Category Archives: Tech Stuff

Video, RAIDs and Bandwidth – oh my

So I’ve been experimenting with video broadcasts since June now, and its been an interesting experience. It seems the “free” services like LiveStream and Justin (can’t speak for the others) are making it harder to get good results.

In June, the demand on the streaming server (an old iMac that I had which was idle) was able to handle things very nicely. As with all software upgrades, they swell up to take all processing power. I started with Wirecast 4.01 which is very easy to setup and get going, and it has worked great. I have 3 video sources that it is handling (2 webcams and 1 screen capture) I was sending audio via the Mac Pro which is running Logic Pro 9 (Agogee Ensemble is the converter) and a MOTU 8Pre to handle the mic inputs. I have 6 mic sources ( 2 mics on vocals, 2 mics on guitars and 2 mics in a Blumlein pair configuration to pickup the room and whirl’s squeeky chair) and one pedal board source. This is all mixed down into 2 stereo channels and sent over to the iMac. This has worked very well.

Wirecast 4.1 came out over the summer, I tried it, but the video results were not good, I was getting quite a lot of frame loss and had to go back to 4.01. This has since been fixed in 4.1.2, so I tried this configuration over the weekend.

The audio now falls out of sync, although when I was testing this. I did not see this problem initially. I understand Wirecast now uses VBR (variable bit rate) which could be the cause of this new issue. So I may have to once again return to 4.01 and wait until a patch comes out for this as well.

In the meantime I have been looking into ways to replace the webcams (I mean they do a decent job for the cost of them I couldn’t ask for better video – they are Logitech C615′s and have a camera mount on the bottom of them (the C910s do not). There are several problems with webcams. First, they have a wide camera angle and it is not possible to change this. Second, on the Mac Logitech got lazy and has never released a driver and supporting software which will allow you to control the camera, so it will blow out the whites in studio lights.

So I have been over to http://www.aja.com picking up two pieces of free software, one is called AJA DataCalc and the other is AJA System Test. The former will tell you who much throughput you need to drive an HD video / audio stream, the later will actually measure the performance of the system, and has options to tell you the disk read/write speed, frame rate your machine will support and the maximum number of video streams your machine can support.

I will need to have 2 HD video sources in order to pull off the next round of “upgrades” to the system, and to do that and record without frames dropping, I have to move up to a RAID in order to get the 55 MB/sec this will require (per video stream). And that is to support recording a 720p @ 30 fps. This is close to the performance of current WD Cavier Black, but there is headroom needed, and if I decide to add more video sources, then I need a design that will support that as well.

More on the RAID design next time…

Mackie and the Firewire Journey

Whirl and I had decided way back in April 2009 to begin playing a little in SecondLife for our friends. So we set out on a journey to find all the pieces, parts and software which would help us to do live performances.

We knew we needed microphones, cables, a soundcard of some kind which would provide a preamp for the microphones and a way to get those signals into the Macintosh.

Next we would need some software which would take the noises we made and mix them together.

And Finally some means to “broadcast” the sounds so that others could hear our noises.

Whirl had worked professionally in music and has recorded on a label in RL. She was familiar with most of the aspects of both live performances and recording, but certainly no expert (they had a sound person who took care of the mundane stuff).

She suggested getting 4 microphones, 2 specific for vocals and 2 specific to the guitars (she did say some studios use 2 mics on the guitars, but one should be fine for our purposes).

She also thought an external mixer would be the best way, without spending a fortune on professional studio gear.

Mixers are kinda of old fashioned today, the computer Digital Audio Workstations (DAW) all have the ability to mix from discrete channels (tracks), so the need for a mixer might obsolete. Although from what I have read this is almost a “religion” on which to do, so I’m going to duck it.

We chose a Mackie Onyx 1220 mixer mostly for the flexibility it could offer and because it promised to provide a way to digitize the signal into discrete channels within the firewire. NOTE: USB can not do this.

Problem: Bart did not read the fine print, which said that the firewire card would not work with any Mac OS X version past 10.4.9 (released in March, 2007). I’m not blaming Mackie for my stupidity, I stand up and take my lumps for a poor choice in interfaces.

The Mackie Pre-amps in the Onyx are almost legendary, for the price point you can not buy better ones (in my humble opinion) and we tested quite a few.

