AAC audio distorted on iOS

Wowza Streaming Engine
1

Hello!

I am transcoding the stream into three profiles.

High profile has audio passthrough but the rest two have 96k and 56k respectively.

When I play the stream on iOS devices (iPad1, iPhone 4S and 5) the sound is heavily distorted for both transcoded audio profiles.

Passtrough audio plays fine and video is fine as well.

There are no problems on other devices like PC (JWplayer) or Android 4.x.

Please suggest what can be done to improve the sound?

Best regards,

Norberts

2

Hi Norberts,

I would suggest following the HE-AAC guide in this article. Please report back your findings. If you are still having issues then you may want to open a ticket by posting to support@wowza.com referencing this forum post and also providing the following details,

  • A ZIP file containing your conf/, logs/, transcoder/ and manager/logs folders. If you are not sure how to get this information please see the following tutorial. Please do make sure you provide logs which show Wowza server starting.

https://www.wowza.com/docs/how-to-create-a-compressed-zip-file-in-windows-os-x-and-linux

  • If you have a live stream please outline the type of encoder in use along with the encoding settings for the stream. If you are using a .stream file to start restreaming please provide this.

  • If you have a on demand stream you may be asked to provide access to the content you are using for further testing. At this stage it is not required.

  • If you are using multiple bitrates (ABR) then please provide the SMIL file associated with your configuration.

Kind regards,

Paul

3

Dear Wowza team,

I also have the problem with audio output when transcoding a live MPEG-TS stream (H264 main profile video + mp2, strereo, 48kHz audio). My profile settings: Video: H264, 512kbps, baseline profile, 640x360; Audio: AAC, 96kbps.

Every about 10 seconds, i hear some “u… u… u…” sound over the original sound. This problem happens when i test on iOS devices (iPhone 3GS, 5), and MS Smooth Test Player, also a Windowphone device (Nokia Lumia 525), but on Android devices, the sound is fine (both using RTSP and HTTP Cupertino streaming).

I also try the HE-AAC, but the problem still happens.

When i use VLC to transcode the input stream and choose PassThrough, the audio is working well (my vlc params: transcode{venc=x264{keyint=60,profile=baseline,level=3.0,nocabac},vcodec=x264,vb=512k,height=360,width=640,acodec=mp4a,ab=96,channels=2,samplerate=48000)

Any ideal for this problem?

Best Regards,

Huy.