FFMPEG不能从Python subprocess.Popen工作，但可以从命令行工作

我正在尝试从

python3.5.2

中运行

FFMPEG

脚本。

FFMPEG

命令在命令行中运行良好，但在python脚本中失败

我用来执行

FFMPEG

命令的函数是

def ffmpeg(args):
    err = None
    command = [
        ffmpegcmd, '-y',
        '-loglevel', loglevel
    ] + args
    print("\n\n\n")
    print(command)
    print("\n\n\n")
    print(" ".join(command))
    ffmpeg = subprocess.Popen(command, stderr=subprocess.PIPE ,stdout=subprocess.PIPE, universal_newlines=True)
    while err == None:
        out, err = ffmpeg.communicate()
        time.sleep(1)
    if err and loglevel=='fatal':
        print(" ".join(command))
        raise Exception(err)
    print(err)

args的值为：

['-i', '/var/www/temp/film.mp4', '-vf', 'scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:x=(1920-iw)/2:y=(1080-ih)/2:color=black', '/var/www/temp/videoHD.mp4']

这样，传递给

subprocess.Popen的结果命令是：

['ffmpeg', '-y', '-loglevel', 'verbose', '-i', '/var/www/temp/film.mp4', '-vf', 'scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:x=(1920-iw)/2:y=(1080-ih)/2:color=black', '/var/www/temp/videoHD.mp4']

ffmpeg version 3.3.4-2~16.04.york0 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  configuration: --prefix=/usr --extra-version='2~16.04.york0' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libavresample   3.  5.  0 /  3.  5.  0
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
  libpostproc    54.  5.100 / 54.  5.100
[h264 @ 0x7f741a37a560] Reinit context to 640x368, pix_fmt: yuv420p
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/var/www/temp/film.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
  Duration: 00:06:19.80, start: 0.000000, bitrate: 451 kb/s
    Stream #0:0(und): Video: h264 (High), 1 reference frame (avc1 / 0x31637661), yuv420p(left), 640x358 (640x368), 313 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, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[h264 @ 0x7f741a3bc700] Reinit context to 640x368, pix_fmt: yuv420p
[graph_1_in_0_1 @ 0x7f741a5315e0] tb:1/48000 samplefmt:fltp samplerate:48000 chlayout:0x3
[Parsed_scale_0 @ 0x7f741a54e000] w:1920 h:1080 flags:'bicubic' interl:0
[graph 0 input from stream 0:0 @ 0x7f741a54f6a0] w:640 h:358 pixfmt:yuv420p tb:1/15360 fr:30/1 sar:0/1 sws_param:flags=2
[Parsed_scale_0 @ 0x7f741a54e000] w:640 h:358 fmt:yuv420p sar:0/1 -> w:1920 h:1074 fmt:yuv420p sar:0/1 flags:0x4
[Parsed_pad_1 @ 0x7f741a54eac0] w:1920 h:1074 -> w:1920 h:1080 x:0 y:2 color:0x000000FF
[libx264 @ 0x7f741a5509e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7f741a5509e0] profile High, level 4.0
[libx264 @ 0x7f741a5509e0] 264 - core 148 r2795 aaa9aa8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/var/www/temp/videoHD.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
    Stream #0:0(und): Video: h264 (libx264), 1 reference frame ([33][0][0][0] / 0x0021), yuv420p(left), 1920x1080, q=-1--1, 30 fps, 15360 tbn, 30 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc57.89.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(und): Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, fltp, delay 1024, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      encoder         : Lavc57.89.100 aac

loglevel的值为
verbose
仅用于故障排除，但旨在作为
致命运行。还有一些
print
命令仅用于故障排除

想要提高分辨率的原因是为了以后可以将其与更高分辨率的视频相结合

从
python
运行时的结果是：

['ffmpeg', '-y', '-loglevel', 'verbose', '-i', '/var/www/temp/film.mp4', '-vf', 'scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:x=(1920-iw)/2:y=(1080-ih)/2:color=black', '/var/www/temp/videoHD.mp4']

