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render_clip

sleap.gui.dialogs.render_clip

Render Video Clip dialog with live preview using sleap-io.

This dialog replaces the YAML-based FormBuilder approach for exporting labeled video clips, providing a pure Qt implementation with real-time preview capabilities using sleap-io's rendering API.

Classes:

Name Description
RenderClipDialog

Dialog for rendering video clips with live preview.

RenderClipDialog

Bases: QDialog

Dialog for rendering video clips with live preview.

This dialog provides a pure Qt interface for configuring video rendering options with real-time preview using sleap-io's render_image() function.

Usage from SLEAP GUI::

# Get frame range if clip is selected
frame_range = None
if context.state["has_frame_range"]:
    frame_range = tuple(context.state["frame_range"])

dialog = RenderClipDialog(
    labels=context.state["labels"],
    video=context.state["video"],
    current_frame=context.state["frame_idx"],
    frame_range=frame_range,
    parent=context.app,
)
if dialog.exec_():
    params = dialog.get_export_params()
    output_path = dialog.get_output_path()
    # Call sio.render_video(...)

Attributes:

Name Type Description
labels

The Labels object containing labeled frames.

video

The current video to render.

Methods:

Name Description
__init__

Initialize the render clip dialog.

get_export_params

Get all export parameters.

get_frame_indices

Get list of frame indices to render.

get_output_path

Get the selected output file path.

Source code in sleap/gui/dialogs/render_clip.py
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class RenderClipDialog(QtWidgets.QDialog):
    """Dialog for rendering video clips with live preview.

    This dialog provides a pure Qt interface for configuring video rendering
    options with real-time preview using sleap-io's `render_image()` function.

    Usage from SLEAP GUI::

        # Get frame range if clip is selected
        frame_range = None
        if context.state["has_frame_range"]:
            frame_range = tuple(context.state["frame_range"])

        dialog = RenderClipDialog(
            labels=context.state["labels"],
            video=context.state["video"],
            current_frame=context.state["frame_idx"],
            frame_range=frame_range,
            parent=context.app,
        )
        if dialog.exec_():
            params = dialog.get_export_params()
            output_path = dialog.get_output_path()
            # Call sio.render_video(...)

    Attributes:
        labels: The Labels object containing labeled frames.
        video: The current video to render.
    """

    def __init__(
        self,
        labels: "sio.Labels",
        video: "sio.Video | None" = None,
        current_frame: int | None = None,
        frame_range: tuple[int, int] | None = None,
        parent: QtWidgets.QWidget | None = None,
    ):
        """Initialize the render clip dialog.

        Args:
            labels: The Labels object containing labeled frames.
            video: The video to render. If None, uses first video in labels.
            current_frame: Initial frame to show in preview. If None, uses
                first labeled frame.
            frame_range: Optional (start, end) tuple for initial frame range.
                If provided, selects "Custom range" and sets start/end values.
                This is typically from the main window's selected clip.
            parent: Parent widget.
        """
        super().__init__(parent)
        self.labels = labels
        self.video = video or (labels.videos[0] if labels.videos else None)
        self._current_frame = current_frame
        self._initial_frame_range = frame_range
        self._output_path: str | None = None

        self._setup_ui()
        self._connect_signals()

        # Initialize frame range from main window's selection
        if frame_range is not None:
            self._set_frame_range(frame_range)

        # Jump to current frame if specified
        if current_frame is not None:
            self._jump_to_frame(current_frame)

        self._update_preview()

    def _set_frame_range(self, frame_range: tuple[int, int]):
        """Set the frame range from an external selection (e.g., main window clip).

        Args:
            frame_range: (start, end) tuple of frame indices.
        """
        start, end = frame_range
        # Select custom range mode
        self.range_custom.setChecked(True)
        # Set the start and end values
        self.start_frame.setValue(start)
        self.end_frame.setValue(end - 1)  # end is exclusive in context, make inclusive

    def _jump_to_frame(self, frame_idx: int):
        """Jump preview to a specific frame index."""
        self.preview.set_frame(frame_idx)

    def _setup_ui(self):
        """Build the dialog UI."""
        self.setWindowTitle("Render Video Clip")
        self.setMinimumSize(1000, 700)

        main_layout = QtWidgets.QHBoxLayout(self)
        main_layout.setSpacing(12)

        # Left: Preview widget (2/3 width)
        self.preview = RenderingPreviewWidget(self.labels, self.video)
        main_layout.addWidget(self.preview, stretch=2)

