I have been using my surface pro for screen casting every now and then and am slightly frustrated with a few things. I'm after clear video, great audio and a small file size. Not much to ask :-)
On one course I use bb flashback to record live lectures (as opposed to our usual automated lecture recording system provided by the university). The audio gives me speech that is perfectly understandable but there is quite a bit of background noise and it isn't that pleasant to listen to. I noticed that even when recording in my office I still get a fair bit of background noise when using the built-in microphone. I suspect it is picking up my office air conditioning and it is definitely picking up the surface fan when it kicks in. This is a problem I want to solve. Initially I thought it would be as simple as shelling out $20-$50 for a decent external microphone. Turns out it isn't that simple.
I've been doing some reading around audio recording and after trialling a bunch of different microphones and audio interfaces have come to the following conclusions:
a) to avoid electronic noise, use usb
b) to avoid background noise from the environment use a good quality directional dynamic microphone (as opposed to a condenser)
c) microphones may need an amplifier to boost the signal
d) if you want really nice audio, expect to shell out a lot for it (e.g. around $500 NZ)
I'll deal with each conclusion in turn.
Cheap external computer microphones (or headset microphones) will often plug into the 3.5mm jack on a laptop. With the surface pro I have found that every microphone that I've plugged into a 3.5mm jack has had issues with noise. My brother who is an electrical engineer (and audiophile) told me that using the 3.5mm jack and onboard circuits for sound processing is likely to result in noise. The included soundcard on portable computers isn't going to be ideal for processing high quality audio. It is better to ditch the 3.5mm jack and get your audio in via the usb connection (so that the signal processing can be done externally). There are a number of well known microphone manufacturers who produce microphones that plug directly into a usb port. Here are a list of the ones I considered after extensive research: the Rode podcaster, the Blue Snowball, the Blue yeti, the Studio projects LSM, the Samson Go-mic and the Audio-Technica ATR2100 USB. You can find youtube reviews on all of these but the most useful site I found was Recording Hacks: http://recordinghacks.com/
All these microphones come highly recommending for podcasting.
Microphones fall into two main categories, condenser microphones (which use a capacitor) and dynamic microphones (which use a magnet and coil). Condenser microphones tend to be much more sensitive and also need to be powered. I tried out a few condenser mircophones (e.g. the Blue Snowball and Blue Yeti) and while the audio was very clear and electronic noise wasn't an issue, background noise was. Despite these microphones having cardiod pickup patterns (which means in theory they only pick up noise in front of them, rather than from all around) condensers are so sensitive that I as picking up noises from behind the microphone at the very far end of the shop I was in. Condensers would be great in a studio environment with sound proofing where background noise wasn't an issue. Since I have air conditioning on in my office, plus a computer fan and the sound of me writing on my surface with a stylus, condensers weren't going to work. By contrast the dynamic cardiod microphones I tried were MUCH better at picking up just my voice and no background noise. They are less sensitive so you have to position your mouth a lot closer to the microphone but this is a small price to pay for less noise. The Rode podcaster did a lot better job of isolating my voice, even though I was testing it in a relatively noisy shop.
Unfortunately the Rode podcaster didn't give me very high input levels so I had to post process the audio recordings and massively scale the gain. It appears that this is a common complaint with usb microphones and that it is often necessarily to increase the amplitude of the signal. While you can do this in software, increasing the signal via post processing can also introduce audible background noise (that wasn't noticeable until you increase the amplitude). A better solution is to use a pre-amp (pre-amplifier) to increase the signal.
If you are going the route of using a pre-amp, then you need an audio-interface, which does the job of both amplifying the microphone's signal and converting the signal to a digital format so that it can go in via usb. The nice thing about going with this route is you are no longer limited to usb microphones, you can use professional audio microphones which make use of the standard XLR connectors present on just about all mics used in the recording industry. I tried out The Shure SM57 instrument mic (an industry standard) with my brother's audio interface (a TASCAM audio interface ) and got fantastic quality. This may well be the way to go.
