Am pleased to see confidence being expressed. But I've yet for the first time, hear sound, produce a video or hear good music from my PC using ubuStu 10.04.1 lts on my ASUS 64AMD or on my Acer Laptop via UbuStu found on it; am having to ask others to do what geeks patiently make feasible. But a non-geek like me wants to believe, I am ever so close to realizing. Keep up the fight; I support you and will stick in here too believing it is okay to use my OS solely to crunch words. Yes I hope I will be producing DVDs showing work I and friends do instead of just wishing I/we could. Million thanks! Just do not stop perfecting end products! Ken
On Thu, Sep 30, 2010 at 10:55 AM, Ralf Mardorf <ralf.mard...@alice-dsl.net>wrote: > On Thu, 2010-09-30 at 17:45 +0200, Ralf Mardorf wrote: > > Hi Ricardo :) > > > > sorry for my broken English, especially at the moment, because I do have > > an influenza. > > > > On Thu, 2010-09-30 at 16:18 +0100, Ricardo Lameiro wrote: > > > Hi Ralf, > > > > > > I didn't understood what did you meant with: > > > > For what do multimedia users (producers, but consumers) need more, > > > but > > > > vanilla + rt-patch? Does somebody run a multi-user data server on > > > the > > > > same machine, as he is using in his audio or audio-video studio? > > > This > > > > would be nonsense. > > > > > > What would be nonsense? audio producers using hard RT preemption on > > > the kernel? > > > Do you think that a webserver needs more Realtime preemption than > > > audio work? > > > > No, I guess for audio and audio-video productions we only need a vanilla > > + rt-patch kernel and nothing more. > > > > Nobody should run a web-server or anything else on a DAW, so there are > > no other kernel patches needed. > > > > I'm pro PREEMPT RT and against PREEMPT only ;) or any kernel patches > > that don't make sense for audio, audio-video productions. > > > > I was asking for reasons to patch a kernel with something like a > > 'generic'-patch. A DAW, resp. audio-video-MIDI workstation don't need a > > special server-kernel, or desktop-kernel etc., just a vanilla kernel + > > rt-patch. > > > > Why does Ubuntu Studio comes without PREEMPT RT, but just PREEMPT?! > > This is my intension. > > > > FWIW, I'm a professional audio and video engineer and did program oldish > > computers and I'm missing hard real-time for modern PCs. Even the > > kernel-rt isn't able to do hard real-time, so I don't understand why > > Ubuntu Studio does prefer a kernel without rt-patch. Today the rt-patch > > isn't good enough > > PS: > > Pardon, it isn't good enough for all needs, but good for a lot of needs, > hence we should use the rt-patch. > > > and any kernel without this patch is useless for > > multimedia production. > > > > So a misunderstanding ;)! > > > > > > > > As I see, If a webserver used a RT kernel, it would have a lot of > > > problems, because it will probably lock in some tasks until they are > > > finished. > > > > > > Audio needs a very low latency, high resolution timer etc, because the > > > Interrupts given by sound cards and by audio software need to be > > > addressed as fast as possible, > > > > This is what I'm thinking off, I sometimes use the hr timer, that on > > Linux still is a PITA on some machines and for some apps. > > > > Anyway, if possible a multimedia distro should use hr timer (HPET), but > > always a kernel-rt only. > > > > > if they arent, what happens is that the audio buffers, either for the > > > souncard playback, or capture will run out of data, and then the > > > continuos steam of audio data will be over, and wait until receive > > > more info. In a Nutshell, you LOSE audio data, and you will never get > > > it back, for professional audio that is unacceptable. Also if You give > > > software RT priorities, it less possible that, for instance, Ardour is > > > left behind of a twitter client.... unaceptable to... > > > > > > I am going to make some simple math with a not so professional cenario > > > to ilstrate just the data stream, not audo software CPU time. > > > > > > > > > Recording and monitoring out 8 channels (8 in 8 out) at 48KS/s at 24 > > > bits > > > > > > 48000 * 24 = 115200 bps = 14.0625KB/s > > > > > > 14.0625 * 16 = 225 KB/s = 1.76MB/s > > > > > > Well, 1.76 MB/s is not to much really, well this calc is simple > > > cenario, provided that the sound card uses real 24 bit audio data > > > stream, if it used 32 bit, welll do the math. > > > > > > Now to a PRO setup.. 