feat: add version_matching module

.gitignore

@@ -12,4 +12,6 @@ local/
 .cache
 .python-version
 .idea/
+.vscode/
+venv/
 pyvenv.cfg

m3u8/parser.py

@@ -15,7 +15,7 @@
     pass
 
 
-from m3u8 import protocol
+from m3u8 import protocol, version_matching
 
 """
 http://tools.ietf.org/html/draft-pantos-http-live-streaming-08#section-3.2
@@ -75,8 +75,12 @@ def parse(content, strict=False, custom_tags_parser=None):
         "current_segment_map": None,
     }
 
+    lines = string_to_lines(content)
+    if strict:
+        version_matching.validate(lines)
+
     lineno = 0
-    for line in string_to_lines(content):
+    for line in lines:
         lineno += 1
         line = line.strip()
 

m3u8/version_matching.py

@@ -0,0 +1,43 @@
+from typing import Callable, List
+
+from m3u8 import protocol
+from m3u8.version_matching_rules import *
+
+
+class VersionMatchingError(Exception):
+    def __init__(self, lineno, line):
+        self.lineno = lineno
+        self.line = line
+
+    def __str__(self):
+        return f"Version matching error at line {self.lineno}: {self.line}"
+
+
+def get_version(file_lines: List[str]):
+    for line in file_lines:
+        if line.startswith(protocol.ext_x_version):
+            version = line.split(":")[1]
+            return float(version)
+
+    return None
+
+
+def valid_in_all_rules(line_number: int, line: str, version: float):
+    rules: List[Callable[[str, float], bool]] = [
+        valid_iv_in_EXT_X_KEY,
+        valid_floating_point_EXTINF,
+        valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY,
+    ]
+
+    for rule in rules:
+        if not rule(line, version):
+            raise VersionMatchingError(line_number, line)
+
+
+def validate(file_lines: List[str]):
+    found_version = get_version(file_lines)
+    if found_version is None:
+        return
+
+    for number, line in enumerate(file_lines):
+        valid_in_all_rules(number, line, found_version)

m3u8/version_matching_rules.py

@@ -0,0 +1,44 @@
+from m3u8 import protocol
+
+
+# You must use at least protocol version 2 if you have IV in EXT-X-KEY.
+def valid_iv_in_EXT_X_KEY(line: str, version: float):
+    if not protocol.ext_x_key in line:
+        return True
+
+    if "IV" in line:
+        return version >= 2
+
+    return True
+
+
+# You must use at least protocol version 3 if you have floating point EXTINF duration values.
+def valid_floating_point_EXTINF(line: str, version: float):
+    if not protocol.extinf in line:
+        return True
+
+    chunks = line.replace(protocol.extinf + ":", "").split(",", 1)
+    duration = chunks[0]
+
+    def is_number(value: str):
+        try:
+            float(value)
+            return True
+        except:
+            return False
+
+    def is_floating_number(value: str):
+        return is_number(value) and "." in value
+
+    if is_floating_number(duration):
+        return version >= 3
+
+    return is_number(duration)
+
+
+# You must use at least protocol version 4 if you have EXT-X-BYTERANGE or EXT-X-IFRAME-ONLY.
+def valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY(line: str, version: float):
+    if not protocol.ext_x_byterange in line and not protocol.ext_i_frames_only in line:
+        return True
+
+    return version >= 4

tests/invalid_versioned_playlists.py

@@ -0,0 +1,28 @@
+# Should have at least version 2 if you have IV in EXT-X-KEY.
+M3U8_RULE_IV = """
+#EXTM3U
+#EXT-X-VERSION: 1
+#EXT-X-KEY: METHOD=AES-128, IV=0x123456789ABCDEF0123456789ABCDEF0, URI="https://example.com/key.bin"
+#EXT-X-TARGETDURATION: 10
+#EXTINF: 10.0,
+https://example.com/segment1.ts
+"""
+
+# Should have at least version 3 if you have floating point EXTINF duration values.
+M3U8_RULE_FLOATING_POINT = """
+#EXTM3U
+#EXT-X-VERSION: 2
+#EXT-X-TARGETDURATION: 10
+#EXTINF: 10.5,
+https://example.com/segment1.ts
+"""
+
+# Should have at least version 4 if you have EXT-X-BYTERANGE or EXT-X-IFRAME-ONLY.
+M3U8_RULE_BYTE_RANGE = """
+#EXTM3U
+#EXT-X-VERSION: 3
+#EXT-X-BYTERANGE: 200000@1000
+#EXT-X-TARGETDURATION: 10
+#EXTINF: 10.0,
+https://example.com/segment1.ts
+"""