        # Right: Options panel (1/3 width)
        options_panel = self._create_options_panel()
        main_layout.addWidget(options_panel, stretch=1)

    def _create_options_panel(self) -> QtWidgets.QWidget:
        """Build the options panel with grouped controls."""
        # Container for scroll + buttons
        container = QtWidgets.QWidget()
        container_layout = QtWidgets.QVBoxLayout(container)
        container_layout.setContentsMargins(0, 0, 0, 0)
        container_layout.setSpacing(8)

        # Scrollable options area
        scroll = QtWidgets.QScrollArea()
        scroll.setWidgetResizable(True)
        scroll.setFrameShape(QtWidgets.QFrame.NoFrame)
        scroll.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)

        widget = QtWidgets.QWidget()
        layout = QtWidgets.QVBoxLayout(widget)
        layout.setSpacing(8)

        # Video selection (for multi-video Labels)
        if len(self.labels.videos) > 1:
            layout.addWidget(self._create_video_selector_group())

        # Frame Range
        layout.addWidget(self._create_frame_range_group())

        # Appearance
        layout.addWidget(self._create_appearance_group())

        # Motion trails
        layout.addWidget(self._create_trails_group())

        # Quality
        layout.addWidget(self._create_quality_group())

        # Output
        layout.addWidget(self._create_output_group())

        # Spacer
        layout.addStretch()

        scroll.setWidget(widget)
        container_layout.addWidget(scroll, stretch=1)

        # Buttons (outside scroll area - always visible)
        container_layout.addWidget(self._create_buttons())

        return container

    def _create_video_selector_group(self) -> QtWidgets.QGroupBox:
        """Create video selection group (for multi-video Labels)."""
        group = QtWidgets.QGroupBox("Video")
        layout = QtWidgets.QFormLayout(group)

        self.video_selector = QtWidgets.QComboBox()
        for i, video in enumerate(self.labels.videos):
            # Get video filename
            name = getattr(video, "filename", None) or getattr(video, "backend", None)
            if name:
                name = os.path.basename(str(name))
            else:
                name = f"Video {i}"
            n_frames = len(
                [lf for lf in self.labels.labeled_frames if lf.video == video]
            )
            self.video_selector.addItem(f"{name} ({n_frames} labeled)", video)

        # Select current video
        if self.video in self.labels.videos:
            self.video_selector.setCurrentIndex(self.labels.videos.index(self.video))

        self.video_selector.currentIndexChanged.connect(self._on_video_changed)
        layout.addRow("Source:", self.video_selector)

        return group

    def _on_video_changed(self, index: int):
        """Handle video selection change."""
        self.video = self.video_selector.itemData(index)
        # Update preview widget
        self.preview.video = self.video
        self.preview._labeled_frame_indices = self.preview._get_labeled_frame_indices()
        self.preview._update_slider_range()
        if self.preview._labeled_frame_indices:
            self.preview._current_frame_idx = self.preview._labeled_frame_indices[0]
            self.preview.frame_slider.setValue(0)
        self.preview._do_render()
        # Update frame range limits
        self._update_frame_range_limits()
        # Re-read source fps — may differ between videos in a multi-video
        # project, and the match-source-fps label/value tracks the active one.
        if hasattr(self, "match_source_fps"):
            self._refresh_match_source_fps()

    def _update_frame_range_limits(self):
        """Update frame range spinboxes based on current video."""
        labeled_frames = [
            lf.frame_idx
            for lf in self.labels.labeled_frames
            if self.video is None or lf.video == self.video
        ]
        if labeled_frames:
            self.start_frame.setValue(min(labeled_frames))
            self.end_frame.setValue(max(labeled_frames))
            self.start_frame.setMaximum(max(labeled_frames))
            self.end_frame.setMaximum(max(labeled_frames))

    def _create_frame_range_group(self) -> QtWidgets.QGroupBox:
        """Create frame range selection group."""
        group = QtWidgets.QGroupBox("Frame Range")
        layout = QtWidgets.QVBoxLayout(group)

        # Radio buttons for range mode
        self.range_all = QtWidgets.QRadioButton("All labeled frames")
        self.range_all.setToolTip("Render all frames with labels")
        self.range_all.setChecked(True)
        layout.addWidget(self.range_all)

        self.range_custom = QtWidgets.QRadioButton("Custom range:")
        self.range_custom.setToolTip("Render a specific frame range")
        layout.addWidget(self.range_custom)

