feat(playlist): compact rows with clean titles and durations

Co-authored-by: Tri Vo Khac <git@trivk.dev>

autotests/CMakeLists.txt

@@ -16,7 +16,7 @@ target_include_directories(glossarystoretest PRIVATE ../src/translate)
 
 ecm_add_test(playlistmodeltest.cpp ../src/playlist/playlistmodel.cpp
     TEST_NAME playlistmodeltest
-    LINK_LIBRARIES Qt6::Qml Qt6::Test
+    LINK_LIBRARIES qtpotato_core Qt6::Qml Qt6::Concurrent Qt6::Test
 )
 target_include_directories(playlistmodeltest PRIVATE ../src/playlist)
 
@@ -24,3 +24,13 @@ ecm_add_test(trackselectiontest.cpp
     TEST_NAME trackselectiontest
     LINK_LIBRARIES qtpotato_core Qt6::Test
 )
+
+ecm_add_test(translationstoretest.cpp
+    TEST_NAME translationstoretest
+    LINK_LIBRARIES qtpotato_core Qt6::Test
+)
+
+ecm_add_test(mediainfotest.cpp
+    TEST_NAME mediainfotest
+    LINK_LIBRARIES qtpotato_core Qt6::Test
+)

autotests/mediainfotest.cpp

@@ -0,0 +1,64 @@
+// SPDX-FileCopyrightText: 2026 Tri Vo Khac
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "mediainfo.h"
+
+#include <QProcess>
+#include <QStandardPaths>
+#include <QTemporaryDir>
+#include <QTest>
+
+using namespace Qt::Literals::StringLiterals;
+
+class MediaInfoTest : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void cleanTitle_data()
+    {
+        QTest::addColumn<QString>("fileName");
+        QTest::addColumn<QString>("title");
+
+        QTest::newRow("scene episode") << u"VisionQuest.S01E01.No.Strings.DSNP.DV.HDR.WEB-DL.DDP5.1.Atmos.H.265-GRP.mkv"_s
+                                       << u"S01E01 · No Strings"_s;
+        QTest::newRow("episode without title") << u"The.Show.S02E10.1080p.WEB.h264-GRP.mkv"_s << u"The Show · S02E10"_s;
+        QTest::newRow("lowercase double episode") << u"show.s01e01e02.pilot.720p.hdtv.mkv"_s << u"S01E01E02 · pilot"_s;
+        QTest::newRow("spaced episode") << u"Mr. Robot - S01E01 - eps1.0_hellofriend.mov.mkv"_s << u"S01E01 · eps1.0 hellofriend.mov"_s;
+        QTest::newRow("movie with year") << u"Dune.Part.Two.2024.2160p.UHD.BluRay.x265-GRP.mkv"_s << u"Dune Part Two (2024)"_s;
+        QTest::newRow("anime release") << u"[SubsPlease] Frieren - 05 (1080p) [A1B2C3D4].mkv"_s << u"Frieren - 05"_s;
+        QTest::newRow("plain name") << u"Holiday 2019 at the beach.mp4"_s << u"Holiday 2019 at the beach"_s;
+        QTest::newRow("music") << u"01 - Intro.flac"_s << u"01 - Intro"_s;
+        QTest::newRow("only tags") << u"1080p.mkv"_s << u"1080p"_s;
+    }
+
+    void cleanTitle()
+    {
+        QFETCH(QString, fileName);
+        QFETCH(QString, title);
+        QCOMPARE(MediaInfo::cleanTitle(fileName), title);
+    }
+
+    void probeDurationReadsTheLength()
+    {
+        const QString ffmpeg = QStandardPaths::findExecutable(u"ffmpeg"_s);
+        if (ffmpeg.isEmpty()) {
+            QSKIP("ffmpeg is needed to make a sample file");
+        }
+        QTemporaryDir dir;
+        const QString path = dir.filePath(u"tone.mka"_s);
+        QProcess process;
+        process.start(ffmpeg, {u"-v"_s, u"error"_s, u"-f"_s, u"lavfi"_s, u"-i"_s, u"sine=duration=3"_s, path});
+        QVERIFY(process.waitForFinished());
+        QCOMPARE(process.exitCode(), 0);
+
+        const std::optional<double> seconds = MediaInfo::probeDuration(path);
+        QVERIFY(seconds);
+        QVERIFY2(qAbs(*seconds - 3) < 0.1, qPrintable(QString::number(*seconds)));
+        QVERIFY(!MediaInfo::probeDuration(dir.filePath(u"missing.mkv"_s)));
+    }
+};
+
+QTEST_GUILESS_MAIN(MediaInfoTest)
+
+#include "mediainfotest.moc"

autotests/playlistmodeltest.cpp

@@ -4,7 +4,9 @@
 #include "playlistmodel.h"
 
 #include <QFile>
+#include <QProcess>
 #include <QSignalSpy>
+#include <QStandardPaths>
 #include <QTemporaryDir>
 #include <QTest>
 
@@ -98,6 +100,31 @@ private Q_SLOTS:
         QCOMPARE(model.playingIndex(), -1);
         QCOMPARE(model.count(), 1);
     }
+
+    void titleAndDurationRoles()
+    {
+        const QString ffmpeg = QStandardPaths::findExecutable(u"ffmpeg"_s);
+        if (ffmpeg.isEmpty()) {
+            QSKIP("ffmpeg is needed to make a sample file");
+        }
+        QTemporaryDir dir;
+        const QString path = dir.filePath(u"Show.S01E02.The.Tone.1080p.WEB.mka"_s);
+        QProcess process;
+        process.start(ffmpeg, {u"-v"_s, u"error"_s, u"-f"_s, u"lavfi"_s, u"-i"_s, u"sine=duration=2"_s, path});
+        QVERIFY(process.waitForFinished());
+        QCOMPARE(process.exitCode(), 0);
+
+        PlaylistModel model;
+        QSignalSpy changed(&model, &QAbstractItemModel::dataChanged);
+        model.append({QUrl::fromLocalFile(path), QUrl(u"https://example.com/a"_s)});
+        QCOMPARE(model.data(model.index(0), PlaylistModel::TitleRole).toString(), u"S01E02 · The Tone"_s);
+        QCOMPARE(model.data(model.index(1), PlaylistModel::TitleRole).toString(), u"https://example.com/a"_s);
+        QCOMPARE(model.data(model.index(1), PlaylistModel::DurationRole).toDouble(), -1.0);
+
+        QTRY_COMPARE(changed.count(), 1);
+        QCOMPARE(changed.first().at(2).value<QList<int>>(), QList<int>{PlaylistModel::DurationRole});
+        QVERIFY(qAbs(model.data(model.index(0), PlaylistModel::DurationRole).toDouble() - 2) < 0.1);
+    }
 };
 
 QTEST_GUILESS_MAIN(PlaylistModelTest)

autotests/trackselectiontest.cpp

@@ -67,6 +67,19 @@ private Q_SLOTS:
         QCOMPARE(TrackSelection::pickSubtitle(tracks, {u"de"_s}, {u"en"_s}, 1, true), 1);
     }
 
+    // A saved translation is turned on when the file opens, over mpv's choice and the
+    // fallback, but not over a subtitle in a preferred language.
+    void picksSavedTranslation()
+    {
+        const QList<Track> tracks{sub(1, u"rus"_s), sub(2, u"rus"_s, u"subrip"_s, false, true), sub(3, u"eng"_s), sub(4, u"vi"_s)};
+        QCOMPARE(TrackSelection::pickSubtitle(tracks, {}, {u"en"_s}, 0, true, 4), 4);
+        QCOMPARE(TrackSelection::pickSubtitle(tracks, {}, {u"en"_s}, 2, true, 4), 4);
+        QCOMPARE(TrackSelection::pickSubtitle(tracks, {u"en"_s}, {u"en"_s}, 0, true, 4), 3);
+        // Automatic subtitles turned off: keep mpv's choice.
+        QCOMPARE(TrackSelection::pickSubtitle(tracks, {}, {u"en"_s}, 0, false, 4), 0);
+        QCOMPARE(TrackSelection::pickSubtitle(tracks, {}, {u"en"_s}, 0, true, 0), 3);
+    }
+
     void picksAudioByPreference()
     {
         const QList<Track> tracks{sub(1, u"en"_s, u"aac"_s), sub(2, u"jpn"_s, u"aac"_s)};