ffmpeg version 3.3.4-2~16.04.york0 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  configuration: --prefix=/usr --extra-version='2~16.04.york0' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libavresample   3.  5.  0 /  3.  5.  0
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
  libpostproc    54.  5.100 / 54.  5.100
[h264 @ 0x7f741a37a560] Reinit context to 640x368, pix_fmt: yuv420p
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/var/www/temp/film.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
  Duration: 00:06:19.80, start: 0.000000, bitrate: 451 kb/s
    Stream #0:0(und): Video: h264 (High), 1 reference frame (avc1 / 0x31637661), yuv420p(left), 640x358 (640x368), 313 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, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[h264 @ 0x7f741a3bc700] Reinit context to 640x368, pix_fmt: yuv420p
[graph_1_in_0_1 @ 0x7f741a5315e0] tb:1/48000 samplefmt:fltp samplerate:48000 chlayout:0x3
[Parsed_scale_0 @ 0x7f741a54e000] w:1920 h:1080 flags:'bicubic' interl:0
[graph 0 input from stream 0:0 @ 0x7f741a54f6a0] w:640 h:358 pixfmt:yuv420p tb:1/15360 fr:30/1 sar:0/1 sws_param:flags=2
[Parsed_scale_0 @ 0x7f741a54e000] w:640 h:358 fmt:yuv420p sar:0/1 -> w:1920 h:1074 fmt:yuv420p sar:0/1 flags:0x4
[Parsed_pad_1 @ 0x7f741a54eac0] w:1920 h:1074 -> w:1920 h:1080 x:0 y:2 color:0x000000FF
[libx264 @ 0x7f741a5509e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7f741a5509e0] profile High, level 4.0
[libx264 @ 0x7f741a5509e0] 264 - core 148 r2795 aaa9aa8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/var/www/temp/videoHD.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
    Stream #0:0(und): Video: h264 (libx264), 1 reference frame ([33][0][0][0] / 0x0021), yuv420p(left), 1920x1080, q=-1--1, 30 fps, 15360 tbn, 30 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc57.89.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(und): Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, fltp, delay 1024, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      encoder         : Lavc57.89.100 aac

这将导致一个没有内容的文件

当我从命令行运行命令时，我需要在
-vf
视频过滤器周围添加单引号
scale=1920:1080:force\u original\u aspect\u ratio=decrease，pad=1920:1080:x=（1920 iw）/2:y=（1080 ih）/2:color=black
，因此整个命令变成：

ffmpeg -y -loglevel verbose -i /var/www/temp/film.mp4 -vf 'scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:x=(1920-iw)/2:y=(1080-ih)/2:color=black' /var/www/temp/videoHD.mp4

