# Logic concatenation and clipping of mp4 files

**URL:** <https://community.wowza.com/t/logic-concatenation-and-clipping-of-mp4-files/51326>\
**Category:** Wowza Streaming Engine\
**Created:** [May 15, 2018, 5:05pm UTC](https://community.wowza.com/t/logic-concatenation-and-clipping-of-mp4-files/51326 "2018-05-15T17:05:05Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Michele\_Porcarelli](https://avatars.discourse-cdn.com/v4/letter/m/bcef8e/32.png) [@Michele\_Porcarelli](https://community.wowza.com/u/Michele_Porcarelli)\
**Post date:** [May 15, 2018, 5:05pm UTC](https://community.wowza.com/t/logic-concatenation-and-clipping-of-mp4-files/51326/1 "2018-05-15T17:05:05Z")

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Hello there, please bear with me as I’m new 🙂 Any help you might provide will be appreciated.

Suppose I have two mp4 files both 30 minutes long. They’re part1 and part2 of a single show so I’d like to serve this content to my users as if it was an uninterrupted 1-hour long video. Something like a playlist but not really because if they were to download the video, they would download it as a single mp4 file. I’m aware I can just concatenate the two mp4 files with ffmpeg but I’m asking if there’s another way. Something like a “logic” or “virtual” video file that just instructs Wowza on which physical files it can find the bits of the show.

I would use this “logic video file” to also do the opposite: i.e. isolate an interesting clip of 1 minute from part1.mp4 and publish on my website as if it was stored on its own mp4 file (users see a duration of 1 minute in their JWPlayer).

I would use this for:

- Partition large video files to make them more manageable on disk;
- Avoid duplication of bits, thus lowering hosting costs.

Is it possibile via the Rest API? Or the Java API? Thanks in advance.

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**Author:** ![Michele\_Porcarelli](https://avatars.discourse-cdn.com/v4/letter/m/bcef8e/32.png) [@Michele\_Porcarelli](https://community.wowza.com/u/Michele_Porcarelli)\
**Post date:** [May 17, 2018, 4:00pm UTC](https://community.wowza.com/t/logic-concatenation-and-clipping-of-mp4-files/51326/2 "2018-05-17T16:00:41Z")

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Hi,

In the meantime I’ve found this, which is good to extract clips from larger mp4 files: [https://www.wowza.com/docs/how-to-specify-a-play-start-time-and-duration-for-http-streaming](https://www.wowza.com/docs/how-to-specify-a-play-start-time-and-duration-for-http-streaming)

However, this looks like a more complete solution since it also supports progressive downloads (which I need that to let users download videos): [https://github.com/kaltura/nginx-vod-module](https://github.com/kaltura/nginx-vod-module)

Can I do progressive downloads with Wowza streaming engine?