[PROBLEM] No audio on many AAC files

[IngoVals]

Not sure if it is on all or just some AAC files but on whole TV series I get no audio. There is no indication anything is wrong. I'm no specialist in sound, I've got sound output as HDMI and 5.1 speakers, I can set audio value while watching these shows so I guess no passthrough.

XBCM log where I play two different files and I do raise/lower volume as a test on both:

http://pastebin.com/zXvUERmp

Software
XBian version: 1.0a5
XBMC version: (12 I think)
Overclock settings: No overclocking

Hardware
Power supply rating:
RPi model (model A/B 256mb/512mb): B
SD card size and make/type: 8GB
Network (wireless or LAN): LAN
Connected devices (TV, USB, network storage, etc.): HDMI to a Yamaha RX-V2600 reciever that plays audio and then HDMI up to Panasonic screen.

[IriDium]

I have a Yamaha RVX-373 and have a similar problem

I have HDMI control on the RV set to on, but if I boot up the RPi normally I get no audio.

What I have to do is switch on the RV first and then the RPi.

Alternatively use setup on the RV remote - turn HDMI control to off - sound should appear and then turn HDMI back on.

[mk01]

@IriDium

I had this problem with RVX-573 and older Samsung plasma screen. When I wanted to engage AV in the setup, I had to turn TV off/on.

Second Yamaha 67x and was ok with the TV. As another newer Samsung TV with RVX-573 and RVX-67x.

@IngoValis

Alpha5 must have quite old RPI firmware. Maybe you could try updating it.

[IngoVals]

(3rd Jan, 2014 03:05 AM)IriDium Wrote:  I have a Yamaha RVX-373 and have a similar problem

I have HDMI control on the RV set to on, but if I boot up the RPi normally I get no audio.

What I have to do is switch on the RV first and then the RPi.

Alternatively use setup on the RV remote - turn HDMI control to off - sound should appear and then turn HDMI back on.

(7th Jan, 2014 10:15 PM)mk01 Wrote:  @IriDium

I had this problem with RVX-573 and older Samsung plasma screen. When I wanted to engage AV in the setup, I had to turn TV off/on.

Second Yamaha 67x and was ok with the TV. As another newer Samsung TV with RVX-573 and RVX-67x.

@IngoValis

Alpha5 must have quite old RPI firmware. Maybe you could try updating it.

My problems are only with audio when it's AAC, most other files play well video and audio. Are you certain you got that part. I'm getting the idea that all audio was missing in your cases.

[IriDium]

Can you play the files correctly on another O/S - OSX or Windoze?

If so, can you provide a sample of an AAC file that is causing issue.

[IngoVals]

(8th Jan, 2014 02:29 AM)IriDium Wrote:  Can you play the files correctly on another O/S - OSX or Windoze?

If so, can you provide a sample of an AAC file that is causing issue.

Yes plays ok on VLC player, Windows.

I'll send you a link.

[IriDium]

Ok - I've got the file - so you can delete it from Dropbox.

I've tried in on my Beta 2 RPi and it plays perfectly Video (via HDMI) and Audio (via analog).

I would try plugging in some headphones into the analog port and see if you get sound there.

If not, then it looks like you will have to look at upgrading. (If you have a spare SDHC card, try installing a fresh Beta 2 first and see if that improves things).

[IngoVals]

(9th Jan, 2014 01:34 AM)IriDium Wrote:  Ok - I've got the file - so you can delete it from Dropbox.

I've tried in on my Beta 2 RPi and it plays perfectly Video (via HDMI) and Audio (via analog).

I would try plugging in some headphones into the analog port and see if you get sound there.

If not, then it looks like you will have to look at upgrading. (If you have a spare SDHC card, try installing a fresh Beta 2 first and see if that improves things).

OK I'll look into that. I should be able to easily try analog with either headphones or just straight into the receiver.

Do you have good knowledge on how digital audio works. I always assumed that the audio itself would be decoded in the Raspberry Pi itself and just some standard audio signal then sent to the receiver.

I'm however now getting the vibe that in some cases a digital signal is sent to the receiver and interpreted there. This is the case with digital 5.1 at least and then would need the receiver to support that standard like DTS for example or in this case AAC.

Could you point me towards something that explains this in layman's terms?
Did you notice if the sample I got you supported 5.1 or was just regular stereo?

[IriDium]

I've just tried on my main RPi (Beta 2)- HDMI (Video and audio) and it also plays fine.

Can you confirm that other files, mp4, mp3 play Ok. If so, looks like you'll need to upgrade.

---

I didn't test for 5.1 only audio, I've also deleted the file.

I'd suggest getting a 5.1 test file (Google it - they do exist) and try that.

I also guess you have run Yamaha's speaker test function?

[mk01]

(2nd Jan, 2014 06:27 AM)IngoVals Wrote:  Not sure if it is on all or just some AAC files but on whole TV series I get no audio. There is no indication anything is wrong. I'm no specialist in sound, I've got sound output as HDMI and 5.1 speakers, I can set audio value while watching these shows so I guess no passthrough.

there are almost no AVRs supporting passthrough for AAC. they can decode AAC, but not receive it as passthrough. that's why XBMC is doing live transcoding of AAC into AC3 when playing. all XBMC versions but RPI. no CPU power. but maybe will be managed later as hw supported AAC -> M LPCM.

so currently you get stereo only. for such media files I put it through ffmpeg - adding additional AC3 track to the file. all original streams are just demuxed and muxed back with additional audio track. takes 2-3 minutes and video quality is untouched.

[IngoVals]

(9th Jan, 2014 01:53 AM)IriDium Wrote:  I've just tried on my main RPi (Beta 2)- HDMI (Video and audio) and it also plays fine.

Can you confirm that other files, mp4, mp3 play Ok. If so, looks like you'll need to upgrade.

---

I didn't test for 5.1 only audio, I've also deleted the file.

I'd suggest getting a 5.1 test file (Google it - they do exist) and try that.

I also guess you have run Yamaha's speaker test function?

There is these two whole series and I've tried several episodes in both and they aren't working. I however have multiple other files that all work fine. Even some that have AAC audio so perhaps blaming AAC is premature. I don't know what else these two series have in common.

(9th Jan, 2014 04:32 AM)mk01 Wrote:  there are almost no AVRs supporting passthrough for AAC. they can decode AAC, but not receive it as passthrough. that's why XBMC is doing live transcoding of AAC into AC3 when playing. all XBMC versions but RPI. no CPU power. but maybe will be managed later as hw supported AAC -> M LPCM.

so currently you get stereo only. for such media files I put it through ffmpeg - adding additional AC3 track to the file. all original streams are just demuxed and muxed back with additional audio track. takes 2-3 minutes and video quality is untouched.

I might try to add a AC3 track though I think these files are stereo only so it might not be the problem. Shouldn't hurt though.

[mk01]

@IngoVals

now I don't recall if we think about the same so will sumarize:
1) XBMC doesn't support AAC passthrough
2) if XBMC is playing multichannel AAC audio and passthrough is allowed in audio settings, XBMC onthefly recodes AAC to AC3 (keeping all channels) and pushing through passthrough
3) XBMC on RPI is not doing that as it lacks needed cpu power
4) if you use ffmepg to add AC3 audio (as recoded original AAC), you doesn't alter your original media, but you make possible of use multichannel and passthrough. but your media file will be cca 500M bigger (2h movie)