3 ms·

Anyone knows if video transcoding on GPUs (with FFMPEG) is viable nowadays? If yes, what are the gains?

by nik736 10y ago

mwilcox 10y ago
They have chips dedicated to video encoding/decoding with the latest cards doing h265. Nvidia has an ffmpeg patch here https://developer.nvidia.com/ffmpeg https://developer.nvidia.com/ffmpeg
nenreme 10y ago
Decoding is good but hw encoding usually has very bad quality/size ratio compared to best software encoders.
scrabble 10y ago
This depends on if you're doing live transcoding or VOD transcoding. I work with live transcode, and it can be beneficial to run on g2 instances. Running c4.4xlarge I can transcode a good number of 1080@30 in with 1080/720/480/360/240@30 out. With a proper g2 instance I can transcode more simultaneously. So cost efficiency really depends on sustained traffic levels. I scale out currently using haproxy and custom code that monitors my pool and scales appropriately. But I monitor sustained traffic levels to know when it makes financial sense to scale up. If your main concern is transcode speed, CPU is likely sufficient -- I am unable to transcode faster than real time with live transcode.
- corobo 10y ago
  > I am unable to transcode faster than real time with live transcode Well, yeah. Maybe quantum computing will change that one day! What is it you're working on? Colour me intrigued.
  - grhmc 10y ago
    I'm not sure if you're kidding or not, but just in case: it is desirable to be able to encode faster than real time (ie: 1 hour of media takes less than 1 hour of time to transcode) so you have leftover processing cycles to do other work.
    - corobo 10y ago
      I know I know aye, the way I read initially amused me for a moment before my brain clicked into gear :)
    - scrabble 10y ago
      This is true. But real time encode is essentially what you need to do with live video instead of VOD transcode. You have other processes doing the other necessary work during the transcode. All in all, I look for somewhere around 0.25s to complete the rest of the work and deliver the segment to CDN.
  - scrabble 10y ago
    I'm doing live video ingestion. Transcode to DASH/HLS at 5 different qualities + alternate audio/subtitles where provided.

Anyone knows if video transcoding on GPUs (with FFMPEG) is viable nowadays? If yes, what are the gains?

by nik736 10y ago

Anyone knows if video transcoding on GPUs (with FFMPEG) is viable nowadays? If yes, what are the gains?

They have chips dedicated to video encoding/decoding with the latest cards doing h265. Nvidia has an ffmpeg patch here https://developer.nvidia.com/ffmpeg https://developer.nvidia.com/ffmpeg

nenreme 10y ago

Decoding is good but hw encoding usually has very bad quality/size ratio compared to best software encoders.

scrabble 10y ago

This depends on if you're doing live transcoding or VOD transcoding. I work with live transcode, and it can be beneficial to run on g2 instances. Running c4.4xlarge I can transcode a good number of 1080@30 in with 1080/720/480/360/240@30 out. With a proper g2 instance I can transcode more simultaneously. So cost efficiency really depends on sustained traffic levels. I scale out currently using haproxy and custom code that monitors my pool and scales appropriately. But I monitor sustained traffic levels to know when it makes financial sense to scale up. If your main concern is transcode speed, CPU is likely sufficient -- I am unable to transcode faster than real time with live transcode.

corobo 10y ago
> I am unable to transcode faster than real time with live transcode Well, yeah. Maybe quantum computing will change that one day! What is it you're working on? Colour me intrigued.
- grhmc 10y ago
  I'm not sure if you're kidding or not, but just in case: it is desirable to be able to encode faster than real time (ie: 1 hour of media takes less than 1 hour of time to transcode) so you have leftover processing cycles to do other work.
  - corobo 10y ago
    I know I know aye, the way I read initially amused me for a moment before my brain clicked into gear :)
  - scrabble 10y ago
    This is true. But real time encode is essentially what you need to do with live video instead of VOD transcode. You have other processes doing the other necessary work during the transcode. All in all, I look for somewhere around 0.25s to complete the rest of the work and deliver the segment to CDN.
- scrabble 10y ago
  I'm doing live video ingestion. Transcode to DASH/HLS at 5 different qualities + alternate audio/subtitles where provided.