我正在将一个视频（用ffmpeg录制，质量很好，全部稳定）与musicfile.mp3合并。但是，音乐每隔几秒钟就会停顿并略有跳动。这似乎很奇怪，因为仅在视频之上添加音乐就听起来像引擎可以放松并花费时间，而没有伪像。 （与录制实时桌面素材相比）。谁能帮我解决这个问题？
系统：MacOS MBP 2015、16GB内存2.7ghz i5
ffmpeg -i "temp/1561246948349.mkv" -i "music/happy.mp3" -vcodec copy -filter_complex amix -map 0:v -map 0:a -map 1:a -shortest -b:a 144k "finished/2019-06-22/1561246948349/output.mkv"
ffmpeg version 4.1.3 Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 10.0.1 (clang-1001.0.46.4)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1.3_1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include/darwin' --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-videotoolbox --disable-libjack --disable-indev=jack --enable-libaom --enable-libsoxr
libavutil 56. 22.100 / 56. 22.100
libavcodec 58. 35.100 / 58. 35.100
libavformat 58. 20.100 / 58. 20.100
libavdevice 58. 5.100 / 58. 5.100
libavfilter 7. 40.101 / 7. 40.101
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 3.100 / 5. 3.100
libswresample 3. 3.100 / 3. 3.100
libpostproc 55. 3.100 / 55. 3.100
Input #0, matroska,webm, from 'temp/1561246948349.mkv':
Metadata:
ENCODER : Lavf58.20.100
Duration: 00:00:21.50, start: 0.000000, bitrate: 5834 kb/s
Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv422p(progressive), 2880x1800, 30 fps, 30 tbr, 1k tbn, 2000k tbc (default)
Metadata:
ENCODER : Lavc58.35.100 libx264
DURATION : 00:00:21.467000000
Stream #0:1: Audio: vorbis, 44100 Hz, stereo, fltp (default)
Metadata:
ENCODER : Lavc58.35.100 libvorbis
DURATION : 00:00:21.496000000
Input #1, mp3, from 'music/happy.mp3':
Metadata:
album : Random
genre : Jazz & Blues
Duration: 00:15:59.84, start: 0.025057, bitrate: 186 kb/s
Stream #1:0: Audio: mp3, 44100 Hz, stereo, fltp, 186 kb/s
Metadata:
encoder : LAME3.100
Stream mapping:
Stream #0:1 (vorbis) -> amix:input0
Stream #1:0 (mp3float) -> amix:input1
amix -> Stream #0:0 (libvorbis)
Stream #0:0 -> #0:1 (copy)
Press [q] to stop, [?] for help
Output #0, matroska, to 'finished/2019-06-22/1561246948349/output.mkv':
Metadata:
encoder : Lavf58.20.100
Stream #0:0: Audio: vorbis (libvorbis) (oV[0][0] / 0x566F), 44100 Hz, stereo, fltp, 144 kb/s (default)
Metadata:
encoder : Lavc58.35.100 libvorbis
Stream #0:1: Video: h264 (High 4:4:4 Predictive) (H264 / 0x34363248), yuv422p(progressive), 2880x1800, q=2-31, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
Metadata:
ENCODER : Lavc58.35.100 libx264
DURATION : 00:00:21.467000000
frame= 640 fps=0.0 q=-1.0 Lsize= 15227kB time=00:00:21.46 bitrate=5810.3kbits/s speed=33.8x
video:14888kB audio:318kB subtitle:0kB other streams:0kB global headers:4kB muxing overhead: 0.139864%