192 KS/s @ 24bits > > > > > > 192000 * 24 = 4608000 = 0.55 MB/s > > > > > > 0.55 * 16 = 8,78 MB/s > > > > > > 8.78 MBytes per second, not mbits, FIrewire is rated at 400 MBit per > > > second... USB in practice is a lot less + Communication overhead. > > > > > > This is only on the Audio tranfer side, then you need to send this > > > streams from each different software, make dsp calculations for > > > Amplitude (volume) or mixing. This takes time.... so YES a Real time > > > kernels is better for audio users than for normal users. Specially if > > > you use Externals Firewire/USB card with high outputs > > > > > > note: this are simple calculations made fast, just to demonstrate the > > > kind of stream we talk about. I assumed 24 bits, this is very rare, > > > usually it goes with 32 bit, that is a lot more data to transfer. > > > > > > If some more explanation on why a RT kernel is prefered for audio, i > > > can try to answer some more questions, i am not a pro in this tough. > > > > > > Ricardo Lameiro > > > > > > 2010/9/30 Ralf Mardorf <ralf.mard...@alice-dsl.net> > > > > > > On Thu, 2010-09-30 at 16:38 +0200, Ralf Mardorf wrote: > > > > On Thu, 2010-09-30 at 07:35 -0400, Ronan Jouchet wrote: > > > > > Hello everybody, > > > > > > > > > > Many are confused about the various realtime kernels, so > > > here is a > > > > > reminder of the situation as of Sept. 2010 (but _please_ > > > see > > > > > > > > https://help.ubuntu.com/community/UbuntuStudio/RealTimeKernel, > > > which is > > > > > more detailed and continuously updated). > > > > > > > > > > ***Summary*** > > > > > vanilla = unpatched kernel straight from kernel.org > > > > > generic = vanilla + ubuntu sauce (it's the default ubuntu > > > kernel) > > > > > > > > > > The *soft realtime kernels, prepared by changing > > > build-time parameters* > > > > > preempt = generic + mild configuration to reduce > > > latency > > > > > lowlatency = generic + aggressive configuration to > > > reduce latency > > > > > > > > > > The *hard realtime kernels, prepared by applying a big > > > patch* from Ingo > > > > > Molnar to the kernel source before building: > > > > > realtime = vanilla + patch (hard to maintain and > > > stabilize because > > > > > merging 2 pieces of code is never easy) > > > > > rt = generic + patch (even harder to maintain and > > > stabilize because > > > > > merging 3 pieces of code is harder than 2) > > > > > > > > > > ***Availability*** > > > > > - for Maverick, generic will be the only kernel in the > > > archives, thus > > > > > the default kernel for ubuntu and ubuntustudio, but > > > Alessio has been > > > > > maintaining a PPA providing lowlatency and realtime > > > > > - for Natty or later: work is being done to include > > > lowlatency in the > > > > > official archives and make it the default ubuntustudio > > > kernel > > > > > > > > > > I hope this clears some doubts. By the way, this confusion > > > is only going > > > > > to get more intense at release time (less informed / > > > technical users). > > > > > Could we include some kind of note informing users about > > > this? Why not a > > > > > "RealTime kernel help" item in the Audio Production menu, > > > redirecting to > > > > > the wiki page? > > > > > > > > > > Good day, > > > > > > > > > > -- Ronan Jouchet > > > > > > > > > > > > > > > 2 cents, > > > > Ralf > > > > > > > > > PS: Ok, on 32-bit architecture some might need support for > > > large RAM in > > > addition, this might be an additional patch, hat's not needed > > > on 64-bit > > > architecture. > > > > > > > > > > > > -- > > > Ubuntu-Studio-users mailing list > > > Ubuntu-Studio-users@lists.ubuntu.com > > > Modify settings or unsubscribe at: > > > https://lists.ubuntu.com/mailman/listinfo/ubuntu-studio-users > > > > > > > > > > > > > > > -- > > > Fagote / Contrafagote > > > Bassoon / Contra-bassoon > > > http://myspace.com/ricardolameiro > > > > > > -- > Ubuntu-Studio-users mailing list > Ubuntu-Studio-users@lists.ubuntu.com > Modify settings or unsubscribe at: > https://lists.ubuntu.com/mailman/listinfo/ubuntu-studio-users >
-- Ubuntu-Studio-users mailing list Ubuntu-Studio-users@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-studio-users
