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Full Version: @Nic : What is your AAC DirectShowFilter doing ;)
Hydrogenaudio Forums > Lossy Audio Compression > AAC > AAC - General
ChristianHJW
Just a quick visit to see what you are doing instead of coding the bloody filter, Nic wink.gif ...

Any news from nando or any other help regarding how to mux AAC with our DivX videos ??
Nic
I know, I know smile.gif

The filter, to be honest, (apart from the bugs smile.gif is done, I cant be arsed to code and get rid of the little bugs until Ive learnt how to mux it. Im going to have to do this myself I know. Im going to have to change the RC2 source and edit it myself.....I should have guessed this from the start & just done it.

However, from reading about I know how its mux'ed properly....You have to find the byte length of the samples to get the correct amount of bytes per section of AVI file (thats a crap explanation, but I know what I mean)

So I will do it.But first I want a bloody DVD drive (do you know ive never even seen a DVD disc nevermind ripped ? smile.gif & a new hard drive then ill finish it. At present im writing my C crack of SafeDisc v2 (but thats for another forum smile.gif

Cheers,
-Nic

ps
Enjoy merry old england... smile.gif (i hope the weather in Bavaria is better than here.... smile.gif
TrNSZ
Any updates or beta releases?
tangent
QUOTE
Originally posted by ChristianHJW
Any news from nando or any other help regarding how to mux AAC with our DivX videos ??

Well, Nando was last seen on the Doom9 forums on the 7/16/2001, and was supposedly going for a 4 week holiday. Kind of worrying if you ask me...
Nic
Yeah, God knows where his got to.He also had a shortish temper so maybe his had ebough of peopl badgering him. I saw that Phreak404 posted a link to Nandub RC3 (the next version) so maybe Nando wants to finish Naddub without everyone (including myself I guess! smile.gif ) hassling him. I hope his alright though....

Cheers,
-Nic
ChristianHJW
I am not sure but i guess RC3 was done by phreak404, not Nando ....
ChristianHJW
Nic, check this thread in the Ogg section :
http://www.hydrogenaudio.org/forums/showth...&t=4271#post774

ingo might be able to help you !!
ChristianHJW
Bump . Any news here ? Lazy Nic, come on, we're waiting wink.gif .... or is Ogg Vorbis now in the center of your interest ??
Nic
LoL! Me Lazy, Ive never heard such insolence smile.gif smile.gif

Im finally getting myself a DVD drive (lol) hopefully today, so maybe my interest will re-appear when I have to put up with low bitrate mp3 on my movies smile.gif

The AAC DShow filter, isn't too bad, theres certain things I could do, (i.e. Make it so it loads AAC files(rather than the need to put a wav header on), better handling of seeking, etc)

However, none of this would help the sync'ing sad.gif

There are rumours of Nando being about again (but not yet at Doom9).........Will have to wait & see.

Take Care,
-Nic
ciber-fred
is somewhere to download for testing purpose ?
ChristianHJW
Nic's homepage, being 'xyz.Nics-stuff.zyx' or similar. Sorry i cant be more precise, but i lost most of my old links recently when i decided to delete an old, unused profile out of my NT4 WinNT directory taking 48 MB but that very unfortunately was my actual profile but marked as unused as i had installed a new program in the same logon ( one of the secret things of Windows you have to learn hard i guess ), so all my shortcuts, favourites etc. were gone ...... sad.gif !!
sven_Bent
hey nic

if it would ever help speed up Directsound filter development i woulde personally send you a dvd drive (region free) and some DVD to rip. :-D

any news on how the developments are going.
and where are you beta files today ???
can't seem to find it anywhere
Nic
Happy Christmas BTW!

Erm....I haven't touched the filter (but I do have a DVD drive now YaY! Just finished ripping the first two series of the Sopranos)....

The filter, is ok. Thats not the problem really. It does have bugs, but they're nothing huge. However, the big problem is mux'ing VBR audio into an AVI file. (The emergence of the mp4 format being used in the near future has my hopes up.)

Read at virtual dub the latest news for a good description of the problems and solutions for mux'ing VBR audio. I may try to mux it properly 2morrow (as its christmas I have time off... smile.gif

Did you know that a guy at DivX Networks asked me to send him the source code smile.gif I haven't as yet....But will do (again maybe tomorrow). Also BlackSun wants me to complete it for his PowerDivX NG 4.

So id better get on it, but recently ive been adding bits & pieces to DVD2AVI (DivX4 2pass, interface for Azid + Lame, Interface for using VStrip, etc etc)

Anyway il keep you posted, ill do something with it 2morrow.

Cheers,
-Nic
sven_Bent
QUOTE
The filter, is ok. Thats not the problem really. It does have bugs, but they're nothing huge. However, the big problem is mux'ing VBR audio into an AVI file. (The emergence of the mp4 format being used in the near future has my hopes up.)


Does this men that AAC CBR work probaly ???
becuase if just this work it rocks. still better then lame vbr at around 128kbits
ChristianHJW
.... good question ..... is there a 'AACtoWAV' available ? If so i guess you could simply use Virtualdub and mux the AAC CBR stream with the video once you gave it a WAV header ...... but what do i know .....
sven_Bent
nic has nade an AAC into wav proggy.

not an conveter but just ad's wav header.

but i never tried it with cbr ..only VBR

so if anyboody knows where to find nic's stuff again it would apriciated
rjamorim
Nic's Stuff page is here:
http://www.freewebz.com/nixstuff/

But I didn't find any aac2wav converter. Only a wma2wav.
Nic
AAC2WAV comes with the filter, The filter only plays AAC files with a wav header (this is just for loading purposes). U can use VDub using the Wav input to mux them, but there will be sync issues.

Unfortunatly CBR AAC is not really CBR, the blocks are not equal in size (in that respect it is kinda like ABR). I asked Ivan a couple of times about making a true CBR AAC (as you can use padding). However, he stated that it would mean a complete overhaul of his encoder & it would mean the files would be hugely oversized for the bitrate used. (or similar...Anyway it is not feasible)

Back to the old drawing board smile.gif

Cheers,
-Nic
Ivan Dimkovic
Nic - in no case AAC is 'fully' CBR, a bit reservoir is defined for each bit rate and sampling rate. For example, for 44100 Hz Stereo 128 Kbit/s encoding the bit reservoir is about 8000 Bits

Encoder can fluctate in that range (add and donate bits to the reservoir as long as bit reservoir is 0<bit_reservoir<bitres_size), so it is necessary to buffer at least 8000 bits in order to start playback.

PsyTEL AAC is a little bit 'nasty' in the behavior and it might overflow/underflow bit reservoir sometimes - I am sorry for that. FhG AAC maintains bit reservoir demands and their files are very near the 128 kbits/s.

It is possible to force encoder not to use bit reservoir at all, and to encode each frame in fixed bitrate of 128 kbits/s, but it would seriously compromise quality and I am not going to do that smile.gif
Nic
Thats what I meant smile.gif I knew that about the bit reservoir from what you had said before & from my own tinkering with AAC.

Thanks for making it clear though smile.gif

Cheers,
-Nic
BlackSun
QUOTE
Did you know that a guy at DivX Networks asked me to send him the source code  I haven't as yet....But will do (again maybe tomorrow). Also BlackSun wants me to complete it for his PowerDivX NG 4.


No !! ohmy.gif Who was his guy ? I want his name please
Nic
Andrea Grazziani

His email came from @divxnetworks.com

Cheers,
-Nic
BlackSun
Ah, so it's e7abe7a, a nice guy.
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