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Old 10th July 2006, 22:10   #21  |  Link
vmesquita
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@tebasuna51
Thanks for the test, I'll check this. I have tested with a small 6h wav and Six Waves and it seemed to work fine (with no need for ^C). I'll run more testes to try to reproduce the issue.
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Old 11th July 2006, 12:23   #22  |  Link
tebasuna51
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After the test I think Aften is the best free ac3 encoder.

I want compare the options with the old reference encoder Sonic Foundry SoftEncode (in speed Aften is clearly the winner, Softencode need hours to encode a 6 chan 130 min long):

Audio service configuration
There are some more options in SoftEncode
-Audio coding mode: mode 4 (L,R,S) and mode 5 (L,C,R,S)
-Bit stream mode: other than Main audio service. Complete main
-Save frames in Intel byte order
I don't need this options.

Bit Stream
-Copyright bit
-Original bit stream
-Audio production information
Default is ok for me.

Preprocessing
-Input filtering->Digital deemphasis
-Input filtering->DC high-pass filter
-Input filtering->Bandwidth low-pass filter
-Input filtering->LFE low-pass filter
-Surround channel processing->90 degree phase shift
-Surround channel processing->3 dB atenuation
All this utilities can be applied to the wav input before the encoder process.
-Dynamic range compression (DRC):
This info must be generated be the encoder and, I think, is the more important difference between free and commercial encoders at this moment.

Conclusions
To improve Aften encoder there are two priorities for me:
-Generate DRC info. I know is not easy, and out of my knowledge, but I think is important.
-Accept 32 bit Int and Float wav's. If we have a more precise source we lose quality converting to 16 bit Int to be accepted by Aften. I can collaborate with this point if needed.

Questions
About ac3 VBR. Is compatible with avi container and DVD authoring programs?

@Kurtnoise. What is the difference between aften.exe and aften_g.exe in your last pack?
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Old 11th July 2006, 14:38   #23  |  Link
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Quote:
Originally Posted by tebasuna51
What is the difference between aften.exe and aften_g.exe in your last pack?
Honestly, I don't know...I tested both and compared bits-to-bits each results : this is the same. I hope that Justin can access as soon as possible in doom9 forum to give some answers.

Otherwise, you can post some notes here.

About compatibility for AVI container : I think this is the same thing like mp3 vbr.

Only worries I have come from vbr mode. Some decoders aren't able to decode/play properly this kind of files (at least on windows). With some Dshow filters like AC3 parser + AC3 filter, it works fine though.
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Old 11th July 2006, 18:40   #24  |  Link
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@ Kurtnoise13
have a new aften version in the homepage
http://jbr.homelinux.org/aften/

thanks

@ tebasuna51
Quote:
After the test I think Aften is the best free ac3 encoder.
good to know.

ot:
i don't know command lines.can you(anyone) please do one single "how to" ?
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Old 12th July 2006, 06:58   #25  |  Link
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iirc, there are no new things in the 0.02 version compared to my 0.01 build. I'll check later because I can't access to the official website right now.

For a "How to", I gave some commands in the 1st post but I'll try to integrate this into BeLight asap.
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Old 12th July 2006, 12:09   #26  |  Link
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this sounds exciting... i missed the thread for a few days, but now i'll be checking regularly

Quote:
About ac3 VBR. Is compatible with avi container and DVD authoring programs?
DVDMaestro spits out VBR (it requires CBR for the duration of each title. DVD in general is probably the same).

avi can probably handle it insofar as it handles VBR mp3 etc (kinda poorly).

about DRC info - i'm sure looking at the source for a dynamics compressor will help don't worry too much about the attack/release times used, as i really don't like the ones used by commercial encoders anyway (attack times are way too long usually). just remember the attack should probably vary depending on how much compression is applied - i'm not sure how decoders handle applying the gain. do they do it per block or interpolate the per-block values? my guess is they just gain each block and let the 50% overlap handle it, in which case too sudden a change would give a very strange effect of volume going down in audible increments.

all that stuff is testable though...

k, i hope at least some of that made sense
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Old 12th July 2006, 17:37   #27  |  Link
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Quote:
I'll try to integrate this into BeLight asap.
will be wonderful,thanks so much.
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Old 14th July 2006, 04:27   #28  |  Link
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@ Kurtnoise13
Quote:
I can't access to the official website right now
me too.i'm trying to open the official website for 3 days.
something wrong?(maybe you know about or have news)
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Old 14th July 2006, 10:32   #29  |  Link
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Seems to be ok now... So, I uploaded 0.02. As I said previously, there are nothing new except the name of some switches which are different.


