起因
写了一个视频的剪裁的，后来就有写了一个视频消音的。
过程
UI还是用了一个视频剪裁的UI。见俺的另外一篇博客《用AI生成一个简单的视频剪辑工具》
因为这次的功能是消音，所以改了一下进度条的背景。在进度条的背景中显示音频的信息。
进度条的的改动非常小 ，只是在html加了个img
<img id="img_audio" style="position: absolute; display: inline-block; width: 100%; height: 100%;" src=" " />
js的改动
document.getElementById("img_audio").src = audioURL;
C#的修改，传了 audio_url 的img的地址
if (e.message == "get_video_url")
{
if (filename_tmp_org == "")
{
filename_tmp_org = System.IO.Path.Combine(TmpDir, Guid.NewGuid().ToString("N") + ".mp4");
filename_tmp_new = System.IO.Path.Combine(TmpDir, Guid.NewGuid().ToString("N") + ".mp4");
System.IO.File.Copy(filename, filename_tmp_org);
}
filename_tmp_org_audio = System.IO.Path.Combine(TmpDir, Guid.NewGuid().ToString("N") + ".jpg");
bool flag= get_audio_bg_url(filename_tmp_org, filename_tmp_org_audio).Result;
Dictionary<string, string> dict = new Dictionary<string, string>();
dict["video_url"] = "file://" + filename_tmp_org;
dict["audio_url"] = "file://" + filename_tmp_org_audio;
e.result = Newtonsoft.Json.JsonConvert.SerializeObject(dict);
}
C#的get_audio_bg_url 的处理比较简单 先用 ffmpeg @"-i ""[fn1]"" -vn -acodec mp3 ""[fn2]"" "
从视频中分离MP3音频。
然后用audio2img 方法， 生成进度条的背景
{
WaveAudioRendererSettings settings = new WaveAudioRendererSettings();
settings.Width = 1024;
settings.TopHeight = 88;
settings.BottomHeight = 88;
Bitmap bmp = AudioInfo.audio2img(mp3, settings);
bmp.Save(filename_tmp_org_audio, ImageFormat.Jpeg);
bmp.Dispose();
}
代码
cs
private async Task<bool> get_audio_bg_url(string filename_tmp_org, string filename_tmp_org_audio)
{
//ffmpeg -i input.mp4 -vn -acodec mp3 output.mp3
string mp3 = System.IO.Path.ChangeExtension(filename_tmp_org_audio, ".mp3");
string arguments = @"-i ""[fn1]"" -vn -acodec mp3 ""[fn2]"" ";
arguments = arguments.Replace("[fn1]", filename_tmp_org);
arguments = arguments.Replace("[fn2]", mp3);
var compressor = new VideoCompressor(ffmpegPath);
bool succ = false;
{
CompressionResult cr = compressor.Exe(arguments);
succ = cr.Success;
if (succ)
{
{
WaveAudioRendererSettings settings = new WaveAudioRendererSettings();
settings.Width = 1024;
settings.TopHeight = 88;
settings.BottomHeight = 88;
Bitmap bmp = AudioInfo.audio2img(mp3, settings);
bmp.Save(filename_tmp_org_audio, ImageFormat.Jpeg);
bmp.Dispose();
}
}
else
{
err = cr.ErrorMessage;
}
}
return succ;
}
cs
public class AudioInfo
{
public static double get_len(string fn)
{
AudioFileReader _reader = new AudioFileReader(fn);
double len = _reader.TotalTime.TotalSeconds;
_reader.Dispose();
return len;
}
public static Bitmap audio2img(string fn, WaveAudioRendererSettings settings)
{
if (settings.TopPeakPen == null)
settings.TopPeakPen = new Pen(Color.FromArgb(75, 243, 167));
if (settings.BottomPeakPen == null)
settings.BottomPeakPen = new Pen(Color.FromArgb(75, 243, 167));
int Width = settings.Width;
int Height = settings.TopHeight + settings.BottomHeight;
Bitmap bmp = new Bitmap(Width, Height);
Graphics g = Graphics.FromImage(bmp);
g.FillRectangle(settings.BackgroundBrush, 0, 0, Width, Height);
// 网格
drawGraid(g, Width, Height);
// 波形
var midPoint = settings.TopHeight;
int x = 0;
MaxPeakProvider _maxPeakProvider = new MaxPeakProvider();
_maxPeakProvider.Init(16, fn);
_maxPeakProvider.Load(settings);
WavePeakInfo currentPeak = _maxPeakProvider.GetPeakInfo(x);
if (currentPeak == null)
return null;
string s = _maxPeakProvider.TotalTime.ToString(@"hh\:mm\:ss");
Rectangle textrect = new Rectangle(0, 0, bmp.Width, bmp.Height);
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Far;
sf.LineAlignment = StringAlignment.Near;
g.DrawString(s, new Font("宋体", 15f, FontStyle.Regular), new SolidBrush(Color.White), textrect, sf);
while (x < settings.Width)
{
WavePeakInfo nextPeak = _maxPeakProvider.GetPeakInfo(x);
for (int n = 0; n < settings.PixelsPerPeak; n++)
{
float lineHeight = settings.TopHeight * currentPeak.Max;
g.DrawLine(settings.TopPeakPen, x, midPoint, x, midPoint - lineHeight);
lineHeight = settings.BottomHeight * currentPeak.Min;
g.DrawLine(settings.BottomPeakPen, x, midPoint, x, midPoint - lineHeight);
x++;
}
for (int n = 0; n < settings.SpacerPixels; n++)
{
float max = Math.Min(currentPeak.Max, nextPeak.Max);
float min = Math.Max(currentPeak.Min, nextPeak.Min);
float lineHeight = settings.TopHeight * max;
g.DrawLine(settings.TopSpacerPen, x, midPoint, x, midPoint - lineHeight);
lineHeight = settings.BottomHeight * min;
