我需要使用ffmpeg将此x.264剪辑映射到matroska容器中：
ffmpeg -i f-0.mp4 -c copy f-0.mkv
这是ffmpeg控制台输出：
ffmpeg -i f-0.mp4 -c copy f-0.mkv
ffmpeg version N-69672-g078be09 Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.9.2 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --enable-decklink --enable-zlib
libavutil 54. 18.100 / 54. 18.100
libavcodec 56. 21.102 / 56. 21.102
libavformat 56. 19.100 / 56. 19.100
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 9.104 / 5. 9.104
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'f-0.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf56.19.100
Duration: 00:02:08.06, start: 0.005333, bitrate: 5030 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 4865 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, stereo, fltp, 160 kb/s (default)
Metadata:
handler_name : SoundHandler
Side data:
unknown side data type 7 (4 bytes)
Output #0, matroska, to 'f-0.mkv':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf56.19.100
Stream #0:0(und): Video: h264 (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 4865 kb/s, 29.97 fps, 29.97 tbr, 1k tbn, 30k tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, 160 kb/s (default)
Metadata:
handler_name : SoundHandler
Side data:
unknown side data type 7 (4 bytes)
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Stream #0:1 -> #0:1 (copy)
...
结果似乎很好，播放同步音频和视频。但是，MediaInfo在Audio下显示了一个新项目（原始剪辑没有）：
Delay relative to video : 1mn 5s
这是来自原始f-0.mp4文件的Mediainfo：
Audio
ID : 2
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : ac-3
Duration : 2mn 8s
Bit rate mode : Constant
Bit rate : 160 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Delay relative to video : 67ms
Stream size : 2.44 MiB (3%)
来自f-0.mkv输出的Mediainfo：
Audio
ID : 2
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : A_AC3
Duration : 2mn 8s
Bit rate mode : Constant
Bit rate : 160 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Delay relative to video : 1mn 5s
Stream size : 2.44 MiB (3%)
Default : Yes
Forced : No
HANDLER_NAME : SoundHandler
没有任何延迟，没有理由插入延迟。
我担心某些播放器或其他应用程序会将此信息（延迟相对于视频）用作应予纠正的延迟。有没有办法防止这种情况发生？
添加ffprobe输出：f-0.mp4 clip
ffprobe -show_entries stream=codec_type,duration,start_time -of compact f-0.mp4
ffprobe version N-69672-g078be09 Copyright (c) 2007-2015 the FFmpeg developers
built with gcc 4.9.2 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --enable-decklink --enable-zlib
libavutil 54. 18.100 / 54. 18.100
libavcodec 56. 21.102 / 56. 21.102
libavformat 56. 19.100 / 56. 19.100
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 9.104 / 5. 9.104
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'f-0.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf56.19.100
Duration: 00:02:08.06, start: 0.005333, bitrate: 5030 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 4865 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, stereo, fltp, 160 kb/s (default)
Metadata:
handler_name : SoundHandler
Side data:
unknown side data type 7 (4 bytes)
stream|codec_type=video|start_time=0.000000|duration=128.061267
stream|codec_type=audio|start_time=-0.005333|duration=128.064000
f-0.mkv剪辑：
ffprobe version N-69672-g078be09 Copyright (c) 2007-2015 the FFmpeg developers
built with gcc 4.9.2 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --enable-decklink --enable-zlib
libavutil 54. 18.100 / 54. 18.100
libavcodec 56. 21.102 / 56. 21.102
libavformat 56. 19.100 / 56. 19.100
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 9.104 / 5. 9.104
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
Input #0, matroska,webm, from 'f-0.mkv':
Metadata:
COMPATIBLE_BRANDS: isomiso2avc1mp41
MAJOR_BRAND : isom
MINOR_VERSION : 512
ENCODER : Lavf56.19.100
Duration: 00:02:08.13, start: 0.061000, bitrate: 5026 kb/s
Stream #0:0(und): Video: h264 (High), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 29.97 fps, 29.97 tbr, 1k tbn, 59.94 tbc (default)
Metadata:
LANGUAGE : und
HANDLER_NAME : VideoHandler
Stream #0:1(und): Audio: ac3, 48000 Hz, stereo, fltp, 160 kb/s (default)
Metadata:
LANGUAGE : und
HANDLER_NAME : SoundHandler
stream|codec_type=video|start_time=0.066000|duration=N/A
stream|codec_type=audio|start_time=0.061000|duration=N/A