        # Custom range inputs
        range_layout = QtWidgets.QHBoxLayout()
        range_layout.setContentsMargins(20, 0, 0, 0)

        self.start_frame = QtWidgets.QSpinBox()
        self.start_frame.setRange(0, 999999)
        self.start_frame.setEnabled(False)
        range_layout.addWidget(QtWidgets.QLabel("Start:"))
        range_layout.addWidget(self.start_frame)

        self.end_frame = QtWidgets.QSpinBox()
        self.end_frame.setRange(0, 999999)
        self.end_frame.setEnabled(False)
        range_layout.addWidget(QtWidgets.QLabel("End:"))
        range_layout.addWidget(self.end_frame)

        range_layout.addStretch()
        layout.addLayout(range_layout)

        # Include-unlabeled toggle. Without this, the render only writes frames
        # that have a LabeledFrame, so a sparse predictions file collapses to a
        # short highlight reel instead of an overlay over the original video.
        self.include_unlabeled = QtWidgets.QCheckBox(
            "Include unlabeled frames in range"
        )
        self.include_unlabeled.setToolTip(
            "When unchecked, only frames with labeled or predicted instances "
            "are written to the output video.\n"
            "When checked, every frame in the selected range is written, with "
            "skeleton overlays drawn on the frames that have instances."
        )
        layout.addWidget(self.include_unlabeled)

        # Connect range mode changes
        self.range_custom.toggled.connect(self.start_frame.setEnabled)
        self.range_custom.toggled.connect(self.end_frame.setEnabled)

        # Set range based on labels
        labeled_frames = [
            lf.frame_idx
            for lf in self.labels.labeled_frames
            if self.video is None or lf.video == self.video
        ]
        if labeled_frames:
            self.start_frame.setValue(min(labeled_frames))
            self.end_frame.setValue(max(labeled_frames))
            self.start_frame.setMaximum(max(labeled_frames))
            self.end_frame.setMaximum(max(labeled_frames))

        return group

    def _create_appearance_group(self) -> QtWidgets.QGroupBox:
        """Create appearance options group."""
        group = QtWidgets.QGroupBox("Appearance")
        layout = QtWidgets.QFormLayout(group)
        layout.setFieldGrowthPolicy(QtWidgets.QFormLayout.ExpandingFieldsGrow)

        # Color by
        self.color_by = QtWidgets.QComboBox()
        self.color_by.addItems(["track", "instance", "node"])
        self.color_by.setToolTip(
            "track: Consistent colors per tracked animal\n"
            "instance: Unique colors per animal per frame\n"
            "node: Unique colors per body part"
        )
        layout.addRow("Color by:", self.color_by)

        # Palette
        self.palette = QtWidgets.QComboBox()
        palettes = [
            "standard",
            "distinct",
            "rainbow",
            "warm",
            "cool",
            "pastel",
            "seaborn",
            "tableau10",
            "viridis",
            "glasbey",
            "glasbey_hv",
            "glasbey_cool",
            "glasbey_warm",
        ]
        self.palette.addItems(palettes)
        self.palette.setCurrentText("tableau10")
        self.palette.setToolTip("Color palette for instances/nodes")
        layout.addRow("Palette:", self.palette)

        # Marker shape
        self.marker_shape = QtWidgets.QComboBox()
        self.marker_shape.addItems(["circle", "square", "diamond", "triangle", "cross"])
        self.marker_shape.setToolTip("Shape of node markers")
        layout.addRow("Marker:", self.marker_shape)

        # Marker size
        self.marker_size = QtWidgets.QDoubleSpinBox()
        self.marker_size.setRange(1.0, 30.0)
        self.marker_size.setValue(4.0)
        self.marker_size.setSingleStep(0.5)
        self.marker_size.setToolTip("Size of node markers in pixels")
        layout.addRow("Marker size:", self.marker_size)

        # Line width
        self.line_width = QtWidgets.QDoubleSpinBox()
        self.line_width.setRange(0.5, 15.0)
        self.line_width.setValue(2.0)
        self.line_width.setSingleStep(0.5)
        self.line_width.setToolTip("Width of skeleton edges in pixels")
        layout.addRow("Line width:", self.line_width)

        # Opacity
        self.alpha = QtWidgets.QDoubleSpinBox()
        self.alpha.setRange(0.1, 1.0)
        self.alpha.setSingleStep(0.1)
        self.alpha.setValue(1.0)
        self.alpha.setToolTip("Opacity of skeleton overlay (0.1-1.0)")
        layout.addRow("Opacity:", self.alpha)