g.DrawLine(settings.BottomSpacerPen, x, midPoint, x, midPoint - lineHeight);
x++;
}
currentPeak = nextPeak;
}
g.Dispose();
_maxPeakProvider.dispose_reader();
return bmp;
}
public static void drawGraid(Graphics g, int width, int height)
{
Pen gridPen = new Pen(Color.FromArgb(18, 59, 40));
for (int i = 0; i < width;)
{
g.DrawLine(gridPen, new Point(i, 0), new Point(i, width));
i += 45;
}
//水平
for (int j = 0; j < height;)
{
g.DrawLine(gridPen, new Point(0, j), new Point(width, j));
j += 45;
}
}
}
public class WaveAudioRendererSettings
{
public WaveAudioRendererSettings()
{
Width = 800;
TopHeight = 150;
BottomHeight = 150;
PixelsPerPeak = 1;
SpacerPixels = 0;
BackgroundColor = Color.Black;
}
// for display purposes only
public string Name { get; set; }
public int Width { get; set; }
public int TopHeight { get; set; }
public int BottomHeight { get; set; }
public int PixelsPerPeak { get; set; }
public int SpacerPixels { get; set; }
public virtual Pen TopPeakPen { get; set; }
public virtual Pen TopSpacerPen { get; set; }
public virtual Pen BottomPeakPen { get; set; }
public virtual Pen BottomSpacerPen { get; set; }
public bool DecibelScale { get; set; }
public Color BackgroundColor { get; set; }
public Image BackgroundImage { get; set; }
public int StartX { get; set; }
public int EndX { get; set; }
public Brush BackgroundBrush
{
get
{
if (BackgroundImage == null)
return new SolidBrush(BackgroundColor);
return new TextureBrush(BackgroundImage, WrapMode.Clamp);
}
}
protected static Pen CreateGradientPen(int height, Color startColor, Color endColor)
{
var brush = new LinearGradientBrush(new Point(0, 0), new Point(0, height), startColor, endColor);
return new Pen(brush);
}
}
public class WavePeakInfo
{
public WavePeakInfo(float min, float max)
{
Max = max;
Min = min;
IsSelected = false;
}
public float Min { get; private set; }
public float Max { get; private set; }
public bool IsSelected { get; set; }
}
public class MaxPeakProvider
{
//private float[] _mCollection = null;
protected int mSamplesPerPeak = 0;
protected int mBitsPerSample = 0;
private List<WavePeakInfo> mWavePeakInfos;
private WaveAudioRendererSettings _settings;
private string _file;
private AudioFileReader _reader;
public TimeSpan TotalTime;
public MaxPeakProvider()
{
mWavePeakInfos = new List<WavePeakInfo>();
}
public void Init(int bitsPerSample, string file)
{
mBitsPerSample = bitsPerSample;
_file = file;
_reader = new AudioFileReader(file);
TotalTime = _reader.TotalTime;
}
public void dispose_reader()
{
if (_reader != null)
{
_reader.Dispose();
_reader = null;
}
}
public void Load(WaveAudioRendererSettings settings)
{
//_mCollection = collection;
_settings = settings;
int bytesPerSample = mBitsPerSample / 4;
var samples = _reader.Length / (bytesPerSample);
//var samplesPerPixel = (int)(samples / settings.Width);
var samplesPerPixel = (int)(samples / settings.Width);
var stepSize = settings.PixelsPerPeak + settings.SpacerPixels;
mSamplesPerPeak = samplesPerPixel * stepSize;
mWavePeakInfos.Clear();
}
public WavePeakInfo GetNextPeak(int index)
{
//if (_mCollection == null || mSamplesPerPeak == 0)
// return null;
//if (_mCollection.Length <= index)
// return null;
//float[] tt = _mCollection.Skip(index * mSamplesPerPeak).Take((index + 1) * mSamplesPerPeak).ToArray();
//var max = (tt == null) ? 0 : tt.Take(mSamplesPerPeak).Max();
//var min = (tt == null) ? 0 : tt.Take(mSamplesPerPeak).Min();
if (mSamplesPerPeak == 0)
return null;
float[] ReadBuffer = new float[mSamplesPerPeak];
var samplesRead = _reader.Read(ReadBuffer, 0, ReadBuffer.Length);
var max = (samplesRead == 0) ? 0 : ReadBuffer.Take(mSamplesPerPeak).Max();
var min = (samplesRead == 0) ? 0 : ReadBuffer.Take(mSamplesPerPeak).Min();
WavePeakInfo info = new WavePeakInfo(min, max);
mWavePeakInfos.Add(info);
return info;
}
public WavePeakInfo GetPeakInfo(int index)
{
if (index >= mWavePeakInfos.Count)
return GetNextPeak(index);
return mWavePeakInfos[index];
}
public void UpdatePeakInfoStatus(int index)
{
if (index > mWavePeakInfos.Count)
return;
mWavePeakInfos[index].IsSelected = !mWavePeakInfos[index].IsSelected;
}
public void ResetPeakInfoStatus()
{
foreach (WavePeakInfo info in mWavePeakInfos)
{
info.IsSelected = false;
}
}
public int GetSize(int index)
{
if (index >= _settings.Width)
{
index = _settings.Width - 1;
}
return index * mSamplesPerPeak * 2;
}
}