Archive | 2:40 pm

Tested some 720p streaming video

22 Jan

I read that the Logitech QuickCam Vision Pro for Mac can stream up to 720p (960 pixels wide and 720 pixel high) at 30 frames per second (30 fps). So with my improved Internet connectivity (1.5 Mbit/s up and 10 Mbit/s down) I decided to give it a try. I used Quicktime Broadcaster to stream video to Justin TV (JTV), and also to record the video on my Mac while streaming.

Below you can watch the video recorded on my end, and here is a link to the archived video clip on JTV.

Again, the quality is quite good, considering the limitations.

I have to remember next time that it can take up to 10 s until JTV picks up the recording. JTV also seems to cut off the recorder 5 s before you end the broadcast. I’m sure the amounts of time vary, depending on how busy the system is.

I used these settings in Quicktime Broadcaster:

Audio: MPEG-4 22.050 Khz 16 bit mono
Video: 960 x 720 (4:3) H.264 30 fps, key frame every 30 frames, limit data rate to 700 kbits/sec

The video shows the Logitech web cam and part of the Mac OS X desktop of my iMac, both switched with CamTwist. The audio came from a Plantronics DSP-400 headset. The digital A/V signal was passed on to Quicktime Broadcaster, which passed it through the Internet to the real-time video servers of Justin TV, which in turn broadcast the stream to the Internet as Flash video for all to see.

Unlike the Flash interface for broadcasters on the website, Quicktime Broadcaster is the interface, so you don’t have to visit the JTV website to start a broadcast. Of course, you would like to monitor the live channel, so you’d see what others see on their screen. For that I use a separate netbook.

That’s enough tech specs for now. The fun is using this stuff as a “small television station on the Internet.”