video-pc/AvRecorder/test/ui/audio_render.cpp

#include "audio_render.h"

#include <QPainter>

AudioRender::AudioRender(QLabel* parent)
    : QLabel(parent)
{
}
void AudioRender::ShowVolume(float volume)
{
    float val = 0;
    if (volume < 0) {
        volume = -volume;
    }

    if (volume > 0.001) {
        val = (20.0f * log10(volume) + 60.0f) / 60.0f;
    }

    float diff = val - _lastShowVal;
    if (diff < -0.015f) {
        diff = -0.015f;
    }
    _lastShowVal += diff;
}

void AudioRender::paintEvent(QPaintEvent* event)
{
    int val = _lastShowVal * width();
    QPainter painter(this);
    QPen pen(Qt::green, height());
    painter.setPen(pen);
    painter.drawLine(0, 0, val, 0);
    pen.setColor(Qt::gray);
    painter.setPen(pen);
    painter.drawLine(val, 0, width(), 0);
}