From 28a80b3c9db8e247de1bef0f575ca57368e33f76 Mon Sep 17 00:00:00 2001
From: emeric <emeric.poupon@laposte.net>
Date: Mon, 13 Nov 2023 11:45:12 +0100
Subject: [PATCH] Subsonic API: added a per-user setting to enable transcoding
 by default (breaking change: default is disabled). fixes #351, ref #367

---
 approot/messages.xml                          |   1 +
 approot/messages_fr.xml                       |   5 +-
 approot/messages_it.xml                       |   1 +
 approot/messages_zh.xml                       |   1 +
 approot/settings.xml                          |  11 ++
 src/libs/services/database/impl/Migration.cpp |   7 +
 src/libs/services/database/impl/Migration.hpp |   2 +-
 .../include/services/database/User.hpp        |   5 +
 src/libs/subsonic/impl/ProtocolVersion.hpp    |   2 +-
 .../impl/entrypoints/MediaRetrieval.cpp       | 131 ++++++++++++------
 src/lms/ui/SettingsView.cpp                   |  15 +-
 11 files changed, 130 insertions(+), 51 deletions(-)

diff --git a/approot/messages.xml b/approot/messages.xml
index a43abc7e..c7c44486 100644
--- a/approot/messages.xml
+++ b/approot/messages.xml
@@ -248,6 +248,7 @@
 <message id="Lms.Settings.default-transcoding-output-bitrate">Default transcoding output bitrate</message>
 <message id="Lms.Settings.default-transcoding-output-format">Default transcoding output format</message>
 <message id="Lms.Settings.demo-cannot-save">Cannot save using a demo account!</message>
+<message id="Lms.Settings.enable-transcoding-by-default">Enable transcoding by default</message>
 <message id="Lms.Settings.feedback">Feedback</message>
 <message id="Lms.Settings.menu-settings"><i class="fa fa-fw fa-cog" aria-hidden="true"></i> Settings</message>
 <message id="Lms.Settings.password-bad">Bad password</message>
diff --git a/approot/messages_fr.xml b/approot/messages_fr.xml
index ff147166..769bc1e9 100644
--- a/approot/messages_fr.xml
+++ b/approot/messages_fr.xml
@@ -245,9 +245,10 @@
 <message id="Lms.Settings.backend.listenbrainz">ListenBrainz</message>
 <message id="Lms.Settings.backend.listenbrainz-token">Jeton d'API ListenBrainz</message>
 <message id="Lms.Settings.change-password">Changement de mot de passe</message>
-<message id="Lms.Settings.default-transcoding-output-bitrate">Bitrate par defaut du transcodage</message>
-<message id="Lms.Settings.default-transcoding-output-format">Format par defaut du transcodage</message>
+<message id="Lms.Settings.default-transcoding-output-bitrate">Bitrate par défaut du transcodage</message>
+<message id="Lms.Settings.default-transcoding-output-format">Format par défaut du transcodage</message>
 <message id="Lms.Settings.demo-cannot-save">Impossible de sauvegarder en utilisant un compte de démo !</message>
+<message id="Lms.Settings.enable-transcoding-by-default">Activer par défaut le transcodage</message>
 <message id="Lms.Settings.feedback">Feedback</message>
 <message id="Lms.Settings.menu-settings"><i class="fa fa-fw fa-cog" aria-hidden="true"></i> Paramètres</message>
 <message id="Lms.Settings.password-bad">Mauvais mot de passe</message>
diff --git a/approot/messages_it.xml b/approot/messages_it.xml
index 5bd7cefa..92d4bcfc 100644
--- a/approot/messages_it.xml
+++ b/approot/messages_it.xml
@@ -249,6 +249,7 @@
 
 <message id="Lms.Settings.demo-cannot-save">Non posso salvare le impostazioni utilizzando l'account demo!</message>
 
+
 <message id="Lms.Settings.menu-settings"><i class="fa fa-fw fa-cog" aria-hidden="true"></i> Impostazioni</message>
 <message id="Lms.Settings.password-bad">Password errata</message>
 <message id="Lms.Settings.password-must-fill-old-password">Devi inserire la password attuale</message>
diff --git a/approot/messages_zh.xml b/approot/messages_zh.xml
index 68a28400..17c96ec7 100644
--- a/approot/messages_zh.xml
+++ b/approot/messages_zh.xml
@@ -249,6 +249,7 @@
 
 <message id="Lms.Settings.demo-cannot-save">使用演示账号时不能保存！</message>
 
+
 <message id="Lms.Settings.menu-settings"><i class="fa fa-fw fa-cog" aria-hidden="true"></i> 设置</message>
 <message id="Lms.Settings.password-bad">无效密码</message>
 <message id="Lms.Settings.password-must-fill-old-password">必须填写旧密码</message>
diff --git a/approot/settings.xml b/approot/settings.xml
index e12b94b1..dbf53bf5 100644
--- a/approot/settings.xml
+++ b/approot/settings.xml
@@ -74,6 +74,17 @@
 		</div>
 		${<if-has-subsonic-api>}
 			<legend>${tr:Lms.Settings.subsonic-api}</legend>
+			<div class="col-12">
+				<div class="form-check">
+					${subsonic-enable-transcoding-by-default class="form-check-input"}
+					<label class="form-check-label" for="${id:subsonic-enable-transcoding-by-default}">
+						${tr:Lms.Settings.enable-transcoding-by-default}
+					</label>
+					<div class="invalid-feedback">
+						${subsonic-enable-transcoding-by-default-info}
+					</div>
+				</div>
+			</div>
 			<div class="col-lg-6">
 				<label class="form-label" for="${id:subsonic-transcoding-output-format}">
 					${tr:Lms.Settings.default-transcoding-output-format}
diff --git a/src/libs/services/database/impl/Migration.cpp b/src/libs/services/database/impl/Migration.cpp
index 044ebdbe..93fb283a 100644
--- a/src/libs/services/database/impl/Migration.cpp
+++ b/src/libs/services/database/impl/Migration.cpp
@@ -243,6 +243,12 @@ CREATE TABLE IF NOT EXISTS "track_backup" (
         ScanSettings::get(session).modify()->incScanVersion();
     }
 
+    void migrateFromV45(Session& session)
+    {
+        // add subsonic_enable_transcoding_by_default, default is disabled
+        session.getDboSession().execute("ALTER TABLE user ADD subsonic_enable_transcoding_by_default INTEGER NOT NULL DEFAULT(" + std::to_string(static_cast<int>(/*User::defaultSubsonicEnableTranscodingByDefault*/0)) + ")");
+    }
+
     void doDbMigration(Session& session)
     {
         static const std::string outdatedMsg{ "Outdated database, please rebuild it (delete the .db file and restart)" };
@@ -266,6 +272,7 @@ CREATE TABLE IF NOT EXISTS "track_backup" (
             {42, migrateFromV42},
             {43, migrateFromV43},
             {44, migrateFromV44},
+            {45, migrateFromV45},
         };
 
         {
diff --git a/src/libs/services/database/impl/Migration.hpp b/src/libs/services/database/impl/Migration.hpp
index bcebebea..d431713d 100644
--- a/src/libs/services/database/impl/Migration.hpp
+++ b/src/libs/services/database/impl/Migration.hpp
@@ -26,7 +26,7 @@ namespace Database
     class Session;
 
     using Version = std::size_t;
-    static constexpr Version LMS_DATABASE_VERSION{ 45 };
+    static constexpr Version LMS_DATABASE_VERSION{ 46 };
     class VersionInfo
     {
     public:
diff --git a/src/libs/services/database/include/services/database/User.hpp b/src/libs/services/database/include/services/database/User.hpp
index b0bc3870..c88269f6 100644
--- a/src/libs/services/database/include/services/database/User.hpp
+++ b/src/libs/services/database/include/services/database/User.hpp
@@ -58,6 +58,7 @@ namespace Database {
 
