我有许多由 MakeMKV 制作的 DVD 和 BR 制作的 MKV，我将它们转换为 MP4，以便可以在 iPad Air 上播放/流式传输。我现在使用此命令将我的 MKV 转换为 MP4：
ffmpeg -i input.mkv -strict experimental -map 0:0 -map 0:1 -map 0:2 -map 0:3 -c:v copy -c:a aac -b:a 384k -c:s copy output.mp4
我有视频、2 个音轨和 1 个字幕。我希望图像和声音的损失尽可能小。我还需要 MKV 中的所有字幕和音轨（通常是 2 个音轨和 1 个字幕）。
我已经从 zeranoe 下载了 32 位静态 ffmpeg 版本。我是 ffmpeg 新手，所以我不知道如何获取 libfdk_aac，我不相信它在 zeranoe 版本中？我读到过 libfdk_aac 是最高质量的。
我还会将其传输到 iPad Air，所以请记住这一点。到目前为止效果很好 :)
有什么想法可以使它变得更好吗？
当前 ffmpeg 日志
C:\Film>ffmpeg -i abc.mkv -strict experimental -map 0:0 -map 0:1 -map 0:2 -map 0:3 -c:v copy -c:a aa
c -b:a 384K -c:s copy film02.mp4
ffmpeg version N-63378-g1d36def Copyright (c) 2000-2014 the FFmpeg developers
built on May 22 2014 22:01:44 with gcc 4.8.2 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzli
b --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libblu
ray --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-
libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libope
njpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex
--enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrw
benc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enab
le-libx265 --enable-libxavs --enable-libxvid --enable-decklink --enable-zlib
libavutil 52. 86.100 / 52. 86.100
libavcodec 55. 63.100 / 55. 63.100
libavformat 55. 40.100 / 55. 40.100
libavdevice 55. 13.101 / 55. 13.101
libavfilter 4. 5.100 / 4. 5.100
libswscale 2. 6.100 / 2. 6.100
libswresample 0. 19.100 / 0. 19.100
libpostproc 52. 3.100 / 52. 3.100
Input #0, matroska,webm, from 'abc.mkv':
Metadata:
encoder : libmakemkv v1.8.10 (1.3.0/1.4.1) win(x86-release)
creation_time : 2014-05-11 07:39:29
Duration: 01:24:07.80, start: 0.000000, bitrate: 7505 kb/s
Chapter #0.0: start 0.000000, end 135.760000
Metadata:
title : Chapter 01
Chapter #0.1: start 135.760000, end 361.200000
Metadata:
title : Chapter 02
Chapter #0.2: start 361.200000, end 665.120000
Metadata:
title : Chapter 03
Chapter #0.3: start 665.120000, end 888.760000
Metadata:
title : Chapter 04
Chapter #0.4: start 888.760000, end 1077.720000
Metadata:
title : Chapter 05
Chapter #0.5: start 1077.720000, end 1240.800000
Metadata:
title : Chapter 06
Chapter #0.6: start 1240.800000, end 1552.120000
Metadata:
title : Chapter 07
Chapter #0.7: start 1552.120000, end 1657.360000
Metadata:
title : Chapter 08
Chapter #0.8: start 1657.360000, end 1769.920000
Metadata:
title : Chapter 09
Chapter #0.9: start 1769.920000, end 2102.680000
Metadata:
title : Chapter 10
Chapter #0.10: start 2102.680000, end 2355.760000
Metadata:
title : Chapter 11
Chapter #0.11: start 2355.760000, end 2747.320000
Metadata:
title : Chapter 12
Chapter #0.12: start 2747.320000, end 2908.440000
Metadata:
title : Chapter 13
Chapter #0.13: start 2908.440000, end 3056.200000
Metadata:
title : Chapter 14
Chapter #0.14: start 3056.200000, end 3285.640000
Metadata:
title : Chapter 15
Chapter #0.15: start 3285.640000, end 3383.360000
Metadata:
title : Chapter 16
Chapter #0.16: start 3383.360000, end 3689.360000
Metadata:
title : Chapter 17
Chapter #0.17: start 3689.360000, end 3828.320000
Metadata:
title : Chapter 18
Chapter #0.18: start 3828.320000, end 3979.000000
Metadata:
title : Chapter 19
Chapter #0.19: start 3979.000000, end 4308.240000
Metadata:
title : Chapter 20
Chapter #0.20: start 4308.240000, end 4432.040000
Metadata:
title : Chapter 21
Chapter #0.21: start 4432.040000, end 4611.560000
Metadata:
title : Chapter 22
Chapter #0.22: start 4611.560000, end 4861.960000
Metadata:
