mpv: Add screenshot action

When activated, it gets from MPV the currently playing frame as raw image data held in memory, which is then used to construct a TQImage, which is passed via DCOP to a newly launched instance of KSnapshot so that the user can choose what to do next like they would do with an ordinary screenshot.

If KSnapshot is not available, a save dialog is shown to choose a local or remote location for writing the image, in all the formats that KImageIO supports writing to.

Signed-off-by: Mavridis Philippe <mavridisf@gmail.com>

kaffeine/src/player-parts/libmpv-part/libmpv_part.cpp

@@ -35,6 +35,7 @@
 #include <tdeparts/genericfactory.h>
 #include <tdeglobalsettings.h>
 #include <tdeio/netaccess.h>
+#include <tdeapplication.h>
 #include <kstandarddirs.h>
 #include <tdemessagebox.h>
 #include <tdefiledialog.h>
@@ -45,6 +46,9 @@
 #include <tdetoolbar.h>
 #include <tdeglobal.h>
 #include <kiconloader.h>
+#include <dcopclient.h>
+#include <tdetempfile.h>
+#include <kimageio.h>
 #include <kdebug.h>
 
 // Kaffeine
@@ -180,6 +184,8 @@ void MpvPart::initActions()
     new KWidgetAction(m_volume, i18n("Volume"), 0, 0, 0, actionCollection(), "player_volume");
 
     /*** Stream recording toolbar ***/
+    new TDEAction(i18n("Take Screenshot"), "ksnapshot", Key_S, this, SLOT(slotShot()), actionCollection(), "record_shot");
+
     m_recordAction = new TDEToggleAction(i18n("&Record stream"), "player_record", Key_R, this, SLOT(slotToggleRecording()), actionCollection(), "record_toggle");
     new TDEAction(i18n("Set recording file"), "document-open", 0, this, SLOT(slotSetRecordingFile()), actionCollection(), "record_open");
     m_recordFile = new TQLabel(0);
@@ -753,4 +759,159 @@ void MpvPart::hideContextMenu() {
     }
 }
 