In summary, to get really good audio you will probably need a good audio interface (for around $200-$300) plus a good dynamic microphone (for around $150-$250) plus stand and cable.
I've been looking at the Shure SM58 or SM48 for the microphone and the Onyx Mackie blackjack as the interface.
My last hope at a cheaper solution is the Audio-technica AT2100USB microphone, which is currently out of stock, so I haven't been able to try it yet.
Showing posts with label screen casting. Show all posts
Showing posts with label screen casting. Show all posts
Wednesday, 19 March 2014
Friday, 20 September 2013
Experiments with screen casting and powerpoint
This week I put my surface through its paces as a presentation machine (partly because the screen on my dell died that day, so it was my only option!). Unfortunately not everything went according to plan (in fact just about nothing did). Fortunately every cloud has a silver lining!
On Tuesday I ran an information evening for prospective mathematics students which included talks from seven different people (using five separate power point presentations). I was curious to see how the surface would go as a presentation computer, where rapidly switching between different power point presentations was required,. I also needed to record the entire event (both video and audio).
I decided to install bb flashback to record the audio and video, as I have a little experience with it and know several colleagues who use it. It turned out that bb flashback comes in three different versions (express, standard and pro). The express version is free and you can trial the other two for a month, free of charge. If you are fortunate your institution may well have a site license for the pro version (which I since discovered was the case for us). I know from past experience that bb flashback is capable of creating much smaller recordings, while still maintaining adequate quality. As a back up I also used the university's own recording facilities but this generates very large files (approx 200Mb for an hour of recording). Obviously large files can be painful if you have to download the recording over a slow connection (or you have a limited amount of data included in your broadband plan).
The results were less than stellar. I had plugged the projector in via a vga adapter and opted to duplicate the displays. Powerpoint 2013 had different ideas though and when I started the full screen slide show, I wasn't given a duplicate view on the surface and the projector. Instead the surface showed a control panel with a smaller view of the slide (allowing you to navigate easily through slides) and only the projector showed the full screen slide view. This normally wouldn't be a problem but I was using bb flashback to capture the screen and unfortunately it captured the surface screen, not the projector screen. Even worse it didn't capture the whole screen (that would have been salvageable). Instead it only captured a portion of it, leaving me with not quite usable video.
The good news is that I got pretty reasonable audio quality via plugging in an external microphone into the single line in/line out port on the surface. I was worried that audio quality might have been an issue but the mic did a pretty good job. The mic I used was a pretty simple one that would normally be worn on a lapel, however I attached it to the e-lectern mic. It was fairly good at picking up audio from all directions, which was helpful as some of the presenters roamed a bit. The downside was you picked up a lot of noise from the audience too, resulting in a fair bit of low background noise. Fortunately the pro version of bb flashback includes functionality to remove background noise (although you end up with a slight echo on the recorded voice at times).
Later experiments with bb flashback seem to indicate there are bugs when capturing regions and windows on the surface. Even with no projector plugged in, it does not capture regions and windows correctly. Instead it grabs a slightly offset area from the region or window selected (it captures most of what you want but the area captured is to the left of the one indicated in red when you set up the area to record). Fortunately full screen capture works (but only if you avoid powerpoint run using a projector).
BB flashback also seems to have a buggy save dialogue, as several times when I went to save a file I got a busy icon that lasted for a minute or two, before I was able to enter a filename to save the recording as. This is NOT a good look when you are in the middle of a presentation, so after the first hang took several minutes to recover from I decided to ditch my original plan of making separate recordings for each speaker. I figured I would be able to split things up in post processing (which turned out to be doable with the pro version).
So how did I get around the problem of not quite usable video? Fortunately I had used the university recording system as a backup and it DID record the video from the projector feed (plus audio). Interestingly the audio recorded through the e-lectern mic was much more directional, which meant less background noise. It also meant that if the speaker wasn't talking to the mic the sound was significantly attenuated (and hence hard to hear). Between the bb flashback recording and the university recording system I had good audio and acceptable video for all speakers but needed some way of combining the two and still producing a small file.