        # Show nodes/edges checkboxes
        visibility_layout = QtWidgets.QHBoxLayout()
        self.show_nodes = QtWidgets.QCheckBox("Nodes")
        self.show_nodes.setChecked(True)
        self.show_nodes.setToolTip("Show node markers")
        self.show_edges = QtWidgets.QCheckBox("Edges")
        self.show_edges.setChecked(True)
        self.show_edges.setToolTip("Show skeleton edges")
        visibility_layout.addWidget(self.show_nodes)
        visibility_layout.addWidget(self.show_edges)
        visibility_layout.addStretch()
        layout.addRow("Show:", visibility_layout)

        # Background
        self.background = QtWidgets.QComboBox()
        self.background.addItems(["video", "black", "white", "gray"])
        self.background.setToolTip(
            "Background for rendering\n"
            "video: Use original video frames\n"
            "black/white/gray: Solid color background"
        )
        layout.addRow("Background:", self.background)

        return group

    def _skeleton_node_names(self) -> list[str]:
        """Return the node names of the first skeleton, or ``[]`` if none.

        Used to populate the trail-node picker. Guarded because a Labels object
        may have no skeleton (e.g. an empty project) or an unusual node type.
        """
        try:
            skeletons = self.labels.skeletons
        except Exception:
            return []
        if not skeletons:
            return []
        names = []
        for node in skeletons[0].nodes:
            names.append(getattr(node, "name", None) or str(node))
        return names

    def _create_trails_group(self) -> QtWidgets.QGroupBox:
        """Create motion-trail options group.

        These map 1:1 to sleap-io's `render_video`/`render_image` trail kwargs.
        Trails work for untracked / single-instance data too: sleap-io keys
        trails by instance position when no tracks are present, so no track
        assignment is required.
        """
        group = QtWidgets.QGroupBox("Motion Trails")
        layout = QtWidgets.QFormLayout(group)
        layout.setFieldGrowthPolicy(QtWidgets.QFormLayout.ExpandingFieldsGrow)

        # Master toggle
        self.show_trails = QtWidgets.QCheckBox("Show motion trails")
        self.show_trails.setToolTip(
            "Draw motion trails tracing node/centroid positions over past "
            "frames.\n"
            "Works for single-instance / untracked data — trails follow each "
            "instance's position across frames, no tracks required."
        )
        layout.addRow("", self.show_trails)

        # Trail length (past frames)
        self.trail_length = QtWidgets.QSpinBox()
        self.trail_length.setRange(1, 1000)
        self.trail_length.setValue(10)
        self.trail_length.setToolTip("Number of past frames included in each trail")
        layout.addRow("Length (frames):", self.trail_length)

        # Trail node (which point the trail follows)
        self.trail_node = QtWidgets.QComboBox()
        self.trail_node.addItem("Centroid", "centroid")
        for name in self._skeleton_node_names():
            self.trail_node.addItem(name, name)
        self.trail_node.setToolTip(
            "Which point each trail follows: the instance centroid (mean of "
            "visible nodes) or a specific skeleton node"
        )
        layout.addRow("Node:", self.trail_node)

        # Trail width
        self.trail_width = QtWidgets.QDoubleSpinBox()
        self.trail_width.setRange(0.5, 15.0)
        self.trail_width.setValue(2.0)
        self.trail_width.setSingleStep(0.5)
        self.trail_width.setToolTip("Trail line width in pixels")
        layout.addRow("Width:", self.trail_width)

        # Trail opacity
        self.trail_alpha = QtWidgets.QDoubleSpinBox()
        self.trail_alpha.setRange(0.0, 1.0)
        self.trail_alpha.setSingleStep(0.1)
        self.trail_alpha.setValue(1.0)
        self.trail_alpha.setToolTip("Global trail opacity (0.0-1.0)")
        layout.addRow("Opacity:", self.trail_alpha)

        # Fade
        self.trail_fade = QtWidgets.QCheckBox("Fade older segments")
        self.trail_fade.setChecked(True)
        self.trail_fade.setToolTip("Fade trails from faint (oldest) to opaque (newest)")
        layout.addRow("", self.trail_fade)

