我正在尝试使用ffmpeg在不同的时间间隔在视频上绘制文本。以下是我的说明：
ffmpeg -i input.mp4 -vf "drawtext=fontfile='C:\arial.ttf':text='Text1':x=5:y=20+24-max_glyph_a:fontsize=24:fontcolor=yellow:box=1:boxcolor=black@0.5:boxborderw=5:enable='between(t,0,20)', drawtext=fontfile='C:\arial.ttf':text='Text2':x=100:y=20+24-max_glyph_a:fontsize=24:fontcolor=yellow:enable='between(t,5,20)', drawtext=fontfile='C:\arial.ttf':text='Text3':x=200:y=20+24-max_glyph_a:fontsize=24:fontcolor=yellow:enable='between(t,10,20)'" output.mp4
我试图在水平线上绘制文本，在开始的5秒内只希望使用Text1，然后在5秒到20秒之间只希望使用Text2，而从10秒到结束则只希望Text3。
执行此操作时，我的第一个文本停留约15秒钟，而后两个则出现在视频的最后4秒钟中。我的指令有问题吗？我是否正确使用了启用功能？
以下是ffmpeg -i input.mp4 -vf showinfo -vsync 0 -f null-：
的日志 ffmpeg version N-91399-g9f0077cc03 Copyright (c) 2000-2018 the FFmpeg developers
built with gcc 7.3.0 (GCC)
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
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 'onlyVideo.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2mp41
encoder : Lavf56.37.100
Duration: 00:00:20.00, start: 0.000000, bitrate: 73 kb/s
Stream #0:0(und): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 640x720 [SAR 1:1 DAR 8:9], 73 kb/s, 0.20 fps, 0.20 tbr, 16384 tbn, 1 tbc (default)
Metadata:
handler_name : VideoHandler
Stream mapping:
Stream #0:0 -> #0:0 (mpeg4 (native) -> wrapped_avframe (native))
Press [q] to stop, [?] for help
[Parsed_showinfo_0 @ 0000019e4ef73140] config in time_base: 1/16384, frame_rate: 1/5
[Parsed_showinfo_0 @ 0000019e4ef73140] config out time_base: 0/0, frame_rate: 0/0
[Parsed_showinfo_0 @ 0000019e4ef73140] n: 0 pts: 0 pts_time:0 pos: 44 fmt:yuv420p sar:1/1 s:640x720 i:P iskey:1 type:I checksum:850631B2 plane_checksum:[6C2678F8 6C5D6575 C2075336] mean:[191 121 133 ] stdev:[67.7 11.8 8.5 ]
[Parsed_showinfo_0 @ 0000019e4ef73140] side data - unknown side data type 17 (1845 bytes)
[Parsed_showinfo_0 @ 0000019e4ef73140] side data - unknown side data type 16 (8 bytes)
Output #0, null, to 'pipe:':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2mp41
encoder : Lavf58.17.101
Stream #0:0(und): Video: wrapped_avframe, yuv420p, 640x720 [SAR 1:1 DAR 8:9], q=2-31, 200 kb/s, 0.20 fps, 0.20 tbn, 0.20 tbc (default)
Metadata:
handler_name : VideoHandler
encoder : Lavc58.20.104 wrapped_avframe
[Parsed_showinfo_0 @ 0000019e4ef73140] n: 1 pts: 81920 pts_time:5 pos: 37980 fmt:yuv420p sar:1/1 s:640x720 i:P iskey:0 type:P checksum:D4B0BD28 plane_checksum:[E0310E7B DC71FA0B 97BCB493] mean:[31 127 132 ] stdev:[25.6 28.9 27.1 ]
[Parsed_showinfo_0 @ 0000019e4ef73140] side data - unknown side data type 17 (1845 bytes)
[Parsed_showinfo_0 @ 0000019e4ef73140] side data - unknown side data type 16 (8 bytes)
frame= 2 fps=0.0 q=-0.0 size=N/A time=00:00:10.00 bitrate=N/A speed=11.1x
[Parsed_showinfo_0 @ 0000019e4ef73140] n: 2 pts: 163840 pts_time:10 pos: 67732 fmt:yuv420p sar:1/1 s:640x720 i:P iskey:0 type:P checksum:9FC30D4F plane_checksum:[1F10F7EB 45F39329 BED7821D] mean:[60 123 125 ] stdev:[61.8 11.0 5.5 ]
[Parsed_showinfo_0 @ 0000019e4ef73140] side data - unknown side data type 17 (1845 bytes)
[Parsed_showinfo_0 @ 0000019e4ef73140] side data - unknown side data type 16 (8 bytes)
[Parsed_showinfo_0 @ 0000019e4ef73140] n: 3 pts: 245760 pts_time:15 pos: 133778 fmt:yuv420p sar:1/1 s:640x720 i:P iskey:0 type:P checksum:9F501A92 plane_checksum:[D1B4E4A7 C4CD0DFA EB7E27E2] mean:[162 129 139 ] stdev:[71.7 27.3 37.2 ]
[Parsed_showinfo_0 @ 0000019e4ef73140] side data - unknown side data type 17 (1845 bytes)
[Parsed_showinfo_0 @ 0000019e4ef73140] side data - unknown side data type 16 (8 bytes)
frame= 4 fps=0.0 q=-0.0 Lsize=N/A time=00:00:20.00 bitrate=N/A speed=21.7x
video:2kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown