[MSE][GStreamer] Support markEndOfStream() before appendBuffer()

https://bugs.webkit.org/show_bug.cgi?id=278726

Reviewed by Xabier Rodriguez-Calvar.

MediaSource::markEndOfStream() causes the SourceBuffer TrackBuffers to push
EOS to playback pipeline through WebKitMediaSrc. When that happens without
any SourceBuffer::appendBuffer() call, the pipeline can't finish autoplugging
and parsebin triggers an unrecoverable error. That's on GStreamer 1.18.6 at
least. On GStreamer 1.24 no error is triggered, but still, playback (of no
data) never finishes.

While it's certainly possible to change parsebin to not trigger the error,
the truth is that this seems legitimate GStreamer behaviour that shouldn't be
altered (and also, doesn't fix the problem by itself, I've checked it,
playback doesn't finish, see previous paragraph).

This commit adds support for temporarily ignoring the error when using an
affected GStreamer version, and asking the pipeline to change to READY state.
It also notifies HTMLMediaElement about timeChanged, so the "ended" event can
be triggered (after all, there's no other position to go beyond 0, as there
are no samples and 0 is already the duration, so technically playback is ended).

See: #1366

* Source/WebCore/html/HTMLMediaElement.cpp:
(WebCore::HTMLMediaElement::mediaPlayerTimeChanged): Allow time change processing when duration is zero and current time is zero.
* Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:
(WebCore::MediaPlayerPrivateGStreamer::handleMessage): Ignore errors when the m_ignoreErrors flag is enabled.
* Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.h: Add m_ignoreErrors flag.
* Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.cpp:
(WebCore::MediaPlayerPrivateGStreamerMSE::updateStates): Report time changed on EOS with no buffer.
(WebCore::MediaPlayerPrivateGStreamerMSE::setEosWithNoBuffers): Set the m_isEosWithNoBuffer flag. Change the pipeline to READY when enabled (with errors disabled on older GStreamer versions).
* Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.h: Added m_isEosWithNoBuffer flag.
* Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.cpp:
(WebCore::MediaSourcePrivateGStreamer::markEndOfStream): Detect the "EOS with no buffers" condition and report it to the player private.
(WebCore::MediaSourcePrivateGStreamer::unmarkEndOfStream): Disable the "EOS with no buffers" condition.
* Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.h: Added unmarkEndOfStream().

Canonical link: https://commits.webkit.org/282958@main

Author: eocanha

Source/WebCore/html/HTMLMediaElement.cpp

@@ -5167,7 +5167,7 @@ void HTMLMediaElement::mediaPlayerTimeChanged()
     double playbackRate = requestedPlaybackRate();
 
     // When the current playback position reaches the end of the media resource then the user agent must follow these steps:
-    if (dur && dur.isValid() && !dur.isPositiveInfinite() && !dur.isNegativeInfinite()) {
+    if ((dur || (!dur && !now)) && dur.isValid() && !dur.isPositiveInfinite() && !dur.isNegativeInfinite()) {
         // If the media element has a loop attribute specified and does not have a current media controller,
         if (loop() && !m_mediaController && playbackRate > 0) {
             m_sentEndEvent = false;

Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp

@@ -1814,7 +1814,7 @@ void MediaPlayerPrivateGStreamer::handleMessage(GstMessage* message)
         gst_message_parse_error(message, &err.outPtr(), &debug.outPtr());
         GST_ERROR_OBJECT(pipeline(), "%s (url=%s) (code=%d)", err->message, m_url.string().utf8().data(), err->code);
 
-        if (m_shouldResetPipeline || !m_missingPluginCallbacks.isEmpty() || m_didErrorOccur)
+        if (m_shouldResetPipeline || !m_missingPluginCallbacks.isEmpty() || m_didErrorOccur || m_ignoreErrors)
             break;
 
         m_errorMessage = String::fromLatin1(err->message);

Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.h

@@ -449,6 +449,7 @@ class MediaPlayerPrivateGStreamer : public MediaPlayerPrivateInterface
 #endif
 
     std::optional<GstVideoDecoderPlatform> m_videoDecoderPlatform;
+    bool m_ignoreErrors { false };
 
