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[Q] Audio stutter in AAC format

OP ChungHung.Chen

30th August 2014, 02:08 PM   |  #1  
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Dear Devs,
I have a MKV file with AAC audio, it played smoothly in PC.
But audio has shutters with MX Player ( HW / HW+ / SW are all tested )
Also tested by 3 different android devices, same results.
Could you help to solve this problem?
Here is the AAC file (85MB) which extracted from MKV.
Thanks!!
31st August 2014, 02:52 AM   |  #2  
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What are the 4 devices you tested it on?
31st August 2014, 05:51 AM   |  #3  
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Quote:
Originally Posted by CDB-Man

What are the 4 devices you tested it on?

Sorry for typo, tested on 3 devices.

Moto XT910 / CM11-nightly-20140828 w/ stock CM11 kernel
Nexus 7 2012 / stock 4.4.4 w/ stock kernel
Asus ME301T / stock 4.2.1 w/ stock kernel

All tested with lastest version of MX player Pro.
If any other information needed, please let me know.
Thanks.

Sent from my XT910 using XDA Free mobile app
3rd September 2014, 10:06 AM   |  #4  
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Any progress or need more information?
7th September 2014, 12:34 PM   |  #5  
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Quote:
Originally Posted by ChungHung.Chen

Any progress or need more information?

I've checked your .aac file but audio itself played with no lag.
I think this is not audio issue but video issue. Would you send full or part of .mkv file?
Thanks
7th September 2014, 02:37 PM   |  #6  
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Quote:
Originally Posted by bleu8888

I've checked your .aac file but audio itself played with no lag.
I think this is not audio issue but video issue. Would you send full or part of .mkv file?
Thanks

Hi,
Here is the Test Video.
Which created by latest MKVMerge.
Thanks for your help.
8th September 2014, 09:26 AM   |  #7  
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Quote:
Originally Posted by ChungHung.Chen

Hi,
Here is the Test Video.
Which created by latest MKVMerge.
Thanks for your help.

It is the problem of .mkv file itself. Audio track contains less frames than video track.
So MX Player is stuttering to keep a/v sync.
8th September 2014, 09:34 AM   |  #8  
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Quote:
Originally Posted by bleu8888

It is the problem of .mkv file itself. Audio track contains less frames than video track.
So MX Player is stuttering to keep a/v sync.

Thanks for your information.
Because my audio track is from another source.
So the root cause is different frame rate of A/V source?
Does any method/tool to fix this issue?
RE-encode whole MKV file?
8th September 2014, 09:38 AM   |  #9  
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Quote:
Originally Posted by ChungHung.Chen

Thanks for your information.
Because my audio track is from another source.
So the root cause is different frame rate of A/V source? -> Yes
Does any method/tool to fix this issue? -> I have no idea. May someone else answer it.
RE-encode whole MKV file? -> Yes. there is no such feature in MX Player to stretch audio frames in realtime.

...
Last edited by bleu8888; 8th September 2014 at 09:40 AM.
10th September 2014, 08:24 AM   |  #10  
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Quote:
Originally Posted by ChungHung.Chen

Thanks for your information.
Because my audio track is from another source.
So the root cause is different frame rate of A/V source? <-- Yes
Does any method/tool to fix this issue? <-- not any simple ways. You could force re-time/timeshift of the audio stream on mux. You could reencode the audio and slow playback speed.
RE-encode whole MKV file?

You should really be asking on a video encoding forum instead. Combining video/audio tracks from different sources is always not a simple task if they differ in any major area, such as length.

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