『漫游』酷论坛>『影音数码技术学习交流』>[请教]新模式的AQ是怎 ..
[请教]新模式的AQ是怎么把以前的2个模式合并的?
superkidx@2008-12-21 12:20
旧AQ MODE 1是帧内调整qp值 MODE 2是帧间调整qp值
那么新AQ是怎么协调的呢 大致是如何决策什么时候用MODE1什么时候用MODE2的?
另外那个强度参数是不是Q值的波动强度呢?
roozhou@2008-12-21 12:28
看源代码
MythCreator@2008-12-21 17:33
x264 rev.968的ChangeLog如下：
Move adaptive quantization to before ratecontrol, eliminate qcomp bias
This change improves VBV accuracy and improves bit distribution in CRF and 2pass.
Instead of being applied after ratecontrol, AQ becomes part of the complexity measure that ratecontrol uses.
This allows for modularity for changes to AQ; a new AQ algorithm can be introduced simply by introducing a new aq_mode and a corresponding if in adaptive_quant_frame.
This also allows quantizer field smoothing, since quantizers are calculated beofrehand rather during encoding.
Since there is no more reason for it, aq_mode 1 is removed. The new mode 1 is in a sense a merger of the old modes 1 and 2.
WARNING: This change redefines CRF when using AQ, so output bitrate for a given CRF may be significantly different from before this change!
superkidx@2008-12-21 23:26
The new mode 1 is in a sense a merger of the old modes 1 and 2.
how？
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