For the one speaker who roamed a lot, I ended up using bb flashback player to play back the captured audio (since my external mic tracked him pretty well). I simultaneously used bb flashback recorder to capture the played audio and new video (a fullscreen view of the powerpoint, which I manually navigated through to sync up with the audio). This worked surprisingly well. I ended up with very acceptable video and audio once I had trimmed unnecessary material from either end (and filtered the noise from the audio track).
For the remaining speakers (who had talked to the mic) I initially tried played the university recording in full screen mode (with audio) and set bb flashback to record the entire thing. This wasn't a particularly elegant solution, as it took an hour to run through. Fortunately it was the kind of thing that you could just set up and leave running. At the end I was left with a HUGE bb flashback file (over 7 Gb) which contained adequate audio and video. Note the video was NOT as good quality as would have been obtained if bb flashback had captured the correct screen in the first place (as the recorded video from the university system is downsampled somewhat). I suspect the HUGE size was due to the display continually changing just a little bit, as the video played. This means that the recorded wasn't just grabbing frames when the powerpoint slides were changed, it was continuously grabbing frames. This left me with the option of going with the slides that were cut off or redoing it manually. After several hours of playing with software in the wee hours of the morning I decided to go with the first option (sleep was starting to appeal).
I definitely want to be able to use powerpoint coupled with screen casting software, so need to find a workaround for bb flashback or need something more reliable (I'll take a look at camtasia, in case that works better).
There were plenty of other bugs on the night too. Powerpoint crashed and starting a full screen powerpoint presentation always generated an exception on the e-lectern computer (as it was accepting the display signal from my surface). I suspect this was due to powerpoint overriding the duplicated display mode.
The silver lining to all this was that I had anticipated the possibility of difficulty in transitioning between powerpoint presentations, so had prepared several discussion points to throw out to the audience. At the close of each presentation I simply gave the audience the next discussion point, before setting to work on working around the bugs and setting up the next presentation. This meant it didn't matter if it took me two to three minutes to get things working again (their focus was on the conversation rathe than on me dealing with the technical issues). It also had the unexpected side effect of keeping the audience more alert and engaged throughout the entire evening Incorporating some discusison points or "active learning" exercises could be a REALLY useful strategy to have up your sleave if you think there might be technical hitches.
On Tuesday I ran an information evening for prospective mathematics students which included talks from seven different people (using five separate power point presentations). I was curious to see how the surface would go as a presentation computer, where rapidly switching between different power point presentations was required,. I also needed to record the entire event (both video and audio).
I decided to install bb flashback to record the audio and video, as I have a little experience with it and know several colleagues who use it. It turned out that bb flashback comes in three different versions (express, standard and pro). The express version is free and you can trial the other two for a month, free of charge. If you are fortunate your institution may well have a site license for the pro version (which I since discovered was the case for us). I know from past experience that bb flashback is capable of creating much smaller recordings, while still maintaining adequate quality. As a back up I also used the university's own recording facilities but this generates very large files (approx 200Mb for an hour of recording). Obviously large files can be painful if you have to download the recording over a slow connection (or you have a limited amount of data included in your broadband plan).
The results were less than stellar. I had plugged the projector in via a vga adapter and opted to duplicate the displays. Powerpoint 2013 had different ideas though and when I started the full screen slide show, I wasn't given a duplicate view on the surface and the projector. Instead the surface showed a control panel with a smaller view of the slide (allowing you to navigate easily through slides) and only the projector showed the full screen slide view. This normally wouldn't be a problem but I was using bb flashback to capture the screen and unfortunately it captured the surface screen, not the projector screen. Even worse it didn't capture the whole screen (that would have been salvageable). Instead it only captured a portion of it, leaving me with not quite usable video.