+#define THROW_ERROR(msg, details) \
+    kdError() << "mpv: " << msg << " (" << details << ")" << endl; \
+    KMessageBox::detailedError(nullptr, i18n(msg), details); \
+
+#define THROW_ERROR_FREE(msg, details) \
+    THROW_ERROR(msg, details) \
+    mpv_free_node_contents(&result);
+
+void MpvPart::slotShot() {
+    mpv_node result;
+    int w, h, stride;
+    char *format;
+    mpv_byte_array *data;
+
+    // Get screenshot as raw data in memory
+    const char *args[] = {"screenshot-raw", nullptr};
+    if (!mpv_command_ret(m_mpv, args, &result) ==  MPV_ERROR_SUCCESS) {
+        THROW_ERROR("Internal error", "screenshot-raw command failed")
+        return;
+    }
+
+    if (result.format != MPV_FORMAT_NODE_MAP) {
+        THROW_ERROR("Internal error", "screenshot-raw command returned wrong data format")
+        return;
+    }
+
+    // Validate the result returned by `screenshot-raw`
+#define CHECK_ARG(index, key) \
+    if (qstrcmp(result.u.list->keys[index], key) != 0) { \
+        TQString error = TQString("screenshot-raw returned wrong argument at #%1: %2") \
+            .arg(index).arg(key); \
+        THROW_ERROR_FREE("Internal error", error) \
+        return; \
+    }
+
+CHECK_ARG(0, "w")
+w = result.u.list->values[0].u.int64;
+
+CHECK_ARG(1, "h")
+h = result.u.list->values[1].u.int64;
+
+CHECK_ARG(2, "stride")
+stride = result.u.list->values[2].u.int64;
+
+CHECK_ARG(3, "format")
+format = result.u.list->values[3].u.string;
+
+CHECK_ARG(4, "data")
+data = result.u.list->values[4].u.ba;
+
+#undef CHECK_ARG
+
+    // Validate image format (we can handle only bgr0, which is the default anyway)
+    kdDebug() << "mpv: screenshot-raw image format: " << format << endl;
+    if (qstrcmp(format, "bgr0") != 0) {
+        THROW_ERROR_FREE("Internal error", "mpv: screenshot-raw returned image format other than bgr0")
+        return;
+    }
+
+    // An empty image is useless but not a fatal error
+    if (w <= 0 || h <= 0) {
+       kdWarning() << "mpv: screenshot-raw returned empty image" << endl;
+    }
+
+    // Create a TQDataStream to easily read the raw image data
+    TQByteArray ba;
+    ba.setRawData(static_cast<char *>(data->data), data->size);
+    TQDataStream s(ba, IO_ReadOnly);
+    s.setByteOrder(TQDataStream::BigEndian);
+
+    // Create image from raw B8G8R8X8 data
+    TQImage img(w, h, 32);
+    for (uint y = 0; y < h; ++y) {
+        TQRgb *scanline = (TQRgb *)img.scanLine(y);
+        for (uint x = 0; x < w; x++) {
+            uchar r, g, b, z;
+            s >> b >> g >> r >> z;
+            scanline[x] = tqRgb(r, g, b);
+        }
+    }
+
+
+    // Try to launch ksnapshot
+    TQString ksError;
+    TQCString ksDcop;
+
+    int ksSuccess = kapp->startServiceByDesktopName("ksnapshot", TQString::null,
+                                                                 &ksError, &ksDcop);
+    if (ksSuccess == 0) {
+        // Serialize the image to pass via dcop
+        TQByteArray pix;
+        TQDataStream ds(pix, IO_WriteOnly);
+        ds << img;
+
+        // Send the serialized image to the newly initialized ksnapshot instance
+        if (!kapp->dcopClient()->send(ksDcop, "interface", "setPixmap(TQPixmap)", pix)) {
+            THROW_ERROR("Unable to launch KSnapshot!", i18n("You seem to be using an incompatible version of KSnapshot."));
+            return;
+        }
+    }
+    else {
+        TQStringList mimeTypes = KImageIO::mimeTypes(KImageIO::Writing);
+        if (mimeTypes.isEmpty()) {
+            THROW_ERROR("No image formats supported!", "KImageIO does not support any image format for export.");
+            return;
+        }
+
+        KFileDialog *saveDlg = new KFileDialog(TQString::null, TQString::null,
+                                               widget(), "screenshotSaver", false);
+        saveDlg->setOperationMode(KFileDialog::Saving);
+        saveDlg->setMimeFilter(mimeTypes);
+
+        if (!saveDlg->exec()) {
+            return;
+        }
+
+        KURL saveURL = saveDlg->selectedURL();
+        if (saveURL.isEmpty()) return;
+
+        TQString type = KImageIO::type(saveURL.url());
+        if (!KImageIO::canWrite(type)) {
+            THROW_ERROR("Cannot write image", "Format " + type + " is unsupported for export.")
+            return;
+        }
+
+        if (saveURL.isLocalFile()) {
+            if (!img.save(saveURL.path(), type.latin1())) {
+                THROW_ERROR("I/O Error", "Could not save file!")
+                return;
+            }
+        }
+        else {
+            KTempFile tempFile;
+            tempFile.setAutoDelete(true);
+            TQString tempFileName = tempFile.name();
+            if (tempFileName.isEmpty()) {
+                THROW_ERROR("I/O Error", "Could not create temporary file!")
+                return;
+            }
+
+            if (!img.save(tempFileName, type.latin1())) {
+                THROW_ERROR("I/O Error", "Could not write to temporary file!")
+                return;
+            }
+
+            if (!TDEIO::NetAccess::upload(tempFileName, saveURL, widget())) {
+                THROW_ERROR("Upload error", "Could not upload image.")
+                return;
+            }
+        }
+    }
+}
+#undef THROW_ERROR
+#undef THROW_ERROR_FREE
+
 #include "libmpv_part.moc"

kaffeine/src/player-parts/libmpv-part/libmpv_part.h

@@ -102,6 +102,8 @@ class MpvPart : public KaffeinePart
         void slotNext();
         void slotSetPosition(uint); /* percent */
 
+        void slotShot();
+
         void slotToggleRecording();
         void startRecording();
         void stopRecording();

kaffeine/src/player-parts/libmpv-part/libmpv_part.rc

@@ -12,7 +12,9 @@
     <Action name="player_previous"/>
     <Action name="player_next"/>
     <Separator/>
+    <Action name="record_shot"/>
     <Action name="record_toggle"/>
+    <Action name="record_open"/>
   </Menu>
 </MenuBar>
 
@@ -34,6 +36,8 @@
   <Separator/>
 </ToolBar>
 <ToolBar name="record" hidden="true"><text>Stream Recorder Toolbar</text>
+  <Action name="record_shot"/>
+  <Separator/>
   <Action name="record_toggle"/>
   <Action name="record_open"/>
   <Action name="record_file"/>
@@ -72,6 +76,7 @@
     <Action name="player_mute"/>
     <Action name="player_volume"/>
 
+    <Action name="record_shot"/>
     <Action name="record_toggle"/>
     <Action name="record_open"/>
     <Action name="record_file"/>
@@ -99,6 +104,7 @@
     <Action name="player_mute"/>
     <Action name="player_volume"/>
 
+    <Action name="record_shot"/>
     <Action name="record_toggle"/>
     <Action name="record_open"/>
     <Action name="record_file"/>
@@ -124,6 +130,8 @@
 
     <Action name="player_mute"/>
     <Action name="player_volume"/>
+
+    <Action name="record_shot"/>
   </enable>
 </State>
 
@@ -143,6 +151,7 @@
     <Action name="player_mute"/>
     <Action name="player_volume"/>
 
+    <Action name="record_shot"/>
     <Action name="record_toggle"/>
     <Action name="record_open"/>
     <Action name="record_file"/>