As you can probably tell, we are super excited about this, feel free to ask me anything : ).
How much work have you had to do around these issues? Did they prove to be bigger or smaller than you anticipated?
How do you deal with the licensing issues regarding open source encoding software? Do you pay the MPEG-LA a fee directly for use of the software? Is it per file/per minute/flat fee?
Just wondering about the mechanics of this, mainly for an in-house streaming application.
MPEG video stuff is generally pretty cheap or free for low volume. Audio codecs are fairly expensive, on the other hand. AAC + MP3 + AMR is >$20K in minimum fees.
So sure, there could be problems we don't know about yet, but that's the price for doing something nobody has done before. We will deal with these problems as they come up. In the worst case that might mean falling back to normal encoding if a ffmpeg child process starts to misbehave.
Ffmpeg only reads as much from stdin as it can process. Node.js gives us a 'drain' event when this happend, which means we can pump more data into it. So we are no throttling the speed, just the flow of data.
Ultimately, if you are a provider of services, these or any other, you will add functionality or run the risk of being eclipsed.
Also, we don't believe individual features themselves will give us a long term advantage. Consistently being a leader of innovation however, will.
2. Publicity. There are a bunch of features that would certainly be equally useful to our customers. However, none of them would get much interest from hacker news. We got a lot of signups and page views from this.
3. It took me probably 4 full days [2] to implement this, including the screencast and blog post. That's reasonable for the value added by this feature.
--fg
[1] We are really infinitely faster if the upload speed is slower than our encoding speed. This is probably the case for 99% of all consumer internet connections at this point. In any case we reduced the time required for an encoding from SUM(Upload, encoding) to MAX(Upload, Encoding).
[2] We already made a lot of technology decisions that lowered the cost of implementing this. A competitor would certainly need much more resources to pull this off.