autotests/translationstoretest.cpp

@@ -0,0 +1,209 @@
+#include "translationstore.h"
+
+#include <QFile>
+#include <QTemporaryDir>
+#include <QTest>
+
+using namespace Qt::Literals::StringLiterals;
+
+namespace
+{
+void writeText(const QString &path, const QByteArray &data)
+{
+    QFile file(path);
+    QVERIFY(file.open(QIODevice::WriteOnly));
+    file.write(data);
+}
+
+QByteArray readText(const QString &path)
+{
+    QFile file(path);
+    return file.open(QIODevice::ReadOnly) ? file.readAll() : QByteArray();
+}
+}
+
+class TranslationStoreTest : public QObject
+{
+    Q_OBJECT
+
+private:
+    QTemporaryDir m_dir;
+    QString m_videos;
+    QString m_cache;
+    QString m_video;
+    QUrl m_videoUrl;
+
+    // The translation as TranslationService leaves it in the cache before publishing.
+    QString cached(const QString &key, const QByteArray &data)
+    {
+        const QString path = TranslationStore::cachePath(m_cache, m_videoUrl, key, u"vi"_s);
+        writeText(path, data);
+        return path;
+    }
+
+private Q_SLOTS:
+    void init()
+    {
+        QVERIFY(m_dir.isValid());
+        QDir root(m_dir.path());
+        root.removeRecursively();
+        QVERIFY(root.mkpath(u"videos"_s));
+        QVERIFY(root.mkpath(u"cache"_s));
+        m_videos = m_dir.filePath(u"videos"_s);
+        m_cache = m_dir.filePath(u"cache"_s);
+        m_video = m_videos + u"/Show.S01E01.mkv"_s;
+        writeText(m_video, "video");
+        m_videoUrl = QUrl::fromLocalFile(m_video);
+    }
+
+    void namesFiles()
+    {
+        QCOMPARE(TranslationStore::languageSuffix(u"Vietnamese"_s), u"vi"_s);
+        QCOMPARE(TranslationStore::languageSuffix(u"vietnamese"_s), u"vi"_s);
+        QCOMPARE(TranslationStore::languageSuffix(u"Klingon!"_s), u"klingon"_s);
+        QCOMPARE(TranslationStore::sidecarPaths(u"/films/Show.S01E01.mkv"_s, u"vi"_s),
+                 QStringList({u"/films/Show.S01E01.vi.srt"_s, u"/films/Show.S01E01.qtpotato.vi.srt"_s}));
+        QCOMPARE(TranslationStore::cachePath(u"/cache"_s, QUrl::fromLocalFile(u"/films/Show.S01E01.mkv"_s), u"abc"_s, u"vi"_s),
+                 u"/cache/Show.S01E01.abc.vi.srt"_s);
+        QCOMPARE(TranslationStore::cachePath(u"/cache"_s, QUrl(u"https://example.com/live.m3u8"_s), u"abc"_s, u"vi"_s),
+                 u"/cache/subtitles.abc.vi.srt"_s);
+        QCOMPARE(TranslationStore::videoKey(QUrl(u"https://example.com/live.m3u8"_s)), u"https://example.com/live.m3u8"_s);
+    }
+
+    void writesNextToVideo()
+    {
+        TranslationStore::Registry registry;
+        const QString cache = cached(u"k1"_s, "one");
+        const auto result = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cache);
+
+        const QString sidecar = m_videos + u"/Show.S01E01.vi.srt"_s;
+        QCOMPARE(result.path, sidecar);
+        QVERIFY(result.nextToVideo);
+        QCOMPARE(readText(sidecar), "one");
+        QVERIFY(TranslationStore::isOwned(registry, sidecar));
+        QCOMPARE(TranslationStore::savedTranslation(registry, m_videoUrl, u"vi"_s), sidecar);
+        QCOMPARE(TranslationStore::savedTranslation(registry, m_videoUrl, u"ja"_s), QString());
+        QCOMPARE(registry.find(TranslationStore::videoKey(m_videoUrl), u"vi"_s)->configKey, u"k1"_s);
+    }
+
+    // Different settings give a new translation, which replaces QtPotato's own file.
+    void replacesOwnFileWithNewSettings()
+    {
+        TranslationStore::Registry registry;
+        TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cached(u"k1"_s, "one"));
+        const auto result = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k2"_s, "two", cached(u"k2"_s, "two"));
+
+        QCOMPARE(result.path, m_videos + u"/Show.S01E01.vi.srt"_s);
+        QCOMPARE(readText(result.path), "two");
+        QCOMPARE(registry.records.size(), 1);
+        QCOMPARE(registry.records.constFirst().configKey, u"k2"_s);
+        QVERIFY(!QFile::exists(m_videos + u"/Show.S01E01.qtpotato.vi.srt"_s));
+    }
+
+    void keepsUserSubtitle()
+    {
+        const QString userFile = m_videos + u"/Show.S01E01.vi.srt"_s;
+        writeText(userFile, "mine");
+        TranslationStore::Registry registry;
+        QVERIFY(!TranslationStore::isOwned(registry, userFile));
+
+        const auto result = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cached(u"k1"_s, "one"));
+        QCOMPARE(result.path, m_videos + u"/Show.S01E01.qtpotato.vi.srt"_s);
+        QCOMPARE(readText(userFile), "mine");
+        QCOMPARE(readText(result.path), "one");
+    }
+
+    // A file QtPotato wrote and the user then edited counts as the user's.
+    void keepsEditedTranslation()
+    {
+        TranslationStore::Registry registry;
+        const auto first = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cached(u"k1"_s, "one"));
+        writeText(first.path, "one, fixed by hand");
+        QVERIFY(!TranslationStore::isOwned(registry, first.path));
+
+        const auto second = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k2"_s, "two", cached(u"k2"_s, "two"));
+        QCOMPARE(second.path, m_videos + u"/Show.S01E01.qtpotato.vi.srt"_s);
+        QCOMPARE(readText(first.path), "one, fixed by hand");
+    }
+
+    // Once on ".qtpotato.vi.srt", stay there instead of leaving a second copy behind.
+    void staysOnPreviousFile()
+    {
+        const QString userFile = m_videos + u"/Show.S01E01.vi.srt"_s;
+        writeText(userFile, "mine");
+        TranslationStore::Registry registry;
+        const auto first = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cached(u"k1"_s, "one"));
+        QFile::remove(userFile);
+
+        const auto second = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k2"_s, "two", cached(u"k2"_s, "two"));
+        QCOMPARE(second.path, first.path);
+        QCOMPARE(readText(second.path), "two");
+        QVERIFY(!QFile::exists(userFile));
+    }
+
+    void fallsBackToCacheWhenFolderIsReadOnly()
+    {
+        QFile::setPermissions(m_videos, QFileDevice::ReadOwner | QFileDevice::ExeOwner);
+        auto restore = qScopeGuard([this] {
+            QFile::setPermissions(m_videos, QFileDevice::ReadOwner | QFileDevice::WriteOwner | QFileDevice::ExeOwner);
+        });
+        if (QFileInfo(m_videos).isWritable()) {
+            QSKIP("Permissions are not enforced here (running as root?)");
+        }
+
+        TranslationStore::Registry registry;
+        const QString cache = cached(u"k1"_s, "one");
+        const auto result = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cache);
+        QCOMPARE(result.path, cache);
+        QVERIFY(!result.nextToVideo);
+        QCOMPARE(TranslationStore::savedTranslation(registry, m_videoUrl, u"vi"_s), cache);
+    }
+
+    void fallsBackToCacheForStreams()
+    {
+        const QUrl stream(u"https://example.com/live.m3u8"_s);
+        const QString cache = TranslationStore::cachePath(m_cache, stream, u"k1"_s, u"vi"_s);
+        writeText(cache, "one");
+        TranslationStore::Registry registry;
+        const auto result = TranslationStore::publish(registry, stream, u"vi"_s, u"k1"_s, "one", cache);
+        QCOMPARE(result.path, cache);
+        QCOMPARE(TranslationStore::savedTranslation(registry, stream, u"vi"_s), cache);
+    }
+
+    void glossaryRewriteKeepsOwnership()
+    {
+        TranslationStore::Registry registry;
+        const auto result = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cached(u"k1"_s, "one"));
+        writeText(result.path, "one, new glossary");
+        TranslationStore::recordRewrite(registry, result.path, "one, new glossary");
+        QVERIFY(TranslationStore::isOwned(registry, result.path));
+    }
+
+    void savesAndLoadsRegistry()
+    {
+        const QString file = m_dir.filePath(u"data/translations.json"_s);
+        TranslationStore::Registry registry;
+        const auto result = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cached(u"k1"_s, "one"));
+        // A record whose file is gone is not worth keeping.
+        registry.put({u"/gone.mkv"_s, u"vi"_s, u"/gone.vi.srt"_s, u"k0"_s, u"00"_s});
+        QVERIFY(TranslationStore::save(file, registry));
+
+        const TranslationStore::Registry loaded = TranslationStore::load(file);
+        QCOMPARE(loaded.records.size(), 1);
+        QVERIFY(TranslationStore::isOwned(loaded, result.path));
+        QCOMPARE(TranslationStore::savedTranslation(loaded, m_videoUrl, u"vi"_s), result.path);
+        QVERIFY(TranslationStore::load(m_dir.filePath(u"missing.json"_s)).records.isEmpty());
+    }
+
+    // The registry is no longer right about a file that disappeared.
+    void forgetsDeletedTranslation()
+    {
+        TranslationStore::Registry registry;
+        const auto result = TranslationStore::publish(registry, m_videoUrl, u"vi"_s, u"k1"_s, "one", cached(u"k1"_s, "one"));
+        QFile::remove(result.path);
+        QCOMPARE(TranslationStore::savedTranslation(registry, m_videoUrl, u"vi"_s), QString());
+    }
+};
+
+QTEST_GUILESS_MAIN(TranslationStoreTest)
+#include "translationstoretest.moc"

