LibMedia: Make Demuxer atomically ref-counted

We'll need to share the demuxer between multiple decoder providers, and
those will hold references to the demuxer from their own decoder
threads.

Author: Zaggy1024

Libraries/LibMedia/Containers/Matroska/MatroskaDemuxer.cpp

@@ -13,19 +13,19 @@
 
 namespace Media::Matroska {
 
-DecoderErrorOr<NonnullOwnPtr<MatroskaDemuxer>> MatroskaDemuxer::from_file(StringView filename)
+DecoderErrorOr<NonnullRefPtr<MatroskaDemuxer>> MatroskaDemuxer::from_file(StringView filename)
 {
-    return make<MatroskaDemuxer>(TRY(Reader::from_file(filename)));
+    return make_ref_counted<MatroskaDemuxer>(TRY(Reader::from_file(filename)));
 }
 
-DecoderErrorOr<NonnullOwnPtr<MatroskaDemuxer>> MatroskaDemuxer::from_mapped_file(NonnullOwnPtr<Core::MappedFile> mapped_file)
+DecoderErrorOr<NonnullRefPtr<MatroskaDemuxer>> MatroskaDemuxer::from_mapped_file(NonnullOwnPtr<Core::MappedFile> mapped_file)
 {
-    return make<MatroskaDemuxer>(TRY(Reader::from_mapped_file(move(mapped_file))));
+    return make_ref_counted<MatroskaDemuxer>(TRY(Reader::from_mapped_file(move(mapped_file))));
 }
 
-DecoderErrorOr<NonnullOwnPtr<MatroskaDemuxer>> MatroskaDemuxer::from_data(ReadonlyBytes data)
+DecoderErrorOr<NonnullRefPtr<MatroskaDemuxer>> MatroskaDemuxer::from_data(ReadonlyBytes data)
 {
-    return make<MatroskaDemuxer>(TRY(Reader::from_data(data)));
+    return make_ref_counted<MatroskaDemuxer>(TRY(Reader::from_data(data)));
 }
 
 static TrackEntry::TrackType matroska_track_type_from_track_type(TrackType type)

Libraries/LibMedia/Containers/Matroska/MatroskaDemuxer.h

@@ -17,10 +17,10 @@ class MatroskaDemuxer final : public Demuxer {
 public:
     // FIXME: We should instead accept some abstract data streaming type so that the demuxer
     //        can work with non-contiguous data.
-    static DecoderErrorOr<NonnullOwnPtr<MatroskaDemuxer>> from_file(StringView filename);
-    static DecoderErrorOr<NonnullOwnPtr<MatroskaDemuxer>> from_mapped_file(NonnullOwnPtr<Core::MappedFile> mapped_file);
+    static DecoderErrorOr<NonnullRefPtr<MatroskaDemuxer>> from_file(StringView filename);
+    static DecoderErrorOr<NonnullRefPtr<MatroskaDemuxer>> from_mapped_file(NonnullOwnPtr<Core::MappedFile> mapped_file);
 
-    static DecoderErrorOr<NonnullOwnPtr<MatroskaDemuxer>> from_data(ReadonlyBytes data);
+    static DecoderErrorOr<NonnullRefPtr<MatroskaDemuxer>> from_data(ReadonlyBytes data);
 
     MatroskaDemuxer(Reader&& reader)
         : m_reader(move(reader))

Libraries/LibMedia/Demuxer.h

@@ -1,11 +1,12 @@
 /*
- * Copyright (c) 2022, Gregory Bertilson <zaggy1024@gmail.com>
+ * Copyright (c) 2022-2025, Gregory Bertilson <gregory@ladybird.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
 #pragma once
 
+#include <AK/AtomicRefCounted.h>
 #include <AK/NonnullOwnPtr.h>
 #include <LibCore/EventReceiver.h>
 
@@ -16,7 +17,7 @@
 
 namespace Media {
 
-class Demuxer {
+class Demuxer : public AtomicRefCounted<Demuxer> {
 public:
     virtual ~Demuxer() = default;
 

Libraries/LibMedia/FFmpeg/FFmpegDemuxer.cpp

@@ -28,10 +28,10 @@ FFmpegDemuxer::~FFmpegDemuxer()
         avformat_close_input(&m_format_context);
 }
 
