使用fluent-ffmpeg将包含空格的选项传递给ffmpeg

Question

I am writing a Node script which copies and re-tags some of my MP4 files using fluent-ffmpeg

It doesn't work with any metadata that contains spaces. The code that does the copying/tagging looks something like this:

const ffmpeg = require('fluent-ffmpeg');

const inputFilename = 'path/to/original.m4a';
const outputFilename = 'path/to/new.m4a';

const options = [
    '-metadata', 'artist=Someone',
    '-metadata', 'album=Some title',
    // ...etc
];

ffmpeg(inputFilename)
  .outputOptions(options)
  .saveToFile(outputFilename);

This results in an error:

events.js:183
      throw er; // Unhandled 'error' event

An error occurred: ffmpeg exited with code 1: title: Invalid argument

I have tried putting Some title in single quotes, double quotes and no quotes. I have tried escaping the spaces in it. I have tried passing the options array as single options rather than tuples, for example: '-metadata album="Some title"' - but whatever I try, it still throws an error when there are spaces.

(It may be relevant to note that this is on Windows)

Can anyone suggest a way of getting it to work?

Answer 1

I solved it! (Or at least, I found a workaround - I believe the problem is caused by a bug in fluent-ffmpeg )

Simply add an extra space at the end of the option containing the space. So, this line:

'-metadata', 'album=Some title',

becomes this:

'-metadata', 'album=Some title ',

It appears that the terminal space is ignored when passed to ffmpeg , ie it does not appear in the metadata of the file produced.

Answer 2

I noticed a similar issue, but not on Windows, only Linux. I'm sending the command line via a Lazarus/FPC GUI. I quote the spaces in titre.Text this way:

If changemeta.Checked then chmeta := '-metadata title=' + quote + titre.Text + quote + ' -metadata:s:v:0 language=' + VLang.Text + ' -metadata:s:a:0 language=' + ALang.Text + ' '

Variable 'quote' is defined as '"' and on Windows, the whole title is properly inserted into the metadata, but on Linux, it appears as "Some title" with the quotes. Changing to single quotes gives 'Some title' in single quotes, inserting a space inserts a space before the closing quote, removing the quotes causes an error.

Maybe a dirty workaround would be to create a function that replaces the spaces with non-breakable spaces, but it is not satisfying, and it could be wrongly displayed in some players.