src/CMakeLists.txt

@@ -1,6 +1,8 @@
-# Code without UI (subtitles, mpv.conf handling), kept apart from the app so autotests
-# can link it.
+# Code without UI (subtitles, mpv.conf handling, where translations are saved), kept
+# apart from the app so autotests can link it.
 add_library(qtpotato_core STATIC
+    media/mediainfo.cpp
+    media/mediainfo.h
     mpv/mpvuserconfig.cpp
     mpv/mpvuserconfig.h
     mpv/trackselection.cpp
@@ -9,8 +11,10 @@ add_library(qtpotato_core STATIC
     subtitles/subtitleparser.h
     subtitles/subtitleextractor.cpp
     subtitles/subtitleextractor.h
+    translate/translationstore.cpp
+    translate/translationstore.h
 )
-target_include_directories(qtpotato_core PUBLIC mpv subtitles)
+target_include_directories(qtpotato_core PUBLIC media mpv subtitles translate)
 target_link_libraries(qtpotato_core PUBLIC
     Qt6::Core
     KF6::I18n

src/media/mediainfo.cpp

@@ -0,0 +1,129 @@
+// SPDX-FileCopyrightText: 2026 Tri Vo Khac
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "mediainfo.h"
+
+#include <QRegularExpression>
+#include <QSet>
+#include <QStringList>
+
+#include <algorithm>
+
+extern "C" {
+#include <libavformat/avformat.h>
+}
+
+using namespace Qt::Literals::StringLiterals;
+
+namespace
+{
+// Words that start the release details in scene-style names; everything after them is dropped.
+bool isReleaseTag(const QString &word)
+{
+    static const QSet<QString> tags{
+        u"web"_s,    u"web-dl"_s, u"webdl"_s,  u"webrip"_s, u"bluray"_s, u"blu-ray"_s, u"bdrip"_s,  u"brrip"_s,  u"hdtv"_s,
+        u"dvdrip"_s, u"hdrip"_s,  u"remux"_s,  u"uhd"_s,    u"dsnp"_s,   u"amzn"_s,    u"nf"_s,     u"hmax"_s,   u"atvp"_s,
+        u"hulu"_s,   u"pcok"_s,   u"dv"_s,     u"hdr"_s,    u"hdr10"_s,  u"hdr10+"_s,  u"sdr"_s,    u"x264"_s,   u"x265"_s,
+        u"h264"_s,   u"h265"_s,   u"hevc"_s,   u"avc"_s,    u"aac"_s,    u"ac3"_s,     u"dts"_s,    u"ddp"_s,    u"10bit"_s,
+        u"8bit"_s,   u"repack"_s, u"proper"_s, u"internal"_s, u"imax"_s, u"multi"_s,
+    };
+    static const QRegularExpression pattern(uR"(^(\d{3,4}[pi]|[248]k|ddp?\d.*|h\d{3}|aac\d.*|dts-.*)$)"_s, QRegularExpression::CaseInsensitiveOption);
+    const QString lower = word.toLower();
+    return tags.contains(lower) || pattern.match(lower).hasMatch();
+}
+
+bool isYear(const QString &word)
+{
+    static const QRegularExpression pattern(uR"(^\(?(19|20)\d\d\)?$)"_s);
+    return pattern.match(word).hasMatch();
+}
+
+// The words before the first release tag, joined by spaces.
+QString untilReleaseTags(const QString &text)
+{
+    QStringList kept;
+    const QStringList words = text.split(u' ', Qt::SkipEmptyParts);
+    for (const QString &word : words) {
+        if (isReleaseTag(word)) {
+            break;
+        }
+        kept.append(word);
+    }
+    // "Movie 2024" reads better as "Movie (2024)".
+    if (kept.size() > 1 && isYear(kept.last())) {
+        QString year = kept.takeLast();
+        year.remove(u'(').remove(u')');
+        kept.append(u"(%1)"_s.arg(year));
+    }
+    QString result = kept.join(u' ');
+    // Leftover separators like "Show -" when the tags followed a dash.
+    static const QRegularExpression trailing(uR"([\s\-–—:·]+$)"_s);
+    static const QRegularExpression leading(uR"(^[\s\-–—:·]+)"_s);
+    return result.remove(trailing).remove(leading);
+}
+}
+
+namespace MediaInfo
+{
+QString cleanTitle(const QString &fileName)
+{
+    QString base = fileName;
+    static const QRegularExpression extension(uR"(\.[A-Za-z0-9]{2,4}$)"_s);
+    base.remove(extension);
+    const QString fallback = base;
+
+    // "[Group] Name [1080p] (ABCD1234)": bracketed parts are release details.
+    static const QRegularExpression brackets(uR"(\[[^\]]*\]|\{[^}]*\})"_s);
+    base.remove(brackets);
+    // Parentheses too, when they hold release tags or a checksum, but not "(2024)".
+    static const QRegularExpression parens(uR"(\(([^)]*)\))"_s);
+    static const QRegularExpression wordSeparator(uR"([\s,]+)"_s);
+    static const QRegularExpression checksum(uR"(^[0-9A-Fa-f]{8}$)"_s);
+    for (auto it = parens.globalMatch(QString(base)); it.hasNext();) {
+        const auto match = it.next();
+        const QStringList words = match.captured(1).split(wordSeparator, Qt::SkipEmptyParts);
+        if (std::any_of(words.begin(), words.end(), isReleaseTag) || checksum.match(match.captured(1)).hasMatch()) {
+            base.replace(match.captured(0), u" "_s);
+        }
+    }
+
+    // Scene names use dots or underscores between words.
+    base.replace(u'_', u' ');
+    if (!base.trimmed().contains(u' ')) {
+        base.replace(u'.', u' ');
+    }
+    base = base.simplified();
+
+    static const QRegularExpression episode(uR"(\b[Ss](\d{1,2})[ ._-]?[Ee](\d{1,3})(?:-?[Ee]\d{1,3})*\b)"_s);
+    if (const auto match = episode.match(base); match.hasMatch()) {
+        const QString code = match.captured(0).toUpper().remove(u' ').remove(u'.').remove(u'_');
+        const QString episodeTitle = untilReleaseTags(base.mid(match.capturedEnd()));
+        if (!episodeTitle.isEmpty()) {
+            return u"%1 · %2"_s.arg(code, episodeTitle);
+        }
+        const QString show = untilReleaseTags(base.left(match.capturedStart()));
+        return show.isEmpty() ? code : u"%1 · %2"_s.arg(show, code);
+    }
+
+    const QString title = untilReleaseTags(base);
+    return title.isEmpty() ? fallback : title;
+}
+
+std::optional<double> probeDuration(const QString &path)
+{
+    AVFormatContext *context = nullptr;
+    if (avformat_open_input(&context, path.toUtf8().constData(), nullptr, nullptr) < 0) {
+        return std::nullopt;
+    }
+    // Most containers store the length in their header; others need a look at the streams.
+    if (context->duration == AV_NOPTS_VALUE || context->duration <= 0) {
+        avformat_find_stream_info(context, nullptr);
+    }
+    std::optional<double> seconds;
+    if (context->duration != AV_NOPTS_VALUE && context->duration > 0) {
+        seconds = double(context->duration) / AV_TIME_BASE;
+    }
+    avformat_close_input(&context);
+    return seconds;
+}
+}

src/media/mediainfo.h

@@ -0,0 +1,19 @@
+// SPDX-FileCopyrightText: 2026 Tri Vo Khac
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <QString>
+
+#include <optional>
+
+namespace MediaInfo
+{
+// A short title for a media file name, without the release tags: "Show.S01E01.Pilot.1080p.WEB.mkv"
+// becomes "S01E01 · Pilot" and "Movie.2024.2160p.BluRay.mkv" becomes "Movie (2024)". Returns the
+// name without its extension when nothing better is found.
+QString cleanTitle(const QString &fileName);
+
+// Length of the media file at \a path in seconds, or nothing when it can't be read.
+std::optional<double> probeDuration(const QString &path);
+}

src/mpv/mpvitem.cpp

@@ -7,6 +7,7 @@
 
 #include <QDir>
 #include <QFile>
+#include <QFileInfo>
 #include <QLocale>
 #include <QSaveFile>
 #include <QStandardPaths>
@@ -44,6 +45,38 @@ QList<TrackSelection::Track> selectionTracks(const QVariantList &tracks)
     return result;
 }
 
