Question

我需要提取原始视频并将其通过管道传输到另一个程序。这可以在终端中完美运行：

ffmpeg -i SampleVideo_1280x720_5mb.mp4 -s 1920x1080 -c:v rawvideo -pix_fmt yuv420p -f rawvideo - | ffplay -f rawvideo -pix_fmt yuv420p -s 1920x1080 -

但是，当我尝试从脚本运行此命令时，它将失败。这是脚本的非常简化的版本：

#!/bin/bash

c='ffmpeg -i SampleVideo_1280x720_5mb.mp4 -s 1920x1080 -c:v rawvideo -pix_fmt yuv420p -f rawvideo - | ffplay -f rawvideo -pix_fmt yuv420p -s 1920x1080 -'
$c

输出

~/ets/videos$ ./test.sh 
ffmpeg version N-91403-gd24c9e5 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609
  configuration: --extra-cflags='-fPIC -I/home/jlbeaussart/ffmpeg_build/include' --extra-ldflags=-L/home/jlbeaussart/ffmpeg_build/lib --extra-libs='-lpthread -lm' --enable-gpl --enable-libaom --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-shared --enable-libcaca --enable-libxvid --enable-libxml2 --enable-opencl --enable-opengl --enable-cuvid --enable-ffnvcodec --enable-libdrm --enable-nvenc --enable-nvdec --enable-vaapi --enable-vdpau --enable-nonfree
  libavutil      56. 18.102 / 56. 18.102
  libavcodec     58. 20.104 / 58. 20.104
  libavformat    58. 17.101 / 58. 17.101
  libavdevice    58.  4.101 / 58.  4.101
  libavfilter     7. 25.100 /  7. 25.100
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
  libpostproc    55.  2.100 / 55.  2.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'SampleVideo_1280x720_5mb.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 1970-01-01T00:00:00.000000Z
    encoder         : Lavf53.24.2
  Duration: 00:00:29.57, start: 0.000000, bitrate: 1421 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1032 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      creation_time   : 1970-01-01T00:00:00.000000Z
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 383 kb/s (default)
    Metadata:
      creation_time   : 1970-01-01T00:00:00.000000Z
      handler_name    : SoundHandler
[NULL @ 0x18d5d40] Unable to find a suitable output format for '|'
|: Invalid argument

ffmpeg管道输出和脚本

0 个答案: