stream.dash: fix segment number iterator

bastimeyer · bastimeyer · commit d388acd6d98c · 2023-03-10T01:36:44.000+01:00
diff --git a/src/streamlink/stream/dash_manifest.py b/src/streamlink/stream/dash_manifest.py
@@ -736,14 +736,12 @@ def segment_numbers(self) -> Iterator[Tuple[int, datetime.datetime]]:
             buffer_time = self.root.minBufferTime
 
             # Segment number
-            # To reduce unnecessary delay, start with the next/upcoming segment: +1
             seconds_offset = (since_start - suggested_delay - buffer_time).total_seconds()
-            number_offset = max(0, int(seconds_offset / self.duration_seconds) + 1)
+            number_offset = max(0, int(seconds_offset / self.duration_seconds))
             number_iter = count(self.startNumber + number_offset)
 
             # Segment availability time
-            # The availability time marks the segment's beginning: -1
-            available_offset = datetime.timedelta(seconds=max(0, number_offset - 1) * self.duration_seconds)
+            available_offset = datetime.timedelta(seconds=number_offset * self.duration_seconds)
             available_start = self.period.availabilityStartTime + available_offset
             available_iter = count_dt(
                 available_start,
diff --git a/tests/stream/test_dash_parser.py b/tests/stream/test_dash_parser.py
@@ -147,15 +147,15 @@ def test_segments_dynamic_number(self):
                 datetime.datetime(2000, 1, 1, 0, 1, 30, tzinfo=UTC),
             ),
             (
-                "http://test/hd-5_000000794.mp4",
+                "http://test/hd-5_000000793.mp4",
                 datetime.datetime(2000, 1, 1, 0, 59, 15, tzinfo=UTC),
             ),
             (
-                "http://test/hd-5_000000795.mp4",
+                "http://test/hd-5_000000794.mp4",
                 datetime.datetime(2000, 1, 1, 0, 59, 20, tzinfo=UTC),
             ),
             (
-                "http://test/hd-5_000000796.mp4",
+                "http://test/hd-5_000000795.mp4",
                 datetime.datetime(2000, 1, 1, 0, 59, 25, tzinfo=UTC),
             ),
         ]

Original file line number	Diff line number	Diff line change
`@@ -147,15 +147,15 @@ def test_segments_dynamic_number(self):`
`147`	`147`	`datetime.datetime(2000, 1, 1, 0, 1, 30, tzinfo=UTC),`
`148`	`148`	`),`
`149`	`149`	`(`
`150`		`- "http://test/hd-5_000000794.mp4",`
	`150`	`+ "http://test/hd-5_000000793.mp4",`
`151`	`151`	`datetime.datetime(2000, 1, 1, 0, 59, 15, tzinfo=UTC),`
`152`	`152`	`),`
`153`	`153`	`(`
`154`		`- "http://test/hd-5_000000795.mp4",`
	`154`	`+ "http://test/hd-5_000000794.mp4",`
`155`	`155`	`datetime.datetime(2000, 1, 1, 0, 59, 20, tzinfo=UTC),`
`156`	`156`	`),`
`157`	`157`	`(`
`158`		`- "http://test/hd-5_000000796.mp4",`
	`158`	`+ "http://test/hd-5_000000795.mp4",`
`159`	`159`	`datetime.datetime(2000, 1, 1, 0, 59, 25, tzinfo=UTC),`
`160`	`160`	`),`
`161`	`161`	`]`