+QString subtitlePath(const QVariantList &tracks, int id)
+{
+    for (const QVariant &entry : tracks) {
+        const QVariantMap track = entry.toMap();
+        if (track.value(QStringLiteral("id")).toInt() == id) {
+            return track.value(QStringLiteral("externalFilename")).toString();
+        }
+    }
+    return {};
+}
+
+int subtitleIdForPath(const QVariantList &tracks, const QString &path)
+{
+    if (path.isEmpty()) {
+        return 0;
+    }
+    for (const QVariant &entry : tracks) {
+        const QVariantMap track = entry.toMap();
+        if (track.value(QStringLiteral("externalFilename")).toString() == path) {
+            return track.value(QStringLiteral("id")).toInt();
+        }
+    }
+    return 0;
+}
+
+// "movie.abc123.vi.srt" -> "vi", the way mpv tags subtitles it finds next to a video.
+QString filenameLanguage(const QString &path)
+{
+    const QStringList parts = QFileInfo(path).completeBaseName().split(QLatin1Char('.'));
+    return parts.size() > 1 ? parts.constLast() : QString();
+}
+
 QString trackLanguage(const QVariantList &tracks, int id)
 {
     for (const QVariant &entry : tracks) {
@@ -112,7 +145,7 @@ MpvItem::MpvItem(QQuickItem *parent)
         // Before the first file, so its options apply from the start.
         applyUserConfig();
         if (m_pendingUrl.isValid()) {
-            loadFile(std::exchange(m_pendingUrl, {}));
+            loadFile(std::exchange(m_pendingUrl, {}), QString(m_openingTranslatedPath), QString(m_openingTranslatedTitle));
         }
     });
 }
@@ -156,12 +189,18 @@ bool MpvItem::isFileLoaded() const
     return m_fileLoaded;
 }
 
-void MpvItem::loadFile(const QUrl &url)
+void MpvItem::loadFile(const QUrl &url, const QString &translatedSubtitle, const QString &translatedTitle)
 {
     if (!url.isValid()) {
         return;
     }
 
+    m_translatedPaths.clear();
+    m_openingTranslatedPath = translatedSubtitle;
+    m_openingTranslatedTitle = translatedTitle;
+    if (!translatedSubtitle.isEmpty()) {
+        m_translatedPaths.append(translatedSubtitle);
+    }
     m_currentUrl = url;
     Q_EMIT currentUrlChanged();
 
@@ -355,6 +394,9 @@ void MpvItem::showTranslatedSubtitleFile(const QUrl &url, const QString &title)
         return;
     }
     const QString path = localPathOrUrl(url);
+    if (!m_translatedPaths.contains(path)) {
+        m_translatedPaths.append(path);
+    }
     for (const QVariant &entry : std::as_const(m_subtitleTracks)) {
         const QVariantMap track = entry.toMap();
         if (track.value(QStringLiteral("externalFilename")).toString() == path) {
@@ -370,11 +412,22 @@ void MpvItem::showTranslatedSubtitleFile(const QUrl &url, const QString &title)
 
 int MpvItem::translationSourceId() const
 {
+    QVariantList sources;
+    for (const QVariant &entry : std::as_const(m_subtitleTracks)) {
+        if (!isTranslatedSubtitle(entry.toMap().value(QStringLiteral("id")).toInt())) {
+            sources.append(entry);
+        }
+    }
     // English first: it is the usual original, and dubbed releases often default to
     // subtitles translated from it.
-    return TrackSelection::pickTranslationSource(selectionTracks(m_subtitleTracks),
+    return TrackSelection::pickTranslationSource(selectionTracks(sources),
                                                  {QStringLiteral("en"), trackLanguage(m_audioTracks, m_audioId)},
-                                                 m_subtitleId);
+                                                 isTranslatedSubtitle(m_subtitleId) ? 0 : m_subtitleId);
+}
+
+bool MpvItem::isTranslatedSubtitle(int id) const
+{
+    return id > 0 && m_translatedPaths.contains(subtitlePath(m_subtitleTracks, id));
 }
 
 void MpvItem::selectInitialTracks()
@@ -382,6 +435,16 @@ void MpvItem::selectInitialTracks()
     // The observed track-list may still describe the previous file; read it directly.
     updateTracks(getProperty(QStringLiteral("track-list")).toList());
 
+    // mpv finds a translation next to the video by itself (sub-auto); one kept in the
+    // cache is added here, before choosing, so it can be chosen.
+    const QString translated = std::exchange(m_openingTranslatedPath, {});
+    int translationId = subtitleIdForPath(m_subtitleTracks, translated);
+    if (!translated.isEmpty() && translationId == 0 && QFileInfo::exists(translated)) {
+        commandBlocking(QStringList{QStringLiteral("sub-add"), translated, QStringLiteral("auto"), m_openingTranslatedTitle, filenameLanguage(translated)});
+        updateTracks(getProperty(QStringLiteral("track-list")).toList());
+        translationId = subtitleIdForPath(m_subtitleTracks, translated);
+    }
+
     const int audioId = TrackSelection::pickAudio(selectionTracks(m_audioTracks), m_preferredAudioLanguages, m_audioId);
     if (audioId != m_audioId) {
         setAudioId(audioId);
@@ -393,7 +456,8 @@ void MpvItem::selectInitialTracks()
                                                         m_preferredSubtitleLanguages,
                                                         fallbackLanguages,
                                                         m_subtitleId,
-                                                        m_autoSelectSubtitle);
+                                                        m_autoSelectSubtitle,
+                                                        translationId);
     if (subtitleId != m_subtitleId) {
         setSubtitleId(subtitleId);
     }

src/mpv/mpvitem.h

@@ -98,7 +98,9 @@ public:
     QStringList loadedUserConfigFiles() const;
     QStringList skippedUserOptions() const;
 
-    Q_INVOKABLE void loadFile(const QUrl &url);
+    // \a translatedSubtitle is the file's saved translation (TranslationService). It is
+    // loaded with the file, named \a translatedTitle, and turned on (see TrackSelection).
+    Q_INVOKABLE void loadFile(const QUrl &url, const QString &translatedSubtitle = {}, const QString &translatedTitle = {});
     // Unloads the current file.
     Q_INVOKABLE void stop();
     Q_INVOKABLE void togglePause();
@@ -114,8 +116,10 @@ public:
     // already loaded.
     Q_INVOKABLE void showTranslatedSubtitleFile(const QUrl &url, const QString &title);
     // Id of the subtitle to translate: the shown one if it is text, else the best text
-    // subtitle. 0 when the file has no text subtitle.
+    // subtitle. Translations are skipped. 0 when the file has no text subtitle.
     Q_INVOKABLE int translationSourceId() const;
+    // True for a subtitle QtPotato translated, as opposed to one to translate from.
+    Q_INVOKABLE bool isTranslatedSubtitle(int id) const;
 
 Q_SIGNALS:
     void currentUrlChanged();
@@ -174,6 +178,11 @@ private:
     int m_chapter = -1;
     // File added by showTranslatedSubtitleFile() that should be shown once mpv lists it.
     QString m_pendingTranslatedPath;
+    // Translated subtitle files of the current file.
+    QStringList m_translatedPaths;
+    // Saved translation to load and turn on when the file opens, and its track title.
+    QString m_openingTranslatedPath;
+    QString m_openingTranslatedTitle;
     bool m_loadUserConfig = false;
     QStringList m_loadedUserConfigFiles;
     QStringList m_skippedUserOptions;

src/mpv/trackselection.cpp

@@ -98,7 +98,12 @@ int pickAudio(const QList<Track> &tracks, const QStringList &preferredLanguages,
     return currentId;
 }
 
-int pickSubtitle(const QList<Track> &tracks, const QStringList &preferredLanguages, const QStringList &fallbackLanguages, int currentId, bool fallback)
+int pickSubtitle(const QList<Track> &tracks,
+                 const QStringList &preferredLanguages,
+                 const QStringList &fallbackLanguages,
+                 int currentId,
+                 bool fallback,
+                 int translationId)
 {
     for (const QString &language : preferredLanguages) {
         if (const int id = firstFull(tracks, [&](const Track &track) {
@@ -107,6 +112,9 @@ int pickSubtitle(const QList<Track> &tracks, const QStringList &preferredLanguag
             return id;
         }
     }
+    if (fallback && translationId > 0) {
+        return translationId;
+    }
     if (currentId > 0 || !fallback) {
         return currentId;
     }

src/mpv/trackselection.h

@@ -28,11 +28,18 @@ bool sameLanguage(const QString &a, const QString &b);
 int pickAudio(const QList<Track> &tracks, const QStringList &preferredLanguages, int currentId);
 
 // The subtitle to turn on when the file opens. A track in one of \a preferredLanguages
-// wins over mpv's own choice \a currentId; without one, \a currentId is kept. When mpv
-// chose nothing and \a fallback is set, picks a full (not forced) subtitle in the first
-// of \a fallbackLanguages that has one, then one flagged default, then the first one.
-// Text subtitles win over bitmap ones in the same step. Returns 0 for no subtitle.
-int pickSubtitle(const QList<Track> &tracks, const QStringList &preferredLanguages, const QStringList &fallbackLanguages, int currentId, bool fallback);
+// wins over mpv's own choice \a currentId. Next comes \a translationId, the file's
+// saved translation, when \a fallback is set; without either, \a currentId is kept.
+// When mpv chose nothing and \a fallback is set, picks a full (not forced) subtitle in
+// the first of \a fallbackLanguages that has one, then one flagged default, then the
+// first one. Text subtitles win over bitmap ones in the same step. Returns 0 for no
+// subtitle.
+int pickSubtitle(const QList<Track> &tracks,
+                 const QStringList &preferredLanguages,
+                 const QStringList &fallbackLanguages,
+                 int currentId,
+                 bool fallback,
+                 int translationId = 0);
 