-ErrorOr<NonnullOwnPtr<FFmpegDemuxer>> FFmpegDemuxer::create(NonnullOwnPtr<SeekableStream> stream)
+ErrorOr<NonnullRefPtr<FFmpegDemuxer>> FFmpegDemuxer::create(NonnullOwnPtr<SeekableStream> stream)
 {
     auto io_context = TRY(Media::FFmpeg::FFmpegIOContext::create(*stream));
-    auto demuxer = make<FFmpegDemuxer>(move(stream), move(io_context));
+    auto demuxer = make_ref_counted<FFmpegDemuxer>(move(stream), move(io_context));
 
     // Open the container
     demuxer->m_format_context = avformat_alloc_context();

Libraries/LibMedia/FFmpeg/FFmpegDemuxer.h

@@ -20,7 +20,7 @@ namespace Media::FFmpeg {
 
 class FFmpegDemuxer : public Demuxer {
 public:
-    static ErrorOr<NonnullOwnPtr<FFmpegDemuxer>> create(NonnullOwnPtr<SeekableStream> stream);
+    static ErrorOr<NonnullRefPtr<FFmpegDemuxer>> create(NonnullOwnPtr<SeekableStream> stream);
 
     FFmpegDemuxer(NonnullOwnPtr<SeekableStream> stream, NonnullOwnPtr<Media::FFmpeg::FFmpegIOContext>);
     virtual ~FFmpegDemuxer() override;

Libraries/LibMedia/PlaybackManager.cpp

@@ -41,8 +41,8 @@ DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> PlaybackManager::from_stream(Nonn
     return create(demuxer_or_error.release_value());
 }
 
-PlaybackManager::PlaybackManager(NonnullOwnPtr<Demuxer>& demuxer, Track video_track, NonnullOwnPtr<VideoDecoder>&& decoder, VideoFrameQueue&& frame_queue)
-    : m_demuxer(move(demuxer))
+PlaybackManager::PlaybackManager(NonnullRefPtr<Demuxer> const& demuxer, Track video_track, NonnullOwnPtr<VideoDecoder>&& decoder, VideoFrameQueue&& frame_queue)
+    : m_demuxer(demuxer)
     , m_selected_video_track(video_track)
     , m_frame_queue(move(frame_queue))
     , m_decoder(move(decoder))
@@ -696,7 +696,7 @@ class PlaybackManager::StoppedStateHandler : public PlaybackManager::PlaybackSta
     PlaybackState get_state() const override { return PlaybackState::Stopped; }
 };
 
-DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> PlaybackManager::create(NonnullOwnPtr<Demuxer> demuxer)
+DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> PlaybackManager::create(NonnullRefPtr<Demuxer> const& demuxer)
 {
     auto optional_track = TRY(demuxer->get_preferred_track_for_type(TrackType::Video));
     if (!optional_track.has_value()) {

Libraries/LibMedia/PlaybackManager.h

@@ -114,7 +114,7 @@ class MEDIA_API PlaybackManager {
     static DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> from_data(ReadonlyBytes data);
     static DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> from_stream(NonnullOwnPtr<SeekableStream> stream);
 
-    PlaybackManager(NonnullOwnPtr<Demuxer>& demuxer, Track video_track, NonnullOwnPtr<VideoDecoder>&& decoder, VideoFrameQueue&& frame_queue);
+    PlaybackManager(NonnullRefPtr<Demuxer> const& demuxer, Track video_track, NonnullOwnPtr<VideoDecoder>&& decoder, VideoFrameQueue&& frame_queue);
     ~PlaybackManager();
 
     void resume_playback();
@@ -153,7 +153,7 @@ class MEDIA_API PlaybackManager {
     class SeekingStateHandler;
     class StoppedStateHandler;
 
-    static DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> create(NonnullOwnPtr<Demuxer> demuxer);
+    static DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> create(NonnullRefPtr<Demuxer> const& demuxer);
 
     void timer_callback();
     // This must be called with m_demuxer_mutex locked!
@@ -173,7 +173,7 @@ class MEDIA_API PlaybackManager {
 
     AK::Duration m_last_present_in_media_time = AK::Duration::zero();
 
-    NonnullOwnPtr<Demuxer> m_demuxer;
+    NonnullRefPtr<Demuxer> m_demuxer;
     Threading::Mutex m_decoder_mutex;
     Track m_selected_video_track;