feature: Add preview from gphoto

api/admin.php

@@ -93,7 +93,7 @@
         $newConfig['login_password'] = NULL;
     }
 
-    if ($newConfig['preview_mode'] != 'device_cam') {
+    if ($newConfig['preview_mode'] != 'device_cam' && $newConfig['preview_mode'] != 'gphoto') {
         $newConfig['previewCamTakesPic'] = false;
     }
 

api/takeVideo.php

@@ -0,0 +1,37 @@
+<?php
+header('Content-Type: application/json');
+
+require_once('../lib/config.php');
+
+function isRunning($pid) {
+    try {
+        $result = shell_exec(
+            sprintf("ps %d", $pid)
+        );
+
+        if ( count(preg_split("/\n/", $result)) > 2) {
+            return true;
+        }
+    } catch(Exception $e) {
+
+    }
+
+    return false;
+}
+
+if ($_POST['play'] === "true" ) {
+    $cmd = sprintf($config['preview']['cmd']);
+    $pid = exec($cmd, $out);
+    sleep(3);
+    die(json_encode([
+        'isRunning' => isRunning($pid),
+        'pid' => $pid - 1
+    ]));
+} elseif($_POST['play'] === "false") {
+    $killcmd = sprintf($config['preview']['killcmd']);
+    exec($killcmd);
+    die(json_encode([
+        'isRunning' => isRunning($_POST['pid']),
+        'pid' => $_POST['pid']
+    ]));
+}

config/config.inc.php

@@ -79,8 +79,9 @@
 
 // P R E V I E W
 // Please read https://github.com/andi34/photobooth/wiki/FAQ#how-to-use-a-live-stream-as-background-at-countdown
-// possible preview_mode values: none, device_cam, url
+// possible preview_mode values: none, device_cam, url, gphoto
 $config['preview_mode'] = 'none';
+$config['preview_gphoto_bsm'] = true;
 $config['previewCamTakesPic'] = false;
 $config['previewCamFlipHorizontal'] = true;
 // possible ipCamPreviewRotation values: '0deg', '90deg', -90deg', '180deg', '45deg', '-45deg'
@@ -229,6 +230,8 @@
 $config['print']['msg'] = null;
 $config['exiftool']['cmd'] = null;
 $config['exiftool']['msg'] = null;
+$config['preview']['cmd'] = null;
+$config['preview']['killcmd'] = null;
 
 
 // R E M O T E   B U Z Z E R

faq/faq.md

@@ -223,6 +223,22 @@ There's different ways depending on your needs and personal setup:
     - Capture pictures via `raspistill` won't work if motion is installed!
     - Requires Photobooth v2.2.1 or later!
 
+3. A device independent preview can also be done using the video mode of your DSLR (Linux only):
+    - install all dependencies `sudo apt install ffmpeg v4l2loopback-dkms -y`
+    - create a virtual webcam `modprobe v4l2loopback exclusive_caps=1 card_label="GPhoto2 Webcam"`
+      - `/dev/video0` is used by default, you can use `v42l-ctl --list-devices` to check which `/dev/*` is the correct one:  
+        If it doesn't match the default setup you need to adjust the `Command to generate a live preview` inside the admin panel!
+    - Give permissions to /dev/video* `sudo gpasswd -a www-data video` (this was done automatically if you used the installation script) and reboot once
+    - Admin panel config *"Preview mode"*: `from gphoto2`
+
+    **Note**
+    - Requires Photobooth v2.11.0 or later!
+    - There's a delay of about 3 seconds until the preview starts, to avoid that disable the `Battery saving mode on gphoto2 live preview` option to generate a preview in background. **This results in a high battery usage and also a general slowdown.**
+    - Sometimes Chromium doesn't detect the V4l2 camera launch from php: you need to run `sudo gphoto2 --stdout --capture-movie | ffmpeg -i - -vcodec rawvideo -pix_fmt yuv420p -threads 0 -f v4l2 /dev/video0` from terminal first and load Chromium a first time with a webpage asking for the camera.
+    - Chromium sometimes has trouble, if there is another webcam like `bcm2835-isp`, it will take it by default instead. Disable other webcams, e.g. `rmmod bcm2835-isp`.
+    - Make sure the countdown is long enough to start the preview and free gphoto2 at the end of the countdown to be able to take a picture (2 seconds before the countdown ends).
+      - For best user experience the countdown should be set at least to 8 seconds.
+
 <hr>
 