 // The subtitle to translate: \a currentId when it is a text subtitle, else a full text
 // subtitle in the first of \a sourceLanguages that has one, then one flagged default,

src/playlist/playlistmodel.cpp

@@ -3,10 +3,13 @@
 
 #include "playlistmodel.h"
 
+#include "mediainfo.h"
+
 #include <QCollator>
 #include <QDir>
 #include <QFileInfo>
 #include <QMimeDatabase>
+#include <QtConcurrentRun>
 
 #include <algorithm>
 
@@ -15,6 +18,13 @@ using namespace Qt::Literals::StringLiterals;
 PlaylistModel::PlaylistModel(QObject *parent)
     : QAbstractListModel(parent)
 {
+    // Reading many files at once from one disk is slower than a few at a time.
+    m_probePool.setMaxThreadCount(2);
+}
+
+PlaylistModel::~PlaylistModel()
+{
+    m_probePool.clear();
 }
 
 int PlaylistModel::rowCount(const QModelIndex &parent) const
@@ -36,6 +46,10 @@ QVariant PlaylistModel::data(const QModelIndex &index, int role) const
         return url.isLocalFile() ? url.fileName() : url.toDisplayString();
     case IsPlayingRole:
         return index.row() == m_playingIndex;
+    case TitleRole:
+        return url.isLocalFile() ? MediaInfo::cleanTitle(url.fileName()) : url.toDisplayString();
+    case DurationRole:
+        return m_durations.value(url, -1);
     }
     return {};
 }
@@ -46,6 +60,8 @@ QHash<int, QByteArray> PlaylistModel::roleNames() const
         {UrlRole, "url"},
         {NameRole, "name"},
         {IsPlayingRole, "isPlaying"},
+        {TitleRole, "title"},
+        {DurationRole, "duration"},
     };
 }
 
@@ -127,6 +143,7 @@ void PlaylistModel::openFile(const QUrl &url, bool loadSiblings)
     m_playingIndex = -1;
     endResetModel();
     Q_EMIT countChanged();
+    probeDurations(m_urls);
     play(std::max<int>(0, int(m_urls.indexOf(url))));
 }
 
@@ -140,6 +157,7 @@ void PlaylistModel::append(const QList<QUrl> &urls)
     m_urls.append(added);
     endInsertRows();
     Q_EMIT countChanged();
+    probeDurations(added);
 }
 
 void PlaylistModel::replace(const QList<QUrl> &urls)
@@ -153,6 +171,7 @@ void PlaylistModel::replace(const QList<QUrl> &urls)
     m_playingIndex = -1;
     endResetModel();
     Q_EMIT countChanged();
+    probeDurations(m_urls);
     play(0);
 }
 
@@ -274,3 +293,25 @@ void PlaylistModel::setPlayingIndex(int index)
     }
     Q_EMIT playingIndexChanged();
 }
+
+void PlaylistModel::probeDurations(const QList<QUrl> &urls)
+{
+    for (const QUrl &url : urls) {
+        // Streams are skipped: opening them can take long and costs bandwidth.
+        if (!url.isLocalFile() || m_durations.contains(url)) {
+            continue;
+        }
+        m_durations.insert(url, -1);
+        QtConcurrent::run(&m_probePool, MediaInfo::probeDuration, url.toLocalFile()).then(this, [this, url](std::optional<double> seconds) {
+            if (!seconds) {
+                return;
+            }
+            m_durations.insert(url, *seconds);
+            for (int row = 0; row < m_urls.size(); ++row) {
+                if (m_urls.at(row) == url) {
+                    Q_EMIT dataChanged(index(row), index(row), {DurationRole});
+                }
+            }
+        });
+    }
+}

src/playlist/playlistmodel.h

@@ -4,7 +4,9 @@
 #pragma once
 
 #include <QAbstractListModel>
+#include <QHash>
 #include <QList>
+#include <QThreadPool>
 #include <QUrl>
 #include <QtQml/qqmlregistration.h>
 
@@ -24,10 +26,15 @@ public:
         UrlRole = Qt::UserRole + 1,
         NameRole,
         IsPlayingRole,
+        // Short name without release tags; see MediaInfo::cleanTitle().
+        TitleRole,
+        // Length in seconds, or -1 while unknown. Local files are read in the background.
+        DurationRole,
     };
     Q_ENUM(Roles)
 
     explicit PlaylistModel(QObject *parent = nullptr);
+    ~PlaylistModel() override;
 
     int rowCount(const QModelIndex &parent = {}) const override;
     QVariant data(const QModelIndex &index, int role) const override;
@@ -66,7 +73,12 @@ Q_SIGNALS:
 private:
     QList<QUrl> expand(const QList<QUrl> &urls) const;
     void setPlayingIndex(int index);
+    void probeDurations(const QList<QUrl> &urls);
 
     QList<QUrl> m_urls;
     int m_playingIndex = -1;
+    // Known lengths in seconds; -1 for files that couldn't be read or are still being read.
+    QHash<QUrl, double> m_durations;
+    // Declared last so it is destroyed first and waits for running probes.
+    QThreadPool m_probePool;
 };

src/qml/Main.qml

@@ -24,7 +24,6 @@ ApplicationWindow {
     // subtitle even while that translated track is selected in mpv.
     property var lastTranslationTrack: null
     property url lastTranslationVideo: ""
-    property var translatedSubtitleUrls: []
 
     function openFile(url: url) {
         playlistModel.openFile(url, QtPotatoSettings.playlistLoadSiblings)
@@ -46,10 +45,15 @@ ApplicationWindow {
         }
     }
 
+    function translatedTrackTitle(): string {
+        return KI18n.i18nc("@item:inlistbox subtitle track, %1 is a language", "%1 (translated)", QtPotatoSettings.targetLanguage)
+    }
+
     function translateCurrentSubtitle() {
         let track = video.subtitleTracks.find(track => track.id === video.subtitleId)
-        if (track && translatedSubtitleUrls.includes(track.externalFilename) && lastTranslationTrack) {
-            track = video.subtitleTracks.find(track => track.id === lastTranslationTrack.id)
+        // Translate the original again, not the translation on screen.
+        if (track && video.isTranslatedSubtitle(track.id)) {
+            track = lastTranslationTrack ? video.subtitleTracks.find(track => track.id === lastTranslationTrack.id) : null
         }
         // No subtitle shown, or a picture-based one: translate the best text subtitle.
         if (!track || track.bitmap) {
@@ -141,7 +145,8 @@ ApplicationWindow {
     PlaylistModel {
         id: playlistModel
         onPlayRequested: url => {
-            video.loadFile(url)
+            // A translation made earlier is loaded and turned on with the file.
+            video.loadFile(url, translationService.savedTranslation(url), appWindow.translatedTrackTitle())
             RecentFilesModel.add(url)
         }
     }
@@ -169,10 +174,7 @@ ApplicationWindow {
     TranslationService {
         id: translationService
         onTranslated: (subtitleUrl, fromCache) => {
-            // mpv exposes local external subtitle filenames as filesystem paths.
-            appWindow.translatedSubtitleUrls.push(decodeURIComponent(subtitleUrl.toString().replace(/^file:\/\//, "")))
-            video.showTranslatedSubtitleFile(subtitleUrl,
-                KI18n.i18nc("@item:inlistbox subtitle track, %1 is a language", "%1 (translated)", QtPotatoSettings.targetLanguage))
+            video.showTranslatedSubtitleFile(subtitleUrl, appWindow.translatedTrackTitle())
             osdItem.message(fromCache
                 ? KI18n.i18nc("@info:osd", "Loaded the saved translation")
                 : KI18n.i18nc("@info:osd", "Translation ready"))
@@ -187,7 +189,6 @@ ApplicationWindow {
             translationService.forgetTranslation()
             appWindow.lastTranslationTrack = null
             appWindow.lastTranslationVideo = ""
-            appWindow.translatedSubtitleUrls = []
             glossaryDialog.close()
         }
 

src/qml/PlaylistItem.qml

@@ -8,20 +8,23 @@ import QtQuick.Layouts
 import org.kde.ki18n
 import org.kde.kirigami as Kirigami
 
-// One row of the playlist: row number, playing icon and file name.
+// One compact row of the playlist: row number (or playing icon), short title, length and,
+// on hover or focus, a remove button.
 Item {
     id: root
 
     required property int index
     required property url url
     required property string name
+    required property string title
+    required property real duration
     required property bool isPlaying
     required property PlaylistModel playlist
     required property MpvItem mpv
     property real alpha: QtPotatoSettings.playlistOverlayVideo ? 0.6 : 1
 
     readonly property bool hovered: hoverHandler.hovered
-    readonly property real fontSize: Kirigami.Theme.defaultFont.pointSize
+    readonly property bool highlighted: root.isPlaying && !root.hovered
     activeFocusOnTab: true
 
     function activate() {
@@ -32,6 +35,18 @@ Item {
         contextMenu.popup()
     }
 
