ffmpeg single quote in drawtext

Question

I haven't been able to get ffmpeg's drawtext video filter to draw apostrophes/single quotes when they are in drawtext's "text=" parameter, even when I escape them. Double quotes work fine, and apostrophes in text loaded from a file (e.g. textfile="example.txt") work fine. Is this a bug?

e.g.

ffmpeg -i test.mpg -vf drawtext="apostrophes don't print" ...
ffmpeg -i test.mpg -vf drawtext="even when they\'re escaped" ...

Answer 1

Special character escapes are like violence: if they're not solving your problem, you're not using enough.

ffmpeg -i test.mpg -vf drawtext=text="It\\\\\'s so easy"

Produces a textual overlay that includes an apostrophe. The text is being parsed a couple times, so you not only have to escape the quote, you also have to escape the slash escaping the quote. Twice.

Your alternative of using a textfile might be a better method in this situation.

Answer 2

I was able to insert Unicode \u2019 into argument string and it worked for single right quote.

Answer 3

Just put your text into a file e.g. myText.txt and use textfile option:

->myText.txt This is my text with special characters :,(,),'

Then instead of using :

ffmpeg -i test.mpg -vf drawtext="This is my text with special characters :,(,),'"

use the following command:

ffmpeg -i test.mpg -vf textfile=textFile.txt

Answer 4

This is probably something to do with magic quotes. Through a bunch of testing I just did using Windows Command Line and MinGW on Windows, I ran into the same problem every time. Since ffmpeg drawtext uses Freetype (I would guess this is where magic quotes are enabled) I doubt there's much to be done to disable magic quotes. I'm not sure there's a way to remove the added slashes in the command line either, as everything I've seen involves PHP scripts. I could be wrong, since I'm no PHP guru, but I'm not aware of how to integrate them into an ffmpeg command.

Answer 5

If you're passing the string via Python, the following works for me:

txt = 'it\'s good!'
txt = txt.replace('\'', '\'\\\\\\\\\\\'\'')

Answer 6

For Windows Users:

The logic: for easier understanding I will call the single quote to be shown as a result: apostrophe and all other single quotes simply single quotes...

You have to put the first part of the text before the apostrophe between single quotes + 3 backslashes before the apostrophe, then the apostrophe itself + the text after the apostrophe between single quotes again"

So to produce: "apostrophes don't print" it would be:

drawtext=text='apostrophes don'\\\''t print'

Using an example:

ffplay -f lavfi  "color=blue:size=700x200,drawtext=text='apostrophes don'\\\''t print':fontsize=40:fontcolor=white:x=(W-tw)/2:y=(H-th)/2"

The other solution seems to be, to use a text file as already mentioned here by others:

drawtext=textfile=somefile.txt

Answer 7

// This works for me

public function replaceSpecialFfmpegChars($text)
    {
        return str_replace(
            ":",
            "\\\\\\\\\\\:",
            str_replace(
                "%",
                "\\\\\\\\\\\%",
                str_replace(
                    "'",
                    "'\\\\\\\\\\\\''",
                    str_replace(
                        "\"",
                        "\\\\\\\\\\\"",
                        str_replace(
                            "\\",
                            "\\\\\\\\\\\\\\\\",
                            $text
                        )
                    )
                )
            )
        );
    }

Answer 8

ricardo-bohner's methods works really well, but just make sure that, you're getting exactly the as shown below:

I used this;

line = it's
str(line.replace("'", "'\\\\\\''"))

but due to the way I code some functions in the executed command, I got '\\\'' like below:

it'\\\''s

Answer 9

in node.js, i am able to put a colon in the text with this line.

let surahTxt = "QURAN " + chapterNo + "\\:"+ from + "-" + to ;

later this variable is used with the drawtext

Answer 10

In case someone needs this for Python, this escape function is working for me (based on the FFmpeg Quoting and Escaping documentation + multi-escaping advice above):

return "'" + text.replace(":", "\\\\:").replace("'", "'\\\\\\\\\\\\''") + "'"