No sound for HE-AAC v2 services (with Parametric Stereo)

[andimik]

Using DABstar-2.6.0-x86_64.AppImage under Linux Mint, on all services with HE-AAC v2 codec the sound disappears after around 1 second (but SLS and DL+ are still updated). Seems that the audio codec is not supported in the AppImage of DABstar.

For example in Austria: Mein Kinderradio and ERF Süd, or LoungeFM.

As you are located in Munich, unfortunately there are no HE-AAC v2 services in Bavaria on air (according to FMLIST), but do you have any change to test Austrian Mux I from Salzburg-Gaisberg (5B)? Or do you need an ETI file or even a RAW file?

I get tons of Warning: Unexpected channel configuration change on the console.

See https://www.fmlist.org/sendertabelle/dab-st_more.php?inputLand=AUT&inputEn=A101 https://www.fmlist.org/sendertabelle/dab-st_more.php?inputLand=AUT&inputEn=A202

other programs

Qt-DAB

Qt-DAB (latest AppImage) has no problem with HE-AAC v2 audio.

dablin_gtk

has no problem with HE-AAC v2 audio, too.

[tomneda]

@andimik thanks for hinting to this issue.

Unfortunately, I have no ensemble here where a service uses "Parametric Stereo" (which seems to need a v2 HE-AAC coded).

As it worked on Qt-DAB and the lower layers in DABstar are mainly original to Qt-DAB (at least at a former state) I compared the AppImages from latest DABstar and latest Qt-DAB. The main difference is that I build my DABstar with faad-AAC decoder, Qt-DAB uses the FDK-AAC decoder. This is switchable with cmake.

So, next I will try to deliver the AppImage with the FDK-AAC instead of faad.

As I read, faad resp faad2 should work with PS/v2, it would be good I could test this. Salzburg-Gaisberg is too far away for my Omni-directional outdoor antenna (around 120km LOS), I am not able to receive a signal on 5B. Are you able to send me a RAW dump of one of your concerned ensembles? Some seconds should be enough.

I am not aware to handle ETI files as input. If Qt-DAB was able to do that I do not somehow maintained it. My first main developing aspects to DABstar were more the SW-related "RF frontend", not the protocol/decoding stages.

Unfortunately, I made an upgrade from Xubuntu 22.04 to 24.04 and my AppImage build-system is currently not working anymore. So, a fix (changing to FDK-AAC, a.o.) could take a while.

[andimik]

I have successfully built it from sources (branch main):

sudo apt-get install libfdk-aac-dev is required, otherwise it will fail.

cmake .. -DAIRSPY=ON -DSDRPLAY_V2=OFF -DSDRPLAY_V3=OFF -DHACKRF=ON -DLIMESDR=OFF -DRTL_TCP=ON -DPLUTO=OFF -DUHD=OFF -DRTLSDR_LINUX=ON -DUSE_HBF=OFF -DDATA_STREAMER=OFF -DVITERBI_SSE=ON -DVITERBI_NEON=OFF -DFDK_AAC=ON

But then the audio is at least not muting, but there are "gunshots" in the audio.

https://github.com/user-attachments/assets/f0efdc3a-d2bc-4d4f-bd66-02d3310b5468

[tomneda]

@andimik: that is a strange effect. I used FDK-ACC (2.0.2-3) since yesterday on non-PS programs and they work fine.

I assume Qt-DAB or AbracaDABra were still working fine with the same service? Does the other PS programs behave the same with the "shotgun sound"?

I would appreciate if you could send a some second long RAW dump of this channel to look at this further here.

[andimik]

Ok, I will prepare one.

[old-dab]

Hi! I can receive a lot of services with HE-AAC v2 codec on channel 7c from Groningen/Drenthe. The DABstar AppImage doesn't work with these services. But if I compile DABstar myself, it works fine. I have just compiled ist with FDK-ACC. Same problem as @andimik.

[andimik]

These are 3 recordings (xml files incl. header) from Austria (DAB+ Austria Mux I, this is only one file, so the description was wrong) and Slovenia (R1 national and R2 West).

https://we.tl/t-3mvLPOeKcY

Please note that the link is only valid till 9th October.

[tomneda]

@andimik your provided files helped me a lot. I could reproduce the problem clearly.

It turned out that the FDK-ACC lib provided with Ubuntu (still in 24.04) is somehow broken. If I rebuild the FDK-AAC lib with the same version (v2.0.2?) for my own then it worked very well.

So I used latest own-built v2.0.3 of the FDK-LIB and made a AppImage for that: V2.7.0

Please check if it works now and close this issue afterwards if yes.