Dolby AC4 sound Track

[Etienne]

Some Channels stating broadcasting with this new codec... and no sound in DVBViewer.

Here under Transedit capturing.

Will we have chance to have soon settings for Ac4 audio codec in Directx settings ?

 

[Griga]

Up to now there is no known DirectShow AC4 decoder and no DirectShow AC4 specification (particularly no AC4 MEDIASUBTYPE GUID). So ATM there is nothing that we can do about it.

[Etienne]

Ok thanks Griga for quick response.

It is true that there are experimental broadcastings ATM.

But some TV / Boxes are compatibles.

PC is a other subject, perhaps some royaltiies will come, it's Dolby machine...

[Radioman]

I have question related to this proposed AC4 audio:
If I record this Test UHD 3 stream (.ts) with DVBViwer it only shows video, when I analyze it. No audio?
If I look at source properties the audio state is connected (PID 230).

BTW the audio plays fine if I watch this channel live with my UHD TV.

[spaceship9876]

Is this helpful at all to get AC-4 working: https://github.com/DolbyLaboratories/dlb_mp4base

[Griga]

vor 12 Stunden schrieb spaceship9876:

Is this helpful at all to get AC-4 working

 

No. As already mentioned, a DirectShow decoder is required for DVBViewer. However, since we don't develop decoders, it comes down to an external solution, e.g.

• an open source implementation, e.g. in FFmpeg, that can be inherited by LAV Filters.
• native support in Windows by the MS audio decoder
• a commercial  decoder, e.g. from MainConcept or Cyberlink, for which you have to pay.

[Etienne]

Hi Griga, some news for this codec ?

[Griga]

https://github.com/Nevcairiel/LAVFilters/issues/411

[Etienne]

Yep, shame.

Olympics games will start on new Mux R9 Dvb T2 with France 2 and France 3 UHD. No AC4 codec .. no T2 Usb stick need..

I think It's royalties and not technical problem.

Edited July 16, 2024 by Etienne