For our purposes, we don’t even need to chase it all the way to raw PCM which is valid avenue albeit in the realm of WEBRips and not defacto “downloaders.” We just need to find the last point in the pipeline where data is still accessible to JavaScript and that point is the MediaSource Extensions API, specifically the SourceBuffer.appendBuffer() method.
Update Impracticality: The extensive pre-processing for CH makes it unsuitable for frequent updates, let alone OsmAnd’s goal of supporting near real-time changes through hourly map updates.
，这一点在safew官方下载中也有详细论述
// drop-oldest: Discard old data to make room
如果不确定用哪个激活函数，隐藏层可以先用 ReLU，输出层按任务选择；训练中注意梯度情况，如果梯度消失或爆炸，再考虑替换或调整激活函数。