Eli5: Why does fastforwarding regularly make streamed videos freeze?
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I think the source of this question stems to an 18+ use case am I right?
Comedy aside, it’s called a buffer, fast forwarding past your buffer will result in buffering.
Your device will reach out to the server for a new handshake and ask to be sent all of the new information required for the remaining X length of video.
Fast forwarding makes you transfer more data to your device. Like you transferred 1 mbps (megabits per second), and on 4x speed you want to receive 4 mbps. Your Internet connection may be fine but that’s not necessarily the truth for the site you’re streaming from. There may be hard and soft restrictions. Hard: site’s allocated bandwidth divided between all concurrent users. Soft: site’s software limits each user to a portion of said bandwidth.
By streamed i assume you are talking about a video/streaming platform like netflix/hbo
When you open a video it starts loading it to your device. It loads from where you started watching(usually at the start of the video) but could be from the middle if you are resuming.
Lets say you start watching a show. Video loads a bit initially and starts playing.
At 0:05 of the video you get bored and decide to skip to 0:35 but the video only loaded 25 seconds(up to 0:30) then it resets and starts loading from your new starting point(0:35) and loads the next few seconds so your video is buffering freezing.
If you had super fast internet this would rarely happen since it would load very fast. If you skipped a lot(like 10 minutes in the first few seconds) it would still buffer(freeze/start loading) but it would be very quick.
The worse your internet speed is the worse the problem is.
There’s an important detail that these answers seem to be missing, which explains why this happens on all digital video, even going back to the DVD days.
So, video codecs take advantage of the fact that a lot of stuff doesn’t change from one frame to the next in the short term. They do this by creating a parent frame, then child frames and “grandchild” frames which relies on the parent frame to fill things in. The parent is an I frame, child are P frames, and the grandchild frames are B frames. Historically, it was not feasible to decode the video fast enough to keep up with the accelerated frame rate of fast forwarding, so you were just presented with the parent frames as it was the least taxing way to display where you are in the video.
With modern processing power and high speed internet connections, it is possible to decode everything at an accelerated frame rate, but it’s unnecessary taxing on the processor and the internet connection when just showing those parent frames is enough for you to get the gist of where you are in the video stream.
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