From dfe59b8a4f27f89fefb51ead56a77641e9b16daa Mon Sep 17 00:00:00 2001
From: Zaggy1024 <Zaggy1024@gmail.com>
Date: Sat, 27 Sep 2025 15:11:06 -0500
Subject: [PATCH] LibMedia+LibWeb: Prefer MatroskaDemuxer for media playback

MatroskaDemuxer supports multiple streams already, and gives us a bit
more control over seeking.
---
 Libraries/LibMedia/PlaybackManager.cpp     | 10 ++++++++--
 Libraries/LibMedia/PlaybackManager.h       |  2 +-
 Libraries/LibWeb/HTML/HTMLMediaElement.cpp |  2 +-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/Libraries/LibMedia/PlaybackManager.cpp b/Libraries/LibMedia/PlaybackManager.cpp
index 643d0e42614..eae5e09204d 100644
--- a/Libraries/LibMedia/PlaybackManager.cpp
+++ b/Libraries/LibMedia/PlaybackManager.cpp
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibMedia/Containers/Matroska/MatroskaDemuxer.h>
 #include <LibMedia/FFmpeg/FFmpegDemuxer.h>
 #include <LibMedia/MutexedDemuxer.h>
 #include <LibMedia/Providers/AudioDataProvider.h>
@@ -16,9 +17,14 @@
 
 namespace Media {
 
-DecoderErrorOr<NonnullRefPtr<PlaybackManager>> PlaybackManager::try_create(NonnullOwnPtr<SeekableStream>&& stream)
+DecoderErrorOr<NonnullRefPtr<PlaybackManager>> PlaybackManager::try_create(ReadonlyBytes data)
 {
-    auto inner_demuxer = DECODER_TRY_ALLOC(FFmpeg::FFmpegDemuxer::create(move(stream)));
+    auto inner_demuxer = TRY([&] -> DecoderErrorOr<NonnullRefPtr<Demuxer>> {
+        auto matroska_result = Matroska::MatroskaDemuxer::from_data(data);
+        if (!matroska_result.is_error())
+            return matroska_result.release_value();
+        return DECODER_TRY_ALLOC(FFmpeg::FFmpegDemuxer::create(make<FixedMemoryStream>(data)));
+    }());
     auto demuxer = DECODER_TRY_ALLOC(try_make_ref_counted<MutexedDemuxer>(inner_demuxer));
 
     // Create the weak wrapper.
diff --git a/Libraries/LibMedia/PlaybackManager.h b/Libraries/LibMedia/PlaybackManager.h
index 341ccdf3367..2194f36c8b4 100644
--- a/Libraries/LibMedia/PlaybackManager.h
+++ b/Libraries/LibMedia/PlaybackManager.h
@@ -36,7 +36,7 @@ public:
 
     using AudioTracks = Vector<Track, EXPECTED_AUDIO_TRACK_COUNT>;
 
-    static DecoderErrorOr<NonnullRefPtr<PlaybackManager>> try_create(NonnullOwnPtr<SeekableStream>&& stream);
+    static DecoderErrorOr<NonnullRefPtr<PlaybackManager>> try_create(ReadonlyBytes data);
     ~PlaybackManager();
 
     AK::Duration current_time() const;
diff --git a/Libraries/LibWeb/HTML/HTMLMediaElement.cpp b/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
index 075d6f51481..96c104b88c9 100644
--- a/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
@@ -1173,7 +1173,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::process_media_data(Function<void(Str
 {
     auto& realm = this->realm();
 
-    auto playback_manager_result = Media::PlaybackManager::try_create(make<FixedMemoryStream>(m_media_data.bytes()));
+    auto playback_manager_result = Media::PlaybackManager::try_create(m_media_data.bytes());
 
     // -> If the media data cannot be fetched at all, due to network errors, causing the user agent to give up trying to fetch the resource
     // -> If the media data can be fetched but is found by inspection to be in an unsupported format, or can otherwise not be rendered at all