An XSLT transform I use for converting itt-formatted subtitles to srt-formatted subtitles

itt-to-srt.xslt

<?xml version="1.0"?>
<!-- 
    This will convert itt-formatted subtitles to srt-formatted subtitles (or captions, if you prefer that)
    Use it like so (using xsltproc in this example, feel free to use whatever engine you like):
    # xsltproc itt-to-srt.xslt input_in_itt.itt > output_in_srt.srt 
-->
<xsl:stylesheet version="1.0" 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:ttp="http://www.w3.org/ns/ttml#parameter" 
    xmlns:tt_feature="http://www.w3.org/ns/ttml/feature/" 
    xmlns:tts="http://www.w3.org/ns/ttml#styling" 
    xmlns:tt_extension="http://www.w3.org/ns/ttml/extension/" 
    xmlns:tt_profile="http://www.w3.org/ns/ttml/profile/" 
    xmlns:ttm="http://www.w3.org/ns/ttml#metadata" 
    xmlns:ry="http://namespace.itunes.apple.com/itt/ttml-extension#ruby" 
    xmlns="http://www.w3.org/ns/ttml" 
    ttp:frameRate="50" 
    ttp:frameRateMultiplier="1 1" 
    xml:lang="en" xmlns:tt="http://www.w3.org/ns/ttml" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    ttp:dropMode="nonDrop" 
    ttp:timeBase="smpte"
    >

    <xsl:output method="text" omit-xml-declaration="yes" indent="no" />
    <xsl:strip-space elements="*" />

    <xsl:template match="/tt:tt/tt:body">
        <xsl:apply-templates/>
    </xsl:template>

    <xsl:template match="/tt:tt/tt:head">
    </xsl:template>

    <xsl:template match="tt:div/tt:p/tt:span/tt:br">
        <xsl:text>&#xa;</xsl:text>
    </xsl:template>

    <xsl:template match="tt:div">
        <xsl:for-each select="tt:p">
            <xsl:value-of select="position()"/>
            <xsl:text>&#xa;</xsl:text>
            <xsl:value-of select='substring(@begin, 0, 9)' />,<xsl:value-of select='concat(substring(@begin, 10, 12), 0)' /> --> <xsl:value-of select='substring(@end, 0, 9)' />,<xsl:value-of select='concat(substring(@end, 10, 12), 0)' />
            <xsl:text>&#xa;</xsl:text>
            <xsl:apply-templates select="tt:span"/>
            <xsl:text>&#xa;</xsl:text>
            <xsl:text>&#xa;</xsl:text>
        </xsl:for-each>
    </xsl:template>

</xsl:stylesheet>

Great xsl, does the work perfectly except for one small caveat, if you have 2 lined with the same timecode, the output will be 2 entries in the SRT with the same timecode, while it is supposed to merge the 2 lines under the same timecode, as some players will do weird things when the SRT file has 2 entries with the same timecode.
I am trying to modify the code to cater for this.

I am trying to modify the code to cater for this.

Hi Bilal. That sounds awesome. I'm by no means an expert in any of this. I just hacked something together that worked for me at the time. I even forgot that I had this Gist. :)
Please feel free to improve on it. I'll be happy to update the Gist if you like.