使用 ffmpeg 生成白噪声/粉噪声/棕噪声/蓝噪声等
# 使用 ffmpeg 生成白噪声/粉噪声/棕噪声/蓝噪声/紫噪声/丝绒噪声 使用的 ffmpeg 版本: ``` > ffmpeg -version ffmpeg version n5.1.2 Copyright (c) 2000-2022 the FFmpeg developers built with gcc 12.2.0 (GCC) configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable-shared --enable-version3 --enable-vulkan libavutil 57. 28.100 / 57. 28.100 libavcodec 59. 37.100 / 59. 37.100 libavformat 59. 27.100 / 59. 27.100 libavdevice 59. 7.100 / 59. 7.100 libavfilter 8. 44.100 / 8. 44.100 libswscale 6. 7.100 / 6. 7.100 libswresample 4. 7.100 / 4. 7.100 libpostproc 56. 6.100 / 56. 6.100 ```
## 生成命令
+ **白噪声**
```
ffmpeg -f lavfi -i anoisesrc=c=0 -t 2s 0.wav
```
示例:
```
> ffmpeg -f lavfi -i anoisesrc=c=0 -t 2s 0.wav
ffmpeg version n5.1.2 Copyright (c) 2000-2022 the FFmpeg developers
built with gcc 12.2.0 (GCC)
configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable-shared --enable-version3 --enable-vulkan
libavutil 57. 28.100 / 57. 28.100
libavcodec 59. 37.100 / 59. 37.100
libavformat 59. 27.100 / 59. 27.100
libavdevice 59. 7.100 / 59. 7.100
libavfilter 8. 44.100 / 8. 44.100
libswscale 6. 7.100 / 6. 7.100
libswresample 4. 7.100 / 4. 7.100
libpostproc 56. 6.100 / 56. 6.100
Input #0, lavfi, from 'anoisesrc=c=0':
Duration: N/A, start: 0.000000, bitrate: 3072 kb/s
Stream #0:0: Audio: pcm_f64le, 48000 Hz, mono, dbl, 3072 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (pcm_f64le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, wav, to '0.wav':
Metadata:
ISFT : Lavf59.27.100
Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, mono, s16, 768 kb/s
Metadata:
encoder : Lavc59.37.100 pcm_s16le
size= 188kB time=00:00:02.00 bitrate= 768.3kbits/s speed= 649x
video:0kB audio:188kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.040625%
```
+ **粉噪声**
```
ffmpeg -f lavfi -i anoisesrc=c=1 -t 2s 1.wav
```
+ **棕噪声**
```
ffmpeg -f lavfi -i anoisesrc=c=2 -t 2s 2.wav
```
+ **蓝噪声**
```
ffmpeg -f lavfi -i anoisesrc=c=3 -t 2s 3.wav
```
+ **紫噪声**
```
ffmpeg -f lavfi -i anoisesrc=c=4 -t 2s 4.wav
```
+ **丝绒噪声**
```
ffmpeg -f lavfi -i anoisesrc=c=5 -t 2s 5.wav
```
## 命令参数解释
`ffmpeg -f lavfi -i anoisesrc=c=0 -t 2s 0.wav`
+ `ffmpeg`
运行 ffmpeg 程序.
+ `-f lavfi`
使用 libavfilter.
这个参数是为了使用后面的 `-i anoisesrc`.
+ `-i anoisesrc=c=0`
使用 `anoisesrc` 生成噪声, 其中 `c=0` 表示噪声类型, `0` 是白噪声.
修改这个参数还可以生成粉噪声, 棕噪声等.
+ `-t 2s`
时长, 此处是 2 秒.
+ `0.wav`
输出文件名, `wav` 后缀表示使用无压缩的声音文件格式.
ffmpeg 会自动根据文件名后缀选择相应的文件格式.
## 帮助信息
```
> ffmpeg -h filter=anoisesrc
ffmpeg version n5.1.2 Copyright (c) 2000-2022 the FFmpeg developers
built with gcc 12.2.0 (GCC)
configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable-shared --enable-version3 --enable-vulkan
libavutil 57. 28.100 / 57. 28.100
libavcodec 59. 37.100 / 59. 37.100
libavformat 59. 27.100 / 59. 27.100
libavdevice 59. 7.100 / 59. 7.100
libavfilter 8. 44.100 / 8. 44.100
libswscale 6. 7.100 / 6. 7.100
libswresample 4. 7.100 / 4. 7.100
libpostproc 56. 6.100 / 56. 6.100
Filter anoisesrc
Generate a noise audio signal.
Inputs:
none (source filter)
Outputs:
#0: default (audio)
anoisesrc AVOptions:
sample_rate
