be correct by default. The blue box in the bottom left of Figure 1 highlights the sample rate. This should be set to Hz. 3

4 3. Open VisiMeet: The next stage is to open VisiMeet and join the room s SEPnet meeting as per the usual procedure. This is just a case of selecting the Meetings tab and clicking the numbered SEPnet meeting room designated for the videoconference room in question (see Figure 2). Figure 2: VisiMeet s Meetings tab. 4. Arranging the Camera Feeds: To save on bandwidth, it isn t usually necessary to broadcast any of the cameras except for the one focusing on the lecturer. Since these lectures are going to be recorded locally, a desktop will be captured as opposed to a specific camera feed. Therefore, it s helpful to resize the camera to cover as much of the desktop as possible so that the videos are easy to edit (see Figure 3). Note: If a device like an interactive whiteboard is going to be used then it may be a good idea to capture a different desktop, such as one of the projector displays. Popups and notifications tend to appear on the primary desktop and may obscure part of the recording. Figure 3: An example of how the camera feed could be arranged. 4

5 5. Camera Position: The cameras pan/tilt angles can be controlled by clicking on the preview feed and dragging in the appropriate direction. The zoom can also be controlled by scrolling. Figure 4 shows an example camera position. The main point here are to make sure that there is enough room for the lecturer, and if possible the lecture slides, to be in full view. More precise camera controls can be found by going to Tools - > Camera - > Camera Controls. Figure 4: An example of a good camera angle. Here the digital lecture slides have been superimposed onto the lecture slide projection during editing to improve readability. 6. Microphones: The room mic s can pickup a lot of unwanted noise and bass frequencies. It is advised for the lecturer to use a lavalier (lapel) microphone so that they can be heard clearly in the recording. This will prevent a lot of the audio problems often met during the editing stages. 7. Recording in VisiMeet: Go to the Recorder tab and click on the red record icon at the bottom of the screen. When prompted enter the recording s name. To help catalogue these videos the following naming convention should be used: YYYY- MM- DD Course Name Lecturer Name Location For example: Black Body Radiation Prof. Max Planck Berlin University After the name has been entered choose Save Locally. You will then be prompted to select which desktop to record; this is the one that the camera feed was placed on originally. 8. Recording in Audacity: The green box in Figure 1 highlights the record button. To begin recording the session s audio just click this button. The next page will explain how to stop the recording after the lecture is over. 5

6 Stopping a Recording: 1. Stopping the VisiMeet Recording: Navigate to the Recordings tab. In place of the original recording icon there will be a red stop icon. Clicking this will stop the recording. The video file can be found in the directory specified in VisiMeet s preferences. This can be changed by going to Tools - > Options - > Video. 2. Stopping the Audacity Recording: The orange box shown in Figure 1 highlights Audacity s stop button. After clicking this button the audio needs to be exported as a WAV file. To do this, go to File - > Export Audio (see Figure 5). Once there it is useful to choose to save the file in the same directory as the VisiMeet recordings, using a similar naming convention: YYYY- MM- DD WAV Course Name Lecturer Name Location For example: WAV Black Body Radiation Prof. Max Planck Berlin University This should make sure that the files can easily be found when they come to be edited. The file format WAV (Microsoft) signed 16 bit PCM should be chosen (this is usually the default value), then click Save. The next page asks us for metadata. In this case this isn t applicable so just leave the fields blank and click OK. Figure 5: Exporting audio in Audacity. 6