+    // "1:02:03" or "4:05".
+    function formatDuration(seconds: real): string {
+        if (seconds < 0) {
+            return ""
+        }
+        const total = Math.round(seconds)
+        const hours = Math.floor(total / 3600)
+        const minutes = Math.floor(total / 60) % 60
+        const secs = String(total % 60).padStart(2, "0")
+        return hours > 0 ? `${hours}:${String(minutes).padStart(2, "0")}:${secs}` : `${minutes}:${secs}`
+    }
+
     Keys.onReturnPressed: root.activate()
     Keys.onEnterPressed: root.activate()
     Keys.onMenuPressed: root.showContextMenu()
@@ -42,15 +57,8 @@ Item {
         }
     }
 
-    function labelColor(): color {
-        if (root.isPlaying && !root.hovered) {
-            return Kirigami.Theme.highlightedTextColor
-        }
-        return Kirigami.Theme.textColor
-    }
-
     implicitWidth: ListView.view.width
-    implicitHeight: fontSize * 3
+    implicitHeight: titleLabel.implicitHeight + Kirigami.Units.smallSpacing * 2
 
     HoverHandler {
         id: hoverHandler
@@ -71,7 +79,7 @@ Item {
         anchors.fill: parent
         Kirigami.Theme.colorSet: Kirigami.Theme.View
         color: {
-            if (root.isPlaying && !root.hovered) {
+            if (root.highlighted) {
                 return Qt.alpha(Kirigami.Theme.highlightColor, root.alpha)
             }
             if (root.hovered) {
@@ -85,67 +93,75 @@ Item {
 
         RowLayout {
             anchors.fill: parent
+            anchors.leftMargin: Kirigami.Units.largeSpacing
+            anchors.rightMargin: removeButton.visible ? Kirigami.Units.smallSpacing : Kirigami.Units.largeSpacing
             spacing: Kirigami.Units.largeSpacing
 
-            Label {
-                text: root.index + 1
-                color: root.labelColor()
-                visible: QtPotatoSettings.playlistShowRowNumber
-                font.pointSize: root.fontSize
-                font.features: { "tnum": 1 }
-                horizontalAlignment: Qt.AlignHCenter
-                Layout.leftMargin: Kirigami.Units.largeSpacing
-                Layout.preferredWidth: rowNumberMetrics.width
-            }
-
-            TextMetrics {
-                id: rowNumberMetrics
-                font.pointSize: root.fontSize
-                text: String(root.playlist.count).replace(/./g, "0")
-            }
-
-            Rectangle {
-                color: Qt.alpha(Kirigami.Theme.textColor, 0.2)
-                visible: QtPotatoSettings.playlistShowRowNumber
-                Layout.preferredWidth: 1
+            // Same width on every row, so the titles line up.
+            Item {
                 Layout.fillHeight: true
-                Layout.topMargin: Kirigami.Units.smallSpacing
-                Layout.bottomMargin: Kirigami.Units.smallSpacing
-            }
+                Layout.preferredWidth: Math.max(QtPotatoSettings.playlistShowRowNumber ? rowNumberMetrics.width : 0,
+                                                Kirigami.Units.iconSizes.small)
 
-            Kirigami.Icon {
-                source: "media-playback-start"
-                color: root.labelColor()
-                visible: root.isPlaying
-                Layout.leftMargin: QtPotatoSettings.playlistShowRowNumber ? 0 : Kirigami.Units.largeSpacing
-                Layout.preferredHeight: Kirigami.Units.iconSizes.smallMedium
-                Layout.preferredWidth: Kirigami.Units.iconSizes.smallMedium
+                Label {
+                    anchors.centerIn: parent
+                    text: root.index + 1
+                    visible: QtPotatoSettings.playlistShowRowNumber && !root.isPlaying
+                    color: Kirigami.Theme.disabledTextColor
+                    font: Kirigami.Theme.smallFont
+                }
+
+                Kirigami.Icon {
+                    anchors.centerIn: parent
+                    width: Kirigami.Units.iconSizes.small
+                    height: Kirigami.Units.iconSizes.small
+                    source: "media-playback-start"
+                    color: root.highlighted ? Kirigami.Theme.highlightedTextColor : Kirigami.Theme.textColor
+                    visible: root.isPlaying
+                }
+
+                TextMetrics {
+                    id: rowNumberMetrics
+                    font: Kirigami.Theme.smallFont
+                    text: String(root.playlist.count).replace(/./g, "0")
+                }
             }
 
             LabelWithTooltip {
-                text: root.name
-                toolTipText: root.url.toString().startsWith("file://") ? decodeURIComponent(root.url.toString().substring(7)) : root.url
-                color: root.labelColor()
+                id: titleLabel
+                text: root.title
+                toolTipText: root.name
+                alwaysShowToolTip: root.title !== root.name
+                color: root.highlighted ? Kirigami.Theme.highlightedTextColor : Kirigami.Theme.textColor
                 elide: Text.ElideRight
-                font.pointSize: root.fontSize
-                font.bold: root.isPlaying
+                maximumLineCount: 1
                 verticalAlignment: Qt.AlignVCenter
                 Layout.fillWidth: true
-                Layout.leftMargin: !QtPotatoSettings.playlistShowRowNumber && !root.isPlaying ? Kirigami.Units.largeSpacing : 0
-                Layout.rightMargin: Kirigami.Units.largeSpacing
             }
 
-            Button {
+            Label {
+                text: root.formatDuration(root.duration)
+                visible: text !== ""
+                color: root.highlighted ? Kirigami.Theme.highlightedTextColor : Kirigami.Theme.disabledTextColor
+                font: Kirigami.Theme.smallFont
+            }
+
+            ToolButton {
+                id: removeButton
                 text: KI18n.i18nc("@action:button remove playlist item", "Remove")
                 icon.name: "list-remove"
+                icon.width: Kirigami.Units.iconSizes.small
+                icon.height: Kirigami.Units.iconSizes.small
                 display: AbstractButton.IconOnly
-                flat: true
+                focusPolicy: Qt.TabFocus
+                visible: root.hovered || root.activeFocus || activeFocus
+                padding: 0
                 Accessible.name: text
                 ToolTip.text: text
                 ToolTip.visible: hovered
                 ToolTip.delay: Kirigami.Units.toolTipDelay
-                Layout.preferredWidth: Kirigami.Units.iconSizes.smallMedium + Kirigami.Units.smallSpacing * 2
-                Layout.rightMargin: Kirigami.Units.smallSpacing
+                Layout.fillHeight: true
+                Layout.preferredWidth: height
                 onClicked: root.playlist.remove(root.index)
             }
         }

src/translate/translationservice.cpp

@@ -3,6 +3,7 @@
 #include "apikeystore.h"
 #include "qtpotatosettings.h"
 #include "translationpresets.h"
+#include "translationstore.h"
 
 #include <KLocalizedString>
 
@@ -39,28 +40,9 @@ constexpr int ParallelRequests = 3;
 // Bump when the prompt changes so old cached translations are not reused.
 constexpr auto CacheVersion = "llm-v2";
 
-// "Vietnamese" -> "vi", so the file ends in ".vi.srt" like other players expect.
-QString languageSuffix(const QString &language)
+QString cacheDir()
 {
-    for (int i = QLocale::C + 1; i <= QLocale::LastLanguage; ++i) {
-        const auto candidate = static_cast<QLocale::Language>(i);
-        if (QLocale::languageToString(candidate).compare(language, Qt::CaseInsensitive) == 0) {
-            const QString code = QLocale::languageToCode(candidate, QLocale::ISO639Part1);
-            return code.isEmpty() ? QLocale::languageToCode(candidate) : code;
-        }
-    }
-    QString suffix = language.toLower();
-    suffix.removeIf([](QChar c) {
-        return !c.isLetterOrNumber() && c != u'-';
-    });
-    return suffix.isEmpty() ? u"translated"_s : suffix;
-}
-
-QString cachePath(const QUrl &videoUrl, const QString &key, const QString &language)
-{
-    const QString dir = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + u"/translations"_s;
-    const QString baseName = videoUrl.isLocalFile() ? QFileInfo(videoUrl.toLocalFile()).completeBaseName() : u"subtitles"_s;
-    return u"%1/%2.%3.%4.srt"_s.arg(dir, baseName, key, languageSuffix(language));
+    return QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + u"/translations"_s;
 }
 
 QList<GlossaryStore::Entry> glossaryEntriesFromVariants(const QVariantList &entries)
@@ -273,6 +255,12 @@ void TranslationService::applyGlossaryEdits(const GlossaryStore::Glossary &previ
     if (m_lastTranslationPath.isEmpty() || !QFileInfo::exists(m_lastTranslationPath)) {
         return;
     }
+    // A translation the user has edited since is theirs; leave it alone.
+    const QString registryFile = TranslationStore::registryFile();
+    TranslationStore::Registry registry = TranslationStore::load(registryFile);
+    if (!TranslationStore::isOwned(registry, m_lastTranslationPath)) {
+        return;
+    }
     QFile file(m_lastTranslationPath);
     if (!file.open(QIODevice::ReadOnly)) {
         return;
@@ -319,10 +307,14 @@ void TranslationService::applyGlossaryEdits(const GlossaryStore::Glossary &previ
         text.replace(markers.at(i), replacements.at(i).second);
     }
 