        # Trail color (uniform override, or match pose colors)
        self.trail_color = QtWidgets.QComboBox()
        self.trail_color.addItem("Match poses", None)
        for c in ["white", "black", "red", "green", "blue", "yellow", "cyan"]:
            self.trail_color.addItem(c, c)
        self.trail_color.setToolTip(
            "Uniform trail color, or 'Match poses' to color trails by "
            "track/instance like the skeleton"
        )
        layout.addRow("Color:", self.trail_color)

        # Sub-controls are only meaningful when trails are enabled.
        self._trail_controls = [
            self.trail_length,
            self.trail_node,
            self.trail_width,
            self.trail_alpha,
            self.trail_fade,
            self.trail_color,
        ]
        self.show_trails.toggled.connect(self._on_show_trails_toggled)
        self._on_show_trails_toggled(self.show_trails.isChecked())

        return group

    def _on_show_trails_toggled(self, checked: bool):
        """Enable/disable trail sub-controls with the master toggle."""
        for widget in self._trail_controls:
            widget.setEnabled(checked)

    def _create_quality_group(self) -> QtWidgets.QGroupBox:
        """Create quality/encoding options group."""
        group = QtWidgets.QGroupBox("Quality")
        layout = QtWidgets.QFormLayout(group)
        layout.setFieldGrowthPolicy(QtWidgets.QFormLayout.ExpandingFieldsGrow)

        # Preset
        self.preset = QtWidgets.QComboBox()
        self.preset.addItems(
            ["preview (0.25x)", "draft (0.5x)", "final (1.0x)", "custom"]
        )
        self.preset.setCurrentText("final (1.0x)")
        self.preset.setToolTip(
            "Quality preset\n"
            "preview: Fast, 0.25x resolution\n"
            "draft: Medium, 0.5x resolution\n"
            "final: Full resolution"
        )
        layout.addRow("Preset:", self.preset)

        # Scale (only enabled for custom preset)
        self.scale = QtWidgets.QDoubleSpinBox()
        self.scale.setRange(0.1, 2.0)
        self.scale.setValue(1.0)
        self.scale.setSingleStep(0.1)
        self.scale.setEnabled(False)
        self.scale.setToolTip("Output scale factor (1.0 = original resolution)")
        layout.addRow("Scale:", self.scale)

        # CRF (video quality)
        self.crf = QtWidgets.QSpinBox()
        self.crf.setRange(2, 51)
        self.crf.setValue(23)
        self.crf.setToolTip(
            "Video quality (CRF)\n"
            "Lower = better quality, larger file\n"
            "Recommended: 18-28"
        )
        layout.addRow("CRF:", self.crf)

        # Connect preset to scale
        self.preset.currentTextChanged.connect(self._on_preset_changed)

        return group

    def _create_output_group(self) -> QtWidgets.QGroupBox:
        """Create output options group."""
        group = QtWidgets.QGroupBox("Output")
        layout = QtWidgets.QFormLayout(group)
        layout.setFieldGrowthPolicy(QtWidgets.QFormLayout.ExpandingFieldsGrow)

        # FPS
        self.fps = QtWidgets.QSpinBox()
        self.fps.setRange(1, 240)
        self.fps.setValue(30)
        self.fps.setToolTip("Output video frame rate")
        layout.addRow("FPS:", self.fps)

        # "Match source FPS" — keeps the output real-time relative to the
        # source. Defaults on when the source fps is readable; otherwise the
        # checkbox is disabled and the spinbox holds whatever default the user
        # picks.
        self.match_source_fps = QtWidgets.QCheckBox("Match source video FPS")
        self.match_source_fps.setToolTip(
            "When checked, the output FPS matches the source video so the "
            "rendered clip plays at the same real-time speed as the original. "
            "Uncheck to set the output FPS manually."
        )
        self.match_source_fps.setChecked(True)
        self.match_source_fps.toggled.connect(self._on_match_source_fps_toggled)
        layout.addRow("", self.match_source_fps)
        self._refresh_match_source_fps()

        # Open when done
        self.open_when_done = QtWidgets.QCheckBox("Open video when done")
        self.open_when_done.setChecked(True)
        layout.addRow("", self.open_when_done)

        return group

    def _source_fps(self) -> float | None:
        """Return the source video's fps, or ``None`` if unavailable.