7 Advice for Lecturers: These video lectures can work well as an on- going resource, allowing students to take full advantage of them well after they are given. Here are a few tips to help make content as engaging as possible. Stay in Frame of the Shot: It s worth taking a little time to look at the camera feed before the lecture begins. This should give you a good idea of where you can stand and still be visible on the camera. Use a Lavalier Microphone: If available it s definitely worth trying to get hold of a clip- on lavalier (lapel) microphone. The room mic s tend to pick up a lot of bass frequencies and unwanted noise, which can make it difficult to understand what is being said. These lavalier mic s do a great job of keeping the audio focused on the speaker. Repeat Questions in Your Answers: Often when students ask questions, whether they be in person or over VisiMeet, they can be difficult to hear. If you make sure to repeat the student s question in your answer then it ll help viewers to engage with the feedback. Avoid Excessive Use of Interactive Whiteboards: Interactive whiteboards and handwritten notes can be useful to show your thought process but unfortunately they aren t recorded well. The camera s video feed doesn t do a great job of picking up handwriting and the digital versions of them are temperamental at best. Where possible it s better to use prepared lecture slides. Clap Before the Lecture Begins: Before you begin the lecture, make sure to clap your hands in the field of view of the camera. This makes matching the audio and video streams up during editing really easy. It s not the most crucial of points but it can save someone a lot of time. 7

8 Installing Audacity: Audacity is a free open source digital audio editor that will allow us to record the microphones audio feed in high quality whilst streaming through VisiMeet. 1. Downloading Audacity: Open up a web browser and navigate to: audacityteam.org/download Figure 6 shows an example of what the page will look like. At the time of writing this, the most recent version was Audacity Once on this page click on the link to download Audacity for Windows. Figure 6: The Audacity download page. Once clicking this link you ll be greeted with a page similar to the one shown in Figure 7. Choose the installer link, in our case it was entitled Audacity installer. Figure 7: The links used to download the Audacity installer. 8

9 Once you re done, the download will begin and you ll likely be asked whether you would like to Run or Save the download. Choosing Run will suffice here. 2. Installing Audacity: This is just a simple case of following Audacity s install wizard; however, it is important to make sure to check the Reset Preferences box. Here is a detailed walkthrough of the installation: The first page is language selection. Choose English then click OK. Next is the welcome page, click Next >. Next up is an information page vis- à- vis licensing, click Next >. You will now be asked to specify an install location; by default this is the program files folder. This location should be fine but if you need to change it do so now. Now comes the Additional Tasks page. It is important to check the Reset Preferences box here. If Audacity has been used on the machine previously, this will prevent any problems that might arise later from the default settings being different. It will also be useful to choose for Audacity to make a desktop shortcut, so make sure this box is also checked. On the next page click Install to commence installation. After this is done click Next >. On the final page make sure that the box is checked that will launch Audacity after you press finish. 3. Resetting Preferences: Once Audacity opens for this first time it will note that we previously opted to reset the preferences. Here just click Yes. After this Audacity will open normally and you will likely see a tool tip window like the one shown in Figure 8. These are just a little bit annoying so you may as well take the time now to check don t show again. Figure 8: That annoying help box that we all love. Audacity should now be installed. 9

10 Advice for Editors: VisiMeet s.webm Video Output: VisiMeet uses a VP8 video codec that is optimised for streaming. Unfortunately, this means that the video files are stored in a.webm format. This codec is notoriously difficult to work with and almost all video editing software will have trouble importing it. Fortunately, I found a program called Freemake Video Converter that can transcode the videos into a usable codec. It can be downloaded from: freemake.com/free_video_converter/ It s quite straightforward to use. I recommend transcoding the videos using the Apple TV preset, and doing a single pass encoding. Be aware that doing this for long videos can take a while (about a third of the video s length on the desktop I was using), so it might be worth queuing up a few videos and leaving it to run. Use Audacity s Audio Output: The WAV files generated by Audacity will be much higher quality that the audio track on the VisiMeet recording. VisiMeet optimises it s audio and video for streaming which means a loss of quality, not to mention artefacts such as clicks and pops that make their way into the mix. Overlaying Lecture Slides: I ve had a lot of success overlaying the digital copies of lecture slides onto the projection that can be seen in the camera s video. Figure 4 shows an example of this. I simply distorted the slide s shape to match the screen, and then applied a Multiply blend mode. 10