 ### Can I use a live stream as background?

install-raspbian.sh

@@ -267,6 +267,7 @@ fi
 info "### Setting permissions."
 chown -R www-data:www-data $INSTALLFOLDERPATH
 gpasswd -a www-data plugdev
+gpasswd -a www-data video
 
 if [ -f "/usr/lib/gvfs/gvfs-gphoto2-volume-monitor" ]; then
     info "### Disabling camera automount."

lib/config.php

@@ -18,6 +18,10 @@
         'exiftool' => [
             'cmd' => '',
             'msg' => '',
+        ],
+        'preview' => [
+            'cmd' => '',
+            'killcmd' => '',
         ]
     ],
     'linux' => [
@@ -32,6 +36,10 @@
         'exiftool' => [
             'cmd' => 'exiftool -overwrite_original -TagsFromFile %s %s',
             'msg' => '',
+        ],
+        'preview' => [
+            'cmd' => 'gphoto2 --stdout --capture-movie | ffmpeg -i - -vcodec rawvideo -pix_fmt yuv420p -threads 0 -f v4l2 /dev/video0 > /dev/null 2>&1 & echo $!',
+            'killcmd' => 'killall gphoto2 && sleep 1',
         ]
     ],
 ];
@@ -65,6 +73,8 @@
 $config['print']['msg'] = $cmds[$os]['print']['msg'];
 $config['exiftool']['cmd'] = $cmds[$os]['exiftool']['cmd'];
 $config['exiftool']['msg'] = $cmds[$os]['exiftool']['msg'];
+$config['preview']['cmd'] = $cmds[$os]['preview']['cmd'];
+$config['preview']['killcmd'] = $cmds[$os]['preview']['killcmd'];
 
 $config['collage_limit'] = 4;
 

lib/configsetup.inc.php

@@ -367,10 +367,16 @@
 			'options' => [
 				'none' => 'None',
 				'device_cam' => 'from device cam',
-				'url' => 'from URL'
+				'url' => 'from URL',
+				'gphoto' => 'from gphoto2'
 			],
 			'value' => $config['preview_mode']
 		],
+		'preview_gphoto_bsm' => [
+			'type' => 'checkbox',
+			'name' => 'preview_gphoto_bsm',
+			'value' => $config['preview_gphoto_bsm']
+		],
 		'previewCamTakesPic' => [
 			'type' => 'checkbox',
 			'name' => 'previewCamTakesPic',
@@ -1063,6 +1069,18 @@
 			'placeholder' => 'exiftool_msg',
 			'name' => 'exiftool[msg]',
 			'value' => htmlentities($config['exiftool']['msg'])
+		],
+		'preview_cmd' => [
+			'type' => 'input',
+			'placeholder' => 'preview_cmd',
+			'name' => 'preview[cmd]',
+			'value' => htmlentities($config['preview']['cmd'])
+		],
+		'preview_killcmd' => [
+			'type' => 'input',
+			'placeholder' => 'preview_killcmd',
+			'name' => 'preview[killcmd]',
+			'value' => htmlentities($config['preview']['killcmd'])
 		]
 	],
 	'remotebuzzer' => [

manual/faq.html

@@ -268,6 +268,23 @@ <h3>How to use a live stream as background at countdown?</h3>
 <ul><li>Do NOT enable <em>"Device cam takes picture"</em> in admin panel config!</li>
 <li>Capture pictures via <code>raspistill</code> won't work if motion is installed!</li>
 <li>Requires Photobooth v2.2.1 or later!</li></ul></li>
+<li><p>A device independent preview can also be done using the video mode of your DSLR (Linux only):</p>
+
+<ul><li>install all dependencies <code>sudo apt install ffmpeg v4l2loopback-dkms -y</code></li>
+<li>create a virtual webcam <code>modprobe v4l2loopback exclusive_caps=1 card_label="GPhoto2 Webcam"</code>
+<ul><li><code>/dev/video0</code> is used by default, you can use <code>v42l-ctl --list-devices</code> to check which <code>/dev/*</code> is the correct one: <br />
+If it doesn't match the default setup you need to adjust the <code>Command to generate a live preview</code> inside the admin panel!</li></ul></li>
+<li>Give permissions to /dev/video* <code>sudo gpasswd -a www-data video</code> (this was done automatically if you used the installation script) and reboot once</li>
+<li>Admin panel config <em>"Preview mode"</em>: <code>from gphoto2</code></li></ul>
+
+<p><strong>Note</strong></p>
+
+<ul><li>Requires Photobooth v2.11.0 or later!</li>
+<li>There's a delay of about 3 seconds until the preview starts, to avoid that disable the <code>Battery saving mode on gphoto2 live preview</code> option to generate a preview in background. <strong>This results in a high battery usage and also a general slowdown.</strong></li>
+<li>Sometimes Chromium doesn't detect the V4l2 camera launch from php: you need to run <code>sudo gphoto2 --stdout --capture-movie | ffmpeg -i - -vcodec rawvideo -pix_fmt yuv420p -threads 0 -f v4l2 /dev/video0</code> from terminal first and load Chromium a first time with a webpage asking for the camera.</li>
+<li>Chromium sometimes has trouble, if there is another webcam like <code>bcm2835-isp</code>, it will take it by default instead. Disable other webcams, e.g. <code>rmmod bcm2835-isp</code>.</li>
+<li>Make sure the countdown is long enough to start the preview and free gphoto2 at the end of the countdown to be able to take a picture (2 seconds before the countdown ends).
+<ul><li>For best user experience the countdown should be set at least to 8 seconds.</li></ul></li></ul></li>
 </ol>
 
