More HE-AAC decoder issues

[lemming]

Hi

This is an ongoing issue that seemed to popup somewhere in the 2.2.6 release (hoped 2.3.6 would fix it). Any HE-AAC audio (all NZ freeview channels) suffer micro stutters in the audio that start out not much of an issue, but if the channel is left running grow substantially worse over time. Occasionally when the wife comes to bed last, she has just turned off the TV, and in the morning when it goes back on the sound is 50% on / off. A simple stop & start resets it.

Advice in the past is decoder selection. I have been through Monogram, DivX & am currently on Lav as part of SAF, and they all demonstrate the issue.... Currently HDMI to TV, but tried reverting to SPDIF straight to amp as original, and problem still exists.

As a test, I installed Media Portal, and running the same decoder setup, found no sound issues (on a sample of around 1/2 hr admittedly)....

So if all 3 decoders used work for other people (and used to work for me!!!), and the decoder I currently have works fine with an alternate PVR, it must be something with NPVR ???

Have attached logs in case they are any help, any suggestions appreciated... Let me know if more info is required.

Cheers Chris

[Lao Pan]

I have been having similar problems using the divX codec for UK HD Freeview (HE-AAC LC) for many months. It only happens on live TV and appears to be caused when the Video is rendering on-screen text or sharp edges - picture on a background in a news broadcast for instance, and is much worse if the background is predominately dark.

I have a feeling it is to do with the de-interlacing using too much memory buffer - not leaving enough for the audio decoding. (I am not a programmer, so could be totally wrong :confused

I have just switched to the LAV Audio decoder to test. So far there has not been any glitching, but the down side is that where the HD Broadcasts are in Stereo rather than 5.1 the sound is now only from the left and right speaker not from the matrixed 5.1 that the divX codec produces.

In a previous google for this problem I did come across a thread in media portal or similar where it was recommended to increase the size of the frame buffers - obviously in NPVR only Sub could do this if he thought it was appropriate / possible.

[lemming]

Good to hear at least 1 other person has a similar issue. My Dad also runs Npvr and has had the same problems, so with you that makes 3. I'll wait for it to get to an annoying state and post an audio recording so it's clear what is occurring...

I would have thought this maybe a more common issue (NZ freeview users???)

[lemming]

Audio capture as demonstration....

Some of the odd sounds are just the wife crashing around in the kitchen

[Reddwarf]

It only happens on live TV and appears to be caused when the Video is rendering on-screen text or sharp edges - picture on a background in a news broadcast for instance, and is much worse if the background is predominately dark.

I just observed this yesterday when watching a recording with HE-AAC sound and H.264 video, when the picture was very dark the sound broke up and lagged badly. I'm using LAV audio decoder. I have never seen this with other audio and video formats.

[Deev8]

I would have thought this maybe a more common issue (NZ freeview users???)

Yes I get audio stuttering on live TV (never when playing recordings) from New Zealand Freeview channels that only have an HE-AAC audio stream.

[gEd]

I have just switched to the LAV Audio decoder to test. So far there has not been any glitching, but the down side is that where the HD Broadcasts are in Stereo rather than 5.1 the sound is now only from the left and right speaker not from the matrixed 5.1 that the divX codec produces.

I have been struggling to get a good stereo down mix as well (so the dialogue is clearer). Seems the LAV peeps are working on it as we speak.
http://forum.doom9.org/showthread.php?t=156191&page=434

[lemming]

Bump...

Sub, any idea why I am getting the audio issues with Npvr, and not MP with the same decoders???

[sub]

Maybe try disabling all audio decoders other than HE-AAC to see if it helps.

[lemming]

Will do, have only the AC3 & HE-AAC decoders selected anyway.. What are you using ??