运行此命令将得到所需的结果

ffmpeg version 3.3.4-2~16.04.york0 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  configuration: --prefix=/usr --extra-version='2~16.04.york0' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libavresample   3.  5.  0 /  3.  5.  0
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
  libpostproc    54.  5.100 / 54.  5.100
[h264 @ 0x7f3a55c17560] Reinit context to 640x368, pix_fmt: yuv420p
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/var/www/temp/film.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
  Duration: 00:06:19.80, start: 0.000000, bitrate: 451 kb/s
    Stream #0:0(und): Video: h264 (High), 1 reference frame (avc1 / 0x31637661), yuv420p(left), 640x358 (640x368), 313 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, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[h264 @ 0x7f3a55c59700] Reinit context to 640x368, pix_fmt: yuv420p
[graph_1_in_0_1 @ 0x7f3a55dce5e0] tb:1/48000 samplefmt:fltp samplerate:48000 chlayout:0x3
[Parsed_scale_0 @ 0x7f3a55deb000] w:1920 h:1080 flags:'bicubic' interl:0
[graph 0 input from stream 0:0 @ 0x7f3a55dec6a0] w:640 h:358 pixfmt:yuv420p tb:1/15360 fr:30/1 sar:0/1 sws_param:flags=2
[Parsed_scale_0 @ 0x7f3a55deb000] w:640 h:358 fmt:yuv420p sar:0/1 -> w:1920 h:1074 fmt:yuv420p sar:0/1 flags:0x4
[Parsed_pad_1 @ 0x7f3a55debac0] w:1920 h:1074 -> w:1920 h:1080 x:0 y:2 color:0x000000FF
[libx264 @ 0x7f3a55ded9e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7f3a55ded9e0] profile High, level 4.0
[libx264 @ 0x7f3a55ded9e0] 264 - core 148 r2795 aaa9aa8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/var/www/temp/videoHD.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
    Stream #0:0(und): Video: h264 (libx264), 1 reference frame ([33][0][0][0] / 0x0021), yuv420p(left), 1920x1080, q=-1--1, 30 fps, 15360 tbn, 30 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc57.89.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(und): Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, fltp, delay 1024, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      encoder         : Lavc57.89.100 aac
frame=   46 fps=0.0 q=0.0 size=       0kB time=00:00:01.62 bitrate=   0.0kbits/s
frame=   59 fps= 47 q=29.0 size=     116kB time=00:00:02.04 bitrate= 464.8kbits/
frame=   74 fps= 41 q=29.0 size=     223kB time=00:00:02.56 bitrate= 714.8kbits/
frame=   87 fps= 35 q=29.0 size=     344kB time=00:00:02.98 bitrate= 942.4kbits/
frame=   98 fps= 33 q=29.0 size=     427kB time=00:00:03.34 bitrate=1043.4kbits/
    blah
    blah
    blah
frame=11347 fps= 21 q=29.0 size=   97550kB time=00:06:18.32 bitrate=2112.3kbits/
frame=11363 fps= 21 q=29.0 size=   97713kB time=00:06:18.85 bitrate=2112.8kbits/
frame=11380 fps= 21 q=29.0 size=   97795kB time=00:06:19.41 bitrate=2111.5kbits/
No more output streams to write to, finishing.
frame=11392 fps= 21 q=-1.0 Lsize=   98519kB time=00:06:19.77 bitrate=2125.1kbits/s speed=0.69x    
video:92124kB audio:5986kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.416313%
Input file #0 (/var/www/temp/film.mp4):
  Input stream #0:0 (video): 11392 packets read (14892948 bytes); 11392 frames decoded; 
  Input stream #0:1 (audio): 17803 packets read (6112540 bytes); 17802 frames decoded (18229248 samples); 
  Total: 29195 packets (21005488 bytes) demuxed
Output file #0 (/var/www/temp/videoHD.mp4):
  Output stream #0:0 (video): 11392 frames encoded; 11392 packets muxed (94334785 bytes); 
  Output stream #0:1 (audio): 17802 frames encoded (18229248 samples); 17803 packets muxed (6129981 bytes); 
  Total: 29195 packets (100464766 bytes) muxed
[libx264 @ 0x7f3a55ded9e0] frame I:74    Avg QP:19.08  size: 51540
[libx264 @ 0x7f3a55ded9e0] frame P:3506  Avg QP:21.34  size: 19348
[libx264 @ 0x7f3a55ded9e0] frame B:7812  Avg QP:24.07  size:  2904
[libx264 @ 0x7f3a55ded9e0] consecutive B-frames:  1.3% 20.2%  4.6% 73.9%
[libx264 @ 0x7f3a55ded9e0] mb I  I16..4: 19.7% 73.6%  6.7%
[libx264 @ 0x7f3a55ded9e0] mb P  I16..4:  3.2%  6.4%  0.1%  P16..4: 52.5%  7.6%  2.6%  0.0%  0.0%    skip:27.6%
[libx264 @ 0x7f3a55ded9e0] mb B  I16..4:  0.2%  0.2%  0.0%  B16..8: 23.2%  0.4%  0.0%  direct: 0.5%  skip:75.5%  L0:51.8% L1:46.6% BI: 1.6%
[libx264 @ 0x7f3a55ded9e0] 8x8 transform intra:66.4% inter:94.0%
[libx264 @ 0x7f3a55ded9e0] coded y,uvDC,uvAC intra: 33.6% 53.4% 7.3% inter: 5.3% 14.2% 0.0%
[libx264 @ 0x7f3a55ded9e0] i16 v,h,dc,p: 22% 27%  5% 46%
[libx264 @ 0x7f3a55ded9e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 29% 19% 20%  4%  7%  7%  7%  5%  4%
[libx264 @ 0x7f3a55ded9e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 31% 28% 11%  3%  9%  7%  6%  3%  2%
[libx264 @ 0x7f3a55ded9e0] i8c dc,h,v,p: 49% 21% 20% 10%
[libx264 @ 0x7f3a55ded9e0] Weighted P-Frames: Y:0.5% UV:0.1%
[libx264 @ 0x7f3a55ded9e0] ref P L0: 63.4%  8.9% 21.4%  6.3%  0.0%
[libx264 @ 0x7f3a55ded9e0] ref B L0: 89.3%  9.1%  1.6%
[libx264 @ 0x7f3a55ded9e0] ref B L1: 98.1%  1.9%
[libx264 @ 0x7f3a55ded9e0] kb/s:1987.38
[aac @ 0x7f3a55deee80] Qavg: 1160.814

