[HN Gopher] How Facebook encodes videos
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How Facebook encodes videos
Author : nl
Score : 62 points
Date : 2021-04-25 06:22 UTC (16 hours ago)
(HTM) web link (engineering.fb.com)
(TXT) w3m dump (engineering.fb.com)
| mappu wrote:
| _> An encoding family requires a minimum set of resolutions to be
| made available before we can deliver a video. [...] For example,
| having one video with all of its VP9 lanes adds more value than
| 10 videos with incomplete (and therefore, undeliverable) VP9
| lanes._
|
| I don't see why this constraint is in place, you can absolutely
| serve video for certain-res users only with certain codecs
| (youtube certainly does this).
| vbsteven wrote:
| I assume Facebook has this requirement for usability reasons.
| They don't want a user to receive a video through one of its
| many share features and then not be able to view it.
| stefan_ wrote:
| Maybe the people at Twitter can read this and learn something.
| calebio wrote:
| They still haven't figured out how to give users control of
| their poor image cropping :(
| zeeshanqureshi wrote:
| Their "race-based" image cropping?
|
| https://youtu.be/Ok5sKLXqynQ?t=103
| wongarsu wrote:
| That looks like cropping on whatever has the highest
| confidence value of being a face. Evidently not a good
| idea, it does look pretty racist.
| blowski wrote:
| These are the kinds of articles that show why Facebook has
| different problems to almost every other tech company. The
| complexity of these kinds of solutions is mind-boggling.
|
| Just imagine if all that ingenuity was focused on solving
| humanity's problems, instead of sharing conspiracy theories and
| advertising.
| bob33212 wrote:
| I wish people spent more time on Facebook. Is that what FB
| employees think? Or are they like the rest of us and think fuck
| this guy, but I'll take his money.
| Const-me wrote:
| At least here, the video quality is not good on FB. I have 120
| mbit/sec connection, youtube plays good quality 4k just fine. I
| don't think I ever saw 1080p served by facebook, both resolution
| and bitrate are very low.
| ericbarrett wrote:
| Your ISP might be throttling Facebook video
| gjs278 wrote:
| doubt it. facebook videos just absolutely suck in quality.
| gruez wrote:
| There's other explanations as well:
|
| * ISP has poor peering to facebook servers
|
| * ISP has cache/CDN node installed, but that's overloaded
|
| * the content that OP viewed isn't popular so it has to be
| pulled from origin, which adds another layer of complications
| londons_explore wrote:
| I'm surprised Facebook still uses software to do video encoding.
|
| Most big companies with millions of hours of video uploaded each
| day have realised it's cheaper to stick a bunch of hardware video
| encoding chips onto an accelerator board and be able to transcode
| 100 HD streams simultaneously into all the formats and
| resolutions you need to host.
|
| The power savings on CPU's pay for the custom hardware in a
| matter of months.
|
| It does reduce flexibility when new video formats get released
| though.
| meteorfox wrote:
| Facebook does have hardware for video transcoding. [1]
| https://youtu.be/0yk4SPRisPA
| [deleted]
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