我需要将ffmpeg的输出作为管道读取。
这是一个代码示例:
public static void PipeTest()
{
Process proc = new Process();
proc.StartInfo.FileName = Path.Combine(WorkingFolder, "ffmpeg");
proc.StartInfo.Arguments = String.Format("$ ffmpeg -i input.mp3 pipe:1");
proc.StartInfo.UseShellExecute = false;
proc.StartInfo.RedirectStandardInput = true;
proc.StartInfo.RedirectStandardOutput = true;
proc.Start();
FileStream baseStream = proc.StandardOutput.BaseStream as FileStream;
byte[] audioData;
int lastRead = 0;
using (MemoryStream ms = new MemoryStream())
{
byte[] buffer = new byte[5000];
do
{
lastRead = baseStream.Read(buffer, 0, buffer.Length);
ms.Write(buffer, 0, lastRead);
} while (lastRead > 0);
audioData = ms.ToArray();
}
using(FileStream s = new FileStream(Path.Combine(WorkingFolder, "pipe_output_01.mp3"), FileMode.Create))
{
s.Write(audioData, 0, audioData.Length);
}
}
这是来自ffmpeg的日志,第一个文件已被读取:
输入 #0,mp3,来自 'norm.mp3': 元数据: 编码器:Lavf58.17.103 Duration: 00:01:36.22, start: 0.023021, bitrate: 128 kb/s Stream #0:0: Audio: mp3, 48000 Hz, stereo, fltp, 128 kb/s Metadata: encoder : Lavc58.27
然后进行管道操作:
[NULL @ 0x7fd58a001e00] 无法找到适合的输出格式'$' $:无效参数
如果我运行“-i input.mp3 pipe:1”,则日志为:
无法找到适合的输出格式'pipe:1' pipe:1:无效参数
如何设置正确的输出?ffmpeg怎么知道输出格式是什么?