结果显示的视频很好

有什么想法吗

干杯

斯图

编辑

有人建议我使用一个新函数来做同样的事情。因此，我添加了以下函数，并将其用于我遇到问题的命令：

def ffmpegPro(args):
    err = None
    for i, arg in enumerate(args):
        if(" " in arg or "(" in arg or "[" in arg):
            args[i] = "\"" + arg + "\""
    command = [
        ffmpegcmd, '-y',
        '-loglevel', loglevel
    ] + args
    commandStr = " ".join(command)
    print("\n\n\n")
    print(command)
    print("\n\n\n")
    print(commandStr)
    ffmpeg = subprocess.Popen(commandStr, stderr=subprocess.PIPE, stdout=subprocess.PIPE, universal_newlines=True, shell=True)
    while err == None:
        out, err = ffmpeg.communicate()
        time.sleep(1)
    if ffmpeg.returncode == 0 and all([os.path.exists(f) for f in (videoStorage['data_small'], videoStorage['data_big'])]):
        print("Job done.")
    else:
        print("ERROR")
        print(err)

现在，生成的命令可以在python中使用，也可以在命令行中使用，而无需进行任何更改。命令是：

ffmpeg -y -loglevel verbose -i /var/www/temp/film.mp4 -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:x=(1920-iw)/2:y=(1080-ih)/2:color=black" /var/www/temp/videoHD.mp4