title : Chapter 23
Chapter #0.23: start 4861.960000, end 5047.800000
Metadata:
title : Chapter 24
Stream #0:0(eng): Video: mpeg2video (Main), yuv420p(tv), 720x576 [SAR 16:15 DAR 4:3], max. 9800
kb/s, 25 fps, 25 tbr, 1k tbn, 50 tbc
Stream #0:1(eng): Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s (default)
Metadata:
title : Surround 5.1
Stream #0:2(nor): Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s
Metadata:
title : Surround 5.1
Stream #0:3(nor): Subtitle: dvd_subtitle, 720x576 (default)
Output #0, mp4, to 'film02.mp4':
Metadata:
encoder : Lavf55.40.100
Chapter #0.0: start 0.000000, end 135.760000
Metadata:
title : Chapter 01
Chapter #0.1: start 135.760000, end 361.200000
Metadata:
title : Chapter 02
Chapter #0.2: start 361.200000, end 665.120000
Metadata:
title : Chapter 03
Chapter #0.3: start 665.120000, end 888.760000
Metadata:
title : Chapter 04
Chapter #0.4: start 888.760000, end 1077.720000
Metadata:
title : Chapter 05
Chapter #0.5: start 1077.720000, end 1240.800000
Metadata:
title : Chapter 06
Chapter #0.6: start 1240.800000, end 1552.120000
Metadata:
title : Chapter 07
Chapter #0.7: start 1552.120000, end 1657.360000
Metadata:
title : Chapter 08
Chapter #0.8: start 1657.360000, end 1769.920000
Metadata:
title : Chapter 09
Chapter #0.9: start 1769.920000, end 2102.680000
Metadata:
title : Chapter 10
Chapter #0.10: start 2102.680000, end 2355.760000
Metadata:
title : Chapter 11
Chapter #0.11: start 2355.760000, end 2747.320000
Metadata:
title : Chapter 12
Chapter #0.12: start 2747.320000, end 2908.440000
Metadata:
title : Chapter 13
Chapter #0.13: start 2908.440000, end 3056.200000
Metadata:
title : Chapter 14
Chapter #0.14: start 3056.200000, end 3285.640000
Metadata:
title : Chapter 15
Chapter #0.15: start 3285.640000, end 3383.360000
Metadata:
title : Chapter 16
Chapter #0.16: start 3383.360000, end 3689.360000
Metadata:
title : Chapter 17
Chapter #0.17: start 3689.360000, end 3828.320000
Metadata:
title : Chapter 18
Chapter #0.18: start 3828.320000, end 3979.000000
Metadata:
title : Chapter 19
Chapter #0.19: start 3979.000000, end 4308.240000
Metadata:
title : Chapter 20
Chapter #0.20: start 4308.240000, end 4432.040000
Metadata:
title : Chapter 21
Chapter #0.21: start 4432.040000, end 4611.560000
Metadata:
title : Chapter 22
Chapter #0.22: start 4611.560000, end 4861.960000
Metadata:
title : Chapter 23
Chapter #0.23: start 4861.960000, end 5047.800000
Metadata:
title : Chapter 24
Stream #0:0(eng): Video: mpeg2video (a[0][0][0] / 0x0061), yuv420p, 720x576 [SAR 16:15 DAR 4:3],
q=2-31, max. 9800 kb/s, 25 fps, 16k tbn, 1k tbc
Stream #0:1(eng): Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, 5.1(side), fltp, 384 kb/s (defa
ult)
Metadata:
title : Surround 5.1
encoder : Lavc55.63.100 aac
Stream #0:2(nor): Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, 5.1(side), fltp, 384 kb/s
Metadata:
title : Surround 5.1
encoder : Lavc55.63.100 aac
Stream #0:3(nor): Subtitle: dvd_subtitle ([224][0][0][0] / 0x00E0), 720x576 (default)
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Stream #0:1 -> #0:1 (ac3 -> aac)
Stream #0:2 -> #0:2 (ac3 -> aac)
Stream #0:3 -> #0:3 (copy)
Press [q] to stop, [?] for help
frame=126195 fps= 52 q=-1.0 Lsize= 4538620kB time=01:24:07.78 bitrate=7365.7kbits/s
video:4066633kB audio:461409kB subtitle:2539kB other streams:0kB global headers:1kB muxing overhead:
> 0.177437%
>
>C:\Film
答案1
如果您对音频和视频编解码器使用复制模式（-c:v/-c:a copy），则不会有质量损失，因此您无法改善它，它将保持不变。此外，如果输入不是 aac，您也不能使用其他编解码器，如 aac（这全都与复制模式有关）。