# VLC transcoder problem on iPhone/iPad

**URL:** https://community.wowza.com/t/vlc-transcoder-problem-on-iphone-ipad/35712
**Category:** Wowza Streaming Engine
**Created:** [September 18, 2011, 3:45pm UTC](https://community.wowza.com/t/vlc-transcoder-problem-on-iphone-ipad/35712 "2011-09-18T15:45:27Z")
**Posts on this page:** 5
**Page:** 1

<div class="post-metadata">

### Author: ![Robert\_Student](https://avatars.discourse-cdn.com/v4/letter/r/53a042/32.png) [@Robert\_Student](https://community.wowza.com/u/Robert_Student)
#### Post date: [September 18, 2011, 3:45pm UTC](https://community.wowza.com/t/vlc-transcoder-problem-on-iphone-ipad/35712/1 "2011-09-18T15:45:27Z")

</div>

I have set up VLC transcoder like this:

```auto
vlc -vvv "C:\temp\video.avi" --sout "#transcode{venc=x264{keyint=60,profile=baseline,level=3.0,nocabac},vcodec=x264,vb=150,scale=0.5,acodec=mp4a,ab=96,channels=2,samplerate=48000}:rtp{dst=ip-of-my-wowza-server,port=10000,mux=ts}"

```

This live video is working only on my computer and android phone. But on iPad and iPhone it hasn’t worked.

The Ifound on internet some other transcoding code:

```auto
vlc -vvv "c:\temp\video.avi" --sout "#transcode{fps=25,vcodec=h264,vb=1280,venc=x264{aud,profile=baseline,level=30, keyint=30,bframes=0,ref=1,nocabac},acodec=mp3,ab=56,audio-sync,deinterlace}:rtp{dst=ip-of-my-wowza-server,port=10000,mux=ts}"

```

And is still doesn’t work on iPhone and iPad.

On a webpage I use thic code for display video:

Have you got any suggestions?

---

<div class="post-metadata">

### Author: ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)
#### Post date: [September 18, 2011, 3:15pm UTC](https://community.wowza.com/t/vlc-transcoder-problem-on-iphone-ipad/35712/2 "2011-09-18T15:15:38Z")

</div>

Try adding these for the audio

```auto
channels=2,samplerate=44100

```

For example:

```auto
vlc -vvv "%WMSAPP_HOME%/content/sample.mp4" --sout "#transcode{venc=x264{keyint=60,profile=baseline,level=3.0,nocabac},vcodec=x264,vb=150,scale=0.5,acodec=mp4a,ab=96,channels=2,samplerate=44100}:rtp{dst=127.0.0.1,port=10000,mux=ts}"

```

Richard

---

<div class="post-metadata">

### Author: ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)
#### Post date: [September 18, 2011, 3:41pm UTC](https://community.wowza.com/t/vlc-transcoder-problem-on-iphone-ipad/35712/3 "2011-09-18T15:41:20Z")

</div>

Actually, I was suggesting stereo (channels=2) and samplerate=44100 for your mp3 encoding, but a more important difference in the full example I showed is AAC audio (acodec=mp4a). Use that instead of mp3.

Richard

---

<div class="post-metadata">

### Author: ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)
#### Post date: [September 19, 2011, 11:13pm UTC](https://community.wowza.com/t/vlc-transcoder-problem-on-iphone-ipad/35712/4 "2011-09-19T23:13:06Z")

</div>

If you are using AAC, the sample rate and stereo are not important. Why 44100hz and stereo are required for MP3 in iOS, I don’t know.

Richard

---

<div class="post-metadata">

### Author: ![Robert\_Student](https://avatars.discourse-cdn.com/v4/letter/r/53a042/32.png) [@Robert\_Student](https://community.wowza.com/u/Robert_Student)
#### Post date: [September 18, 2011, 8:58pm UTC](https://community.wowza.com/t/vlc-transcoder-problem-on-iphone-ipad/35712/5 "2011-09-18T20:58:10Z")

</div>

Thanks Richard for your kindness! Everything is working perfect.

Why is audio samplerate 44100 so important for HTML5 and Apple devices? Can you give me also more theoretical answer what is happening with packages? In my option samplerate 48000 I had got only 3 packeges inside m3u8 file which size were around 17kB, but for computer were everything all right with samplerate 48000.
