# Ip camera video delay after G.711 transcoding

**URL:** <https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389>\
**Category:** Wowza Streaming Engine\
**Created:** [March 26, 2012, 2:26pm UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389 "2012-03-26T14:26:24Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Andras\_Szocs](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@Andras\_Szocs](https://community.wowza.com/u/Andras_Szocs)\
**Post date:** [March 26, 2012, 2:26pm UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/1 "2012-03-26T14:26:24Z")

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Hi!

I’ve got a Sunell Ip camera which has got H264 and G.711 alaw/mulaw audio output format.

I would like to stream the video+audio live. I tried the transcoder but it isnt working.

The problem is that the video and audio is not synchronised,the video plays more slow (about half speed) and there is a strange “do-re-mi” sound in the audio signal. If i set the audio bitrate to lower eg:8000bps the video speed become normal, but there is no sound. If I set the bitrate to eg: 96000bps the video slows down again.

Have you ever seen this problem?

my conf/application.xml and transcode.xml are the following:

[http://cruisher.digitaltrip.hu/nenezdmeg/Application.xml](http://cruisher.digitaltrip.hu/nenezdmeg/Application.xml)

[http://cruisher.digitaltrip.hu/nenezdmeg/transcodeAudio.xml](http://cruisher.digitaltrip.hu/nenezdmeg/transcodeAudio.xml)

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**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:** [March 26, 2012, 11:57pm UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/2 "2012-03-26T23:57:58Z")

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The do re mi is the Wowza Transcoder audio watermark.

Are you playing the source stream instead of one of the transcoded streams output by Wowza Transcoder?

Richard

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**Author:** ![Randall\_Auriemma](https://avatars.discourse-cdn.com/v4/letter/r/85e7bf/32.png) [@Randall\_Auriemma](https://community.wowza.com/u/Randall_Auriemma)\
**Post date:** [March 26, 2012, 8:18pm UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/3 "2012-03-26T20:18:27Z")

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Looks like you’re trying to upsample the audio from 8kbps to 64kbps in your template, which you probably don’t want to do. Try lowering the bitrate in your transcoder template to equal to or less than your source bitrate or use: ${SourceAudioBitrate}

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**Author:** ![Randall\_Auriemma](https://avatars.discourse-cdn.com/v4/letter/r/85e7bf/32.png) [@Randall\_Auriemma](https://community.wowza.com/u/Randall_Auriemma)\
**Post date:** [March 26, 2012, 9:34pm UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/4 "2012-03-26T21:34:33Z")

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Where are you setting the bitrate? Try setting the bitrate on your camera to 64k, and setting the template to ${SourceAudioBitrate}.

The bitrate should not be above the bitrate of your encoding, generally speaking.

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**Author:** ![Lisa\_Wong](https://avatars.discourse-cdn.com/v4/letter/l/34f0e0/32.png) [@Lisa\_Wong](https://community.wowza.com/u/Lisa_Wong)\
**Post date:** [March 27, 2012, 7:40am UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/5 "2012-03-27T07:40:33Z")

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Set the bitrate in the template instead of using a variable.

```auto
<Audio>
<!-- AAC, PassThru -->
<Codec>AAC</Codec>
<Bitrate>96000</Bitrate>
</Audio>

```

You can log extra debug information to the log file regarding the RTSP handshake between Wowza Media Server and the IP camera (RTSP/RTP source) by adding the following property to the MediaCaster/Properties container in [install-dir]/conf/[application]/Application.xml:

```auto
<Property>
    <Name>debugRTSPSession</Name>
    <Value>true</Value>
    <Type>Boolean</Type>
</Property>

```

Also check to see if there is a firmware update for your camera. If problems persist, email support@wowza.com with a zip of [install-dir]/conf and logs directories, URL to your live camera feed if possible, and please reference this thread.

-Lisa

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**Author:** ![Andras\_Szocs](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@Andras\_Szocs](https://community.wowza.com/u/Andras_Szocs)\
**Post date:** [March 27, 2012, 6:23am UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/6 "2012-03-27T06:23:28Z")

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> The do re mi is the Wowza Transcoder audio watermark.
> 
> Are you playing the source stream instead of one of the transcoded streams output by Wowza Transcoder?
> 
> Richard

No, I’m playing the camera.stream\_rtp. This is the transcoded stream.

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<div class="post-metadata">

**Author:** ![Andras\_Szocs](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@Andras\_Szocs](https://community.wowza.com/u/Andras_Szocs)\
**Post date:** [March 27, 2012, 8:00am UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/7 "2012-03-27T08:00:34Z")

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> Looks like you’re trying to upsample the audio from 8kbps to 64kbps in your template, which you probably don’t want to do. Try lowering the bitrate in your transcoder template to equal to or less than your source bitrate or use: ${SourceAudioBitrate}

I tried with many bitrate. If I set to 8000 or more, i hear the watermark and the camera microphone sound, but the video goes about half speed.

If I set the bitrate to 5000 or below, there is no sound but the video speed is correct.

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<div class="post-metadata">

**Author:** ![Andras\_Szocs](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@Andras\_Szocs](https://community.wowza.com/u/Andras_Szocs)\
**Post date:** [March 27, 2012, 8:52am UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/8 "2012-03-27T08:52:52Z")

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I set the bitrate in the transcodeAudio xml file :

AAC

${SourceAudioBitrate}

In the camera menu there isn’t any possibility to set the bitrate, only the encoding type.

The video delay is very high, about 10-20sec, the audio delay is about 3sec.

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<div class="post-metadata">

**Author:** ![Andras\_Szocs](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@Andras\_Szocs](https://community.wowza.com/u/Andras_Szocs)\
**Post date:** [March 29, 2012, 1:40pm UTC](https://community.wowza.com/t/ip-camera-video-delay-after-g-711-transcoding/38389/9 "2012-03-29T13:40:54Z")

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I put the debugRTSPSession, but i don’t see any information wich can cause the low video speed.

I think I let these Sunell cameras, i will use Vivotek instead.

Thanks for the help!
