我使用以下命令将我服务器上的mp4转换为webm，作为Node.js脚本的一部分。
var command = execSync('ffmpeg -i '+video+' -vpre libvpx-720p -cpu-used -5 -deadline realtime -b 3900k -an -f webm -y '+saveTo);
在常规终端中运行命令时，它可以正常工作。但是，当使用execSync（）节点包运行它时，我得到以下控制台输出。
Error: ffmpeg version 1.0.8 Copyright (c) 2000-2013 the FFmpeg developers
built on Mar 27 2014 17:09:06 with gcc 4.7.3 (Gentoo 4.7.3-r1 p1.3, pie-0.5.5)
configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --enable-shared --cc=x86_64-pc-linux-gnu-gcc --cxx=x86_64-pc-linux-gnu-
g++ --ar=x86_64-pc-linux-gnu-ar --optflags='-O2 -pipe -march=native -fomit-frame-pointer' --extra-cflags='-O2 -pipe -march=native -fomit-frame-pointer' --extra-cxxflags
='-O2 -pipe -march=native -fomit-frame-pointer' --disable-static --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --enable-avresample --disable-stripp
ing --disable-debug --disable-doc --disable-vaapi --disable-vdpau --disable-ffplay --disable-runtime-cpudetect --enable-libmp3lame --enable-libvo-aacenc --enable-libthe
ora --enable-libfdk-aac --enable-nonfree --disable-indev=v4l2 --disable-indev=alsa --disable-indev=oss --disable-indev=jack --disable-outdev=alsa --disable-outdev=oss -
-disable-outdev=sdl --enable-libvorbis --enable-libvpx --disable-amd3dnow --disable-amd3dnowext --disable-altivec --disable-avx --disable-mmxext --disable-ssse3 --disab
le-vis --disabl libavutil 51. 73.101 / 51. 73.101
libavcodec 54. 59.100 / 54. 59.100
libavformat 54. 29.104 / 54. 29.104
libavdevice 54. 2.101 / 54. 2.101
libavfilter 3. 17.100 / 3. 17.100
libswscale 2. 1.101 / 2. 1.101
libswresample 0. 15.100 / 0. 15.100
libpostproc 52. 0.100 / 52. 0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/path/to/video/input.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42isomavc1
creation_time : 2013-08-24 21:58:35
encoder : HandBrake 0.9.9 2013051800
Duration: 00:06:31.46, start: 0.000000, bitrate: 5092 kb/s
Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 4919 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
Metadata:
creation_time : 2013-08-24 21:58:35
Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 168 kb/s
Metadata:
creation_time : 2013-08-24 21:58:35
Please use -b:a or -b:v, -b is ambiguous
[libvpx @ 0x7f0c40] v1.3.0
Output #0, webm, to '/path/to/video/output.webm':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42isomavc1
encoder : Lavf54.29.104
Stream #0:0(und): Video: vp8, yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=11-51, 3900 kb/s, 1k tbn, 25 tbc
encoder : Lavf54.29.104 [4009/9202]
Stream #0:0(und): Video: vp8, yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=11-51, 3900 kb/s, 1k tbn, 25 tbc
Metadata:
creation_time : 2013-08-24 21:58:35
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> libvpx)
Press [q] to stop, [?] for help
[h264 @ 0x8f42a0] AVC: nal size 3235393
Last message repeated 1 times
[h264 @ 0x8f42a0] no frame!
[h264 @ 0x7be7e0] concealing 7123 DC, 7123 AC, 7123 MV errors in P frame
[h264 @ 0x8f46c0] AVC: nal size 2572289
Last message repeated 1 times
[h264 @ 0x8f46c0] no frame!
[h264 @ 0x8f4ae0] AVC: nal size 11559745
Last message repeated 1 times
[h264 @ 0x8f4ae0] no frame!
[h264 @ 0x8f4f00] AVC: nal size 781975966
Last message repeated 1 times
[h264 @ 0x8f4f00] no frame!
[h264 @ 0x7be7e0] AVC: nal size -1537130086
Last message repeated 1 times
[h264 @ 0x7be7e0] no frame!
Error while decoding stream #0:0: Operation not permitted
[h264 @ 0x8f42a0] AVC: nal size -1303101030
Last message repeated 1 times
[h264 @ 0x8f42a0] no frame!
Error while decoding stream #0:0: Operation not permitted
[h264 @ 0x8f46c0] AVC: nal size 833290655
Last message repeated 1 times
[h264 @ 0x8f46c0] no frame!
Error while decoding stream #0:0: Operation not permitted
[h264 @ 0x8f4ae0] AVC: nal size -816365157
Last message repeated 1 times
[h264 @ 0x8f4ae0] no frame!
Error while decoding stream #0:0: Operation not permitted
[h264 @ 0x8f4f00] AVC: nal size 776798623
Last message repeated 1 times
[h264 @ 0x8f4f00] no frame!
Error while decoding stream #0:0: Operation not permitted
[h264 @ 0x7be7e0] AVC: nal size -824622693
Last message repeated 1 times
[h264 @ 0x7be7e0] no frame!
Error while decoding stream #0:0: Operation not permitted
[h264 @ 0x8f42a0] AVC: nal size 1276789151
Error while decoding stream #0:0: Operation not permitted
frame= 4 fps=0.0 q=0.0 Lsize= 107kB time=00:00:00.16 bitrate=5476.5kbits/s
video:106kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.473334%
Received signal 2: terminating.
＆＃39; no frame＆＃39;比特在到达最后一节之前重复几千次。
有人能告诉我什么是错的吗？
感谢您的帮助