在
python
中执行时的结果是

ffmpeg version 3.3.4-2~16.04.york0 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  configuration: --prefix=/usr --extra-version='2~16.04.york0' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libavresample   3.  5.  0 /  3.  5.  0
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
  libpostproc    54.  5.100 / 54.  5.100
[h264 @ 0x7fb75053d560] Reinit context to 640x368, pix_fmt: yuv420p
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/var/www/temp/film.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
  Duration: 00:06:19.80, start: 0.000000, bitrate: 451 kb/s
    Stream #0:0(und): Video: h264 (High), 1 reference frame (avc1 / 0x31637661), yuv420p(left), 640x358 (640x368), 313 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, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[h264 @ 0x7fb75057f700] Reinit context to 640x368, pix_fmt: yuv420p
[graph_1_in_0_1 @ 0x7fb7506f45e0] tb:1/48000 samplefmt:fltp samplerate:48000 chlayout:0x3
[Parsed_scale_0 @ 0x7fb750711000] w:1920 h:1080 flags:'bicubic' interl:0
[graph 0 input from stream 0:0 @ 0x7fb7507126a0] w:640 h:358 pixfmt:yuv420p tb:1/15360 fr:30/1 sar:0/1 sws_param:flags=2
[Parsed_scale_0 @ 0x7fb750711000] w:640 h:358 fmt:yuv420p sar:0/1 -> w:1920 h:1074 fmt:yuv420p sar:0/1 flags:0x4
[Parsed_pad_1 @ 0x7fb750711ac0] w:1920 h:1074 -> w:1920 h:1080 x:0 y:2 color:0x000000FF
[libx264 @ 0x7fb7507139e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7fb7507139e0] profile High, level 4.0
[libx264 @ 0x7fb7507139e0] 264 - core 148 r2795 aaa9aa8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/var/www/temp/videoHD.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
    Stream #0:0(und): Video: h264 (libx264), 1 reference frame ([33][0][0][0] / 0x0021), yuv420p(left), 1920x1080, q=-1--1, 30 fps, 15360 tbn, 30 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc57.89.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(und): Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, fltp, delay 1024, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      encoder         : Lavc57.89.100 aac
Killed