        Older / malformed video backends may not expose ``fps`` or may raise
        when queried; callers must treat ``None`` as "unknown".
        """
        video = self.video
        if video is None:
            return None
        try:
            backend = getattr(video, "backend", None)
            if backend is None:
                return None
            fps = getattr(backend, "fps", None)
            return float(fps) if fps else None
        except Exception:
            return None

    def _refresh_match_source_fps(self):
        """Update the match-source-fps checkbox label / enabled state / value
        based on the currently selected video.
        """
        src = self._source_fps()
        if src is None:
            self.match_source_fps.setText("Match source video FPS (unavailable)")
            # Avoid emitting toggled() while we flip state.
            self.match_source_fps.blockSignals(True)
            self.match_source_fps.setChecked(False)
            self.match_source_fps.blockSignals(False)
            self.match_source_fps.setEnabled(False)
            self.fps.setEnabled(True)
            return

        self.match_source_fps.setEnabled(True)
        # ``%g`` avoids a trailing ".0" for integer rates like 120.
        self.match_source_fps.setText(f"Match source video FPS ({src:g})")
        if self.match_source_fps.isChecked():
            self.fps.setValue(int(round(src)))
            self.fps.setEnabled(False)
        else:
            self.fps.setEnabled(True)

    def _on_match_source_fps_toggled(self, checked: bool):
        if checked:
            src = self._source_fps()
            if src is None:
                # Nothing to match — bail by unchecking.
                self.match_source_fps.blockSignals(True)
                self.match_source_fps.setChecked(False)
                self.match_source_fps.blockSignals(False)
                self.fps.setEnabled(True)
                return
            self.fps.setValue(int(round(src)))
            self.fps.setEnabled(False)
        else:
            self.fps.setEnabled(True)

    def _create_buttons(self) -> QtWidgets.QWidget:
        """Create dialog buttons (fixed at bottom, outside scroll area)."""
        widget = QtWidgets.QWidget()
        layout = QtWidgets.QHBoxLayout(widget)
        layout.setContentsMargins(0, 8, 0, 0)

        layout.addStretch()

        self.cancel_btn = QtWidgets.QPushButton("Cancel")
        self.cancel_btn.clicked.connect(self.reject)
        layout.addWidget(self.cancel_btn)

        self.render_btn = QtWidgets.QPushButton("Render Video...")
        self.render_btn.setDefault(True)
        self.render_btn.clicked.connect(self._on_render)
        layout.addWidget(self.render_btn)

        return widget

    def _connect_signals(self):
        """Connect all control signals to preview updates."""
        # Appearance controls
        self.color_by.currentTextChanged.connect(self._update_preview)
        self.palette.currentTextChanged.connect(self._update_preview)
        self.marker_shape.currentTextChanged.connect(self._update_preview)
        self.marker_size.valueChanged.connect(self._update_preview)
        self.line_width.valueChanged.connect(self._update_preview)
        self.alpha.valueChanged.connect(self._update_preview)
        self.show_nodes.toggled.connect(self._update_preview)
        self.show_edges.toggled.connect(self._update_preview)
        self.background.currentTextChanged.connect(self._update_preview)

        # Motion trail controls
        self.show_trails.toggled.connect(self._update_preview)
        self.trail_length.valueChanged.connect(self._update_preview)
        self.trail_node.currentTextChanged.connect(self._update_preview)
        self.trail_width.valueChanged.connect(self._update_preview)
        self.trail_alpha.valueChanged.connect(self._update_preview)
        self.trail_fade.toggled.connect(self._update_preview)
        self.trail_color.currentTextChanged.connect(self._update_preview)

        # Quality controls that affect preview
        self.preset.currentTextChanged.connect(self._update_preview)
        self.scale.valueChanged.connect(self._update_preview)

    def _on_preset_changed(self, preset_text: str):
        """Handle preset change - enable/disable scale spinbox."""
        is_custom = preset_text == "custom"
        self.scale.setEnabled(is_custom)

        # Update scale value based on preset
        if not is_custom:
            preset_scales = {
                "preview (0.25x)": 0.25,
                "draft (0.5x)": 0.5,
                "final (1.0x)": 1.0,
            }
            self.scale.setValue(preset_scales.get(preset_text, 1.0))

    def _get_render_params(self, for_preview: bool = True) -> dict:
        """Get current render parameters from controls.

