# wowza transcode overlay image can not use passthrough ??

**URL:** <https://community.wowza.com/t/wowza-transcode-overlay-image-can-not-use-passthrough/45124>\
**Category:** Wowza Streaming Engine\
**Created:** [September 27, 2015, 7:58pm UTC](https://community.wowza.com/t/wowza-transcode-overlay-image-can-not-use-passthrough/45124 "2015-09-27T19:58:06Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![todafuture\_todafutur](https://avatars.discourse-cdn.com/v4/letter/t/ea666f/32.png) [@todafuture\_todafutur](https://community.wowza.com/u/todafuture_todafutur)\
**Post date:** [September 27, 2015, 7:58pm UTC](https://community.wowza.com/t/wowza-transcode-overlay-image-can-not-use-passthrough/45124/1 "2015-09-27T19:58:06Z")

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I want to put an overlay image on wowza stream without having to encode it again but if I use Passthrough, no image was put ?

I have to use encode H.264 then the image was put on the stream but that cost CPU for the only action is to put image on the stream.

I tried it in both Encode and Decode section but they all require H.264 in the video codec in the Encode section which requires ENCode and cost CPU?? - Passthrough wont work.

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**Author:** ![Jason\_Hilton](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/jason_hilton/32/437_2.png) [@Jason\_Hilton](https://community.wowza.com/u/Jason_Hilton)\
**Post date:** [September 28, 2015, 2:51pm UTC](https://community.wowza.com/t/wowza-transcode-overlay-image-can-not-use-passthrough/45124/2 "2015-09-28T14:51:21Z")

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Hi,

This is the expected behaviour, in order to add an overlay with the transcoder the stream being created must be a source that’s decoded and then encoded adding the overlay to either the decode (adding to all created encodes for this source) or the individual encodes (chosen specifically in the transcoding template). Please see [Transcoder overlay image requirements](https://www.wowza.com/docs/transcoder-overlay-image-requirements) for details.

When using “PassThru” the video is not being edited by the transcoder to add the overlay.

Jason

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**Author:** ![Daren\_Johnson](https://avatars.discourse-cdn.com/v4/letter/d/ee59a6/32.png) [@Daren\_Johnson](https://community.wowza.com/u/Daren_Johnson)\
**Post date:** [October 6, 2015, 10:24pm UTC](https://community.wowza.com/t/wowza-transcode-overlay-image-can-not-use-passthrough/45124/3 "2015-10-06T22:24:32Z")

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Hi,

Encoding definitely has to take place in order for the overlay to be rendered in the stream.

FFMPEG is certainly very capable of this sort of rendering during encoding.

Best regards,

Daren

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**Author:** ![todafuture\_todafutur](https://avatars.discourse-cdn.com/v4/letter/t/ea666f/32.png) [@todafuture\_todafutur](https://community.wowza.com/u/todafuture_todafutur)\
**Post date:** [September 28, 2015, 5:06pm UTC](https://community.wowza.com/t/wowza-transcode-overlay-image-can-not-use-passthrough/45124/4 "2015-09-28T17:06:11Z")

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If that is the case then putting the overlay image in ffmpeg process is a more efficient way and it does not take another transcoding process.