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View Full Version : I'm a programming n00b but i wanna learn stuff about audio



neilthecellist
01-09-2005, 10:31 PM
1. OK! Can someone refer me to a website that has to do with ......the actual code behind audio?

2. Why is the ogg vorbis codec the slowest? What in the compression routines makes it slow? Is it because that it sounds better because it's slow?

3. As much as I hate Microsoft, I'm beginning to admire the wma codec. It sounds great at 128 kbps a second for any ordinary music file.... What's the code behind it? Why is it SOOOOOOO fast to encode with dMC? I get around 34x realtime encoding and i have a Pentium 4 1.8 ghz processor. pretty weak. but the encoding's so fast for wma. why?

4. How long does it take to understand the Ogg Vorbis code? I got the source code but I don't understand it all...

My only programming experience is with Visual Basic......and I've only just started it.



-Neil

Razgo
01-10-2005, 12:16 AM
you might find some discussions on this sort of thing over at hydrogenaudio.org , and you will find so called blind listening tests done over there.

it could be that technically or scientifically speaking ogg may be better which is why it is slower? i really don't know. but in the end who cares? if it sounds ok then it is :D . but i do understand those with obsessions of having the most superior codec is a must have.

and i am also impressed with wma since the lossless codec came out. it's easy to use and the majority of OS systems can play it.

neilthecellist
01-10-2005, 05:10 PM
ok. i just noticed that the Ogg Vorbis CLI is the fastest of all lossy codecs on my computer. Of course, this could just be because I have a Pentium 4...:confused:

I'm just curious as to what you guys' minimum bitrate for each codec is.....for example, my preference with the LAME 3.96 codec is at least 192 kbps , but preferably 224 kbps if possible. With Ogg Vorbis, my minimum is 128, but 160~192 if possible....my minimum with WMA is currently undecided.......what is yours? I'm just curious.....trying to gather as much info as possible.

neilthecellist
01-10-2005, 05:19 PM
what makes a conversion faster? I already have a pretty decent CPU and s***loads of memory (768 megabytes ~ 266 mhz) , a 52X CD-RW Lite-On drive, but i don't know the motherboard name. What makes it faster? is it the CPU mostly?

LtData
01-10-2005, 09:08 PM
what makes a conversion faster? I already have a pretty decent CPU and s***loads of memory (768 megabytes ~ 266 mhz) , a 52X CD-RW Lite-On drive, but i don't know the motherboard name. What makes it faster? is it the CPU mostly?
In approximate order of importance, I'd say CPU performance(type and speed), amount of RAM and speed of RAM. There's probalby a few other factors also, but these are the main ones. By performance of the CPU, I mean its performance relative to other CPUs.

ChristinaS
01-10-2005, 10:56 PM
You forgot to mention it is inversely proportional to how fast you want it ;)

neilthecellist
01-11-2005, 11:16 AM
You forgot to mention it is inversely proportional to how fast you want it ;)


wait, what do you mean? I think my system is pretty good for audio conversions.....I'm just saying: What would make it faster?

And why is my Pentium 4 1.8 ghz CPU always at 13% CPU under task manager? It's not spyware that's taking it up; I checked under Task Manager and it says "System" is at 13%...HOW does this make sense? Does this affect the speed of my audio conversions??

How do I speed up my processor? Is it possible to overclock a processor? Would overclocking my processor speed up my audio conversions??

Whew.... That was a lot of questions....

Oh and by the way, I'M AT SCHOOL RIGHT NOW!!! (Don't worry, I'm not in class, class just let out and I had 5 minutes to type this up. ^_^

ChristinaS
01-11-2005, 04:14 PM
LOL! Neil, if you attempt to overclock your processor you'd better really know what you're doing and be prepared to accept the consequences, which often may mean a totally destroyed computer.

LtData
01-11-2005, 06:12 PM
Can you overclock? Yes. Do I recommend it to you? No way. If you try this, you will only have an expensive doorstop. Speed them up? Get a better computer. That's pretty much it, sorry.

neilthecellist
01-11-2005, 07:01 PM
Ok, can you at least tell me how? My brother did it to his computer......except he has an AMD so it's easy to overclock......He overclocked his GeForce FX5700 ULTRA 256 MB 8X AGP card to the max..........but he has a conventional fan sitting in the back of his computer that constantly blows air into the computer. I have something just like that too, so it should be safe to overclock. Can you PLZ tell me how to overclock just the processor??? I'm beggin' you guys!!!

