# Input required for an mp4frag cheat sheet

**URL:** https://discourse.nodered.org/t/input-required-for-an-mp4frag-cheat-sheet/74768
**Category:** General
**Created:** [6 February 2023 06:34 UTC](https://discourse.nodered.org/t/input-required-for-an-mp4frag-cheat-sheet/74768 "2023-02-06T06:34:29Z")
**Posts on this page:** 1
**Showing post:** 11

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### Author: ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)
#### Post date: [12 February 2023 08:19 UTC](https://discourse.nodered.org/t/input-required-for-an-mp4frag-cheat-sheet/74768/11 "2023-02-12T08:19:23Z")

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Ok, digested your last feedback and updated the cheat sheet.  
I have also used two colors, to highlight the separate _ **recording** _ (orange) and **live viewing** (green) chains:

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/2/d/2d711c6d3f6f15084bbaa1a91d9c08c0802950d4.png)

The number of questions in my brain is decreasing.  
So hold tight a little bit 😉

> [@kevinGodell](#):
>
> there should be an initialization fragment that first comes out of ffmpeg

The first buffer that arrives from the ffmpeg node (when starting a new stream) is smaller:

![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/1/3/137ef96647265f8adfa2a763fe73193059aacf83.png)

Is that the initialization segment?

And my two last questions at the moment:

1. Why do you push two links to the dashboard (both mp4 and hls playlist). Isn't the playlist enough?
2. Still not sure where the pre-buffer (number of keyframes) is located in this diagram, and what it exactly does 😳

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_[View the full topic](https://discourse.nodered.org/t/input-required-for-an-mp4frag-cheat-sheet/74768)._