Rockbox

  • Status Unconfirmed
  • Percent Complete
    0%
  • Task Type Bugs
  • Category Music playback
  • Assigned To No-one
  • Operating System Sansa AMSv2
  • Severity Low
  • Priority Very Low
  • Reported Version Release 3.12
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by Takla - 2013-04-21

FS#12856 - HE-AAC plays back at wrong speed

Rockbox 3.1.3 on Clip+ (also iriver h140/340. also previous versions of rockbox).

Some HE-AAC files play back at half speed.

Example file info (comment/lyric fields removed as very long):

General
Complete name : Witness_-_The_Khmer_Rouge_take_power.m4a
Format : MPEG-4
Format profile : Apple audio with iTunes info
Codec ID : M4A
File size : 4.09 MiB
Duration : 9mn 0s
Overall bit rate mode : Constant
Overall bit rate : 63.5 Kbps
Album : Witness
Album/Performer : BBC Radio
Track name : The Khmer Rouge take power
Grouping : News
Performer : BBC World Service
Composer : BBC iPlayer
Genre : News
Recorded date : 2013-04-18T08:50:00+01:00
Tagged date : UTC 2013-04-18 09:07:25
Writing application : Lavf55.0.100

Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : HE-AAC / LC
Codec ID : 40
Duration : 9mn 0s
Duration_LastFrame : -1ms
Bit rate mode : Constant
Bit rate : 62.7 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz / 24.0 KHz
Compression mode : Lossy
Stream size : 4.04 MiB (99%)

30 second sample attached (cut with ffmpeg, full metadata)

Forum report http://forums.rockbox.org/index.php/topic,43012.0.html

Takla commented on 2013-04-21 21:44

I don't see the attachment so here it is again

   wit.m4a (234.4 KiB)
porjo commented on 2013-08-23 19:05

I'm having the same problem in every respect except my .m4a file is not HE-AAC. I've attached a 30sec sample here: 'go.m4a' which demonstrates the issue.

Media info is as follows:

General
Complete name : go.m4a
Format : MPEG-4
Format profile : Apple audio with iTunes info
Codec ID : M4A
File size : 93.7 KiB
Duration : 30s 47ms
Overall bit rate mode : Variable
Overall bit rate : 25.6 Kbps
Writing application : Lavf52.64.2

Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 30s 47ms
Bit rate mode : Variable
Bit rate : 24.0 Kbps
Channel count : 2 channels
Original Channel count : 1 channel
Channel positions : Front: C
Sampling rate : 22.05 KHz
Compression mode : Lossy
Stream size : 88.0 KiB (94%)

   go.m4a (93.7 KiB)
porjo commented on 2013-08-23 19:24

The attachments on this bug report are getting mangled by the web server and are un-playable.

porjo commented on 2013-08-24 09:27

Running my file through mp4box fixes this issue e.g. MP4Box -add go.m4a go2.m4a

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