本文最后更新于：2015-05-25 13:12:00原文：http://www.yaosansi.com/post/ffmpeg-burn-subtitles-into-video
向视频文件里添加字幕是件很常见的事，本文使用FFmpeg 将字幕文件集成到视频文件里。
在CentOS上编译安装FFmpeg
字幕文件转换 字幕文件有很多种，常见的有 .srt , .ass 文件等,下面使用FFmpeg进行相互转换。
将.srt文件转换成.ass文件
1 ffmpeg -i subtitle.srt subtitle.ass
将.ass文件转换成.srt文件
1 ffmpeg -i subtitle.ass subtitle.srt
集成字幕，选择播放 这种字幕集成比较简单，播放时需要在播放器中选择相应的字幕文件。
1 ffmpeg -i input.mp4 -i subtitles.srt -c:s mov_text -c:v copy -c:a copy output.mp4
嵌入SRT字幕到视频文件 单独SRT字幕 字幕文件为subtitle.srt
1 ffmpeg -i video.avi -vf subtitles=subtitle.srt out.avi
嵌入在MKV等容器的字幕 将video.mkv中的字幕（默认）嵌入到out.avi文件
1 ffmpeg -i video.mkv -vf subtitles=video.mkv out.avi
将video.mkv中的字幕（第二个）嵌入到out.avi文件
1 ffmpeg -i video.mkv -vf subtitles=video.mkv:si=1 out.avi
嵌入ASS字幕到视频文件 1 ffmpeg -i video.avi -vf "ass=subtitle.ass" out.avi
不能加载fontconfig文件 1 2 3 4 Fontconfig error: Cannot load default config file [Parsed_ass_0 @ 0000000002bfa3e0] No usable fontconfig configuration file found, using fallback. Fontconfig error: Cannot load default config file
出现类似错误的原因是无法加载字体配置文件。
环境变量 FFmpeg使用的默认字体文件是使用系统环境变量中对应的文件位置。
默认文件名：fonts.conf
环境变量 FONTCONFIG_FILE 可以覆盖默认配置文件FONTCONFIG_PATH 可以覆盖默认配置文件目录
Linux 默认配置文件：fonts.conf
使用步骤：
以root权限登录
建立/etc/fonts目录
下载fonts.conf文件到/etc/fonts目录
设置fonts.conf文件权限为可读
Linux/Mac 系统 在~/.bashrc 最后添加：
1 export FONTCONFIG_PATH=/opt/X11/lib/X11/fontconfig
使之有效：
编辑 /opt/X11/lib/X11/fontconfig/fonts.conf 在字体目录添加 /Library/Fonts
1 2 3 4 5 6 <!-- Font directory list --> <dir>/opt/X11/share/fonts</dir> <dir>/usr/X11R6/lib/X11/fonts</dir> <dir>~/.fonts</dir> <dir>/Library/Fonts</dir>
Windows系统 在系统环境变量中添加：
name: FONTCONFIG_PATHJ:/ffmpeg (我本机ffmpeg目录，与fonts.conf同目录即可)
将fonts.conf文件放至上述指定目录。
以下为yaosansi 使用的fonts.conf文件：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 <?xml version="1.0"?> <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> <!-- /etc/fonts/fonts.conf file to configure system font access --> <fontconfig> <!-- DO NOT EDIT THIS FILE. IT WILL BE REPLACED WHEN FONTCONFIG IS UPDATED. LOCAL CHANGES BELONG IN 'local.conf'. The intent of this standard configuration file is to be adequate for most environments. If you have a reasonably normal environment and have found problems with this configuration, they are probably things that others will also want fixed. Please submit any problems to the fontconfig bugzilla system located at fontconfig.org Note that the normal 'make install' procedure for fontconfig is to replace any existing fonts.conf file with the new version. Place any local customizations in local.conf which this file references. Keith Packard --> <!-- Font directory list --> <dir>C:/Windows/Fonts</dir> <!-- Accept deprecated 'mono' alias, replacing it with 'monospace' --> <match target="pattern"> <test qual="any" name="family"> <string>mono</string> </test> <edit name="family" mode="assign"> <string>monospace</string> </edit> </match> <!-- Accept alternate 'sans serif' spelling, replacing it with 'sans-serif' --> <match target="pattern"> <test qual="any" name="family"> <string>sans serif</string> </test> <edit name="family" mode="assign"> <string>sans-serif</string> </edit> </match> <!-- Accept deprecated 'sans' alias, replacing it with 'sans-serif' --> <match target="pattern"> <test qual="any" name="family"> <string>sans</string> </test> <edit name="family" mode="assign"> <string>sans-serif</string> </edit> </match> <!-- Mark common families with their generics so we'll get something reasonable --> <!-- Serif faces --> <alias> <family>Times New Roman</family> <default><family>serif</family></default> </alias> <!-- If the font still has no generic name, add sans-serif --> <match target="pattern"> <test qual="all" name="family" compare="not_eq"> <string>sans-serif</string> </test> <test qual="all" name="family" compare="not_eq"> <string>serif</string> </test> <test qual="all" name="family" compare="not_eq"> <string>monospace</string> </test> <edit name="family" mode="append_last"> <string>sans-serif</string> </edit> </match> <!