yt-dlp fix m3u8 that hides video streams inside PNGs

README.md

Attemps to handle this: yt-dlp/yt-dlp#4381

How to use:

yt-dlp --fix-fake-header m3u8_url

fix_fake_header.patch

diff --git a/README.md b/README.md
index 2df72b749..e3ebd1232 100644
--- a/README.md
+++ b/README.md
@@ -526,6 +526,7 @@ ## Download Options:
                                     downloading is finished
     --no-keep-fragments             Delete downloaded fragments after
                                     downloading is finished (default)
+    --fix-fake-header               Fix fake header
     --buffer-size SIZE              Size of download buffer, e.g. 1024 or 16K
                                     (default is 1024)
     --resize-buffer                 The buffer size is automatically resized
diff --git a/yt_dlp/__init__.py b/yt_dlp/__init__.py
index a7665159b..9d5f883da 100644
--- a/yt_dlp/__init__.py
+++ b/yt_dlp/__init__.py
@@ -846,6 +846,7 @@ def parse_options(argv=None):
         'retry_sleep_functions': opts.retry_sleep,
         'skip_unavailable_fragments': opts.skip_unavailable_fragments,
         'keep_fragments': opts.keep_fragments,
+        'fix_fake_header': opts.fix_fake_header,
         'concurrent_fragment_downloads': opts.concurrent_fragment_downloads,
         'buffersize': opts.buffersize,
         'noresizebuffer': opts.noresizebuffer,
diff --git a/yt_dlp/downloader/external.py b/yt_dlp/downloader/external.py
index 6c1ec403c..8e467aedc 100644
--- a/yt_dlp/downloader/external.py
+++ b/yt_dlp/downloader/external.py
@@ -181,7 +181,11 @@ def _call_downloader(self, tmpfilename, info_dict):
                     continue
                 self.report_error(f'Unable to open fragment {frag_index}; {err}')
                 return -1
-            dest.write(decrypt_fragment(fragment, src.read()))
+            frag_content = src.read()
+            if self.params.get('fix_fake_header'):
+                ts_start_pos = frag_content.find(b'\x47\x40')
+                frag_content = frag_content[ts_start_pos:]
+            dest.write(decrypt_fragment(fragment, frag_content))
             src.close()
             if not self.params.get('keep_fragments', False):
                 self.try_remove(encodeFilename(fragment_filename))
diff --git a/yt_dlp/downloader/fragment.py b/yt_dlp/downloader/fragment.py
index 0d00196e2..f79839c1f 100644
--- a/yt_dlp/downloader/fragment.py
+++ b/yt_dlp/downloader/fragment.py
@@ -141,6 +141,9 @@ def _read_fragment(self, ctx):
             raise
         ctx['fragment_filename_sanitized'] = frag_sanitized
         frag_content = down.read()
+        if self.params.get('fix_fake_header'):
+            ts_start_pos = frag_content.find(b'\x47\x40')
+            frag_content = frag_content[ts_start_pos:]
         down.close()
         return frag_content
 
diff --git a/yt_dlp/options.py b/yt_dlp/options.py
index 6c6a0b3f9..d36761be6 100644
--- a/yt_dlp/options.py
+++ b/yt_dlp/options.py
@@ -973,6 +973,10 @@ def _alias_callback(option, opt_str, value, parser, opts, nargs):
         '--no-keep-fragments',
         action='store_false', dest='keep_fragments',
         help='Delete downloaded fragments after downloading is finished (default)')
+    downloader.add_option(
+        '--fix-fake-header',
+        action='store_true', dest='fix_fake_header', default=False,
+        help='Fix fake header')
     downloader.add_option(
         '--buffer-size',
         dest='buffersize', metavar='SIZE', default='1024',