如何确定每一层的视频比特率? [英] How to ditermine video bitrates for each layer?
问题描述
您好，尊敬的支持者，
我想了解一种为每个演绎即层提供视频比特率的算法.当我要形成编码器自定义预设时.
我发现了kush Gauge，我们可以依靠它吗?以某种方式尝试获取常数并将其保留在所有层中?
示例:
我有一个用youtube编码的具有这些层的视频，我们如何计算视频比特率以使视频质量达到最佳?
我从youtube下载了许多视频，并获得了它们的比特率，然后进行了比较并尝试了一种算法.
| 176x144p | 426x240 | 640x360 | 854x480 | 1280x720 | 1920x1080 | 原始 | |
| 109 kb/s | 255 kb/s | 431 kb/s | 971 kb/s | 1 950 kb/s | 3926 | 4 995 kb/s，1080p原始 |
| 99.3 kb/s | 216 kb/s | 427 kb/s | 707 kb/s | 1 537 kb/s | 1 107 kb/s，720p orig | |
| 52.4 kb/s | 199 kb/s | 267 kb/s | 267 kb/s，360p orig | |||
| 124 kb/s | 279 kb/s | 358 kb/s | 1252 kb/s | 1 685 kb/s | 2 453 kb/s，720p orig | |
| 56.6 kb/s | 195 kb/s | 367 kb/s | 595 kb/s | 411 kb/s，480p orig | ||
| 49.0 kb/s | 104 kb/s | 260 kb/s | 287 kb/s，360p orig |
是否有特定的算法?我读到有关库什(Kush Gauge)和尝试以相反的方式应用它，以获取一个常数，并以此方式通过它来确定每种视频分辨率的比特率:
假设帧频在转换中保持不变，我们可以将每个视频的公式简化为:
W * H * X =比特率
X =原始比特率/(原始W *原始H)
(AxB)=?的比特率
bitrate(AxB)= X * A * B =原始比特率* A * B/(原始W *原始H)
我尝试在上面的示例中应用它，但是我注意到，对于低质量的视频，例如，在50以下，比特率会变小，并且其值与youtube中的值不同.
此外，我签出了youtube，似乎他使用的是建议的原始视频分辨率的最低比特率.并且，如果超出其分辨率建议的最大比特率，则使用最大比特率.但并非总是如此，不是因为质量较低. example 480 他们没有.但是，如何涵盖所有扣除的案件?
然后我一直在寻找，我想知道，也许您知道一种标准方法，该方法允许我们构建自定义预设(视频比特率)，从而生成优质的视频点播服务.
我有1442403604804807201080.
在这件事上您有什么帮助吗?
Kush-Gauge计算器基于宽度，高度，帧速率和运动使用比特率的线性估计.
当分辨率降低时，比特率不应线性下降，因为较低分辨率的开销比率要比高分辨率视频的开销比率大得多.我们已经通过此方法回答了您有关按标题编码的问题 链接.它应该为您提供更好的解决方案.
Hello, Dear Support,
I want to learn about an algorithm to provision video bitrates for each rendition i.e layer. When I want to form encoder custom presets.
I discovered kush Gauge, can we depend on it? in a way that we try to get the constant and keep it for all layers?
example:
I have a video encoded with youtube with these layers, how can we calculate the video bitrate such that the video quality is optimal?
I downloaded many videos from youtube and get their bitrates and compared and try get an algorithm.
| 176x144p | 426x240 | 640x360 | 854x480 | 1280x720 | 1920x1080 | original | |
| 109 kb/s | 255 kb/s | 431 kb/s | 971 kb/s | 1 950 kb/s | 3926 | 4 995 kb/s,1080p orig |
| 99.3 kb/s | 216 kb/s | 427 kb/s | 707 kb/s | 1 537 kb/s | 1 107 kb/s,720p orig | |
| 52.4 kb/s | 199 kb/s | 267 kb/s | 267 kb/s,360p orig | |||
| 124 kb/s | 279 kb/s | 358 kb/s | 1 252 kb/s | 1 685 kb/s | 2 453 kb/s,720p orig | |
| 56.6 kb/s | 195 kb/s | 367 kb/s | 595 kb/s | 411 kb/s, 480p orig | ||
| 49.0 kb/s | 104 kb/s | 260 kb/s | 287 kb/s,360p orig |
Is there a specific algorithm? I read about Kush Gauge and I tried to apply it in a reverse way, to get a constant and use it to determine the bitrate for each video resolution by this way:
assume frame rate stay the same in conversion, we can simplify the formula for each video to:
W*H*X=bitrate
X=original bitrate/(original W* original H)
bitrate for (AxB)=?
bitrate(AxB)=X*A*B=original bitrate*A*B/(originalW*Original H)
I tried to apply it in the above example, but I notice that for low qualities I get smaller bitrates bellow 50 for example and the values are not similar to that in youtube.
Also, I checked out youtube and seems that he uses the minimum recommended bitrate of the resolution of the original video. And if it is more than its resolution recommended max bitrate, they use the max. but not always, not for lower qualities. example 480 they don't. But how to cover all cases in deduction?
And I am keeping looking then I wondered, maybe you know a standard way that permits us to build custom presets(video bitrate) that generate good video on demand service.
I have 144 240 360 480 720 1080.
Do you have any help in this matter?
The Kush-Gauge calculator uses a linear estimation of bitrate based on width, height, framerate, and motion.
When the resolution reduces, the bitrate should not go down linearly because the overhead ratio for the lower resolution is much bigger than that for the high resolution video. We've responded to your question about per-title encoding with this link. It should offer a better solution for you.
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