DOC: Demonstrate how to programatically start/stop recording, save

Author: thewtex

.gitignore

@@ -27,6 +27,7 @@ examples/Bunny.vtp
 examples/uGridEx.vtk
 examples/input.tiff
 examples/Normal071-VascularNetwork.tre
+examples/video.mp4
 
 js/lib/ZstdDecompress/web-build/
 .pytest_cache/

examples/RecordAVideo.ipynb

@@ -9,18 +9,21 @@
     "# Install dependencies for this example\n",
     "# Note: This does not include itkwidgets, itself\n",
     "# The page may need to be reloaded after ipywebrtc is installed\n",
+    "# And another note: As of this writing, ipywebrtc has not been updated to work\n",
+    "# with JupyterLab 2 or JupyterLab 3 -- JupyterLab 1 or the Jupyter Notebook is required.\n",
     "import sys\n",
-    "!{sys.executable} -m pip install itk-io ipywebrtc>=0.5.1"
+    "!{sys.executable} -m pip install itk-io ipywebrtc"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 7,
    "metadata": {},
    "outputs": [],
    "source": [
     "from urllib.request import urlretrieve\n",
     "import os\n",
+    "import time\n",
     "\n",
     "import itk\n",
     "\n",
@@ -31,7 +34,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -44,18 +47,18 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 4,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "application/vnd.jupyter.widget-view+json": {
-       "model_id": "2d337065a4ba48bdaf7693d44eae7d9c",
+       "model_id": "216f67a967bb476cafa57ef208dc6df7",
        "version_major": 2,
        "version_minor": 0
       },
       "text/plain": [
-       "Viewer(annotations=False, cmap='BuRd', geometries=[], gradient_opacity=0.22, point_sets=[], rendered_image=<it…"
+       "Viewer(annotations=False, cmap=['BuRd'], geometries=[], gradient_opacity=0.22, point_sets=[], rendered_image=<…"
       ]
      },
      "metadata": {},
@@ -71,18 +74,18 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 5,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "application/vnd.jupyter.widget-view+json": {
-       "model_id": "19b8e9ffead7440ea807df5d810c7a16",
+       "model_id": "045847c75ed440b4a020960e705f4378",
        "version_major": 2,
        "version_minor": 0
       },
       "text/plain": [
-       "VideoRecorder(autosave=True, filename='widget_video.webm', stream=Viewer(annotations=False, cmap='BuRd', geome…"
+       "VideoRecorder(autosave=True, filename='widget_video.webm', stream=Viewer(annotations=False, background=(0.9333…"
       ]
      },
      "metadata": {},
@@ -94,6 +97,34 @@
     "recorder"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The recorder widget has button to record, playback, and download the video, but this is also possible programmatically."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "recorder.recording = True\n",
+    "time.sleep(3)\n",
+    "recorder.recording = False"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Save to a different file in a different format\n",
+    "recorder.save('video.mp4')"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -144,6 +175,19 @@
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
    "version": "3.7.6"
+  },
+  "toc": {
+   "base_numbering": 1,
+   "nav_menu": {},
+   "number_sections": false,
+   "sideBar": false,
+   "skip_h1_title": false,
+   "title_cell": "Table of Contents",
+   "title_sidebar": "Contents",
+   "toc_cell": false,
+   "toc_position": {},
+   "toc_section_display": false,
+   "toc_window_display": false
   }
  },
  "nbformat": 4,