# How to sync slides with audio/video, a few alternatives


I really enjoy giving presentations and talks. They are a great way for
me to think through my ideas, and systematize them, and I can trace some
of my ideas now through a series of talk as they were gradually
developed (with help from the audience). I try to be an interesting and
engaging speaker (although I can always improve), and I usually spend
quite a lot of time thinking through what I want to say, designing the
slides, etc.

Ever since I gave my first public talk at Indian Institute of Public
Administration, I've recorded my talks. Usually just using Audacity on
my MacBook, with the built in microphone. Sometimes the talks have also
been video-recorded, or there are even fancy systems that try to capture
the slides and video together (although these systems are often fickle,
and can fail completely). I began putting my slides on
[SlideShare](http://slideshare.net) early on, and have really enjoyed
the exposure that website has given me. ([All my presentations on
SlideShare](http://www.slideshare.net/houshuang)).

SlideShare offers one very neat feature called SlideCasting. You can
upload or link to an MP3 of the talk, and use a syncing tool to have
slides automatically progress at the right time during your talk. In
that way, someone visiting the site can simply press play, and listen to
the talk, with the slides advancing at the right time. Or they can jump
straight to a certain slide, and hear what I said about that slide. It's
a great concept, and most of my presentations use this feature. I try to
not overload my slides with text, so if you just see them without
hearing what I said, the presentation looses much of its value.

There are some issues with the SlideCasting feature however. It takes a
lot of time to edit a one hour presentation, with maybe 150 slides. It's
also very difficult to put slides close together, so if you rapidly
progress through a set of slides (less than 5 seconds on each), it
becomes difficult. I've also had some issues where I lost all the
timings, or the timings came out of sync.

I wish SlideShare let me download a text file containing all the timings
for a presentation I uploaded. Or import a file in the same format. This
would have several benefits. Firstly, I would feel much safer that I can
get my data out (I spend a lot of time creating timings, but if
SlideShare ever goes under, or I want to move to another hosting site, I
loose the timings. If I have the file, there is no guarantee that the
other site will accept them, but it's at least a possibility). It's also
a backup in case the timings disappear. And finally, it opens for
creating tools that would for example record all my timings when I give
my presentation, so that I could directly import these and save a lot of
time.

I was just preparing my latest presentation, when I ran into a lot of
problems. First, it turned out that the MP3 hadn't uploaded completely,
it ended five minutes before it should. I only realized this after I had
created timings for the whole file. After e-mailing support, they told
me there was no way of preserving the timings, if I reuploaded the file!
So I lost all that work. Then I did it all again, but somehow when I
view it, the timings seem to all be out of sync.

So being quite fed up, I decided to investigate some other options.
[Omnisio](http://www.omnisio.com/) looked promising, but it has been
bought by Google to be integrated with YouTube, and does not allow new
sign-ups (but we might see an interesting addition to YouTube once
Google has finished "digesting" them). Finally, I decided to turn it
into a video. I had a video of my entire talk, so I positioned that
player on my screen, and the PDF of my presentation slides in a small
Preview window right next to the video. I then used
[ScreenFlow](http://www.telestream.net/screen-flow/overview.htm) to
record the screen, and the system audio. I simply played the entire
video, and manually advanced the slides at the appropriate time.

This process has some advantages. It's actually faster than creating the
timings with SlideShare's tool - it only takes the amount of time it
takes to watch the entire presentation. It's also much easier to have
very rapid slide advancement, and it also preserves transitions (which
SlideShare doesn't), although I rarely use those.

After recording the whole thing (I had to do it in two sections, and
splice together, because I got a warning message about two little space
left on the HD in the middle), I cropped it in ScreenFlow to only
display the two boxes (video and slides), and exported it to a QuickTime
file. This took quite a bit (and don't try to turn on multi-pass, it
will take all night). I uploaded the finished file to Vimeo, and voilà.
([See finished presentation on Vimeo](http://vimeo.com/12407128)).

Although the editing was a bit faster, the post-editing, rendering, and
uploading to Vimeo took longer. It's also far from as elegant, since
people cannot easily download the slides, copy and paste from slides,
click on links in slides, or search on the content (SlideShare exposes
the content as text, to make it Googleable). So still not ideal, but it
was a fun experiment that worked fairly well. (It's surprising how often
screencasting comes in handy for grabbing a piece of video that's
streaming in a weird format, I also used it to grab some of the pieces I
used in my [Open Education around the world
medley](http://www.youtube.com/user/houshuang#p/a/u/2/eRbWXKnxB2c)).

Stian