         static inline constexpr std::size_t             MinNameLength{ 3 };
         static inline constexpr std::size_t             MaxNameLength{ 15 };
+        static inline constexpr bool                    defaultSubsonicEnableTranscodingByDefault{ false };
         static inline constexpr TranscodingOutputFormat defaultSubsonicTranscodingOutputFormat{ TranscodingOutputFormat::OGG_OPUS };
         static inline constexpr Bitrate                 defaultSubsonicTranscodingOutputBitrate{ 128000 };
         static inline constexpr UITheme                 defaultUITheme{ UITheme::Dark };
@@ -83,6 +84,7 @@ namespace Database {
         void setLastLogin(const Wt::WDateTime& dateTime) { _lastLogin = dateTime; }
         void setPasswordHash(const PasswordHash& passwordHash) { _passwordSalt = passwordHash.salt; _passwordHash = passwordHash.hash; }
         void setType(UserType type) { _type = type; }
+        void setSubsonicEnableTranscodingByDefault(bool value) { _subsonicEnableTranscodingByDefault = value; }
         void setSubsonicDefaultTranscodintOutputFormat(TranscodingOutputFormat encoding) { _subsonicDefaultTranscodingOutputFormat = encoding; }
         void setSubsonicDefaultTranscodingOutputBitrate(Bitrate bitrate);
         void setCurPlayingTrackPos(std::size_t pos) { _curPlayingTrackPos = pos; }
@@ -99,6 +101,7 @@ namespace Database {
         bool                    isAdmin() const { return _type == UserType::ADMIN; }
         bool                    isDemo() const { return _type == UserType::DEMO; }
         UserType                getType() const { return _type; }
+        bool                    getSubsonicEnableTranscodingByDefault() const { return _subsonicEnableTranscodingByDefault; }
         TranscodingOutputFormat getSubsonicDefaultTranscodingOutputFormat() const { return _subsonicDefaultTranscodingOutputFormat; }
         Bitrate                 getSubsonicDefaultTranscodingOutputBitrate() const { return _subsonicDefaultTranscodingOutputBitrate; }
         std::size_t             getCurPlayingTrackPos() const { return _curPlayingTrackPos; }
@@ -118,6 +121,7 @@ namespace Database {
             Wt::Dbo::field(a, _passwordSalt, "password_salt");
             Wt::Dbo::field(a, _passwordHash, "password_hash");
             Wt::Dbo::field(a, _lastLogin, "last_login");
+            Wt::Dbo::field(a, _subsonicEnableTranscodingByDefault, "subsonic_enable_transcoding_by_default");
             Wt::Dbo::field(a, _subsonicDefaultTranscodingOutputFormat, "subsonic_default_transcode_format");
             Wt::Dbo::field(a, _subsonicDefaultTranscodingOutputBitrate, "subsonic_default_transcode_bitrate");
             Wt::Dbo::field(a, _subsonicArtistListMode, "subsonic_artist_list_mode");
@@ -153,6 +157,7 @@ namespace Database {
 
         // User defined settings
         SubsonicArtistListMode  _subsonicArtistListMode{ defaultSubsonicArtistListMode };
+        bool                    _subsonicEnableTranscodingByDefault{ defaultSubsonicEnableTranscodingByDefault };
         TranscodingOutputFormat _subsonicDefaultTranscodingOutputFormat{ defaultSubsonicTranscodingOutputFormat };
         int                     _subsonicDefaultTranscodingOutputBitrate{ defaultSubsonicTranscodingOutputBitrate };
 
diff --git a/src/libs/subsonic/impl/ProtocolVersion.hpp b/src/libs/subsonic/impl/ProtocolVersion.hpp
index 86b9f3aa..6dd17d54 100644
--- a/src/libs/subsonic/impl/ProtocolVersion.hpp
+++ b/src/libs/subsonic/impl/ProtocolVersion.hpp
@@ -31,7 +31,7 @@ namespace API::Subsonic
     };
 
     static inline constexpr ProtocolVersion defaultServerProtocolVersion{ 1, 16, 0 };
-    static inline constexpr std::string_view serverVersion{ "3" };
+    static inline constexpr std::string_view serverVersion{ "4" };
 }
 
 namespace StringUtils
diff --git a/src/libs/subsonic/impl/entrypoints/MediaRetrieval.cpp b/src/libs/subsonic/impl/entrypoints/MediaRetrieval.cpp
index 80aaf1de..574fb546 100644
--- a/src/libs/subsonic/impl/entrypoints/MediaRetrieval.cpp
+++ b/src/libs/subsonic/impl/entrypoints/MediaRetrieval.cpp
@@ -40,8 +40,9 @@ namespace API::Subsonic
 {
     using namespace Database;
 
