Fix was for ffmpeg-7.0.1 (masked) but the change was backported to 6.1.2.

Should hardly be an issue but it does cause a test failure when it
attempts to compare the return error when reading a (intentionally)
corrupted file (aborts either way, just differently). Still some time
until 6.7.3, and prefer to keep tests in a working state meanwhile.

https://bugreports.qt.io/browse/QTBUG-126687
https://github.com/qt/qtmultimedia/commit/8d809d56697f8d23669a9b1476ac0b0748e32e0d
From: Pavel Dubsky <pavel.dubsky@qt.io>
Date: Wed, 10 Jul 2024 14:42:51 +0200
Subject: [PATCH] Process FFmpeg AVERROR_INVALIDDATA from avformat_open_input

FFmpeg version n7.0.1 changed the error code that is returned from
function mp3_read_header: AVERROR(EINVAL) -> AVERROR_INVALIDDATA.

Task-number: QTBUG-126687
Pick-to: 6.8 6.7 6.5
Change-Id: I6aee7771a9d1f80ea459376711d5264bed9a7bac
Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>
--- a/src/plugins/multimedia/ffmpeg/playbackengine/qffmpegmediadataholder.cpp
+++ b/src/plugins/multimedia/ffmpeg/playbackengine/qffmpegmediadataholder.cpp
@@ -194,7 +194,7 @@ loadMedia(const QUrl &mediaUrl, QIODevice *stream, const std::shared_ptr<ICancel
         auto code = QMediaPlayer::ResourceError;
         if (ret == AVERROR(EACCES))
             code = QMediaPlayer::AccessDeniedError;
-        else if (ret == AVERROR(EINVAL))
+        else if (ret == AVERROR(EINVAL) || ret == AVERROR_INVALIDDATA)
             code = QMediaPlayer::FormatError;
 
         return MediaDataHolder::ContextError{ code, QMediaPlayer::tr("Could not open file") };
--- a/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp
+++ b/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp
@@ -962,7 +962,7 @@ void tst_QMediaPlayerBackend::setSource_emitsError_whenSdpFileIsLoaded()
     });
 
     m_fixture->player.setSource(sdpUrl);
-    QTRY_COMPARE_EQ(m_fixture->player.error(), QMediaPlayer::ResourceError);
+    QTRY_COMPARE_EQ(m_fixture->player.error(), QMediaPlayer::FormatError);
 #endif // QT_CONFIG(process)
 }