我想只延迟两个输入文件中的一个。但是，即使值为 5，itsoffset 也不起作用....为什么？
ffmpeg -itsoffset 5 -i one.m4a -i five.m4a -strict -2 -filter_complex "[0:a][1:a]amerge,pan=stereo:c0<c0+c2:c1<c1+c3[aout]" -map "[aout]" out.m4a
ffmpeg version 2.3 Copyright (c) 2000-2014 the FFmpeg developers
built on Jul 16 2014 21:03:06 with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
configuration: --prefix=/Volumes/tempdisk/sw --as=yasm --enable-gpl --enable-pthreads --disable-ffplay --disable-ffserver --disable-shared --enable-static --enable-libvpx --disable-decoder=libvpx --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libx265 --enable-libxvid --enable-zlib --enable-avfilter --enable-fontconfig --enable-libfreetype --enable-libass --enable-libutvideo --enable-filters --enable-postproc --enable-runtime-cpudetect
libavutil 52. 92.100 / 52. 92.100
libavcodec 55. 69.100 / 55. 69.100
libavformat 55. 48.100 / 55. 48.100
libavdevice 55. 13.102 / 55. 13.102
libavfilter 4. 11.100 / 4. 11.100
libswscale 2. 6.100 / 2. 6.100
libswresample 0. 19.100 / 0. 19.100
libpostproc 52. 3.100 / 52. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'one.m4a':
Metadata:
major_brand : M4A
minor_version : 512
compatible_brands: isomiso2
creation_time : 1970-01-01 00:00:00
encoder : Lavf52.64.2
Duration: 00:00:04.41, start: 0.000000, bitrate: 153 kb/s
Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 149 kb/s (default)
Metadata:
creation_time : 1970-01-01 00:00:00
handler_name : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'five.m4a':
Metadata:
major_brand : M4A
minor_version : 512
compatible_brands: isomiso2
creation_time : 1970-01-01 00:00:00
encoder : Lavf52.64.2
Duration: 00:00:04.41, start: 0.000000, bitrate: 151 kb/s
Stream #1:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 147 kb/s (default)
Metadata:
creation_time : 1970-01-01 00:00:00
handler_name : SoundHandler
[Parsed_pan_1 @ 0x7f8f63d038e0] This syntax is deprecated. Use '|' to separate the list items.
[Parsed_amerge_0 @ 0x7f8f63d035a0] No channel layout for input 1
[Parsed_amerge_0 @ 0x7f8f63d035a0] Input channel layouts overlap: output layout will be determined by the number of distinct input channels
Output #0, ipod, to 'o.m4a':
Metadata:
major_brand : M4A
minor_version : 512
compatible_brands: isomiso2
encoder : Lavf55.48.100
Stream #0:0: Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)
Metadata:
encoder : Lavc55.69.100 aac
Stream mapping:
Stream #0:0 (aac) -> amerge:in0
Stream #1:0 (aac) -> amerge:in1
pan -> Stream #0:0 (aac)
Press [q] to stop, [?] for help
size= 70kB time=00:00:06.41 bitrate= 89.7kbits/s
video:0kB audio:69kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.148568%