-    namespace {
-        std::optional<Av::Transcoding::OutputFormat> subsonicStreamFormatToAvFormat(std::string_view format)
+    namespace 
+    {
+        std::optional<Av::Transcoding::OutputFormat> subsonicStreamFormatToAvOutputFormat(std::string_view format)
         {
             for (const auto& [str, avFormat] : std::initializer_list<std::pair<std::string_view, Av::Transcoding::OutputFormat>>{
                 {"mp3", Av::Transcoding::OutputFormat::MP3},
@@ -68,6 +69,25 @@ namespace API::Subsonic
             return Av::Transcoding::OutputFormat::OGG_OPUS;
         }
 
+        bool isCodecCompatibleWithOutputFormat(Av::DecodingCodec codec, Av::Transcoding::OutputFormat outputFormat)
+        {
+            switch (outputFormat)
+            {
+            case Av::Transcoding::OutputFormat::MP3:
+                return codec == Av::DecodingCodec::MP3;
+
+            case Av::Transcoding::OutputFormat::OGG_OPUS:
+            case Av::Transcoding::OutputFormat::MATROSKA_OPUS:
+                return codec == Av::DecodingCodec::OPUS;
+
+            case Av::Transcoding::OutputFormat::OGG_VORBIS:
+            case Av::Transcoding::OutputFormat::WEBM_VORBIS:
+                return codec == Av::DecodingCodec::VORBIS;
+            }
+
+            return true;
+        }
+
         struct StreamParameters
         {
             Av::Transcoding::InputParameters inputParameters;
@@ -75,70 +95,93 @@ namespace API::Subsonic
             bool estimateContentLength{};
         };
 
+        bool isOutputFormatCompatible(const std::filesystem::path& trackPath, Av::Transcoding::OutputFormat outputFormat)
+        {
+            try
+            {
+                const auto audioFile{ Av::parseAudioFile(trackPath) };
+
+                const auto streamInfo{ audioFile->getBestStreamInfo() };
+                if (!streamInfo)
+                    throw RequestedDataNotFoundError{}; // TODO 404?
+
+                return isCodecCompatibleWithOutputFormat(streamInfo->codec, outputFormat);
+            }
+            catch (const Av::Exception& e)
+            {
+                // TODO 404?
+                throw RequestedDataNotFoundError{};
+            }
+        }
+
         StreamParameters getStreamParameters(RequestContext& context)
         {
             // Mandatory params
             const TrackId id{ getMandatoryParameterAs<TrackId>(context.parameters, "id") };
 
             // Optional params
-            std::size_t maxBitRate{ getParameterAs<std::size_t>(context.parameters, "maxBitRate").value_or(0) }; // "If set to zero, no limit is imposed"
+            std::size_t maxBitRate{ getParameterAs<std::size_t>(context.parameters, "maxBitRate").value_or(0) * 1000 }; // "If set to zero, no limit is imposed", given in kpbs
             const std::string format{ getParameterAs<std::string>(context.parameters, "format").value_or("") };
             std::size_t timeOffset{ getParameterAs<std::size_t>(context.parameters, "timeOffset").value_or(0) };
             bool estimateContentLength{ getParameterAs<bool>(context.parameters, "estimateContentLength").value_or(false) };
 
             StreamParameters parameters;
 
-            std::size_t bitrate{};
-            parameters.estimateContentLength = estimateContentLength;
-
-            {
-                auto transaction{ context.dbSession.createSharedTransaction() };
-
-                const auto track{ Track::find(context.dbSession, id) };
-                if (!track)
-                    throw RequestedDataNotFoundError{};
-
-                parameters.inputParameters.trackPath = track->getPath();
-                parameters.inputParameters.duration = track->getDuration();
-                bitrate = track->getBitrate() / 1000;
-            }
-
-            if (format == "raw") // raw => no transcode
-                return parameters;
-
-            const auto audioFile{ Av::parseAudioFile(parameters.inputParameters.trackPath) };
-
-            // check if transcode is really needed or not
-            // same format as requested, bitrate is lower than requested => no need to transcode
-            if (const auto streamInfo{ audioFile->getBestStreamInfo() })
-            {
-                // assume reported codec is "mp3", "opus", "vorbis", etc.
-                if (StringUtils::stringCaseInsensitiveEqual(streamInfo->codecName, format) && (maxBitRate == 0 || (bitrate != 0 && bitrate <= maxBitRate)))
-                {
-                    LMS_LOG(API_SUBSONIC, DEBUG) << "stream parameters are compatible with actual file: no transcode";
-                    return parameters;
-                }
-            }
-
             auto transaction{ context.dbSession.createSharedTransaction() };
 
             const User::pointer user{ User::find(context.dbSession, context.userId) };
             if (!user)
                 throw UserNotAuthorizedError{};
 
