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Mpeg4 Part10 Level 3.0 & Aac-he Audio


Bobben

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well lets put it this way: the viewer is able to handle this aac. But there will be no codec which is able to handle this.

 

Why exactly wont there be no codec able to handle it? Legal issues or?

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the only one currently able to decode this stuff can not be bought by the enduser. If it were to bundle with the DVBViewer, it will affect the price of the DVBViewer and you will have to pay for updates in the future cause this decoder is not free.

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I have read 'Mainconcept' somewhere... where was it... hmmm.... let me think. I suggest you check Radioten's post :( .

Edited by CiNcH
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I guess there are licence fee's to be paid to ISO for supporting ISO/IEC 14496 HE-AAC ?

 

I don't think its a big problem if the codec will not be free when it becomes available.

We simply buy the codec and have HE-AAC working :(

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I could say its done when its done :) Well it definitively within this year and most likely even within this months. All smaller bugs are fixed and also the smaller features we had on our todo list (e.g. the shoutcast one i just forgot within the last months).

 

Christian

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Thanks for the update. Really apreciate these small 'status reports'. Its so much better than not knowing anything at all. But be careful, the 'you said' trolls might bite back at a later date :)

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Maybe you should check the TerraTec Home Cinema 5.36 Beta. It installs a AAC audio decoder with LATM support.

 

THC 5.36 Beta

 

Dunno whether it installs on systems without TerraTec hardware. But I think that those decoders will start to show up now...

Edited by CiNcH
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I gave that stuff a quick 'n dirty try: at least it installed without any TerraTec hardware in my PC. However, it is not clear if all parts were installed - there was a warning message in the beginning. And norwegian TV in my DVBViewer still is without sound. I guess it is not as simple... :)

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It was more ment for developers (or simply informational so that you see that at least LATM is starting to show up) as the public version of DVBViewer is not prepared for AAC within TS at all... I perfectly know that it is not that simple :) .

 

Sorry for the misunderstanding...

Edited by CiNcH
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  • 2 weeks later...
I gave that stuff a quick 'n dirty try: at least it installed without any TerraTec hardware in my PC. However, it is not clear if all parts were installed - there was a warning message in the beginning. And norwegian TV in my DVBViewer still is without sound. I guess it is not as simple... :blush:

 

FYI

After installing the latest version of TerraTec Home Cinema (5.39.00.226), the AAC-HE coded sound is working. This is tested (NRK1-2-3) on a Terratec Cinergy Piranha DVB-T tuner.

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Which settings do you use in DVBViewer Options|DirectX?

I guess in your case decoding of the AAC-HE sound is related to your TerraTec hardware. With my TechniSat Airstar 2, the DVBViewer remains silent... :blush:

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Which settings do you use in DVBViewer Options|DirectX?

I guess in your case decoding of the AAC-HE sound is related to your TerraTec hardware. With my TechniSat Airstar 2, the DVBViewer remains silent... :blush:

 

There is no hardware decoding in the Terratec Cinergy Piranha tuner. This is a tiny DVB-T / DAB tuner in a USB stick. http://tven.terratec.net/images/topics/CinergyPiranha.jpg

All decoding is done in software and the AAC-HE sound suddenly came to life after upgrading to the latest beta version of HomeCinema (ver 5.39.00.226). Terratec must have found the sollution to this, but I don't know if Terratec codecs can be used on other players. DVBViewer is tried without success.

 

This is the settings in HomeCinema

 

- Video renderer: Overlay Mixer

- Audio renderer: Default DirectSound Device

- Video decoder: Cyberlink Video/SP Decoder (Terratec)

- Audio decoder: Cyberlink Audio Decoder (TerraTec)

- H.264 decoder: Cybelink H.264/AVC Decoder

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There is no hardware decoding in the Terratec Cinergy Piranha tuner. All decoding is done in software and the AAC-HE sound suddenly came to life after upgrading to the latest beta version of HomeCinema (ver 5.39.00.226).

Nevertheless it will only work if the TerraTec Piranha is present, because without a special activation file that is installed with this device the Cyberlink audio decoder refuses to decode AAC.

 

After some trial and error, additional coding and some help from TerraTec I managed to let DVBViewer play HE AAC audio with the Cyberlink decoder. However, it's still a bit buggy. It has difficulties to find a starting point in the stream, and it doesn't perform SBR upsampling resp. high frequency reconstruction. The output samplerate should be 48 khz in case of Norwegian AAC, but it's 24 khz. So Cyberlink will have to work on it a bit more.

 

Have you decided any release date for the new viewer yet?

There is already a DVBViewer version out that fully supports HE AAC playback (DVBViewer GE 2.4.3), but it's useless without a particular decoder (the only one supported by this GE version up to now), and we don't know when it will be released. Sorry, that is not in our hands. If it is available I will inform you here and additionally provide a new DVBViewer Filter version with an AAC output pin in the members area.

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After some trial and error, additional coding and some help from TerraTec I managed to let DVBViewer play HE AAC audio with the Cyberlink decoder.

 

So is this a special non-public edition of the audio decoder? Or a dedicated AAC decoder?

Edited by CiNcH
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So is this a special non-public edition of the audio decoder? Or a dedicated AAC decoder?