+    const QByteArray data = text.toUtf8();
     QSaveFile output(m_lastTranslationPath);
-    if (!output.open(QIODevice::WriteOnly) || output.write(text.toUtf8()) < 0 || !output.commit()) {
+    if (!output.open(QIODevice::WriteOnly) || output.write(data) < 0 || !output.commit()) {
         return;
     }
+    // Still QtPotato's file, so a later translation may replace it.
+    TranslationStore::recordRewrite(registry, m_lastTranslationPath, data);
+    TranslationStore::save(registryFile, registry);
     Q_EMIT translated(QUrl::fromLocalFile(m_lastTranslationPath), true);
 }
 
@@ -480,7 +472,8 @@ QCoro::Task<> TranslationService::run(QUrl videoUrl, QVariantMap track)
     const QString sourceSrt = Subtitles::toSrt(cues);
 
     // Same subtitles, model, language, prompt settings and glossary give the same file, so it is translated once.
-    const auto outputPathFor = [&](const GlossaryStore::Glossary &g) {
+    const QString suffix = TranslationStore::languageSuffix(config.targetLanguage);
+    const auto configKeyFor = [&](const GlossaryStore::Glossary &g) {
         QCryptographicHash hash(QCryptographicHash::Sha1);
         hash.addData(CacheVersion);
         hash.addData(config.model.toUtf8());
@@ -489,16 +482,13 @@ QCoro::Task<> TranslationService::run(QUrl videoUrl, QVariantMap track)
         hash.addData(config.customInstructions.toUtf8());
         hash.addData(GlossaryStore::serialize(g).toUtf8());
         hash.addData(sourceSrt.toUtf8());
-        return cachePath(videoUrl, QString::fromLatin1(hash.result().toHex().left(12)), config.targetLanguage);
+        return QString::fromLatin1(hash.result().toHex().left(12));
     };
-    QString outputPath = outputPathFor(glossary);
+    QString configKey = configKeyFor(glossary);
+    QString outputPath = TranslationStore::cachePath(cacheDir(), videoUrl, configKey, suffix);
 
     if (QFileInfo::exists(outputPath)) {
-        m_lastTranslationPath = outputPath;
-        m_job.reset();
-        setBusy(false);
-        setStatusText({});
-        Q_EMIT translated(QUrl::fromLocalFile(outputPath), true);
+        finish(job, videoUrl, suffix, configKey, outputPath, true);
         co_return;
     }
 
@@ -545,13 +535,10 @@ QCoro::Task<> TranslationService::run(QUrl videoUrl, QVariantMap track)
         } else {
             setStatusText(i18n("Glossary unavailable; translating without it."));
         }
-        outputPath = outputPathFor(glossary);
+        configKey = configKeyFor(glossary);
+        outputPath = TranslationStore::cachePath(cacheDir(), videoUrl, configKey, suffix);
         if (QFileInfo::exists(outputPath)) {
-            m_lastTranslationPath = outputPath;
-            m_job.reset();
-            setBusy(false);
-            setStatusText({});
-            Q_EMIT translated(QUrl::fromLocalFile(outputPath), true);
+            finish(job, videoUrl, suffix, configKey, outputPath, true);
             co_return;
         }
     }
@@ -610,11 +597,38 @@ QCoro::Task<> TranslationService::run(QUrl videoUrl, QVariantMap track)
         co_return;
     }
 
+    finish(job, videoUrl, suffix, configKey, outputPath, false);
+}
+
+void TranslationService::finish(const std::shared_ptr<Job> &job,
+                                const QUrl &videoUrl,
+                                const QString &suffix,
+                                const QString &configKey,
+                                const QString &cacheFile,
+                                bool fromCache)
+{
+    QFile file(cacheFile);
+    if (!file.open(QIODevice::ReadOnly)) {
+        fail(job, i18n("Could not read the translation from %1: %2", cacheFile, file.errorString()));
+        return;
+    }
+    // The cache keeps every version; the published copy is the one players load.
+    const QString registryFile = TranslationStore::registryFile();
+    TranslationStore::Registry registry = TranslationStore::load(registryFile);
+    const TranslationStore::PublishResult published = TranslationStore::publish(registry, videoUrl, suffix, configKey, file.readAll(), cacheFile);
+    TranslationStore::save(registryFile, registry);
+
     m_job.reset();
-    m_lastTranslationPath = outputPath;
+    m_lastTranslationPath = published.path;
     setBusy(false);
     setStatusText({});
-    Q_EMIT translated(QUrl::fromLocalFile(outputPath), false);
+    Q_EMIT translated(QUrl::fromLocalFile(published.path), fromCache);
+}
+
+QString TranslationService::savedTranslation(const QUrl &videoUrl) const
+{
+    const QString suffix = TranslationStore::languageSuffix(QtPotatoSettings::self()->targetLanguage().trimmed());
+    return TranslationStore::savedTranslation(TranslationStore::load(TranslationStore::registryFile()), videoUrl, suffix);
 }
 
 QCoro::Task<LlmClient::BatchResult> TranslationService::translateLines(std::shared_ptr<Job> job, QStringList lines, QStringList context)

src/translate/translationservice.h

@@ -18,8 +18,8 @@
 
 class QNetworkAccessManager;
 
-// Translates a whole subtitle track with an LLM, batch by batch, and caches the result
-// as an .srt file that mpv can load as a subtitle track.
+// Translates a whole subtitle track with an LLM, batch by batch, caches the result as an
+// .srt file and saves a copy next to the video (see TranslationStore).
 class TranslationService : public QObject
 {
     Q_OBJECT
@@ -62,6 +62,9 @@ public:
     Q_INVOKABLE void fetchModels();
     Q_INVOKABLE void clearError();
     Q_INVOKABLE void forgetTranslation();
+    // Path of the translation of \a videoUrl into the target language set in Settings,
+    // or an empty string when there is none.
+    Q_INVOKABLE QString savedTranslation(const QUrl &videoUrl) const;
     Q_INVOKABLE void loadGlossary(const QUrl &videoUrl);
     Q_INVOKABLE bool saveGlossary(const QVariantList &entries, const QStringList &episodes = {});
     Q_INVOKABLE void clearGlossary();
@@ -97,6 +100,8 @@ private:
     // something is missing.
     QCoro::Task<std::pair<LlmClient::Config, QString>> loadConfig();
     void fail(const std::shared_ptr<Job> &job, const QString &error);
+    // Saves the translation in \a cacheFile where players find it and announces it.
+    void finish(const std::shared_ptr<Job> &job, const QUrl &videoUrl, const QString &suffix, const QString &configKey, const QString &cacheFile, bool fromCache);
 
     void setBusy(bool busy);
     void setProgress(double progress);