There is a work around for the Mackie Firewire card, so I set out on a journey (yesterday) to try and back level one of my Macs so that it would work with the version of the OS.

I just happen to have an original MacBook Pro which is from March 2007 and came with the older OS X Tiger (10.4.5).

So I loaded up that version, booted up the Mac and was immediately given the option to update my system to 10.4.11. Well I know that wont work. So I declined the update.

I went instead to the Apple web site to try to find the 10.4.9 Combo updater. After about 15-20 minutes of hunting, I found it, downloaded it and performed the install.

It work! So far so good. The updater once again fired up and told me to update about 15 components. One of which was the 10.4.11 again.

I unchecked the 10.4.11 update, and lets the other stuff get updated. Big mistake. Once I came back up, iTunes would not run. Garageband (version which came with the original MacBookPro) would not run. No indications as to why, so I started looking at the logs.

No help, just said iTunes is not supported on this version of the OS.

Ok start over, from the initial OS X load.

Everything came back up and was working. Yay!

So i shutoff the updates and resolved to do everything manually.

The MacBook Pro is back at 10.4.5, so I installed the 10.4.9 update, everything was still working.

I go check the versions if iLife that I have, iLife09, was no go as it won’t support anything older than 10.5, iLife08, will support 10.4.9. Well Alight!

So I installed that, everything is working, I see there is an update to Garageband, so I install that.

Garageband patched will not run. It needs a newer version of Quicktime. hmmm, I go find the level of quicktime it needs, ok this is odd the version it says it needs will not support 10.4.9. So I find a slightly older version of Quicktime and install it. Keeping my fingers crossed the old version of Quicktime will work. And…Garageband is happy, but there maybe problems down the road since these two versions may have never been tested together.

iTunes now works too (version 8.02), latest version will not work because of the age of the OS.

Ok, so lets go hook up the Mackie mixer to the firewire port. Only one Firewire 400 port on the original Macbook Pro (Intel). And the MacBook Pro finds it, no problem.

Next open Garageband and set up 4 tracks, all is good, I route the output back through the mixer. I record a short test, volumes are a little low, but that is ok, we can work on the issue as time permits. The recording otherwise sounds good. I let it run for awhile to see if the firewire clock sync problem returns. And it does not.

Ok! Next step I need to be able to broadcast this mix. I usually use Nicecast to send the sound output into Shoutcast, so that Secondlifer’s can hear it on the music stream.

I download Nicecast, fire it up, and….and no dice Nicecast refuses to run on this version of the OS. I check the Rogue Ameoba website for older versions of their code. I do not see any.

So here I am stuck, I could ask Rogue Amoeba for an older version, they are very nice folks and probably would, but is that right to expect a company to support such an old version of the software?

I will probably have to compile a version of icecast, install it on the Macbook and broadcast to a public IceCast server in order to get this to work.

The second work around on the Mackie website is to download and install an old Firewire SDK from the Apple Developers Center (v2.01). This version has been removed by Apple and is not longer available as I write this.

I am still using the Mackie, but I now have a MOTU 823mkii which is handling the firewire interface chores. It works just fine with Snow Leopard and MOTU takes the time to certify their drivers with Apple, something apparently Mackies does not do.

Mackie does have a post on their forums from June 21, 2007 that they are working with Apple to get a fix to the problem. In the meantime, Mackie released a whole new set of mixers called the Onyx “i” series which support up to 10.6.0 (note they do not support the latest patch level 10.6.1 as I write this).

The odd thing is, Mackie still offers the Firewire board for the older Onyx mixers…I guess that’s for Windows users.

There are other issues besides 3rd party application compatibility with running old versions of Mac OS X. The two biggest issues are any security patches later than the ones for 10.4.9 may or may not work, so you have the choice or risking your setup to incompatibilities or you leave your system vunerable to the security risk that the patch fixes.

The second biggest issue is that Apple doesn’t just release new Operating Systems patches for the fun of it. They do it to provide new features, to support new versions of their product lines, and update device drivers. Not being able to update leaves you held hostage to old equipment, which as it is ages becomes more prone to failure.

In my opinion, Mackie has made some poor choices and we the consumer are stuck with their poor marketing/engineering decisions. As an analog mixer I still think their stuff is the best at the price point, but for use with 21st century studios, perhaps this is not the right company to bet your business on.