 <hr>

resources/lang/en.json

@@ -17,6 +17,8 @@
   "commands": "Commands",
   "commands_exiftool_cmd": "EXIFtool command",
   "commands_exiftool_msg": "Success message for EXIF preservation",
+  "commands_preview_cmd": "Command to generate a live preview",
+  "commands_preview_killcmd": "Command to kill live preview",
   "commands_print_cmd": "Print command",
   "commands_print_msg": "Success message for print",
   "commands_take_picture_cmd": "Take picture command",
@@ -121,6 +123,8 @@
   "manual_chroma_keying": "If enabled, chromakeying can be accessed from gallery for your pictures.",
   "manual_commands_exiftool_cmd": "EXIFtool command line which is executed after taking a picture if \"Preserve EXIF data\" is enabled.",
   "manual_commands_exiftool_msg": "Message returned from EXIFtool commandline.",
+  "manual_commands_preview_cmd": "Command line which is executed to generate a live preview.",
+  "manual_commands_preview_killcmd": "Command line which is executed to kill the live preview.",
   "manual_commands_print_cmd": "Command line which is executed while pressing the \"Print\" button.",
   "manual_commands_print_msg": "Message returned from print command.",
   "manual_commands_take_picture_cmd": "Command line which is executed while pressing the \"Take Pic\" button. On Linux you can for example use <a href=\"http://www.gphoto.org\"  target=\"_blank\">gphoto2</a> to take pictures, on Windows you can use <a href=\"http://digicamcontrol.com\"  target=\"_blank\">digiCamControl</a>.",
@@ -200,6 +204,7 @@
   "manual_previewCamFlipHorizontal": "If enabled, preview from device cam is flipped horizontal.",
   "manual_previewCamTakesPic": "If enabled, a picture is taken from device cam instead executing the \"Take picture command\". Please note that the resolution depends on the given hight and width because it's acts like taking a screenshot.",
   "manual_preview_camera_mode": "Choose between front- or back facing camera mode of your device cam.",
+  "manual_preview_gphoto_bsm": "If enabled, gphoto2 live preview is started once a photo get triggered. This results in a delay of ~3 seconds until the preview is visible at countdown. If disabled, a preview is generated in background which results in a high battery usage and also a general slowdown.",
   "manual_preview_ipCamPreviewRotation": "Choose to rotate the preview from URL.",
   "manual_preview_ipCamURL": "CSS style to use a stream from an URL for preview while countdown. <p>Example: <code>url(../img/bg_bluegray.jpg)</code></p>",
   "manual_preview_mode": "Choose a live preview mode. By default live preview is disabled, you can choose between a preview at countdown by your device cam and a preview from a URL. Preview \"from device cam\" will always use the camera of the device where Photobooth get opened in a Browser (e.g. on a tablet it will always show the tablet camera while on a smartphone it will always show the smartphone camera instead)! A secure origin or exception is required! You can find out how to set an exception <a href=\"https://medium.com/@Carmichaelize/enabling-the-microphone-camera-in-chrome-for-local-unsecure-origins-9c90c3149339\"  target=\"_blank\">here</a>.",
@@ -289,6 +294,7 @@
   "previewCamFlipHorizontal": "Flip image from device cam horizontally",
   "previewCamTakesPic": "Device cam takes picture",
   "preview_camera_mode": "Camera facing mode",
+  "preview_gphoto_bsm": "Battery saving mode on gphoto2 live preview",
   "preview_ipCamPreviewRotation": "Rotate preview from URL",
   "preview_ipCamURL": "Preview-URL",
   "preview_mode": "Preview mode",