Page 49 of 49 FirstFirst ... 394546474849
Results 481 to 482 of 482
  1. Collapse Details
    Senior Member
    Join Date
    May 2011
    Posts
    233
    Default
    Keep in mind that video codecs like H.264 and H.265 (HEVC) were primarily designed as delivery codecs (rather than acquisition or editing codecs like ProRes). And so most of the attention is focused on improving encoding quality at the bitrates typically used for video delivery, which these days is often at low bitrates over the internet.

    These delivery bitrates are often around 1/10th or less of the bitrate most cameras record at. Because the streaming providers in particular want to deliver the best video quality they can to a wide range of viewers that may not have fast connections (especially on mobile devices). And they also want to save on bandwidth costs as this is one of the single largest expenses for streaming services (aside from what they pay for content).

    As an example, Netflix's fixed bitrate encoding ladder used to max out at 5.8 Mbps for 1080p video. They have since switched to using per-title encoding, where the bitrate used varies depending on the video (and how much visual complexity it contains), and only a few of the titles they tested required more than 8 Mbps at 1080p to look good (for their standards anyway):
    https://medium.com/netflix-techblog/...n-7e99442b62a2

    The Moscow State University comparison Cary mentioned tells a similar story. Most of the codecs they tested (H.264, H.265, VP9, AV1) are able to achieve an SSIM rating of 0.98-0.99 (maximum is 1) at a bitrate of 10 Mbps for 1080p25 or 1080p30 video. So most of the significant differences in video codecs are below that bitrate.

    One final thing to be aware of, is that most of the video codec comparisons are done for offline video encoding, often using software video encoders that may run slower than realtime (especially for 4K video). But when recording in camera or other live encoding applications, the encoding needs to be much faster since it is done in realtime. Hardware based encoders also tend to be simpler in terms of implementation and since they are resource constrained (in terms of power usage and computational complexity), they are often less good at exploiting all of the features of a video codec to achieve the maximum video quality. So I would expect that realtime in-camera H.264 video encoders are typically much less efficient than the best quality that can be achieved with the best software encoder like x264. So an in-camera encoder probably requires a higher bitrate to achieve the same video quality as x264.


    Reply With Quote
     

  2. Collapse Details
    Senior Member joe 1008's Avatar
    Join Date
    Dec 2005
    Location
    Barcelona
    Posts
    1,066
    Default
    Quote Originally Posted by filmguy123 View Post
    Our local member here with source nailed it, which likely means we can count on the following as well:
    Anything new about the 60p mode? Will it be full frame or crop?


    Reply With Quote
     

Page 49 of 49 FirstFirst ... 394546474849

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •