Command line interface (CLI) user guide

This page contains guidelines on using the ReadAlongs CLI. See also Command line interface (CLI) reference for the full CLI reference.

The ReadAlongs CLI has two main commands: readalongs prepare and readalongs align.

  • If your data is a plain text file, you can run prepare to turn it into XML, which you can then align with align. Doing this in two steps allows you to modify the XML file before aligning it (e.g., to mark that some text is in a different language, to flag some do-not-align text, or to drop anchors in).

  • Alternatively, if your plain text file does not need to be modified, you can run align directly and use the -i option to indicate that the input is plain text and not xml. You’ll also need the -l <language> option to indicate what language your text is in.

Two additional commands are sometimes useful: readalongs tokenize and readalongs g2p.

  • tokenize takes the output of prepare and tokenizes it, wrapping each word in the text in a <w> element.

  • g2p takes the output of tokenize and mapping each word to its phonetic transcription using the g2p library. The phonetic transcription is represented using the ARPABET phonetic codes and are added in the ARPABET attribute to each <w> element.

The result of tokenize or g2p can be fixed manually if necessary and then used as input to align.

Getting from TXT to XML with readalongs prepare

Run readalongs prepare to prepare an XML file for align from a TXT file.

readalongs prepare [options] [story.txt] [story.xml]

[story.txt]: path to the plain text input file (TXT)

[story.xml]: Path to the XML output file

The plain text file must be plain text encoded in UTF-8 with one sentence per line. Paragraph breaks are marked by a blank line, and page breaks are marked by two blank lines.

Key Options

Option descriptions

-l, --language (required)

The language code for story.txt.

-f, --force-overwrite

Force overwrite output files (handy if you’re troubleshooting and will be aligning repeatedly)

-h, --help

Displays CLI guide for prepare

The -l, --language argument requires a language’s 3 character ISO code as an argument.

The languages supported by RAS can be listed by running readalongs prepare -h and they can also be found in the readalongs prepare reference.

So, a full command for a story in Algonquin would be something like:

readalongs prepare -l alq Studio/story.txt Studio/story.xml

The generated XML will be parsed in to sentences. At this stage you can edit the XML to have any modifications, such as adding do-not-align as an attribute of any element in your XML.

Handling mismatches: do-not-align

There are two types of “do-not-align” (DNA) content: DNA audio and DNA text.

To use DNA text, add do-not-align as an attribute to any element in the xml (word, sentence, paragraph, or page).

<w do-not-align="true" id="t0b0d0p0s0w0">dog</w>

If you have already run readalongs prepare, there will be documentation for DNA text in comments at the beginning of the generated xml file.

<!-- To exclude any element from alignment, add the do-not-align="true" attribute to
     it, e.g., <p do-not-align="true">...</p>, or
     <s>Some text <foo do-not-align="true">do not align this</foo> more text</s> -->

To use DNA audio, you can specify a frame of time in milliseconds in the config.json file which you want the aligner to ignore.

"do-not-align":
    {
    "method": "remove",
    "segments":
    [
        {
            "begin": 1,
            "end": 17000
        }
    ]
    }

Use cases for DNA

  • Spoken introduction in the audio file that has no accompanying text (DNA audio)

  • Text that has no matching audio, such as credits/acknowledgments (DNA text)

Aligning your text and audio with readalongs align

Run readalongs align to align a text file (XML or TXT) and an audio file to create a time-aligned audiobook.

readalongs align [options] [story.txt/xml] [story.mp3/wav] [output_base]

[story.txt/xml]: path to the text file (TXT or XML)

[story.mp3/wav]: path to the audio file (MP3, WAV or any format supported by ffmpeg)

[output_base]: path to the directory where the output files will be created, as output_base*

Key Options

Option descriptions

-l, --language

The language code for story.txt. (required if input is plain text)

-c, --config PATH

Use ReadAlong-Studio configuration file (in JSON format)

-i, --text-input

Input is plain text (TXT) (otherwise it’s assumed to be XML)

--g2p-fallback G2P_FALLBACK

Colon-separated list of fallback langs for g2p; enables the g2p cascade

--g2p-verbose

Display verbose g2p error messages

-s, --save-temps

Save intermediate stages of processing and temporary files (dictionary, FSG, tokenization, etc.)

-f, --force-overwrite

Force overwrite output files (handy if you’re troubleshooting and will be aligning repeatedly)

-h, --help

Displays CLI guide for align

See above for more information on the -l, --language argument.

A full command would be something like:

readalongs align -f -c Studio/config.json Studio/story.xml Studio/story.mp3 Studio/story/aligned

The config.json file

Some additional parameters can be specified via a config file: create a JSON file called config.json, possibly in the same folder as your other ReadAlong input files for convenience. The config file currently accepts two components: adding images to your ReadAlongs, and DNA audio (see Handling mismatches: do-not-align).

To add images, indicate the page number as the key, and the name of the image file as the value, as an entry in the "images" dictionary.

{ "images": { "0": "p1.jpg", "1": "p2.jpg" } }

Both images and DNA audio can be specified in the same config file, such as in the example below:

{
    "images":
        {
            "0": "image-for-page1.jpg",
            "1": "image-for-page1.jpg",
            "2": "image-for-page2.jpg",
            "3": "image-for-page3.jpg"
        },

    "do-not-align":
        {
        "method": "remove",
        "segments":
            [
                {   "begin": 1,     "end": 17000   },
                {   "begin": 57456, "end": 68000   }
            ]
        }
}

Warning: mind your commas! The JSON format is very picky: commas separate elements in a list or dictionnary, but if you accidentally have a comma after the last element (e.g., by cutting and pasting whole lines), you will get a syntax error.

The g2p cascade

Sometimes the g2p conversion of the input text will not succeed, for various reasons. A word might use characters not recognized by the g2p for the language, or it might be in a different language. Whatever the reason, the output for the g2p conversion will not be valid ARPABET, and so the system will not be able to proceed to alignment by the readalongs aligner, SoundSwallower.

If you know the language for that text, you can mark it as such in the XML. E.g., <s xml:lang="eng">This sentence is in English.</s>. The xml:lang attribute can be added to any element in the XML structure and will apply to text at any depth within that element, unless the attribute is specified again at a deeper level, e.g., <s xml:lang="eng">English mixed with <foo xml:lang="fra">français</foo>.</s>.

There is also a simpler option available: the g2p cascade. When the g2p cascade is enabled, the g2p mapping will be done by first trying the language specified in the XML file (or with the -l flag on the command line, if the input is plain text). For each word where the result is not valid ARPABET, the g2p mapping will be attempted again with each of the languages specified in the g2p cascade, in order, until a valid ARPABET conversion is obtained. If not valid conversion is possible, are error message is printed and alignment is not attempted.

To enable the g2p cascade, add the --g2p-fallback l1:l2:... option to readalongs g2p or readalongs align:

readalongs g2p --g2p-fallback fra:eng:und myfile.tokenize.xml myfile.g2p.xml
readalongs align --g2p-fallback fra:eng:und myfile.xml myfile.wav output

The “Undetermined” language code: und

Notice that the two examples above use und as the last language in the cascade. und, for Undetermined, is a special language mapping that uses the Unicode definition of all known characters in all alphabets, and maps them as if the name of that character was how it is pronounced. While crude, this mapping works surprisingly well for the purposes of forced alignment, and allows readalongs align to successfully align most text with a few foreign words without any manual intervention. We recommend systematically using und at the end of the cascade. Note that adding another language after und will have no effect, since the Undetermined mapping will map any string to valid ARPABET.

Debugging g2p mapping issues

The warning messages issued by readalongs g2p and readalongs align indicate which words are causing g2p problems. It can be worth inspecting to input text to fix any encoding or spelling errors highlighted by these warnings. More detailed messages can be produced by adding the --g2p-verbose switch, to obtain a lot more information about g2p’ing words in each language g2p was unsucessfully attempted.

Breaking up the pipeline

Two commands were added to the CLI in the last year to break processing up step by step.

The following series of commands:

readalongs prepare -l lang  file.txt file.xml
readalongs tokenize file.xml file.tokenized.xml
readalongs g2p file.tokenized.xml file.g2p.xml
readalongs align file.g2p.xml file.wav output

is equivalent to the single command:

readalongs align -i -l lang file.txt file.wav output

except that when running the pipeline as four separate commands, you can edit the XML files between each step to make any required adjustments and corrections.

Anchors: marking known alignment points

Long audio/text file pairs can sometimes be difficult to align correctly, because the aligner might get lost part way through the alignment process. Anchors can be used to tell the aligner about known correspondance points between the text and the audio stream.

Anchor syntax

Anchors are inserted in the XML file (the output of readalongs prepare, readalongs tokenize or readalongs g2p) using the following syntax: <anchor time="3.42s"/> or <anchor time="3420ms"/>. The time can be specified in seconds (this is the default) or milliseconds.

Anchors can be placed anywhere in the XML file: between/before/after any element or text.

Example:

<?xml version='1.0' encoding='utf-8'?> <TEI> <text xml:lang="eng"> <body>
    <anchor time="143ms"/>
    <div type="page">
    <p>
        <s>Hello.</s>
        <anchor time="1.62s"/>
        <s>This is <anchor time="3.81s"/> <anchor time="3.94s"/> a test</s>
        <s><anchor time="4123ms"/>weirdword<anchor time="4789ms"/></s>
    </p>
    </div>
    <anchor time="6.74s"/>
</body> </text> </TEI>

Anchor semantics

When anchors are used, the alignment task is divided at each anchor, creating a series of segments that are aligned independently from one another. When alignment is performed, the aligner sees only the audio and the text from the segment being processed, and the results are joined together afterwards.

The beginning and end of files are implicit anchors: n anchors define n+1 segments: from the beginning of the audio and text to the first anchor, between pairs of anchors, and from the last anchor to the end of the audio and text.

Special cases equivalent to do-not-align audio: - If an anchor occurs before the first word in the text, the audio up to that anchor’s timestamps is excluded from alignment. - If an anchor occurs after the last word, the end of the audio is excluded from alignment. - If two anchors occur one after the other, the time span between them in the audio is excluded from alignment. Using anchors to define do-not-align audio segments is effectively the same as marking them as “do-not-align” in the config.json file, except that DNA segments declared using anchors have a known alignment with respect to the text, while the position of DNA segments declared in the config file are inferred by the aligner.

Anchor use cases

  1. Alignment fails because the stream is too long or too difficult to align.

    When alignment fails, listen to the audio stream and try to identify where some words you can pick up start or end. Even if you don’t understand the language, there might be some words you’re able to pick up and use as anchors to help the aligner.

  2. You already know where some words/sentences/paragraphs start or end, because the data came with some partial alignment information. For example, the data might come from an ELAN file with sentence alignments.

    These known timestamps can be converted to anchors.