From 985ab687187147e4b96f39248f47047679e6ab7a Mon Sep 17 00:00:00 2001
From: Brandon Casey <2381475+brandonocasey@users.noreply.github.com>
Date: Wed, 20 Jan 2021 10:37:14 -0500
Subject: [PATCH] feat: add support for #EXT-X-PART-INF (#126)

https://developer.apple.com/documentation/http_live_streaming/enabling_low-latency_hls#3282434
https://tools.ietf.org/html/draft-pantos-hls-rfc8216bis-08#section-4.4.3.7
---
 src/parse-stream.js                | 16 ++++++++++++++++
 src/parser.js                      |  3 +++
 test/fixtures/m3u8/llhls.json      |  3 +++
 test/fixtures/m3u8/llhlsDelta.json |  3 +++
 4 files changed, 25 insertions(+)

diff --git a/src/parse-stream.js b/src/parse-stream.js
index fb43c83..a82a137 100644
--- a/src/parse-stream.js
+++ b/src/parse-stream.js
@@ -520,6 +520,22 @@ export default class ParseStream extends Stream {
         this.trigger('data', event);
         return;
       }
+      match = (/^#EXT-X-PART-INF:(.*)$/).exec(newLine);
+      if (match && match[1]) {
+        event = {
+          type: 'tag',
+          tagType: 'part-inf'
+        };
+        event.attributes = parseAttributes(match[1]);
+        ['PART-TARGET'].forEach(function(key) {
+          if (event.attributes.hasOwnProperty(key)) {
+            event.attributes[key] = parseFloat(event.attributes[key]);
+          }
+        });
+
+        this.trigger('data', event);
+        return;
+      }
 
       match = (/^#EXT-X-PRELOAD-HINT:(.*)$/).exec(newLine);
       if (match && match[1]) {
diff --git a/src/parser.js b/src/parser.js
index 2fd7c6d..e7dc109 100644
--- a/src/parser.js
+++ b/src/parser.js
@@ -401,6 +401,9 @@ export default class Parser extends Stream {
             'rendition-report'() {
               this.manifest.renditionReports = this.manifest.renditionReports || [];
               this.manifest.renditionReports.push(entry.attributes);
+            },
+            'part-inf'() {
+              this.manifest.partInf = entry.attributes;
             }
           })[entry.tagType] || noop).call(self);
         },
diff --git a/test/fixtures/m3u8/llhls.json b/test/fixtures/m3u8/llhls.json
index 1e8093d..7614219 100644
--- a/test/fixtures/m3u8/llhls.json
+++ b/test/fixtures/m3u8/llhls.json
@@ -13,6 +13,9 @@
     {"LAST-MSN": 273, "LAST-PART": 2, "URI": "../1M/waitForMSN.php"},
     {"LAST-MSN": 273, "LAST-PART": 1, "URI": "../4M/waitForMSN.php"}
   ],
+  "partInf": {
+    "PART-TARGET": 0.33334
+  },
   "parts": [
     {
       "DURATION": 0.33334,
diff --git a/test/fixtures/m3u8/llhlsDelta.json b/test/fixtures/m3u8/llhlsDelta.json
index e5341a2..4905c84 100644
--- a/test/fixtures/m3u8/llhlsDelta.json
+++ b/test/fixtures/m3u8/llhlsDelta.json
@@ -13,6 +13,9 @@
     {"LAST-MSN": 273, "LAST-PART": 3, "URI": "../1M/waitForMSN.php"},
     {"LAST-MSN": 273, "LAST-PART": 3, "URI": "../4M/waitForMSN.php"}
   ],
+  "partInf": {
+    "PART-TARGET": 0.33334
+  },
   "parts": [
     {
       "DURATION": 0.33334,