注意结尾处的
已终止
。这是否重要？为什么只有在脚本中执行时才会发生

下面是命令行的输出，它将生成一个成功的视频文件

ffmpeg version 3.3.4-2~16.04.york0 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  configuration: --prefix=/usr --extra-version='2~16.04.york0' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libavresample   3.  5.  0 /  3.  5.  0
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
  libpostproc    54.  5.100 / 54.  5.100
[h264 @ 0x7fb52cfb3560] Reinit context to 640x368, pix_fmt: yuv420p
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/var/www/temp/film.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
  Duration: 00:06:19.80, start: 0.000000, bitrate: 451 kb/s
    Stream #0:0(und): Video: h264 (High), 1 reference frame (avc1 / 0x31637661), yuv420p(left), 640x358 (640x368), 313 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, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[h264 @ 0x7fb52cff5700] Reinit context to 640x368, pix_fmt: yuv420p
[graph_1_in_0_1 @ 0x7fb52d16a5e0] tb:1/48000 samplefmt:fltp samplerate:48000 chlayout:0x3
[Parsed_scale_0 @ 0x7fb52d187000] w:1920 h:1080 flags:'bicubic' interl:0
[graph 0 input from stream 0:0 @ 0x7fb52d1886a0] w:640 h:358 pixfmt:yuv420p tb:1/15360 fr:30/1 sar:0/1 sws_param:flags=2
[Parsed_scale_0 @ 0x7fb52d187000] w:640 h:358 fmt:yuv420p sar:0/1 -> w:1920 h:1074 fmt:yuv420p sar:0/1 flags:0x4
[Parsed_pad_1 @ 0x7fb52d187ac0] w:1920 h:1074 -> w:1920 h:1080 x:0 y:2 color:0x000000FF
[libx264 @ 0x7fb52d1899e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7fb52d1899e0] profile High, level 4.0
[libx264 @ 0x7fb52d1899e0] 264 - core 148 r2795 aaa9aa8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/var/www/temp/videoHD.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
    Stream #0:0(und): Video: h264 (libx264), 1 reference frame ([33][0][0][0] / 0x0021), yuv420p(left), 1920x1080, q=-1--1, 30 fps, 15360 tbn, 30 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc57.89.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(und): Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, fltp, delay 1024, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      encoder         : Lavc57.89.100 aac
frame=   47 fps=0.0 q=0.0 size=       0kB time=00:00:01.66 bitrate=   0.0kbits/s
frame=   59 fps= 41 q=29.0 size=     116kB time=00:00:02.04 bitrate= 464.8kbits/
frame=   71 fps= 35 q=29.0 size=     201kB time=00:00:02.45 bitrate= 671.3kbits/
frame=   80 fps= 31 q=29.0 size=     276kB time=00:00:02.75 bitrate= 822.0kbits/
    Blah
    Blah
    Blah
frame=11337 fps= 21 q=29.0 size=   97503kB time=00:06:17.98 bitrate=2113.2kbits/
frame=11351 fps= 21 q=26.0 size=   97572kB time=00:06:18.45 bitrate=2112.1kbits/
frame=11371 fps= 21 q=29.0 size=   97745kB time=00:06:19.11 bitrate=2112.1kbits/
frame=11390 fps= 21 q=29.0 size=   97852kB time=00:06:19.73 bitrate=2111.0kbits/
No more output streams to write to, finishing.
frame=11392 fps= 21 q=-1.0 Lsize=   98519kB time=00:06:19.77 bitrate=2125.1kbits/s speed=0.688x    
video:92124kB audio:5986kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.416313%
Input file #0 (/var/www/temp/film.mp4):
  Input stream #0:0 (video): 11392 packets read (14892948 bytes); 11392 frames decoded; 
  Input stream #0:1 (audio): 17803 packets read (6112540 bytes); 17802 frames decoded (18229248 samples); 
  Total: 29195 packets (21005488 bytes) demuxed
Output file #0 (/var/www/temp/videoHD.mp4):
  Output stream #0:0 (video): 11392 frames encoded; 11392 packets muxed (94334785 bytes); 
  Output stream #0:1 (audio): 17802 frames encoded (18229248 samples); 17803 packets muxed (6129981 bytes); 
  Total: 29195 packets (100464766 bytes) muxed
[libx264 @ 0x7fb52d1899e0] frame I:74    Avg QP:19.08  size: 51540
[libx264 @ 0x7fb52d1899e0] frame P:3506  Avg QP:21.34  size: 19348
[libx264 @ 0x7fb52d1899e0] frame B:7812  Avg QP:24.07  size:  2904
[libx264 @ 0x7fb52d1899e0] consecutive B-frames:  1.3% 20.2%  4.6% 73.9%
[libx264 @ 0x7fb52d1899e0] mb I  I16..4: 19.7% 73.6%  6.7%
[libx264 @ 0x7fb52d1899e0] mb P  I16..4:  3.2%  6.4%  0.1%  P16..4: 52.5%  7.6%  2.6%  0.0%  0.0%    skip:27.6%
[libx264 @ 0x7fb52d1899e0] mb B  I16..4:  0.2%  0.2%  0.0%  B16..8: 23.2%  0.4%  0.0%  direct: 0.5%  skip:75.5%  L0:51.8% L1:46.6% BI: 1.6%
[libx264 @ 0x7fb52d1899e0] 8x8 transform intra:66.4% inter:94.0%
[libx264 @ 0x7fb52d1899e0] coded y,uvDC,uvAC intra: 33.6% 53.4% 7.3% inter: 5.3% 14.2% 0.0%
[libx264 @ 0x7fb52d1899e0] i16 v,h,dc,p: 22% 27%  5% 46%
[libx264 @ 0x7fb52d1899e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 29% 19% 20%  4%  7%  7%  7%  5%  4%
[libx264 @ 0x7fb52d1899e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 31% 28% 11%  3%  9%  7%  6%  3%  2%
[libx264 @ 0x7fb52d1899e0] i8c dc,h,v,p: 49% 21% 20% 10%
[libx264 @ 0x7fb52d1899e0] Weighted P-Frames: Y:0.5% UV:0.1%
[libx264 @ 0x7fb52d1899e0] ref P L0: 63.4%  8.9% 21.4%  6.3%  0.0%
[libx264 @ 0x7fb52d1899e0] ref B L0: 89.3%  9.1%  1.6%
[libx264 @ 0x7fb52d1899e0] ref B L1: 98.1%  1.9%
[libx264 @ 0x7fb52d1899e0] kb/s:1987.38
[aac @ 0x7fb52d18ae80] Qavg: 1160.814