LtData
01-11-2005, 09:18 PM
Ok, can you at least tell me how? My brother did it to his computer......except he has an AMD so it's easy to overclock......He overclocked his GeForce FX5700 ULTRA 256 MB 8X AGP card to the max..........but he has a conventional fan sitting in the back of his computer that constantly blows air into the computer. I have something just like that too, so it should be safe to overclock. Can you PLZ tell me how to overclock just the processor??? I'm beggin' you guys!!!
Did you buy the computer prebuilt or did you build it or have it built? If you just bought it prebuilt, then your out of luck most likely. And seriously, if you don't know how to do it, don't start trying with your only computer. That's just asking for trouble.

neilthecellist
01-12-2005, 09:14 AM
prebuilt: Dell Dimesion 4500. I added in a Lite on 52X CD-RW drive, and 512 mb of memory, so now my total memory is 768.

What do you mean out of luck? Just tell me how, I won't blame you guys if my computer gets all smoked up the next day, ok? I have a really good cooling system and i have a conventional fan sitting in the back of the computer, constantly fanning air inside.

I've overclocked my video card already, and it's only crashed once because I didn't have a conventional fan yet. (Gainward FX 5200 128mb 8x agp)

drspy00
01-12-2005, 10:02 AM
If your brother is so good at overclocking computers, why dont you ask him about it? This isnt even an overclocking forum, lol.

Overclocking is a silly thing to do especially when you are doing it to make converting audio faster. DMC is probably the fastest audio converters/encoders around and why would you want it any faster than that?

If you really have a real problem with the speed of it, instead of wrecking or damaging your computer, why not use the file selector and convert the files overnight?
just some suggestions!

LtData
01-12-2005, 02:23 PM
prebuilt: Dell Dimesion 4500. I added in a Lite on 52X CD-RW drive, and 512 mb of memory, so now my total memory is 768.

What do you mean out of luck?
Out of luck as in you cannot access the necessary BIOS options needed for overclocking. There is a small chance that you have jumpers on the board you can adjust, but unless you have a third-party GOOD cooling system, you WILL destroy your CPU.

neilthecellist
01-13-2005, 09:16 AM
poop.

I don't have a good cooler, I just have this gigantic fan i usually use to fan a large room full of people sitting in the back of my computer.

Oh yeah and this guy at school told me that the Dell Dimension 4500 can't have its processor overclocked...Is this true?

LtData
01-13-2005, 10:22 AM
Oh yeah and this guy at school told me that the Dell Dimension 4500 can't have its processor overclocked...Is this true?
Like I said above, Dell probably locked out the ways that you overclock. Most Dell's in general cannot be overclocked.

neilthecellist
01-13-2005, 05:23 PM
ok fine. :)

Can someone explain to me what the difference between 1-pass CBR and 2-pass CBR is for Windows Media Audio? Is there a difference in audio quality between the two?

ChristinaS
01-13-2005, 05:30 PM
ok fine. :)

Can someone explain to me what the difference between 1-pass CBR and 2-pass CBR is for Windows Media Audio? Is there a difference in audio quality between the two?
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmform95/htm/choosinganencodingmethod.asp

neilthecellist
01-14-2005, 01:15 PM
erm.....i still dont' understand the two differences....

ChristinaS
01-14-2005, 07:22 PM
Did you follow the links to more information?

neilthecellist
01-14-2005, 07:41 PM
Did you follow the links to more information?


of course i did. otherwise i wouldn't have made that last post.

ChristinaS
01-14-2005, 07:45 PM
What part of this don't you understand?



Two-pass encoding is an encoding method available with some codecs, like the Windows Media Video 9 codec. When you use two-pass encoding, the codec processes all of the samples for the stream twice. On the first pass, the codec gathers information about the content of the stream. On the second pass, the codec uses the information gathered on the first pass to optimize the encoding process for the stream.
In the Constant Bit Rate encoding mode, files that are encoded in two passes are generally more efficient than files encoded in a single pass. Quality-based VBR, which is one pass, produces more consistent quality than bit-rate-based VBR, which is two-pass.

You cannot use two-pass encoding on live streams.

neilthecellist
01-20-2005, 09:27 AM
er, does that make 2 Pass Filtering sound better?

iTunesIsEvil
02-03-2005, 01:30 PM
er, does that make 2 Pass Filtering sound better?