-- AMT provides metric and shape compatible fonts for these three web font families. --> <alias> <family>Times New Roman</family> <accept><family>Thorndale AMT</family></accept> </alias> <alias> <family>Arial</family> <accept><family>Albany AMT</family></accept> </alias> <alias> <family>Courier New</family> <accept><family>Cumberland AMT</family></accept> </alias> <!-- Some Asian fonts misadvertise themselves as monospaced when in fact they are dual-spaced (half and full). This makes FreeType very confused as it forces all widths to match. Undo this magic by disabling the width forcing code --> <match target="font"> <test name="family"><string>GulimChe</string></test> <edit name="globaladvance"><bool>false</bool></edit> </match> <match target="font"> <test name="family"><string>DotumChe</string></test> <edit name="globaladvance"><bool>false</bool></edit> </match> <match target="font"> <test name="family"><string>BatangChe</string></test> <edit name="globaladvance"><bool>false</bool></edit> </match> <match target="font"> <test name="family"><string>GungsuhChe</string></test> <edit name="globaladvance"><bool>false</bool></edit> </match> <config> <!-- These are the default Unicode chars that are expected to be blank in fonts. All other blank chars are assumed to be broken and won't appear in the resulting charsets --> <blank> <int>0x0020</int> <!-- SPACE --> <int>0x00A0</int> <!-- NO-BREAK SPACE --> <int>0x00AD</int> <!-- SOFT HYPHEN --> <int>0x034F</int> <!-- COMBINING GRAPHEME JOINER --> <int>0x0600</int> <!-- ARABIC NUMBER SIGN --> <int>0x0601</int> <!-- ARABIC SIGN SANAH --> <int>0x0602</int> <!-- ARABIC FOOTNOTE MARKER --> <int>0x0603</int> <!-- ARABIC SIGN SAFHA --> <int>0x06DD</int> <!-- ARABIC END OF AYAH --> <int>0x070F</int> <!-- SYRIAC ABBREVIATION MARK --> <int>0x115F</int> <!-- HANGUL CHOSEONG FILLER --> <int>0x1160</int> <!-- HANGUL JUNGSEONG FILLER --> <int>0x1680</int> <!-- OGHAM SPACE MARK --> <int>0x17B4</int> <!-- KHMER VOWEL INHERENT AQ --> <int>0x17B5</int> <!-- KHMER VOWEL INHERENT AA --> <int>0x180E</int> <!-- MONGOLIAN VOWEL SEPARATOR --> <int>0x2000</int> <!-- EN QUAD --> <int>0x2001</int> <!-- EM QUAD --> <int>0x2002</int> <!-- EN SPACE --> <int>0x2003</int> <!-- EM SPACE --> <int>0x2004</int> <!-- THREE-PER-EM SPACE --> <int>0x2005</int> <!-- FOUR-PER-EM SPACE --> <int>0x2006</int> <!-- SIX-PER-EM SPACE --> <int>0x2007</int> <!-- FIGURE SPACE --> <int>0x2008</int> <!-- PUNCTUATION SPACE --> <int>0x2009</int> <!-- THIN SPACE --> <int>0x200A</int> <!-- HAIR SPACE --> <int>0x200B</int> <!-- ZERO WIDTH SPACE --> <int>0x200C</int> <!-- ZERO WIDTH NON-JOINER --> <int>0x200D</int> <!-- ZERO WIDTH JOINER --> <int>0x200E</int> <!-- LEFT-TO-RIGHT MARK --> <int>0x200F</int> <!-- RIGHT-TO-LEFT MARK --> <int>0x2028</int> <!-- LINE SEPARATOR --> <int>0x2029</int> <!-- PARAGRAPH SEPARATOR --> <int>0x202A</int> <!-- LEFT-TO-RIGHT EMBEDDING --> <int>0x202B</int> <!-- RIGHT-TO-LEFT EMBEDDING --> <int>0x202C</int> <!-- POP DIRECTIONAL FORMATTING --> <int>0x202D</int> <!-- LEFT-TO-RIGHT OVERRIDE --> <int>0x202E</int> <!-- RIGHT-TO-LEFT OVERRIDE --> <int>0x202F</int> <!-- NARROW NO-BREAK SPACE --> <int>0x205F</int> <!-- MEDIUM MATHEMATICAL SPACE --> <int>0x2060</int> <!-- WORD JOINER --> <int>0x2061</int> <!-- FUNCTION APPLICATION --> <int>0x2062</int> <!-- INVISIBLE TIMES --> <int>0x2063</int> <!-- INVISIBLE SEPARATOR --> <int>0x206A</int> <!-- INHIBIT SYMMETRIC SWAPPING --> <int>0x206B</int> <!-- ACTIVATE SYMMETRIC SWAPPING --> <int>0x206C</int> <!-- INHIBIT ARABIC FORM SHAPING --> <int>0x206D</int> <!-- ACTIVATE ARABIC FORM SHAPING --> <int>0x206E</int> <!-- NATIONAL DIGIT SHAPES --> <int>0x206F</int> <!-- NOMINAL DIGIT SHAPES --> <int>0x3000</int> <!-- IDEOGRAPHIC SPACE --> <int>0x3164</int> <!-- HANGUL FILLER --> <int>0xFEFF</int> <!-- ZERO WIDTH NO-BREAK SPACE --> <int>0xFFA0</int> <!-- HALFWIDTH HANGUL FILLER --> <int>0xFFF9</int> <!-- INTERLINEAR ANNOTATION ANCHOR --> <int>0xFFFA</int> <!-- INTERLINEAR ANNOTATION SEPARATOR --> <int>0xFFFB</int> <!-- INTERLINEAR ANNOTATION TERMINATOR --> </blank> <!-- Rescan configuration every 30 seconds when FcFontSetList is called --> <rescan> <int>30</int> </rescan> </config> </fontconfig>
参考
