Here is description how to get video link
but I don’t understand what means "Non-partnered channels" in this? And how many viewers should be on channel (“don’t have enough viewers”)?
“Non-partnered channels or channels that just don’t have enough viewers will only have one URL in the response, channels that are partnered/have enough viewers and are transcoded will contain URL’s for “Source”, “High”, “Medium”, “Low” and “Mobile” quality levels.”
Partnered channels have an agreement with twitch and can play ads, have quality options, and have the option for users to subscribe to them. A stream will also get quality options if it is one of the top 100 viewed streams on twitch (IIRC).
How to get the agreement with twitch to myself?
You can make an application here. Last I checked they recommended 400 stable viewers per stream before applying.
It is not 100, but based on capacity.
Is the the Twitch video high quality HD or it is just me? the quality for me appears so poor, even though I do mark the high option…
The bitrate should be around 1500 @ high.