alt Hacker NewsI'm not familiar with video hosting but have played with html5 video player but I have this question: on the servers side, do I have to host a specific endpoint that serves chunks of video? Lets say I take 720p video @ 800mb and I chunk it into 2mb pieces with ffmpeg. So I have a folder somewhere (webserver, cdn, blob storage) with the original 4K video, then generate downscaled versions for 1440p, 1080p, 720p, so I end up with 4 large files, and then for each of those, I chunk them into reasonable sizes that aligns with bitrates / key frames. And then some thumbnail generation. Any advise on what the "best" way would be to chunk/host video files so that videojs runs the best and smoothest? I feel that I should build a very lean/fast chunk & thumbnail server, just one or two endpoints. Or is it best to let the webserver do the lifting? Or off-the-shelf media servers (like in the self-hosting community)?
Replies
If you don't need to switch versions at runtime (ABR), you don't even need to chunk it manully. Your server has to support range requests and then the browser does the reasonable thing automatically.
The simplest option is to use some basic object storage service and it'll usually work well out of the box (I use DO Spaces with built-in CDN, that's basically it).
It's not quite as simple as that because the chunks should be self-contained; they need to start with an IDR keyframe, which fully resets the decoder. That allows the player to seek to the start of any chunk.
That means when you're encoding the downscaled variants, the encoder wants to know the size of the file segments so it can insert those IDR frames. Therefore it's common to do the encoding and segmentation in a single step (e.g. with ffmpeg's "dash" formatter).
You can have variable-duration or fixed-duration segments. Supposedly some decoders are happier with fixed-duration segments, but it can be fiddly to get the ffmpeg settings just right, especially if you want the audio and video to have exactly the same segment size (here's a useful little calculator for that: https://anton.lindstrom.io/gop-size-calculator/)
For hosting, a typical setup would be to start with a single high-quality video file, have an encoder/segmenter pipeline that generates a bunch of video and audio chunks and DASH (.mpd) and/or HLS (.m3u8) manifests, and put all the chunks and manifests on S3 or similar. As long as all the internal links are relative they can be placed anywhere. The video player will start with the top-level manifest URL and locate everything else it needs from there.
Maybe look at MPE-DASH?
[dead]
Just convert it to HLS, which is naturally chunked at 1-2 second intervals, and serve all the pieces from nginix. No dynamic content needed. I do this with videojs and it works great. Added bonus of HLS is that my LG TV supports it natively from <video> tags.