音视频：JavaCV 使用FFmpeg命令行（不需要系统安装FFmpeg）

需要进行简单的音视频编程，如果不是特别熟悉C/C++，那么JavaCV应该是比较好的选择，下面记录一下使用JavaCV 使用FFmpeg命令行（不需要系统安装FFmpeg）的方法。

1. 实现代码

这种方式跟平时使用FFmpeg命令是一样的：

public class Sample27 {

	public static void main(String[] args) throws InterruptedException, IOException {
		avutil.av_log_set_level(avutil.AV_LOG_DEBUG);
		String ffmpeg = Loader.load(org.bytedeco.ffmpeg.ffmpeg.class);
		ProcessBuilder pb = new ProcessBuilder(ffmpeg, "-i", "E:\\lpl.mp4", "-vcodec", "h264", "E:\\lpl.h264");
		pb.inheritIO().start().waitFor();
	}
}

2. 日志打印

下面是Proccess打印出来的日志：

ffmpeg version 4.3.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 7.3.0 (Rev2, Built by MSYS2 project)
  configuration: --prefix=.. --disable-iconv --disable-opencl --disable-sdl2 --disable-bzlib --disable-lzma --disable-linux-perf --enable-shared --enable-gpl --enable-version3 --enable-nonfree --enable-runtime-cpudetect --enable-zlib --enable-libmp3lame --enable-libspeex --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libvo-amrwbenc --enable-openssl --enable-libopenh264 --enable-libx264 --enable-libx265 --enable-libvpx --enable-libfreetype --enable-libopus --enable-cuda --enable-cuvid --enable-nvenc --enable-libmfx --enable-w32threads --enable-indev=dshow --target-os=mingw32 --cc='gcc -m64' --extra-cflags=-I../include/ --extra-ldflags=-L../lib/ --extra-libs='-static-libgcc -static-libstdc++ -Wl,-Bstatic -lstdc++ -lgcc_eh -lWs2_32 -lcrypt32 -lpthread -lz -lm -Wl,-Bdynamic'
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'E:\lpl.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
  Duration: 00:13:08.00, start: 0.046000, bitrate: 899 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 2560x1600 [SAR 1:1 DAR 8:5], 823 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 64 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
Press [q] to stop, [?] for help
[libx264 @ 0000000002c3d740] using SAR=1/1
[libx264 @ 0000000002c3d740] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0000000002c3d740] profile High, level 5.0, 4:2:0, 8-bit
Output #0, h264, to 'E:\lpl.h264':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.45.100
    Stream #0:0(und): Video: h264 (libx264), yuv420p, 2560x1600 [SAR 1:1 DAR 8:5], q=-1--1, 30 fps, 30 tbn, 30 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc58.91.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame=   17 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A dup=1 drop=0 speed=   0x    
frame=   53 fps= 51 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A dup=1 drop=0 speed=   0x    
frame=   82 fps= 53 q=29.0 size=     141kB time=00:00:00.40 bitrate=2891.2kbits/s dup=1 drop=0 speed=0.26x    
frame=  125 fps= 61 q=29.0 size=     224kB time=00:00:01.83 bitrate= 999.9kbits/s dup=1 drop=0 speed=0.897x    
frame=  153 fps= 60 q=29.0 size=     256kB time=00:00:02.76 bitrate= 758.0kbits/s dup=1 drop=0 speed=1.09x