一行命令解决电视盒子播放下载的电视剧无声音的问题
快过年了，防止无聊，下载了部经典喜剧在电视盒子上看看。
现在片源越来越不好找了，好不容易下了部
回家在机顶盒上一播放，傻眼了，有图像没声音，声道切换也不管用
这点事情难不倒程序猿，ffprobe查看视频属性
ffprobe 01.mkv结果
ffprobe version 4.1.3 Copyright (c) 2007-2019 the FFmpeg developers
built with Apple LLVM version 10.0.1 (clang-1001.0.46.4)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1.3_1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include/darwin' --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-libvorbis --enable-libvpx --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-videotoolbox --disable-libjack --disable-indev=jack --enable-libaom --enable-libsoxr
libavutil 56. 22.100 / 56. 22.100
libavcodec 58. 35.100 / 58. 35.100
libavformat 58. 20.100 / 58. 20.100
libavdevice 58. 5.100 / 58. 5.100
libavfilter 7. 40.101 / 7. 40.101
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 3.100 / 5. 3.100
libswresample 3. 3.100 / 3. 3.100
libpostproc 55. 3.100 / 55. 3.100
Input #0, matroska,webm, from '01.mkv':
Metadata:
encoder : libebml v1.3.0 + libmatroska v1.4.0
creation_time : 2014-08-06T02:14:45.000000Z
Duration: 00:42:07.96, start: 0.000000, bitrate: 2324 kb/s
Stream #0:0: Video: h264 (High), yuv420p(progressive), 720x540 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 1k tbn, 50 tbc (default) (forced)
Metadata:
title : CMCT@小五压制
Stream #0:1: Audio: ac3, 48000 Hz, 5.1(side), fltp, 384 kb/s (default) (forced)
Metadata:
title : 国语
Stream #0:2: Subtitle: ass (default) (forced)
Metadata:
title : 简体中字
Stream #0:3: Subtitle: ass
Metadata:
title : 繁体中字根据以往经验，删除掉多出的几个Stream，应该就能顺利播放
新建out目录
mkdir out用一行代码解决这个问题：
find . | grep mkv| sed 's#./##g' |xargs -n 1 -I {} ffmpeg -i {} -map 0:0 -map 0:1 -vcodec copy -acodec copy out/{}所有处理后的视频都放到当前文件夹out子目录里
再次用ffprob查看处理后的结果
ffprobe 01.mkv
ffprobe version 4.1.3 Copyright (c) 2007-2019 the FFmpeg developers
built with Apple LLVM version 10.0.1 (clang-1001.0.46.4)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1.3_1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include/darwin' --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-libvorbis --enable-libvpx --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-videotoolbox --disable-libjack --disable-indev=jack --enable-libaom --enable-libsoxr
libavutil 56. 22.100 / 56. 22.100
libavcodec 58. 35.100 / 58. 35.100
libavformat 58. 20.100 / 58. 20.100
libavdevice 58. 5.100 / 58. 5.100
libavfilter 7. 40.101 / 7. 40.101
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 3.100 / 5. 3.100
libswresample 3. 3.100 / 3. 3.100
libpostproc 55. 3.100 / 55. 3.100
Input #0, matroska,webm, from '01.mkv':
Metadata:
ENCODER : Lavf58.20.100
Duration: 00:42:07.96, start: 0.000000, bitrate: 2325 kb/s
Stream #0:0: Video: h264 (High), yuv420p(progressive), 720x540 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 1k tbn, 50 tbc (default) (forced)
Metadata:
title : CMCT@小五压制
DURATION : 00:42:07.960000000
Stream #0:1: Audio: ac3, 48000 Hz, 5.1(side), fltp, 384 kb/s (default) (forced)
