Sound broken mp4

[correx]

Could someone tell me why the sound is not working on IPodf ( on PC the sound works ok ) for the following file :

Thank you!


General
Complete name : alofp.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 42.5 MiB
Duration : 22s 990ms
Overall bit rate mode : Variable
Overall bit rate : 15.5 Mbps
Encoded date : UTC 2014-09-24 12:54:41
Tagged date : UTC 2014-09-24 12:54:41
Writing application : Lavf51.12.1

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Baseline@L4.0
Format settings, CABAC : No
Format settings, ReFrames : 1 frame
Format settings, GOP : M=1, N=12
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 22s 990ms
Bit rate : 15.3 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.247
Stream size : 42.0 MiB (99%)
Language : English
Encoded date : UTC 2014-09-24 12:54:41
Tagged date : UTC 2014-09-24 12:54:41

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 22s 919ms
Bit rate mode : Variable
Bit rate : 144 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz
Compression mode : Lossy
Stream size : 408 KiB (1%)
Language : English
Encoded date : UTC 2014-09-24 12:54:41
Tagged date : UTC 2014-09-24 12:54:41

[El Heggunte]

Perhaps because it was muxed by:

Writing application : Lavf51.12.1

Try remuxing with MP4Box, which has an -ipod option.

[correx]

MP4box said : Muxing failed.
Still, it outputed a file for which mediainfo says what I put below. I have no way to check if it works on apple devices yet. Do you think it will work on IPad.Iphone/Ipod this time ?

Thank you!
Correx.

General
Complete name : F:\mov\alofp.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 41.6 MiB
Duration : 22s 988ms
Overall bit rate mode : Variable
Overall bit rate : 15.2 Mbps
Encoded date : UTC 2014-09-23 18:38:49
Tagged date : UTC 2014-09-23 18:38:49

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Baseline@L4.0
Format settings, CABAC : No
Format settings, ReFrames : 1 frame
Format settings, GOP : M=1, N=12
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 22s 988ms
Bit rate : 15.0 Mbps
Maximum bit rate : 29.0 Mbps
Width : 640 pixels
Height : 768 pixels
Display aspect ratio : 0.833
Frame rate mode : Constant
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 1.020
Stream size : 41.2 MiB (99%)
Language : English
Encoded date : UTC 2014-09-24 12:44:55
Tagged date : UTC 2014-09-23 18:38:49

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 22s 917ms
Bit rate mode : Variable
Bit rate : 144 Kbps
Maximum bit rate : 200 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz
Compression mode : Lossy
Stream size : 408 KiB (1%)
Language : English
Encoded date : UTC 2014-09-23 18:38:49
Tagged date : UTC 2014-09-23 18:38:49

[El Heggunte]

I have no way to check if it works on apple devices yet. Do you think it will work on IPad.Iphone/Ipod this time ?

Sorry, I have zero devices made by Apple.

Now I think it's possible that the AAC stream itself is somehow non-compliant or broken...
and in this case, a mere remux will be pointless

Suggested workaround: use ffmpeg to decode the audio to an uncompressed .WAV file,
re-encode this latter with fhgaacenc or qaac,
remux the original video with the re-encoded audio,
TEST.

[hello_hello]

If I remember correctly..... and I may be wrong..... but I kind of remember the maximum AAC audio bitrate is 160kbps and it must be constant bitrate. I don't own an ianything either though so maybe someone else will know.

[El Heggunte]

@hello_hello: the maximum bitrate for AAC is 256kbps per channel.

BTW, we still don't know whether the MP4 file was created by the OP themselves, or gotten from elsewhere...

I have already seen borked MP3 streams that could be played correctly, or at all, only through MPlayer...

and now I also think that similarly-broken AAC streams can be generated by some obscure/half-assed AAC encoder(s)...

[Cornucopia]

Not sure what the max actually is supposed to be (it is probably different for mono vs. stereo/2ch vs. 5.1), but for stereo it is listed in Wikipedia as 529kbps. I know for a fact that, when using LameXP, I can do up to 400kbps (stereo). And it can do CBR AND VBR (and ABR and VBR-constrained).

Now, how well MacOS or iOS apps & devices accept the range of the spec, I also have no idea. Of course, it took forever before Quicktime even accepted AAC-HE (vs. AAC-LC), so go figure. I know QT7proWin can both encode & decode up to 320kbps, and it is usually the most "crippled" of the QT products, so I'm confident that pretty much every QT-based (and this includes AVFoundation-based as well) app/device should at least be able to do that.

Scott

AAH...El Heggunte beat me to it!

[hello_hello]

@hello_hello: the maximum bitrate for AAC is 256kbps per channel.

I was referring to what an ipod will play, not the AAC spec itself. This is from the first ipod specs I found via Google. I don't know which iflavour of ipod the OP owns. I think the ipad is the same.

iPod touch 16GB (5th generation, Mid 2013)
Audio
AAC (8 to 320 Kbps), Protected AAC (from iTunes Store), HE-AAC, MP3 (8 to 320 Kbps), MP3 VBR, Audible (formats 2, 3, 4, Audible Enhanced Audio, AAX, and AAX+), Apple Lossless, AIFF, and WAV
TV and Video
H.264 video up to 1080p, 30 frames per second, Main Profile level 4.1 with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats

As I said, I've never owned an ianything but I remember the 160kbps being a constant bitrate. It seems odd VBR MP3 is specified but for AAC it's not, although AAC needing to be constant bitrate.... maybe I imagined it.
I assume only stereo (or mono) audio is supported, although the audio is stereo in this case.

[correx]

Hey guys,
I sent the result file to whom it requested it from me, but unfortunately I got no feedback ( yet, maybe ).
The only thing I can say is that, the original .mov file , from which I made ( using xilisoft ) the mp4 file described in my first post , played fine on mplayer and vlc, but did not play correctly in media player classic ( not even video ) and I couldn't even add it to Itunes library.
For the moment I don't need to solve this anymore, but thank a tone to all of you for you efforts!