尝试替换

execFFmpegBinary("-i " + path + " -ss " + startMs / 1000 + 
       " -to " + endMs / 1000 + " -c copy " + destPath);

使用

execFFmpegBinary(new String[] {"-i", path, "-ss", "" + startMs / 1000,           
       "-to", "" + endMs / 1000, "-c", "copy", destPath});

ffmpeg-android-java的修复可以追溯到2015年.

The fix to ffmpeg-android-java dates back to 2015.