Parsing HLS m3u8 Regex

Question

I am trying to parse HLS m3u8 file and where am stuck at is matching m3u8 links. So, if URI= exists, from #EXT-XI-FRAME-STREAM-INF , grab the one in quotation marks, and if it doesn't, #EXT-X-STREAM-INF , grab the link from new line.

Text:

#EXT-X-STREAM-INF:BANDWIDTH=263851,CODECS="mp4a.40.2, avc1.4d400d",RESOLUTION=416x234,AUDIO="bipbop_audio",SUBTITLES="subs"
gear1/prog_index.m3u8 <== new line link
#EXT-X-I-FRAME-STREAM-INF:URI="gear1/iframe_index.m3u8",CODECS="avc1.4d400d",BANDWIDTH=28451

Regex:

(?:#EXT-X-STREAM-INF:|#EXT-X-I-FRAME-STREAM-INF:)(?:BANDWIDTH=(?<BANDWIDTH>\d+),?|CODECS=(?<CODECS>"[^"]*"),?|RESOLUTION=(?<RESOLUTION>\d+x\d+),?|AUDIO=(?<AUDIO>"[^"]*"),?|SUBTITLES=(?<SUBTITLES>"[^"]*"),?|URI=(?<URI>"[^"]*"),?)*

Regex demo

Answer 1

A quick fix for your pattern will look like this:

• Capture the #EXT-X-STREAM-INF part into Group 1
• Add (?J) modifier to allow named capturing groups with identical names
• Add a conditional construct that will capture the whole line after the current pattern if Group 1 matched.

The pattern will look like

(?J)(?:(#EXT-X-STREAM-INF)|#EXT-X-I-FRAME-STREAM-INF):(?:BANDWIDTH=(?<BANDWIDTH>\d+),?|CODECS=(?<CODECS>"[^"]*"),?|RESOLUTION=(?<RESOLUTION>\d+x\d+),?|AUDIO=(?<AUDIO>"[^"]*"),?|SUBTITLES=(?<SUBTITLES>"[^"]*"),?|URI=(?<URI>"[^"]*"),?)*(?<URI>(?:(?!#EXT)\S)+))

See the regex demo

So, basically, I added (?<URI>(?:(?!#EXT)\\S)+)) at the end and captured (#EXT-X-STREAM-INF) at the start.

The conditional construct matches like this:

• (? - start of the conditional construct
  • (1) - if Group 1 matched
  • \\R - a line break
  • (?<URI> - start of a named capturing group
    • (?:(?!#EXT)\\S)+) - any non-whitespace char ( \\S ), 1 or more occurrences ( + ), that is not a starting char of a #EXT char sequence (the so called "tempered greedy token" )
  • ) - end of the named capturing group
• ) - end of the conditional construct