The good news is that I got pretty reasonable audio quality via plugging in an external microphone into the single line in/line out port on the surface. I was worried that audio quality might have been an issue but the mic did a pretty good job. The mic I used was a pretty simple one that would normally be worn on a lapel, however I attached it to the e-lectern mic. It was fairly good at picking up audio from all directions, which was helpful as some of the presenters roamed a bit. The downside was you picked up a lot of noise from the audience too, resulting in a fair bit of low background noise. Fortunately the pro version of bb flashback includes functionality to remove background noise (although you end up with a slight echo on the recorded voice at times).
Later experiments with bb flashback seem to indicate there are bugs when capturing regions and windows on the surface. Even with no projector plugged in, it does not capture regions and windows correctly. Instead it grabs a slightly offset area from the region or window selected (it captures most of what you want but the area captured is to the left of the one indicated in red when you set up the area to record). Fortunately full screen capture works (but only if you avoid powerpoint run using a projector).
BB flashback also seems to have a buggy save dialogue, as several times when I went to save a file I got a busy icon that lasted for a minute or two, before I was able to enter a filename to save the recording as. This is NOT a good look when you are in the middle of a presentation, so after the first hang took several minutes to recover from I decided to ditch my original plan of making separate recordings for each speaker. I figured I would be able to split things up in post processing (which turned out to be doable with the pro version).
So how did I get around the problem of not quite usable video? Fortunately I had used the university recording system as a backup and it DID record the video from the projector feed (plus audio). Interestingly the audio recorded through the e-lectern mic was much more directional, which meant less background noise. It also meant that if the speaker wasn't talking to the mic the sound was significantly attenuated (and hence hard to hear). Between the bb flashback recording and the university recording system I had good audio and acceptable video for all speakers but needed some way of combining the two and still producing a small file.
For the one speaker who roamed a lot, I ended up using bb flashback player to play back the captured audio (since my external mic tracked him pretty well). I simultaneously used bb flashback recorder to capture the played audio and new video (a fullscreen view of the powerpoint, which I manually navigated through to sync up with the audio). This worked surprisingly well. I ended up with very acceptable video and audio once I had trimmed unnecessary material from either end (and filtered the noise from the audio track).
For the remaining speakers (who had talked to the mic) I initially tried played the university recording in full screen mode (with audio) and set bb flashback to record the entire thing. This wasn't a particularly elegant solution, as it took an hour to run through. Fortunately it was the kind of thing that you could just set up and leave running. At the end I was left with a HUGE bb flashback file (over 7 Gb) which contained adequate audio and video. Note the video was NOT as good quality as would have been obtained if bb flashback had captured the correct screen in the first place (as the recorded video from the university system is downsampled somewhat). I suspect the HUGE size was due to the display continually changing just a little bit, as the video played. This means that the recorded wasn't just grabbing frames when the powerpoint slides were changed, it was continuously grabbing frames. This left me with the option of going with the slides that were cut off or redoing it manually. After several hours of playing with software in the wee hours of the morning I decided to go with the first option (sleep was starting to appeal).
I definitely want to be able to use powerpoint coupled with screen casting software, so need to find a workaround for bb flashback or need something more reliable (I'll take a look at camtasia, in case that works better).
There were plenty of other bugs on the night too. Powerpoint crashed and starting a full screen powerpoint presentation always generated an exception on the e-lectern computer (as it was accepting the display signal from my surface). I suspect this was due to powerpoint overriding the duplicated display mode.
The silver lining to all this was that I had anticipated the possibility of difficulty in transitioning between powerpoint presentations, so had prepared several discussion points to throw out to the audience. At the close of each presentation I simply gave the audience the next discussion point, before setting to work on working around the bugs and setting up the next presentation. This meant it didn't matter if it took me two to three minutes to get things working again (their focus was on the conversation rathe than on me dealing with the technical issues). It also had the unexpected side effect of keeping the audience more alert and engaged throughout the entire evening Incorporating some discusison points or "active learning" exercises could be a REALLY useful strategy to have up your sleave if you think there might be technical hitches.
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