Audio Cuts Out For Short Bursts With Some Of My MP4's Options

[Nitemann]

i have spent a few weeks trying to figure this out, and i am baffled, or i think it must be a firmware glitch.

almost all my mp4's are aac audio with 2 and 6 track audio, and some, not all of the ones i get have audio that cuts out for a split second.

a buddy of mine also has the same unit (WDTV Live) and we determined together that is not the video file, its something in the audio tracks. for instance, both of us got a blu ray rip of shooter, and from different people, and we found that our audio cut outs are in the same spots.

I have no idea why, and i have tried removing the 6 channel and then alternately removing the 2 channel, and still haven't been able to nail down the problem.

heres the mediainfo on one of the files in question.

I have been doing all my MP4 Ripping with the original ac3 passthru and have no issues, but these are giving me problems.

Any Ideas?

CODE

General
Complete name                    : I:\My Videos\Movies\New Additions\Shooter.mp4
Format                           : MPEG-4
Format profile                   : Base Media
Codec ID                         : isom
File size                        : 2.16 GiB
Duration                         : 2h 5mn
Overall bit rate                 : 2 460 Kbps
Encoded date                     : UTC 2010-02-02 22:26:37
Tagged date                      : UTC 2010-02-02 22:26:37
Cover                            : Yes

Video
ID                               : 1
Format                           : AVC
Format/Info                      : Advanced Video Codec
Format profile                   : High@L4.1
Format settings, CABAC           : Yes
Format settings, ReFrames        : 8 frames
Codec ID                         : avc1
Codec ID/Info                    : Advanced Video Coding
Duration                         : 2h 5mn
Bit rate mode                    : Variable
Bit rate                         : 2 138 Kbps
Maximum bit rate                 : 20.7 Mbps
Width                            : 1 280 pixels
Height                           : 528 pixels
Display aspect ratio             : 2.40:1
Frame rate mode                  : Constant
Frame rate                       : 23.976 fps
Resolution                       : 8 bits
Colorimetry                      : 4:2:0
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.132
Stream size                      : 1.88 GiB (87%)
Title                            : Shooter By 3Li
Writing library                  : x264 core 80 r1376M 3feaec2
Encoding settings                : cabac=1 / ref=8 / deblock=1:-2:-2 / analyse=0x3:0x113 / me=umh / subme=9 / psy=1 / psy_rd=0.2:0.0 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-1 / threads=3 / sliced_threads=0 / slices=2 / nr=0 / decimate=0 / mbaff=0 / constrained_intra=0 / bframes=6 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=1 / wpredb=1 / wpredp=2 / keyint=250 / keyint_min=25 / scenecut=40 / rc_lookahead=42 / rc=2pass / mbtree=1 / bitrate=2138 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
Encoded date                     : UTC 2010-02-02 04:51:34
Tagged date                      : UTC 2010-02-02 22:27:44

Audio
ID                               : 2
Format                           : AAC
Format/Info                      : Advanced Audio Codec
Format version                   : Version 4
Format profile                   : LC
Format settings, SBR             : No
Codec ID                         : 40
Duration                         : 2h 5mn
Bit rate mode                    : Variable
Bit rate                         : 320 Kbps
Maximum bit rate                 : 331 Kbps
Channel(s)                       : 6 channels
Channel positions                : Front: L C R, Side: L R, LFE
Sampling rate                    : 48.0 KHz
Stream size                      : 287 MiB (13%)
Title                            : Shooter
Language                         : English
Encoded date                     : UTC 2010-02-02 22:27:28
Tagged date                      : UTC 2010-02-02 22:27:44

[WDUser]

for instance, both of us got a blu ray rip of shooter, and from different people, and we found that our audio cut outs are in the same spots.

This is what confused me. I mean, two different MP4s, even if from the same source, shouldn't exhibit the exact same error at the same spot unless the problem lies with the source itself. Wouldn't you agree? All I can think of is that the bitrate might be spiking too much at those spots and the Live's not able to handle the same. Still...

Which FW version do you have BTW? Also, how are you playing the audio? From an external receiver? HDMI? TOSLink? Can you try the composite connection and see if 2-channel works fine?

[Nitemann]

just running to the television, no receiver, via hdmi, i did try and hook up with the rca cable, but the audio cut out in the same place.

i do have the most recent firmware.

i think you may be right, there is something in that spot that's causing the audio decoder or whatever to cut for a sec, what i dont get is that it does the same thing whether its the 2 channel or 6.

Sure is crazy, i think it has to be a firmware glitch. i gave my original wdtv to my brother when i got my live, ima have him try the same file tomorrow and see if it does it there.

i started going thru all my mp4s today, and i am finding this same problem on lots of them. i dont think its encoding, because i pull from several different sources, and still have similar issues.

ac3 does fine, but something about aac is off.

[Nitemann]

So Am i the only one that's experiencing this?

[Nitemann]

i believe i have found the problem. someone said that wdtv live doesnt support aac with 6 channels, but it does with 2.

u can try switching audio if there are 2 and you still have the audio cutting out, but if you remove the 6 channel with mp4 muxer, it appears to fix the problem

[WDUser]

u can try switching audio if there are 2 and you still have the audio cutting out, but if you remove the 6 channel with mp4 muxer, it appears to fix the problem

I thought you already tried doing that?

I have no idea why, and i have tried removing the 6 channel and then alternately removing the 2 channel, and still haven't been able to nail down the problem.

Anyway, good you got it to work finally, though I guess an external receiver with AAC support should have no problems playing such 6-channel MP4s.