+            const auto track{ Track::find(context.dbSession, id) };
+            if (!track)
+                throw RequestedDataNotFoundError{};
+
+            parameters.inputParameters.trackPath = track->getPath();
+            parameters.inputParameters.duration = track->getDuration();
+            parameters.estimateContentLength = estimateContentLength;
+
+            if (format == "raw") // raw => no transcoding
+                return parameters;
+
+            std::optional<Av::Transcoding::OutputFormat> requestedFormat{ subsonicStreamFormatToAvOutputFormat(format) };
+            if (!requestedFormat)
+            {
+                if (user->getSubsonicEnableTranscodingByDefault())
+                    requestedFormat = userTranscodeFormatToAvFormat(user->getSubsonicDefaultTranscodingOutputFormat());
+            }
+
+            if (!requestedFormat && (maxBitRate == 0 || track->getBitrate() <= maxBitRate ))
+            {
+                LMS_LOG(API_SUBSONIC, DEBUG) << "File's bitrate is compatible with parameters => no transcoding";
+                return parameters; // no transcoding needed
+            }
+
+            // scan the file to check if its format is compatible with the actual requested format
+            //  same codec => apply max bitrate
+            //  otherwise => apply default bitrate (because we can't really compare bitrates between formats) + max bitrate)
+            std::size_t bitrate{};
+            if (requestedFormat && isOutputFormatCompatible(track->getPath(), *requestedFormat))
+            {
+                if (maxBitRate == 0 || track->getBitrate() <= maxBitRate)
+                {
+                    LMS_LOG(API_SUBSONIC, DEBUG) << "File's bitrate and format are compatible with parameters => no transcoding";
+                    return parameters; // no transcoding needed
+                }
+                bitrate = maxBitRate;
+            }
+            
+            if (!requestedFormat)
+                requestedFormat = userTranscodeFormatToAvFormat(user->getSubsonicDefaultTranscodingOutputFormat());
+            if (!bitrate)
+                bitrate = std::min<std::size_t>(user->getSubsonicDefaultTranscodingOutputBitrate(), maxBitRate);
+
             Av::Transcoding::OutputParameters& outputParameters{ parameters.outputParameters.emplace() };
 
             outputParameters.stripMetadata = false; // We want clients to use metadata (offline use, replay gain, etc.)
             outputParameters.offset = std::chrono::seconds{ timeOffset };
-
-            if (std::optional<Av::Transcoding::OutputFormat> requestedFormat{ subsonicStreamFormatToAvFormat(format) })
-                outputParameters.format = *requestedFormat;
-            else
-                outputParameters.format = userTranscodeFormatToAvFormat(user->getSubsonicDefaultTranscodingOutputFormat());
-
-            outputParameters.bitrate = user->getSubsonicDefaultTranscodingOutputBitrate();
-            if (maxBitRate != 0)
-                outputParameters.bitrate = Utils::clamp(outputParameters.bitrate, std::size_t{ 48000 }, maxBitRate * 1000);
+            outputParameters.format = *requestedFormat;
+            outputParameters.bitrate = bitrate;
 
             return parameters;
         }
diff --git a/src/lms/ui/SettingsView.cpp b/src/lms/ui/SettingsView.cpp
index ef9a4f89..2c311077 100644
--- a/src/lms/ui/SettingsView.cpp
+++ b/src/lms/ui/SettingsView.cpp
@@ -44,7 +44,7 @@
 #include "LmsApplication.hpp"
 #include "MediaPlayer.hpp"
 
-namespace UserInterface 
+namespace UserInterface
 {
     using namespace Database;
 