tests/test_invalid_versioned_playlists.py

@@ -0,0 +1,24 @@
+# coding: utf-8
+# Copyright 2014 Globo.com Player authors. All rights reserved.
+# Use of this source code is governed by a MIT License
+# license that can be found in the LICENSE file.
+
+import invalid_versioned_playlists
+import pytest
+
+import m3u8
+
+
+@pytest.mark.xfail
+def test_should_fail_if_iv_in_EXT_X_KEY_and_version_less_than_2():
+    m3u8.parse(invalid_versioned_playlists.M3U8_RULE_IV)
+
+
+@pytest.mark.xfail
+def test_should_fail_if_floating_point_EXTINF_and_version_less_than_3():
+    m3u8.parse(invalid_versioned_playlists.M3U8_RULE_FLOATING_POINT)
+
+
+@pytest.mark.xfail
+def test_should_fail_if_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY_and_version_less_than_4():
+    m3u8.parse(invalid_versioned_playlists.M3U8_RULE_BYTE_RANGE)

tests/test_strict_validations.py

@@ -3,8 +3,11 @@
 # Use of this source code is governed by a MIT License
 # license that can be found in the LICENSE file.
 
+import invalid_versioned_playlists
 import pytest
 
+import m3u8
+
 
 @pytest.mark.xfail
 def test_should_fail_if_first_line_not_EXTM3U():
@@ -33,7 +36,7 @@ def test_should_fail_if_EXT_X_MEDIA_SEQUENCE_is_not_a_number():
 
 @pytest.mark.xfail
 def test_should_validate_supported_EXT_X_VERSION():
-    assert 0
+    m3u8.parse(invalid_versioned_playlists.M3U8_RULE_IV)
 
 
 @pytest.mark.xfail

tests/test_version_matching_rules.py

@@ -0,0 +1,70 @@
+from m3u8.version_matching_rules import (
+    valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY,
+    valid_floating_point_EXTINF,
+    valid_iv_in_EXT_X_KEY,
+)
+
+
+def test_invalid_iv_in_EXT_X_KEY():
+    result = valid_iv_in_EXT_X_KEY(
+        "#EXT-X-KEY: METHOD=AES-128, IV=0x123456789ABCDEF0123456789ABCDEF0, URI=https://example.com/key.bin",
+        1,
+    )
+    assert result == False
+
+
+def test_valid_iv_in_EXT_X_KEY():
+    result = valid_iv_in_EXT_X_KEY(
+        "#EXT-X-KEY: METHOD=AES-128, URI=https://example.com/key.bin", 1
+    )
+    assert result == True
+    result = valid_iv_in_EXT_X_KEY(
+        "#EXT-X-KEY: METHOD=AES-128, IV=0x123456789ABCDEF0123456789ABCDEF0, URI=https://example.com/key.bin",
+        2,
+    )
+    assert result == True
+    result = valid_iv_in_EXT_X_KEY(
+        "#EXT-X-KEY: METHOD=AES-128, IV=0x123456789ABCDEF0123456789ABCDEF0, URI=https://example.com/key.bin",
+        3,
+    )
+    assert result == True
+
+
+def test_invalid_floating_point_EXTINF():
+    result = valid_floating_point_EXTINF("#EXTINF: 10.5,", 2)
+    assert result == False
+    result = valid_floating_point_EXTINF("#EXTINF: A,", 3)
+    assert result == False
+
+
+def test_valid_floating_point_EXTINF():
+    result = valid_floating_point_EXTINF("#EXTINF: 10,", 2)
+    assert result == True
+    result = valid_floating_point_EXTINF("#EXTINF: 10.5,", 3)
+    assert result == True
+    result = valid_floating_point_EXTINF("#EXTINF: 10.5,", 4)
+    assert result == True
+
+
+def test_invalid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY():
+    result = valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY(
+        "#EXT-X-BYTERANGE: 200000@1000", 3
+    )
+    assert result == False
+    result = valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY("#EXT-X-I-FRAMES-ONLY", 3)
+    assert result == False
+
+
+def test_valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY():
+    result = valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY(
+        "#EXT-X-BYTERANGE: 200000@1000", 4
+    )
+    assert result == True
+    result = valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY("#EXT-X-I-FRAMES-ONLY", 4)
+    assert result == True
+    result = valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY(
+        "#EXT-X-BYTERANGE: 200000@1000", 5
+    )
+    assert result == True
+    result = valid_EXT_X_BYTERANGE_or_EXT_X_I_FRAMES_ONLY("#EXT-X-I-FRAMES-ONLY", 5)
+    assert result == True