还有什么想法可以解释为什么在
python
中与命令行不同地处理这个问题

我相信这是一个版本问题，这就是为什么下面的答案对我不起作用的原因，在我升级之前一切都很好，但从那时起，很多事情都在升级。我升级了
ffmpeg
和
python
两个版本，如果可以避免的话，我真的不想回去

谢谢

Stu
我正在通过如下子流程执行ffmpeg：

1.）ffmpeg命令作为字符串而不是列表。

2.
-vf
选项的双引号。

3.
shell=True


4.
-y
强制ffmpeg覆盖新文件。

5.）Python2.7/Python3.6上的ffmpeg 3.4版

cmd = "ffmpeg -threads %s -i %s " % (_threads, _videoFile['path'])
for fmt in ('640:360', '1024:576'):
    cmd += ' ... alot of string concentration here ...' 

print "ffmpeg command is:"
print cmd
print ""

cmd = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
out, err = cmd.communicate()
if cmd.returncode == 0 and all([os.path.exists(f) for f in (videoStorage['data_small'], videoStorage['data_big'])]):
    print "Job done."
else:
    print "ERROR"
    print out

输出：

ffmpeg command is:
ffmpeg -threads 2 -i /home/f3k/mini.elapsed.mov    -to 0:00:41   -vf "boxblur=enable='between(t,5.646,23.353)'"  -s 640:360 -sn -codec:a copy -q:v 1 -threads 2 -y /tmp/result.small.mp4    -to 0:00:41   -vf "boxblur=enable='between(t,5.646,23.353)'"  -s 1024:576 -sn -codec:a copy -q:v 1 -threads 2 -y /tmp/result.big.mp4 

Job done.

胡乱猜测：在Python中也将过滤器描述放在附加的单引号中（用双引号括起来）：
['ffmpeg'，…，“'scale=…color=black'，”
@MichaelButscher这引入了一个新的错误：
[AVFilterGraph@0x7f4500b19280]没有这样的过滤器：'scale=1920:1080:force\u original\u aspect\u ratio=red，pad=1920:1080:x=（1920 iw）/2:y=（1080 ih）/2:color=black'重新初始化过滤器时出错！
。这是因为它将单引号视为参数的一部分，而不是将其全部打包。答案是我首先更改了使用这些单引号的代码，并修复了以前的问题。
out，err=ffmpeg.communicate（）
也许ffmpeg通过stderr“返回给你”，所以它退出得太快了…@rogerdpack，所以我使用
而err==None:
和
out，err=ffmpeg.communicate（）
，为了避免在任何事情完成之前退出，你认为我做得不对吗？还有其他方法吗？你有什么建议吗？我添加了
打印（ffmpeg.returncode）
当此命令失败时，结果是
137
。我已将新函数的使用扩展到我运行的其他命令，它们工作正常，并按预期返回
0
的代码。您知道这
137
的含义以及为什么我会得到它吗？这仍然会导致从命令l运行时出现不同的结果在脚本中。我将编辑问题以添加我尝试过的内容和输出。我已在问题末尾包含了有关此想法和结果的信息。我认为这与版本有关。我确实喜欢你的代码，它非常整洁，但不幸的是，它仍然会为我带来相同的结果。还有其他想法吗？调查e进程被终止的原因：）关于子进程，我可以想到两件事：删除communicate（）周围的while循环，不睡觉，尝试少写到stdout或管道到文件中。否则，除了查看操作系统/系统级别（可用CPU、内存、磁盘空间等）外，我不知道-但这对我来说没有多大意义，因为命令在shell中运行良好。我删除了while循环，但仍然没有结果。至于stdout，它立即失败，所以不要认为这与资源有关。