        Args:
            for_preview: If True, always use scale=1.0 for accurate preview.
                If False, use the actual scale setting for export.
        """
        params = {
            "color_by": self.color_by.currentText(),
            "palette": self.palette.currentText(),
            "marker_shape": self.marker_shape.currentText(),
            "marker_size": self.marker_size.value(),
            "line_width": self.line_width.value(),
            "alpha": self.alpha.value(),
            "show_nodes": self.show_nodes.isChecked(),
            "show_edges": self.show_edges.isChecked(),
        }

        # Background
        bg = self.background.currentText()
        if bg != "video":
            params["background"] = bg

        # Motion trails. Only forwarded when enabled so that, when off, both the
        # preview and export keep sleap-io's default (show_trails=False) and the
        # preview stays on its lightweight bare-LabeledFrame render path.
        if self.show_trails.isChecked():
            params["show_trails"] = True
            params["trail_length"] = self.trail_length.value()
            params["trail_node"] = self.trail_node.currentData()
            params["trail_width"] = self.trail_width.value()
            params["trail_alpha_fade"] = self.trail_fade.isChecked()
            params["trail_alpha"] = self.trail_alpha.value()
            trail_color = self.trail_color.currentData()
            if trail_color is not None:
                params["trail_color"] = trail_color

        # Scale: always 1.0 for preview (accurate display), use setting for export
        if for_preview:
            # Preview always at full resolution for accurate display
            params["scale"] = 1.0
        else:
            params["scale"] = self.scale.value()

        return params

    def _update_preview(self):
        """Update preview with current settings."""
        params = self._get_render_params()
        self.preview.set_render_params(**params)

    def _on_render(self):
        """Handle render button click - prompt for output file."""
        # Generate default filename
        default_name = "rendered_clip.mp4"
        if self.video:
            video_name = getattr(self.video, "filename", None) or getattr(
                self.video, "backend", None
            )
            if video_name:
                base = os.path.splitext(os.path.basename(str(video_name)))[0]
                default_name = f"{base}_rendered.mp4"

        filename, _ = QtWidgets.QFileDialog.getSaveFileName(
            self,
            "Save Rendered Video",
            default_name,
            "MP4 Video (*.mp4);;All Files (*)",
        )

        if not filename:
            return

        if not filename.lower().endswith(".mp4"):
            filename += ".mp4"

        self._output_path = filename
        self.accept()

    def get_output_path(self) -> str | None:
        """Get the selected output file path."""
        return self._output_path

    def get_export_params(self) -> dict:
        """Get all export parameters.

        Returns:
            Dictionary of parameters for `sio.render_video()`.
        """
        # Use actual scale setting for export (not preview's scale=1.0)
        params = self._get_render_params(for_preview=False)
        params["fps"] = self.fps.value()
        params["crf"] = self.crf.value()
        params["open_when_done"] = self.open_when_done.isChecked()

        include_unlabeled = self.include_unlabeled.isChecked()
        if include_unlabeled:
            params["include_unlabeled"] = True

        # Frame range. sleap-io's `end` is exclusive while the dialog spinbox
        # is inclusive, so add 1 when forwarding. start/end are only consumed
        # downstream when frame_inds is None (i.e. include_unlabeled is on).
        if self.range_custom.isChecked():
            params["start"] = self.start_frame.value()
            params["end"] = self.end_frame.value() + 1

        return params

    def get_frame_indices(self) -> list[int] | None:
        """Get list of frame indices to render.

        Returns:
            Sorted list of frame indices to include in the rendered video, or
            ``None`` when "Include unlabeled frames" is checked — in that case
            ``sio.render_video()`` enumerates frames itself from the video and
            the start/end range, which is required for the unlabeled frames
            to actually appear in the output.

            Sorting is required because ``Labels.labeled_frames`` is not
            guaranteed to be in frame order, and ``sio.render_video()`` writes
            frames in the order given by ``frame_inds``.
        """
        if self.include_unlabeled.isChecked():
            return None

        if self.range_all.isChecked():
            # All labeled frames for current video
            return sorted(
                lf.frame_idx
                for lf in self.labels.labeled_frames
                if self.video is None or lf.video == self.video
            )
        else:
            # Custom range - all labeled frames within range
            start = self.start_frame.value()
            end = self.end_frame.value()
            return sorted(
                lf.frame_idx
                for lf in self.labels.labeled_frames
                if (self.video is None or lf.video == self.video)
                and start <= lf.frame_idx <= end
            )

__init__(labels, video=None, current_frame=None, frame_range=None, parent=None)

Initialize the render clip dialog.

Parameters:

Name Type Description Default
labels 'sio.Labels'

The Labels object containing labeled frames.

required
video 'sio.Video | None'

The video to render. If None, uses first video in labels.

