我想将mkv文件转换为mp4文件。在mkv文件中有一个我不想要的副标题。但是，我想添加另一个副标题。
流如下：
输入＃1 anothersubtitle.srt *
我给出的命令如下：
ffmpeg -i video.mkv -i anothersubtitle.srt -map 0:v -c:v copy -map 0:a -c:a:0 aac -ab:a:0 256k -ar:a:0 48000 -ac:a:0 2 -metadata:s:a:0 language=eng -metadata:s:a:0 title=Stereo -map 1 -map -0:s output.mp4
Ffmpeg给出错误：
Automatic encoder selection failed for output stream #0:2. Default encoder for format ipod (codec none) is probably disabled. Please choose an encoder manually.
Error selecting an encoder for stream 0:2
它出现的错误是关于带有我不想要的副标题的流。添加“ -c：s mov_text ”或“ -scodec mov_text ”仍会选择不需要的字幕。这将添加我想要的副标题，但它也添加了我不想要的副标题。
在这个和其他网站上有很多例子可以添加或减去想要的或不想要的流，但我找不到一种方法可以让一个字幕出来并添加另一个。你能救我一下吗？
编辑（根据要求添加完整的控制台输出）：
ffmpeg version 3.3.1 Copyright (c) 2000-2017 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.42)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.1 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
libavutil 55. 58.100 / 55. 58.100
libavcodec 57. 89.100 / 57. 89.100
libavformat 57. 71.100 / 57. 71.100
libavdevice 57. 6.100 / 57. 6.100
libavfilter 6. 82.100 / 6. 82.100
libavresample 3. 5. 0 / 3. 5. 0
libswscale 4. 6.100 / 4. 6.100
libswresample 2. 7.100 / 2. 7.100
libpostproc 54. 5.100 / 54. 5.100
Input #0, matroska,webm, from 'movie.mkv':
Metadata:
encoder : libebml v1.0.0 + libmatroska v1.0
Duration: 03:15:12.66, start: 0.000000, bitrate: 9616 kb/s
Chapter #0:0: start 0.000000, end 203.161000
Metadata:
title : 00:00:00.000
Chapter #0:1: start 203.161000, end 612.153000
Metadata:
title : 00:03:23.161
Chapter #0:2: start 612.153000, end 891.307000
Metadata:
title : 00:10:12.153
Chapter #0:3: start 891.307000, end 1048.714000
Metadata:
title : 00:14:51.307
Chapter #0:4: start 1048.714000, end 1302.384000
Metadata:
title : 00:17:28.714
Chapter #0:5: start 1302.384000, end 1428.010000
Metadata:
title : 00:21:42.384
Chapter #0:6: start 1428.010000, end 1837.669000
Metadata:
title : 00:23:48.010
Chapter #0:7: start 1837.669000, end 2063.728000
Metadata:
title : 00:30:37.669
Chapter #0:8: start 2063.728000, end 2503.751000
Metadata:
title : 00:34:23.728
Chapter #0:9: start 2503.751000, end 2656.737000
Metadata:
title : 00:41:43.751
Chapter #0:10: start 2656.737000, end 3055.761000
Metadata:
title : 00:44:16.737
Chapter #0:11: start 3055.761000, end 3309.431000
Metadata:
title : 00:50:55.761
Chapter #0:12: start 3309.431000, end 3404.860000
Metadata:
title : 00:55:09.431
Chapter #0:13: start 3404.860000, end 4424.754000
Metadata:
title : 00:56:44.860
Chapter #0:14: start 4424.754000, end 4625.704000
Metadata:
title : 01:13:44.754
Chapter #0:15: start 4625.704000, end 5162.115000
Metadata:
title : 01:17:05.704
Chapter #0:16: start 5162.115000, end 5366.319000
Metadata:
title : 01:26:02.115
Chapter #0:17: start 5366.319000, end 5521.182000
Metadata:
title : 01:29:26.319
Chapter #0:18: start 5521.182000, end 5916.869000
Metadata:
title : 01:32:01.182
Chapter #0:19: start 5916.869000, end 6199.777000
Metadata:
title : 01:38:36.869
Chapter #0:20: start 6199.777000, end 6576.612000
Metadata:
title : 01:43:19.777
Chapter #0:21: start 6576.612000, end 6945.981000
Metadata:
title : 01:49:36.612
Chapter #0:22: start 6945.981000, end 7122.824000
Metadata:
title : 01:55:45.981
Chapter #0:23: start 7122.824000, end 7379.789000
Metadata:
title : 01:58:42.824
Chapter #0:24: start 7379.789000, end 7609.310000
Metadata:
title : 02:02:59.789
Chapter #0:25: start 7609.310000, end 7811.637000
Metadata:
title : 02:06:49.310
Chapter #0:26: start 7811.637000, end 8024.725000
Metadata:
title : 02:10:11.637
Chapter #0:27: start 8024.725000, end 8301.376000
Metadata:
title : 02:13:44.725
Chapter #0:28: start 8301.376000, end 8806.506000
Metadata:
title : 02:18:21.376
Chapter #0:29: start 8806.506000, end 9255.621000
Metadata:
title : 02:26:46.506
Chapter #0:30: start 9255.621000, end 9528.018000
Metadata:
title : 02:34:15.621
Chapter #0:31: start 9528.018000, end 9675.416000
Metadata:
title : 02:38:48.018
Chapter #0:32: start 9675.416000, end 9981.763000
Metadata:
title : 02:41:15.416
Chapter #0:33: start 9981.763000, end 10092.332000
Metadata:
title : 02:46:21.763
Chapter #0:34: start 10092.332000, end 10223.171000
Metadata:
title : 02:48:12.332
Chapter #0:35: start 10223.171000, end 10528.393000
Metadata:
title : 02:50:23.171
Chapter #0:36: start 10528.393000, end 10911.359000
Metadata:
title : 02:55:28.393
Chapter #0:37: start 10911.359000, end 11106.721000
Metadata:
title : 03:01:51.359
Chapter #0:38: start 11106.721000, end 11331.278000
Metadata:
title : 03:05:06.721
Chapter #0:39: start 11331.278000, end 11712.659000
Metadata:
title : 03:08:51.278
Stream #0:0(eng): Video: h264 (High), yuv420p(progressive), 1920x1040, SAR 1:1 DAR 24:13, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
Stream #0:1(eng): Audio: dts (DTS), 48000 Hz, 5.1(side), fltp, 1536 kb/s (default)
Metadata:
title : DTS
Stream #0:2(eng): Subtitle: subrip
Metadata:
title : English
Input #1, srt, from 'anothersubtitle.srt':
Duration: N/A, bitrate: N/A
Stream #1:0: Subtitle: subrip
Automatic encoder selection failed for output stream #0:2. Default encoder for format mp4 (codec none) is probably disabled. Please choose an encoder manually.
Error selecting an encoder for stream 0:2