It's possible. To me, it sounds like 2-Pass takes a stream, looks at it so it knows what its about to get hit with, and then can make better decisions about how to use resources (CPU & RAM) to deal with what is coming it's way. It's possible that this just speeds things up, and its also possible that this just makes things run much more smoothly. For example, lets say you're going to Canada for vacation in February (why the hell you would do that is something that I may never know), and lets also say youre going to drive. You know that Canada is North of you (I'm in Indiana, hence my example). While you could just hop in a jeep and try driving North over hills, rocks, trees, streams, and small fluffy animals, most of us would rather get a map, and follow a highway. I personally think that that is what 2-Pass does, it basically makes a map for itself of whats in front of it, so it can make sure it know's what it's doing. I could be talking out 'o my ass though... these are just personal opinions.


How long does it take to understand the Ogg Vorbis code? I got the source code but I don't understand it all...

My only programming experience is with Visual Basic......and I've only just started it.

It takes about as long as it takes man. If your only experience is really with VB then youre going to have a hard time with it. I'm gonna guess that the Ogg Vorbis code is in C/C++ which is probably pretty difficult if youre only starting VB because theyre pretty much nothing like one another.

neilthecellist
02-25-2005, 05:44 PM
WHEE!!! I'm done with vBasic. Just graduated from my computer programming class. in two years, I'm officially taking AP Computer Science, where I'll learn--

OH NO!! They only teach Java, not C++. DAM˝IT!!!

LtData
02-25-2005, 08:22 PM
WHEE!!! I'm done with vBasic. Just graduated from my computer programming class. in two years, I'm officially taking AP Computer Science, where I'll learn--

OH NO!! They only teach Java, not C++. DAM˝IT!!!
Yup, and Java sucks. The main reason they're doing that is probably the same reason everyone else is, including my college: To make sure you learn Object-Oriented Programming.

donny
02-26-2005, 05:03 PM
now don't be so harsh on java, it is a really well done language, and it has almost all of the good sides of C, and a few extra tricks up it's sleeve... mainly the extreme portability, so if you write something in java, it will work on any computer with java virtual machine, not just on windows, but on mac, linux or whatever you're "driving"...

and no I'm not saying that you should quit C and go for java, but that you should show some respect for a very well concepted language, and as another fact it is a lot more easier to teach and learn, because people get lost easily in C, and I think that you would have to agree that it is not for everyone...

C does have it's practical advances such as it is very spread and you can easily find help for any problem you have...

enough with the yapping, I'm done

and yes I do know what is dAP written in, before you ask...

neilthecellist
02-26-2005, 08:44 PM
dAP was made in C or C++?

isn't Visual C++ object oriented?

LtData
02-26-2005, 09:35 PM
C++ CAN be Object-Oriented at times, but the language does not require it to be. Java forces you to be Object-Oriented.

And as for my dislike of Java, it is mostly the result of the teacher that I had for it. He read us PowerPoint presentations to "teach" us.

neilthecellist
02-27-2005, 12:51 AM
OMG! My vBasic teacher used ppt's to teach us too! It was a nightmare!

donny
02-27-2005, 09:06 AM
yes there are many teachers who really can't think how to teach or are just not motivated enough to do something normal...
I am on the otehr side most of the time lucky with the teachers I have... and there is one assistent who is also showing us power point presentations, but he is actually cool, and he really is trying hard to make them and explaint them... I think it is probably just the way power point should be used...

neilthecellist
02-28-2005, 08:15 PM
i hate ppl who can't teach. It doesn't matter HOW they teach it, what kind of materials they use to teach or whatever, it's their inability to get the student to understand. that's the main point. :-)


I like powerpoints, i just hate how they're used in class.

milfzor
08-06-2005, 11:43 AM
back along the lines of audio compression...a big part of it (from what i understand...i wish i knew a little more in detail of this) is how well the codecs are optimized, which is why if you download the SSE2 version of the ogg codec, it runs HORRENDOUSLY faster than the regular (non optimized) version. On my computer, i can convert an audio file to ogg ALMOST as fast as wav. Btw, neilthecellist, i have NEARLY the same rig as you...768mb ram with (im pretty sure) the same cdrw drive, i just recently threw in a lite on dvd burner, too...those guys make AMAZING drives. my processor is SLIGHTLY faster (2ghz and AMD instead of p4) but my results should be fairly comparable to yours....i can get around 40-45x speed with conversion to wav, and somewhere around 30-35x for conversion to ogg (at least sourced from a cd) I really wish that there was some more optimization thrown into the .la codec, its GREAT for compression, but HORRIBLE for compression time.

LtData
08-06-2005, 03:28 PM
Umm.. but your 2GHz AMD will run circles around his 1.8P4. Especially since I think he had one of the early P4s, which is walked on by a 1.66GHz AMD. :D

neilthecellist
08-07-2005, 11:31 PM
Yeah, your AMD > my Pentium.

Wow, a huge thread bump. Thanks guys! :)