No. There is an additional file associated with the audio decoder (claud.ax) that activates / deactivates features like AAC or AC3 decoding according to the licence conditions. E.g. the TerraTec Piranha is intended for reception of channels with AAC audio (particularly DVB-H and DMB), so AAC decoding is activated.

 

If someone guesses which file it is, please don't post or attach it here. We will not accept licence infringements in this board.

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  • 2 weeks later...

Hey guys

 

AAC playback works fine. :D

I've created my own AAC samples (in MP4 container) with the Nero AAC Encoder which you can download from Neros HP. The only thing thats a little bit strange that I have severel installed AAC decoders like CoreAAC, AAC decoder from Avermedia or the Cyberlink AAC decoder. But only the Cyberlink AAC decoder is shown in the dropdown list in the settings menu. Instead other decoders like the Avermedia AAC decoder will be displayed in the list of filters under View when playbacking. I thought when I choose the filter in the dropdown list thats the filter which is used.

 

And when I play back the file in WMP the AC3Filter is used. :)

 

Whats up there?

Edited by Filico
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And BTW you still did not get what DirectShow is all about. AAC within MP4 should have never been a problem as DVBViewer can build a default graph for file playback and AAC within file is not LATM. So this is no problem at all and has nothing to do with this thread.

 

DVBViewer just did not support AAC within TS. And because your file is played back has nothing to do with the recent modifications. And still you need a different decoder for AAC LATM...

 

The selection within DVBViewer most likely has no impact on MP4 AAC file playback.

Edited by CiNcH
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Thanks for your answer. Now, its obvious to me. So that means that filter selection in settings menu has nothing to do with the decoder selection for file playback.

 

Sorry for misunderstanding. But now, I know at least something more about de/muxing and transcoding from different audio formats to AAC. Also not bad, for me. :)

 

And whats LATM? Where can I read anything about this?

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And whats LATM? Where can I read anything about this?

There are different layers of packaging AAC data transmitted via DVB. From outside to inside:

 

TS (DVB transport stream) contains

PES (packetized elementary stream) contains

LOAS (low overhead audio stream) contains

LATM (low overhead audio transport multiplex) contains

AAC audio data (advanced audio coding)

 

like the Russian matrjoschka dolls :)

 

The LOAS and LATM syntax and semantics are defined in the ISO/IEC 14496-3 specifications - unfortunately the PDF is quite expensive :D LATM is a sophisticated and flexible way of multiplexing several audio streams, channels and layers in one transport stream. DVB transmissions only use part of it, since TS already provides stream multiplexing. LOAS adds a synchronisation layer to LATM, which means, headers with a sync word and a kind of frame length field, enabling applications or decoders to determine the beginning and length of the LATM data units after picking the stream up at a random point.

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Nice explanation. <_<

However, am I right: there is still no alternative for decoding norwegian DVB-t sound than to buy a TerraTec Piranha, plug it in, install their latest Home Cinema Beta software and then use its activated HE-AAC decoder? ;)

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  • 2 weeks later...
there is still no alternative for decoding norwegian DVB-t sound than to buy a TerraTec Piranha

There will be an alternative soon, most likely this year :) We managed to build a DirectShow wrapper for an open source library (as dll), and it seems to be able to decode Norwegian AAC pretty well. I'll upload it to the members area after some internal tests, and there will be needs for beta testers. So please stay tuned...

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Hi Griga,

 

I have a little question concerning the availability of this wrapper. DVBSHOP has just bought quite some licences of the DVBViewer Lite Edition (or whatever it is called) to bundle them with TT hardware, called the DVBSHOP.TVplayer, just like Digital Everywhere did with their FireDTV Viewer. From changelog I can see that later versions of the demuxer in the Lite Edition also support LOAS/LATM. So is this wrapper only ment for GE/Pro customers or can the DVBSHOP provide this wrapper within their downloadable version resp. provide it to customers together with the DVBViewer Lite Edition?

 

I know it is beta for now. Just asking...

Edited by CiNcH
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So is this wrapper only ment for GE/Pro customers or can the DVBSHOP provide this wrapper within their downloadable version resp. provide it to customers together with the DVBViewer Lite Edition?

Ask Christian. The beta version is supposed to be available for DVBViewer Pro/GE users only. Let's first see how it works. And (@everybody) pay attention to licence conditions concerning AAC decoding. It's up to you to take care of it. That's why we don't provide the decoder library here, but only the DirectShow wrapper. :)

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as a late christmas present for all people from Norway

..not only for people from Norge :) I would say right on time for an exotic transponder from Astra3 on 23,5E, though only few people will succeed to receive this carrier with an extremely low SR (555 kbaud).

 

Alas the filter/wrapper doesn't work with the (Austrian) radio channels. The extracted ESs play well in winamp.

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Ask Christian. The beta version is supposed to be available for DVBViewer Pro/GE users only. Let's first see how it works. And (@everybody) pay attention to licence conditions concerning AAC decoding. It's up to you to take care of it. That's why we don't provide the decoder library here, but only the DirectShow wrapper.

 

Ok, so I will come back when you give it the final status. BTW, the TS sample from this thread plays fine with the DVBSHOP.TVplayer/"DVBViewer Lite" v1.0.2.51 and its integrated PushSource (not Derrick's, but the first one).

Edited by CiNcH
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