Wanted to share this success story. I now have pretty good audio
after fiddling around as follows:
Buffer Delay: 12 seconds
TTL: 25
Compressor: MPEG-4 Audio
Rate: 32 kHz
Options:
Bit Rate: 32 kbs
Output sample rate: 32
Encoder: High
The "spasms" have disappeared and I'm pleased w/ what we have.
Apparently, using the broadcaster on the same machine with a TV
tuner and related drivers engenders a sensitivity that doesn't exist
where the source is external. Still, I'd like to understand this
better so please chime in on this if you will.
For example, what makes the most difference, increasing the buffer?
Lowering the bit rate?
While I'm waiting for our networking and computer support people to
figure out why our multicast is not getting to all Windows clients
on our LAN (either a switch/router config issue or a Windows
registry issue [see:
http://www.winguides.com/registry/display.php/729/]), I am trying
to streamline our system for re-broadcasting our local University
TV signal over our LAN.
Here's what I started with that worked fine but tied-up a lot of equipment:
1 Dual-gig G4 with Formac DV. Input from the TV cable, analog
output to a Sony DVMC then to a second Dual-gig G4 running
QuickTime Broadcaster 1.0.1 sending out the multicast using MPEG-4
for both audio and video. QuickTime 6.1.1 throughout.
Here's my only semi-successful attempt to use both QT Broadcaster &
Formac DV on the same machine:
Using either Formac's "StudioTVR" or Mitz Pettel's "Vidi," I tune
in the desired video signal and note that both audio and video are
of excellent quality. Vidi has a neat little Control Panel that
allows one to switch channels and make video (not audio)
adjustments during a broadcast so I favor it.
Quitting the tuner software, I crank up QT Broadcaster and set it
up for a high quality multicast using MPEG-4 for both audio and
video. I check the video and audio (via Play Through Speaker) and
note that both are excellent.
Starting the broadcast and exporting a movie to pick up the
multicast on other computers, I note that, on the receiving
computers in my office, the video is excellent but the the audio is
frequently punctuated with a staccato blip blip blip ..... that is
as if the sound is being cut out at a pretty fast rate. Needless
to say that these episodes, which seem to increase in frequency
over time, render speech unintelligible, thereby making the
broadcast pretty useless.
Apparently, QT Broadcaster is snagging the source internally since
the sound pref panel has no effect as far as I can tell. What I
would like to know is why these audio "spasms" are occuring and,
most importantly, how to work around this issue so that I'm not
tieing up two machines and going analog to digital and back again.
Switching the audio to Qualcom's PureVoice at full rate produces a
"ChipMunk" sounding audio with a cyclical pattern of static
overlayed on top of that. Much worse.
So, how can I get intelligible audio with this single machine setup.