Metadata:
title : 国语
DURATION : 00:42:07.904000000现在是单音轨+单视频Stream了，电视盒子应该可以了吧！
再次播放，又傻眼了，还是无法播放！
查看能正常播放出声音的视频
ffprobe 01.mkv
ffprobe version 4.1.3 Copyright (c) 2007-2019 the FFmpeg developers
built with Apple LLVM version 10.0.1 (clang-1001.0.46.4)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1.3_1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include/darwin' --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-libvorbis --enable-libvpx --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-videotoolbox --disable-libjack --disable-indev=jack --enable-libaom --enable-libsoxr
libavutil 56. 22.100 / 56. 22.100
libavcodec 58. 35.100 / 58. 35.100
libavformat 58. 20.100 / 58. 20.100
libavdevice 58. 5.100 / 58. 5.100
libavfilter 7. 40.101 / 7. 40.101
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 3.100 / 5. 3.100
libswresample 3. 3.100 / 3. 3.100
libpostproc 55. 3.100 / 55. 3.100
Input #0, matroska,webm, from '01.mkv':
Metadata:
encoder : libebml v0.7.9 + libmatroska v0.8.1
creation_time : 2010-05-06T07:47:43.000000Z
Duration: 00:42:04.24, start: 0.000000, bitrate: 487 kb/s
Stream #0:0: Video: h264 (Main), yuv420p(progressive), 608x448 [SAR 1:1 DAR 19:14], 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
Metadata:
title : XTM HALFCD TEAM
Stream #0:1: Audio: aac (HE-AACv2), 48000 Hz, stereo, fltp (default)发现声音编码用的是
Stream #0:1: Audio: aac (HE-AACv2), 48000 Hz, stereo, fltp (default)而不能播放的视频用的是
Stream #0:1: Audio: ac3, 48000 Hz, 5.1(side), fltp, 384 kb/s (default) 转换成aac 应该就ok了，执行转换命令
ffmpeg -i 01.mkv -map 0:0 -map 0:1 -vcodec copy -acodec copy -c:a libfdk_aac -vbr 2 out01.mkv提示错误
brew安装的ffmpeg默认不带libfdk_aac
修改默认ffmpeg.rb
brew edit ffmpeg在args后面加上两行
--enable-libfdk-aac
--enable-nonfree重新从源码安装ffmpeg
brew reinstall -s ffmpegcpu负荷升高，可以感知到在默默编译，并安装完成
实验下效果，执行
ffmpeg -i 01.mkv -map 0:0 -map 0:1 -vcodec copy -acodec copy -c:a libfdk_aac -vbr 2 out01.mkv顺利执行
Stream #0:1: Audio: aac (libfdk_aac) ([255][0][0][0] / 0x00FF), 48000 Hz, 5.1, s16 (default) (forced)
Metadata:
title : 国语
encoder : Lavc58.54.100 libfdk_aac
frame= 326 fps=0.0 q=-1.0 size= 1442kB time=00:00:13.16 bitrate= 897.7kbitsframe= 665 fps=664 q=-1.0 size= 4263kB time=00:00:26.64 bitrate=1310.7kbitsframe= 995 fps=662 q=-1.0 size= 8574kB time=00:00:40.10 bitrate=1751.4kbits查看执行结果，audio已经被转换
Stream #0:0: Video: h264 (High), yuv420p(progressive), 720x540 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 1k tbn, 50 tbc (default) (forced)
Metadata:
title : CMCT@小五压制
DURATION : 00:42:08.003000000
Stream #0:1: Audio: aac (LC), 48000 Hz, 5.1, fltp (default) (forced)
Metadata:
title : 国语
ENCODER : Lavc58.54.100 libfdk_aac
DURATION : 00:42:07.947000000又回到用一行代码解决问题，执行所有文件转换，并保存到out目录下，执行前需要先删除上次生成的out目录
mkdir out && find . | grep mkv| sed 's#./##g' |xargs -n 1 -I {} ffmpeg -i {} -map 0:0 -map 0:1 -vcodec copy -acodec copy -c:a libfdk_aac -vbr 2 out/{}视频处理完，继续在电视盒子上播放！视频和图像都OK！
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