src/translate/translationstore.cpp

@@ -0,0 +1,231 @@
+#include "translationstore.h"
+
+#include <QCryptographicHash>
+#include <QDir>
+#include <QFile>
+#include <QFileInfo>
+#include <QJsonArray>
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QLocale>
+#include <QSaveFile>
+#include <QStandardPaths>
+
+using namespace Qt::Literals::StringLiterals;
+
+namespace
+{
+constexpr int RegistryVersion = 1;
+
+QString normalized(const QString &path)
+{
+    return path.isEmpty() ? QString() : QFileInfo(path).absoluteFilePath();
+}
+
+std::optional<QByteArray> readFile(const QString &path)
+{
+    QFile file(path);
+    if (!file.open(QIODevice::ReadOnly)) {
+        return std::nullopt;
+    }
+    return file.readAll();
+}
+
+bool writeFile(const QString &path, const QByteArray &data)
+{
+    // No direct-write fallback: a folder that can't take a temporary file is treated
+    // as read-only, and the translation stays in the cache.
+    QSaveFile file(path);
+    return file.open(QIODevice::WriteOnly) && file.write(data) == data.size() && file.commit();
+}
+}
+
+namespace TranslationStore
+{
+QString languageSuffix(const QString &language)
+{
+    for (int i = QLocale::C + 1; i <= QLocale::LastLanguage; ++i) {
+        const auto candidate = static_cast<QLocale::Language>(i);
+        if (QLocale::languageToString(candidate).compare(language, Qt::CaseInsensitive) == 0) {
+            const QString code = QLocale::languageToCode(candidate, QLocale::ISO639Part1);
+            return code.isEmpty() ? QLocale::languageToCode(candidate) : code;
+        }
+    }
+    QString suffix = language.toLower();
+    suffix.removeIf([](QChar c) {
+        return !c.isLetterOrNumber() && c != u'-';
+    });
+    return suffix.isEmpty() ? u"translated"_s : suffix;
+}
+
+QString videoKey(const QUrl &videoUrl)
+{
+    return videoUrl.isLocalFile() ? normalized(videoUrl.toLocalFile()) : videoUrl.toString();
+}
+
+QString cachePath(const QString &cacheDir, const QUrl &videoUrl, const QString &configKey, const QString &suffix)
+{
+    const QString baseName = videoUrl.isLocalFile() ? QFileInfo(videoUrl.toLocalFile()).completeBaseName() : u"subtitles"_s;
+    return u"%1/%2.%3.%4.srt"_s.arg(cacheDir, baseName, configKey, suffix);
+}
+
+QStringList sidecarPaths(const QString &videoPath, const QString &suffix)
+{
+    const QFileInfo info(videoPath);
+    const QString stem = info.absolutePath() + u'/' + info.completeBaseName();
+    return {u"%1.%2.srt"_s.arg(stem, suffix), u"%1.qtpotato.%2.srt"_s.arg(stem, suffix)};
+}
+
+QByteArray contentHash(const QByteArray &data)
+{
+    return QCryptographicHash::hash(data, QCryptographicHash::Sha256).toHex();
+}
+
+std::optional<Record> Registry::find(const QString &video, const QString &language) const
+{
+    for (const Record &record : records) {
+        if (record.video == video && record.language == language) {
+            return record;
+        }
+    }
+    return std::nullopt;
+}
+
+std::optional<Record> Registry::findPath(const QString &path) const
+{
+    const QString wanted = normalized(path);
+    for (const Record &record : records) {
+        if (record.path == wanted) {
+            return record;
+        }
+    }
+    return std::nullopt;
+}
+
+void Registry::put(const Record &record)
+{
+    Record stored = record;
+    stored.path = normalized(record.path);
+    for (Record &existing : records) {
+        if (existing.video == stored.video && existing.language == stored.language) {
+            existing = stored;
+            return;
+        }
+    }
+    records.append(stored);
+}
+
+Registry load(const QString &file)
+{
+    Registry registry;
+    const auto data = readFile(file);
+    if (!data) {
+        return registry;
+    }
+    const QJsonObject root = QJsonDocument::fromJson(*data).object();
+    for (const QJsonValue &value : root.value(u"translations"_s).toArray()) {
+        const QJsonObject object = value.toObject();
+        Record record{object.value(u"video"_s).toString(),
+                      object.value(u"language"_s).toString(),
+                      object.value(u"path"_s).toString(),
+                      object.value(u"configKey"_s).toString(),
+                      object.value(u"contentHash"_s).toString()};
+        if (!record.video.isEmpty() && !record.language.isEmpty() && !record.path.isEmpty()) {
+            registry.put(record);
+        }
+    }
+    return registry;
+}
+
+bool save(const QString &file, const Registry &registry, QString *error)
+{
+    QJsonArray translations;
+    for (const Record &record : registry.records) {
+        if (!QFileInfo::exists(record.path)) {
+            continue;
+        }
+        translations.append(QJsonObject{{u"video"_s, record.video},
+                                        {u"language"_s, record.language},
+                                        {u"path"_s, record.path},
+                                        {u"configKey"_s, record.configKey},
+                                        {u"contentHash"_s, record.contentHash}});
+    }
+    const QJsonObject root{{u"version"_s, RegistryVersion}, {u"translations"_s, translations}};
+
+    QDir().mkpath(QFileInfo(file).absolutePath());
+    QSaveFile output(file);
+    if (!output.open(QIODevice::WriteOnly) || output.write(QJsonDocument(root).toJson()) < 0 || !output.commit()) {
+        if (error) {
+            *error = output.errorString();
+        }
+        return false;
+    }
+    return true;
+}
+
+QString registryFile()
+{
+    return QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) + u"/translations.json"_s;
+}
+
+bool isOwned(const Registry &registry, const QString &path)
+{
+    const auto record = registry.findPath(path);
+    if (!record) {
+        return false;
+    }
+    const auto data = readFile(path);
+    return data && contentHash(*data) == record->contentHash.toLatin1();
+}
+
+PublishResult publish(Registry &registry,
+                      const QUrl &videoUrl,
+                      const QString &suffix,
+                      const QString &configKey,
+                      const QByteArray &data,
+                      const QString &cacheFile)
+{
+    const QString video = videoKey(videoUrl);
+    const QByteArray hash = contentHash(data);
+    PublishResult result{normalized(cacheFile), false};
+
+    if (videoUrl.isLocalFile()) {
+        QStringList candidates = sidecarPaths(videoUrl.toLocalFile(), suffix);
+        // Keep using the file written last time, so a translation does not move to
+        // ".vi.srt" and leave its ".qtpotato.vi.srt" copy behind.
+        if (const auto previous = registry.find(video, suffix);
+            previous && candidates.contains(previous->path) && isOwned(registry, previous->path)) {
+            candidates.removeAll(previous->path);
+            candidates.prepend(previous->path);
+        }
+        for (const QString &path : std::as_const(candidates)) {
+            if (QFileInfo::exists(path) && !isOwned(registry, path)) {
+                continue;
+            }
+            const auto current = readFile(path);
+            if ((current && contentHash(*current) == hash) || writeFile(path, data)) {
+                result = {path, true};
+            }
+            // Both names are in the same folder; when one can't be written, neither can.
+            break;
+        }
+    }
+
+    registry.put({video, suffix, result.path, configKey, QString::fromLatin1(hash)});
+    return result;
+}
+
+void recordRewrite(Registry &registry, const QString &path, const QByteArray &data)
+{
+    if (auto record = registry.findPath(path)) {
+        record->contentHash = QString::fromLatin1(contentHash(data));
+        registry.put(*record);
+    }
+}
+
+QString savedTranslation(const Registry &registry, const QUrl &videoUrl, const QString &suffix)
+{
+    const auto record = registry.find(videoKey(videoUrl), suffix);
+    return record && QFileInfo::exists(record->path) ? record->path : QString();
+}
+}

src/translate/translationstore.h

@@ -0,0 +1,83 @@
+#pragma once
+
+#include <QByteArray>
+#include <QList>
+#include <QString>
+#include <QStringList>
+#include <QUrl>
+
+#include <optional>
+
+// Where translated subtitles live. A translation is written next to the video as
+// "<video>.<lang>.srt" so mpv and other players load it, and recorded in a registry so
+// QtPotato knows which files it wrote, with which settings, and can find the copy it
+// had to keep in the cache when the video's folder was read-only or the video remote.
+namespace TranslationStore
+{
+// "Vietnamese" -> "vi", so the file ends in ".vi.srt" like other players expect.
+QString languageSuffix(const QString &language);
+
+// The registry's name for a video: its absolute path, or the URL of a stream.
+QString videoKey(const QUrl &videoUrl);
+
+// "<cacheDir>/<video basename>.<configKey>.<suffix>.srt". Every settings combination
+// gets its own file, so going back to earlier settings needs no new translation.
+QString cachePath(const QString &cacheDir, const QUrl &videoUrl, const QString &configKey, const QString &suffix);
+
+// Files next to \a videoPath to try, in order: "<base>.<suffix>.srt", then
+// "<base>.qtpotato.<suffix>.srt" for when the user has a subtitle of their own there.
+QStringList sidecarPaths(const QString &videoPath, const QString &suffix);
+
+QByteArray contentHash(const QByteArray &data);
+
+struct Record {
+    QString video;
+    QString language;
+    QString path;
+    // Hash of the source subtitle and the settings it was translated with.
+    QString configKey;
+    // Hash of the file as QtPotato last wrote it. A file that no longer matches was
+    // changed by someone else and is not overwritten.
+    QString contentHash;
+};
+
+// One record per video and language.
+struct Registry {
+    QList<Record> records;
+
+    std::optional<Record> find(const QString &video, const QString &language) const;
+    std::optional<Record> findPath(const QString &path) const;
+    void put(const Record &record);
+};
+
+Registry load(const QString &file);
+// Records whose file is gone are dropped.
+bool save(const QString &file, const Registry &registry, QString *error = nullptr);
+// ~/.local/share/qtpotato/translations.json
+QString registryFile();
+
+// True when \a path holds a translation QtPotato wrote and nobody changed since.
+bool isOwned(const Registry &registry, const QString &path);
+
+struct PublishResult {
+    QString path;
+    bool nextToVideo = false;
+};
+
+// Puts \a data, the translation of \a videoUrl already saved at \a cacheFile, where
+// players find it: next to the video when the folder takes it, without touching a
+// subtitle QtPotato did not write, otherwise \a cacheFile. Records the result.
+PublishResult publish(Registry &registry,
+                      const QUrl &videoUrl,
+                      const QString &suffix,
+                      const QString &configKey,
+                      const QByteArray &data,
+                      const QString &cacheFile);
+
+// After QtPotato edited one of its files (glossary changes), keeps it marked as its own.
+void recordRewrite(Registry &registry, const QString &path, const QByteArray &data);
+
+// The saved translation of \a videoUrl into \a suffix that still exists, or an empty
+// string. Also the check for "has this video been translated yet".
+QString savedTranslation(const Registry &registry, const QUrl &videoUrl, const QString &suffix);
+}