None
current_frame int | None

Initial frame to show in preview. If None, uses first labeled frame.

None
frame_range tuple[int, int] | None

Optional (start, end) tuple for initial frame range. If provided, selects "Custom range" and sets start/end values. This is typically from the main window's selected clip.

None
parent QWidget | None

Parent widget.

None
Source code in sleap/gui/dialogs/render_clip.py
def __init__(
    self,
    labels: "sio.Labels",
    video: "sio.Video | None" = None,
    current_frame: int | None = None,
    frame_range: tuple[int, int] | None = None,
    parent: QtWidgets.QWidget | None = None,
):
    """Initialize the render clip dialog.

    Args:
        labels: The Labels object containing labeled frames.
        video: The video to render. If None, uses first video in labels.
        current_frame: Initial frame to show in preview. If None, uses
            first labeled frame.
        frame_range: Optional (start, end) tuple for initial frame range.
            If provided, selects "Custom range" and sets start/end values.
            This is typically from the main window's selected clip.
        parent: Parent widget.
    """
    super().__init__(parent)
    self.labels = labels
    self.video = video or (labels.videos[0] if labels.videos else None)
    self._current_frame = current_frame
    self._initial_frame_range = frame_range
    self._output_path: str | None = None

    self._setup_ui()
    self._connect_signals()

    # Initialize frame range from main window's selection
    if frame_range is not None:
        self._set_frame_range(frame_range)

    # Jump to current frame if specified
    if current_frame is not None:
        self._jump_to_frame(current_frame)

    self._update_preview()

get_export_params()

Get all export parameters.

Returns:

Type Description
dict

Dictionary of parameters for sio.render_video().

Source code in sleap/gui/dialogs/render_clip.py
def get_export_params(self) -> dict:
    """Get all export parameters.

    Returns:
        Dictionary of parameters for `sio.render_video()`.
    """
    # Use actual scale setting for export (not preview's scale=1.0)
    params = self._get_render_params(for_preview=False)
    params["fps"] = self.fps.value()
    params["crf"] = self.crf.value()
    params["open_when_done"] = self.open_when_done.isChecked()

    include_unlabeled = self.include_unlabeled.isChecked()
    if include_unlabeled:
        params["include_unlabeled"] = True

    # Frame range. sleap-io's `end` is exclusive while the dialog spinbox
    # is inclusive, so add 1 when forwarding. start/end are only consumed
    # downstream when frame_inds is None (i.e. include_unlabeled is on).
    if self.range_custom.isChecked():
        params["start"] = self.start_frame.value()
        params["end"] = self.end_frame.value() + 1

    return params

get_frame_indices()

Get list of frame indices to render.

Returns:

Type Description
list[int] | None

Sorted list of frame indices to include in the rendered video, or None when "Include unlabeled frames" is checked — in that case sio.render_video() enumerates frames itself from the video and the start/end range, which is required for the unlabeled frames to actually appear in the output.

Sorting is required because Labels.labeled_frames is not guaranteed to be in frame order, and sio.render_video() writes frames in the order given by frame_inds.

Source code in sleap/gui/dialogs/render_clip.py
def get_frame_indices(self) -> list[int] | None:
    """Get list of frame indices to render.

    Returns:
        Sorted list of frame indices to include in the rendered video, or
        ``None`` when "Include unlabeled frames" is checked — in that case
        ``sio.render_video()`` enumerates frames itself from the video and
        the start/end range, which is required for the unlabeled frames
        to actually appear in the output.

        Sorting is required because ``Labels.labeled_frames`` is not
        guaranteed to be in frame order, and ``sio.render_video()`` writes
        frames in the order given by ``frame_inds``.
    """
    if self.include_unlabeled.isChecked():
        return None

    if self.range_all.isChecked():
        # All labeled frames for current video
        return sorted(
            lf.frame_idx
            for lf in self.labels.labeled_frames
            if self.video is None or lf.video == self.video
        )
    else:
        # Custom range - all labeled frames within range
        start = self.start_frame.value()
        end = self.end_frame.value()
        return sorted(
            lf.frame_idx
            for lf in self.labels.labeled_frames
            if (self.video is None or lf.video == self.video)
            and start <= lf.frame_idx <= end
        )

get_output_path()

Get the selected output file path.

Source code in sleap/gui/dialogs/render_clip.py
def get_output_path(self) -> str | None:
    """Get the selected output file path."""
    return self._output_path