@@ -58,6 +58,7 @@ namespace UserInterface
         static inline const Field ReplayGainModeField{ "replaygain-mode" };
         static inline const Field ReplayGainPreAmpGainField{ "replaygain-preamp" };
         static inline const Field ReplayGainPreAmpGainIfNoInfoField{ "replaygain-preamp-no-rg-info" };
+        static inline const Field SubsonicEnableTranscodingByDefault{ "subsonic-enable-transcoding-by-default" };
         static inline const Field SubsonicArtistListModeField{ "subsonic-artist-list-mode" };
         static inline const Field SubsonicTranscodingOutputFormatField{ "subsonic-transcoding-output-format" };
         static inline const Field SubsonicTranscodingOutputBitrateField{ "subsonic-transcoding-output-bitrate" };
@@ -85,6 +86,7 @@ namespace UserInterface
             addField(ReplayGainModeField);
             addField(ReplayGainPreAmpGainField);
             addField(ReplayGainPreAmpGainIfNoInfoField);
+            addField(SubsonicEnableTranscodingByDefault);
             addField(SubsonicTranscodingOutputBitrateField);
             addField(SubsonicTranscodingOutputFormatField);
             addField(FeedbackBackendField);
@@ -162,6 +164,9 @@ namespace UserInterface
             }
 
             {
+                bool subsonicEnableTranscodingByDefault{ Wt::asNumber(value(SubsonicEnableTranscodingByDefault)) != 0 };
+                user.modify()->setSubsonicEnableTranscodingByDefault(subsonicEnableTranscodingByDefault);
+
                 auto subsonicTranscodingOutputBitrateRow{ _transcodingOutputBitrateModel->getRowFromString(valueText(SubsonicTranscodingOutputBitrateField)) };
                 if (subsonicTranscodingOutputBitrateRow)
                     user.modify()->setSubsonicDefaultTranscodingOutputBitrate(_transcodingOutputBitrateModel->getValue(*subsonicTranscodingOutputBitrateRow));
@@ -173,7 +178,6 @@ namespace UserInterface
                 auto subsonicArtistListModeRow{ _subsonicArtistListModeModel->getRowFromString(valueText(SubsonicArtistListModeField)) };
                 if (subsonicArtistListModeRow)
                     user.modify()->setSubsonicArtistListMode(_subsonicArtistListModeModel->getValue(*subsonicArtistListModeRow));
-
             }
 
             {
@@ -232,6 +236,8 @@ namespace UserInterface
             }
 
             {
+                setValue(SubsonicEnableTranscodingByDefault, user->getSubsonicEnableTranscodingByDefault());
+
                 auto subsonicTranscodingOutputBitrateRow{ _transcodingOutputBitrateModel->getRowFromValue(user->getSubsonicDefaultTranscodingOutputBitrate()) };
                 if (subsonicTranscodingOutputBitrateRow)
                     setValue(SubsonicTranscodingOutputBitrateField, _transcodingOutputBitrateModel->getString(*subsonicTranscodingOutputBitrateRow));
@@ -356,7 +362,7 @@ namespace UserInterface
         ::Auth::IPasswordService* _authPasswordService{};
         bool _withOldPassword{};
 
-        std::shared_ptr<TranscodingModeModel>	                        _transcodingModeModeModel;
+        std::shared_ptr<TranscodingModeModel>	                    _transcodingModeModeModel;
         std::shared_ptr<ValueStringModel<Bitrate>>                  _transcodingOutputBitrateModel;
         std::shared_ptr<ValueStringModel<TranscodingOutputFormat>>  _transcodingOutputFormatModel;
         std::shared_ptr<ReplayGainModeModel>                        _replayGainModeModel;
@@ -490,6 +496,9 @@ namespace UserInterface
         {
             t->setCondition("if-has-subsonic-api", Service<IConfig>::get()->getBool("api-subsonic", true));
 
+            // Enable transcoding by default
+            t->setFormWidget(SettingsModel::SubsonicEnableTranscodingByDefault, std::make_unique<Wt::WCheckBox>());
+
             // Format
             auto transcodingOutputFormat{ std::make_unique<Wt::WComboBox>() };
             transcodingOutputFormat->setModel(model->getTranscodingOutputFormatModel());