Concerning this into BeLight, my first tests show that it doesn't work properly...:s and I don't know why. I'll check out when I'll have more time.
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Old 14th July 2006, 18:42   #30  |  Link
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@Tebasuna :
Quote:
Originally Posted by Justin Ruggles
"aften_g" is compiled with debugging symbols. The "g" refers to the gcc option "-g". This makes debugging easier (gdb will give the file, function, and line number of an error), but the binary is larger. The "aften" binary is the same as "aften_g", but the debugging symbols are stripped so the file is smaller.
All in all, for whose who prefer GUIs instead of command lines, I've made a small one. Drag&Drop is enabled. You can also have some infos by clicking in the Input Files list (Duration, Sampling-Rate, Bitrate, Channels Number). aften.exe must be in the same folder. If you have some suggests, I'm open...
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Old 14th July 2006, 20:04   #31  |  Link
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thank you so much for the Gui Kurtnoise13,you're very cool.
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Old 15th July 2006, 18:28   #32  |  Link
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Kurtnoise13,
selecting the output as "E:/temp" or any other folder,the AftenGui is saving the files in the root of the drive choosed( E:/ )
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Old 16th July 2006, 05:37   #33  |  Link
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Kurtnoise13

using 0.02
I suddenly have found myself working on sound features in avsFilmCutter and thought I would say thanks for the find and add my 2 cents.

I encoded a 2:21:29 clip and found the overall quality to be very poor.

I used all default settings and it sounded as if it was dropping bits or the buffer had under run. The time was reported at over 10 hours.

When used with a three minute clip at a CBR of 192,000 the times reported by the player were correct and the sound improved.

Seemed like there was junk in the stream, too. Data fields from the decoder ( AC3Filter ver 1.01a_rc5 ) keep jumping.

Both were 2 channel 16 bit waves at 48000 Hz.

Nice start, sure is easy to use.
Will keep watch.

Thanks again.
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Old 16th July 2006, 10:06   #34  |  Link
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@Raquete : fixed...

@Elbotron : yeah, as I said previously, files encoded with vbr mode have some issues during the decoding. an AC3 parser is needed. Or AC3 decoders need to be updated to support vbr...

For the moment, CBR mode is recommended.

Last edited by Kurtnoise; 30th July 2006 at 20:08.
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Old 16th July 2006, 10:41   #35  |  Link
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thank you so much .

why the AftenGui is not in the first post of the thread?!!!
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Old 17th July 2006, 23:17   #36  |  Link
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Ok, I can finally reply! To answer a few questions...

aften_g is not really different from aften in any significant way. The "aften_g" executable has debugging symbols, where "aften" does not. The size of the binary is larger for aften_g, but it is useful in finding problems in the code.

DRC is something that will be tricky to add. I do wish I had access to a good reference encoder to compare with. Maybe getting some DVD's and making a simple parser would give some clues as to how to calculate it properly.

24/32/float wav files will be supported sometime soon. It won't be that hard...I just have to rework the API a bit.

Filtering...I agree with adding a filter for LFE and DC, but not for bandwidth. That is effectively taken care of by excluding the highest MDCT coefficients. The only advantage I can see is maybe a smoother transition band.

I'm sorry that the site was down for a few days...I was out-of-town and it seems a power flicker reset my web server.

VBR and containers: As mentioned by others, it can be done in AVI the same way as with MP3. Also, I just found a place in the spec where it implies that VBR should be supported in MPEG-TS. There are two sets of bitrate codes for the audio stream descriptor. One set is for exact bit rate, while the other is for bit rate upper limit. I have gotten VBR to "work" in avi, mpeg-ps, mpeg-ts, and matroska. Decoding support will probably still be very limited though. I am really hoping that DVD players will support it. I would guess yes since most of the manufacturers probably paid for a Dolby-certified decoder so they could put the logo on the player.

Thanks for the GUI kurtnoise13. I don't have Windows, so could someone post a screenshot somewhere? I'm just curious. I might have an old version of Aften I wrote in Java lying around on my computer somewhere. If so, I could easily write a cross-platform GUI for that. For the record, I don't care much for Java when it comes to mathematical stuff because of the lack of unsigned types and pointer control, but it's wonderful for quick-n-easy graphical interfaces...and card games .

If I forgot anything or there are any other questions, ask away.

-Justin
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Old 18th July 2006, 00:08   #37  |  Link
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If someone wants to test this in various decoders, here is an MPEG2-PS file with VBR AC3.

http://jbr.homelinux.org/aften/right_place.mpg

-Justin
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Old 18th July 2006, 04:40   #38  |  Link
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Quote:
I am really hoping that DVD players will support it. I would guess yes since most of the manufacturers probably paid for a Dolby-certified decoder so they could put the logo on the player
well, that came with paying for the DVD logo... and DVD doesn't support VBR ac3. i'm sure one could hack a DVD to have VBR audio, but i doubt it'd play on anything at all. there are no authoring programs that support it, so one would have to use ifoedit or similar to place the VBR stream into the movie.

it'd be an interesting test though.
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Old 18th July 2006, 05:56   #39  |  Link
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Quote:
I don't have Windows, so could someone post a screenshot somewhere? I'm just curious.


welcome jruggle
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Old 18th July 2006, 06:03   #40  |  Link
Kurtnoise
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Quote:
Originally Posted by raquete
why the AftenGui is not in the first post of the thread?!!!
ok..done.

Quote:
Originally Posted by jruggle
I don't have Windows, so could someone post a screenshot somewhere? I'm just curious.
Welcome on Doom9 Justin . Here is a screenshot.(edit: oups, raquete is faster than me.) I plan to make a new GUI with GTK later...


Radiohead is good... Your mpg file works fine with mplayer and some other directshow players (MPC, TCMP).

Last edited by Kurtnoise; 18th July 2006 at 06:11.
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