根据文档，%{}:,应使用斜杠转义。但是当我转义时%，未添加文本。错误消息说Stray % near ')'。但是它是什么意思，我该如何解决？命令和输出：
$ /usr/bin/ffmpeg -y -i /home/www/255871.mov -af 'aresample=async=1:min_hard_comp=0.100000' -vf 'scale=480:trunc(ow/a/2)*2,transpose=1 [in];movie=watermarks/text-box440.mov,scale=320:55 [bg];[in][bg] overlay=x=20:y=main_h-80,drawtext=fontsize=20:fix_bounds=1:fontfile=Helvetica\\:Style=bold:fontcolor=0xe6b300:text=small kitten \%\):x=30:y=h-80+ascent/2:draw=gte(t\,0)\;lt(t\,5) [out]' -pix_fmt yuv420p -r 24.39 -map_metadata -1 -movflags +faststart -f mp4 -vcodec libx264 -b:v 800k -maxrate 1100k -bufsize 2M -bt 256k -profile:vbaseline -acodec libfdk_aac -ab 64k -ar 44100 -ac 1 /tmp/kitten.mp4
ffmpeg version 1.2 Copyright (c) 2000-2013 the FFmpeg developers
built on Mar 15 2013 18:40:14 with gcc 4.4.6 (GCC) 20120305 (Red Hat 4.4.6-4)
configuration: --enable-gpl …ffmpeg ×1