我正试图使用以下命令将png作为覆盖添加到带有ffmpeg(版本4.2.2(的mov视频中：
ffmpeg -i ./input.mov -i ./overlay.png -y -filter_complex "overlay=enable='between(t,1,4)'" ./output.mp4
现在我对overlay=enable='between(t,1,4)的理解是，自视频开始以来，覆盖将在1秒内添加，并在4秒后删除，但输出在某种程度上有所不同。
覆盖层大约在2:66添加，在5:14删除。
尝试使用不同的值会导致更令人困惑的输出。
例如：
-
between(t,3,10)-->3:12|11:05 -
between(t,2,7)-->2:65|7:22 -
between(t,1,2)-->覆盖没有添加到所有
输入视频的元数据如下
Metadata:
major_brand : qt
minor_version : 0
compatible_brands: qt
creation_time : 2020-04-19T08:09:00.000000Z
Duration: 00:00:14.84, start: 0.053333, bitrate: 849 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, smpte170m/bt709/unknown), 828x1792 [SAR 1:1 DAR 207:448], 848 kb/s, 23.34 fps, 600 tbr, 600 tbn, 1200 tbc (default)
Metadata:
creation_time : 2020-04-19T08:09:00.000000Z
handler_name : Core Media Video
encoder : H.264
在应用覆盖之前，我还尝试将视频转换为mp4(使用ffmpeg -i input.mov -vcodec copy -acodec copy out.mp4(，但问题仍然存在。
编辑：我下载了一个测试mp4视频，命令按预期工作，所以我的输入视频肯定有问题。知道是什么吗？
编辑2：这是ffmpeg命令的输出：
ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
built with Apple clang version 11.0.0 (clang-1100.0.33.17)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --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-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --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-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
libavutil 56. 31.100 / 56. 31.100
libavcodec 58. 54.100 / 58. 54.100
libavformat 58. 29.100 / 58. 29.100
libavdevice 58. 8.100 / 58. 8.100
libavfilter 7. 57.100 / 7. 57.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from './input.mov':
Metadata:
major_brand : qt
minor_version : 0
compatible_brands: qt
creation_time : 2020-04-22T07:49:31.000000Z
Duration: 00:00:17.80, start: 0.051667, bitrate: 1097 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, smpte170m/unknown/unknown), 750x1334 [SAR 1:1 DAR 375:667], 1097 kb/s, 12.96 fps, 60 tbr, 600 tbn, 1200 tbc (default)
Metadata:
creation_time : 2020-04-22T07:49:31.000000Z
handler_name : Core Media Video
encoder : H.264
Input #1, png_pipe, from './overlay.png':
Duration: N/A, bitrate: N/A
Stream #1:0: Video: png, rgba(pc), 83x128, 25 tbr, 25 tbn, 25 tbc
Stream mapping:
Stream #0:0 (h264) -> overlay:main
Stream #1:0 (png) -> overlay:overlay
overlay -> Stream #0:0 (libx264)
Press [q] to stop, [?] for help
[libx264 @ 0x7fcad0001200] using SAR=1/1
[libx264 @ 0x7fcad0001200] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x7fcad0001200] profile High, level 4.0
[libx264 @ 0x7fcad0001200] 264 - core 155 r2917 0a84d98 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - 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=18 lookahead_threads=3 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 './output.mp4':
Metadata:
major_brand : qt
minor_version : 0
compatible_brands: qt
encoder : Lavf58.29.100
Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 750x1334 [SAR 1:1 DAR 375:667], q=-1--1, 60 fps, 15360 tbn, 60 tbc (default)
Metadata:
encoder : Lavc58.54.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
frame= 326 fps=0.0 q=31.0 size= 0kB time=00:00:04.35 bitrate= 0.1kbits/frame= 499 fps=461 q=31.0 size= 256kB time=00:00:07.23 bitrate= 290.0kbits/frame= 830 fps=494 q=31.0 size= 512kB time=00:00:12.75 bitrate= 329.0kbits/frame= 956 fps=491 q=-1.0 Lsize= 593kB time=00:00:15.88 bitrate= 306.0kbits/s dup=726 drop=0 speed=8.16x
video:581kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.030694%
[libx264 @ 0x7fcad0001200] frame I:6 Avg QP:18.73 size: 30783
[libx264 @ 0x7fcad0001200] frame P:288 Avg QP:21.57 size: 1150
[libx264 @ 0x7fcad0001200] frame B:662 Avg QP:30.94 size: 119
[libx264 @ 0x7fcad0001200] consecutive B-frames: 4.9% 6.9% 4.1% 84.1%
[libx264 @ 0x7fcad0001200] mb I I16..4: 19.1% 64.5% 16.4%
[libx264 @ 0x7fcad0001200] mb P I16..4: 0.8% 0.9% 0.5% P16..4: 2.4% 0.4% 0.1% 0.0% 0.0% skip:94.9%
[libx264 @ 0x7fcad0001200] mb B I16..4: 0.0% 0.1% 0.0% B16..8: 1.8% 0.0% 0.0% direct: 0.0% skip:98.0% L0:43.8% L1:55.9% BI: 0.3%
[libx264 @ 0x7fcad0001200] 8x8 transform intra:53.9% inter:64.1%
[libx264 @ 0x7fcad0001200] coded y,uvDC,uvAC intra: 18.2% 20.8% 13.9% inter: 0.1% 0.4% 0.1%
[libx264 @ 0x7fcad0001200] i16 v,h,dc,p: 35% 63% 1% 1%
[libx264 @ 0x7fcad0001200] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 48% 17% 29% 1% 1% 1% 1% 1% 1%
[libx264 @ 0x7fcad0001200] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 33% 32% 15% 3% 4% 4% 3% 3% 3%
[libx264 @ 0x7fcad0001200] i8c dc,h,v,p: 71% 21% 7% 1%
[libx264 @ 0x7fcad0001200] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x7fcad0001200] ref P L0: 74.6% 4.0% 13.4% 8.0%
[libx264 @ 0x7fcad0001200] ref B L0: 80.0% 17.6% 2.3%
[libx264 @ 0x7fcad0001200] ref B L1: 97.6% 2.4%
[libx264 @ 0x7fcad0001200] kb/s:298.58
我找到了一个解决方法：
在不复制视频和音频编解码器(ffmpeg -i input.mov output.mp4(的情况下转换视频会导致输出，其中使用上面写的命令正确应用覆盖。
我认为这个问题与视频的开始时间有关。不确定是否有一个不涉及转换视频的更清洁的解决方案。