     String errorMessage() const override { return m_errorMessage; }
 

Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.cpp

@@ -429,6 +429,11 @@ void MediaPlayerPrivateGStreamerMSE::updateStates()
     } else if (!isSeeking && !shouldBePlaying && m_isPipelinePlaying) {
         if (changePipelineState(GST_STATE_PAUSED) == ChangePipelineStateResult::Failed)
             GST_ERROR_OBJECT(pipeline(), "Setting the pipeline to PAUSED failed");
+    } else if (m_isEosWithNoBuffers) {
+        if (m_player) {
+            // Trigger playback end detection in HTMLMediaElement.
+            m_player->timeChanged();
+        }
     }
 }
 
@@ -476,6 +481,23 @@ void MediaPlayerPrivateGStreamerMSE::startSource(const Vector<RefPtr<MediaSource
     webKitMediaSrcEmitStreams(WEBKIT_MEDIA_SRC(m_source.get()), m_tracks);
 }
 
+void MediaPlayerPrivateGStreamerMSE::setEosWithNoBuffers(bool eosWithNoBuffers)
+{
+    m_isEosWithNoBuffers = eosWithNoBuffers;
+    // Parsebin will trigger an error, instruct MediaPlayerPrivateGStreamer to ignore it.
+    if (eosWithNoBuffers) {
+        // On GStreamer 1.18.6, EOS with no buffers causes a parsebin error here:
+        // https://github.com/GStreamer/gst-plugins-base/blob/1.18.6/gst/playback/gstparsebin.c#L3495
+        // On GStreamer 1.24 (at least) that doesn't happen. Let's play safe and protect against the
+        // error in lower versions.
+        if (!webkitGstCheckVersion(1, 24, 0))
+            m_ignoreErrors = true;
+        changePipelineState(GST_STATE_READY);
+        if (!webkitGstCheckVersion(1, 24, 0))
+            m_ignoreErrors = false;
+    }
+}
+
 void MediaPlayerPrivateGStreamerMSE::getSupportedTypes(HashSet<String, ASCIICaseInsensitiveHash>& types)
 {
     GStreamerRegistryScannerMSE::getSupportedDecodingTypes(types);

Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.h

@@ -84,6 +84,8 @@ class MediaPlayerPrivateGStreamerMSE : public MediaPlayerPrivateGStreamer {
     void startSource(const Vector<RefPtr<MediaSourceTrackGStreamer>>& tracks);
     WebKitMediaSrc* webKitMediaSrc() { return reinterpret_cast<WebKitMediaSrc*>(m_source.get()); }
 
+    void setEosWithNoBuffers(bool);
+
 #if !RELEASE_LOG_DISABLED
     WTFLogChannel& logChannel() const final { return WebCore::LogMediaSource; }
 #endif
@@ -112,6 +114,7 @@ class MediaPlayerPrivateGStreamerMSE : public MediaPlayerPrivateGStreamer {
     Vector<RefPtr<MediaSourceTrackGStreamer>> m_tracks;
 
     bool m_isWaitingForPreroll = true;
+    bool m_isEosWithNoBuffers = false;
     MediaPlayer::ReadyState m_mediaSourceReadyState = MediaPlayer::ReadyState::HaveNothing;
     MediaPlayer::NetworkState m_mediaSourceNetworkState = MediaPlayer::NetworkState::Empty;
 };

Source/WebCore/platform/graphics/gstreamer/mse/MediaSourcePrivateGStreamer.cpp

@@ -136,15 +136,23 @@ void MediaSourcePrivateGStreamer::markEndOfStream(EndOfStreamStatus endOfStreamS
     }
     GST_DEBUG_OBJECT(m_playerPrivate.pipeline(), "Marking EOS, status is %s", statusString);
 #endif
-    if (endOfStreamStatus == EosNoError)
+    if (endOfStreamStatus == EosNoError) {
         m_playerPrivate.setNetworkState(MediaPlayer::NetworkState::Loaded);
+
+        auto bufferedRanges = buffered();
+        if (!bufferedRanges || !bufferedRanges->length()) {
+            GST_DEBUG("EOS with no buffers");
+            m_playerPrivate.setEosWithNoBuffers(true);
+        }
+    }
     m_isEnded = true;
 }
 
 void MediaSourcePrivateGStreamer::unmarkEndOfStream()
 {
     ASSERT(isMainThread());
     GST_DEBUG_OBJECT(m_playerPrivate.pipeline(), "Un-marking EOS");
+    m_playerPrivate.setEosWithNoBuffers(false);
     m_isEnded = false;
 }