Option to limit the framerate of dizqueTV's output

src/api.js

@@ -303,6 +303,10 @@ function api(db, channelDB, fillerDB, xmltvInterval,  guideService ) {
       try {
         db['ffmpeg-settings'].update({ _id: req.body._id }, req.body)
         let ffmpeg = db['ffmpeg-settings'].find()[0]
+        let err = fixupFFMPEGSettings(ffmpeg);
+        if (typeof(err) !== 'undefined') {
+          return res.status(400).send(err);
+        }
         res.send(ffmpeg)
       } catch(err) {
         console.error(err);
@@ -323,6 +327,14 @@ function api(db, channelDB, fillerDB, xmltvInterval,  guideService ) {
 
     })
 
+    function fixupFFMPEGSettings(ffmpeg) {
+      if (typeof(ffmpeg.maxFPS) === 'undefined') {
+        ffmpeg.maxFPS = 60;
+      } else if ( isNaN(ffmpeg.maxFPS) ) {
+        return "maxFPS should be a number";
+      }
+    }
+
     // PLEX SETTINGS
     router.get('/api/plex-settings', (req, res) => {
       try {

src/database-migration.js

@@ -20,7 +20,7 @@
 const path = require('path');
 var fs = require('fs');
 
-const TARGET_VERSION = 600;
+const TARGET_VERSION = 601;
 
 const STEPS = [
     // [v, v2, x] : if the current version is v, call x(db), and version becomes v2
@@ -31,6 +31,7 @@ const STEPS = [
     [    400,    500, (db,channels) => splitServersSingleChannels(db, channels) ],
     [    500,    501, (db) => fixCorruptedServer(db) ],
     [    501,    600, () => extractFillersFromChannels() ],
+    [    600,    601, (db) => addFPS(db) ],
 ]
 
 const { v4: uuidv4 } = require('uuid');
@@ -392,6 +393,7 @@ function ffmpeg() {
         normalizeAudioCodec: true,
         normalizeResolution: true,
         normalizeAudio: true,
+        maxFPS: 60,
     }
 }
 
@@ -662,6 +664,13 @@ function extractFillersFromChannels() {
    
 }
 
+function addFPS(db) {
+    let ffmpegSettings = db['ffmpeg-settings'].find()[0];
+    let f = path.join(process.env.DATABASE, 'ffmpeg-settings.json');
+    ffmpegSettings.maxFPS = 60;
+    fs.writeFileSync( f, JSON.stringify( [ffmpegSettings] ) );
+}
+
 module.exports = {
     initDB: initDB,
     defaultFFMPEG: ffmpeg,

src/ffmpeg.js

@@ -2,6 +2,7 @@ const spawn = require('child_process').spawn
 const events = require('events')
 
 const MAXIMUM_ERROR_DURATION_MS = 60000;
+const REALLY_RIDICULOUSLY_HIGH_FPS_FOR_DIZQUETVS_USECASE = 120;
 
 class FFMPEG extends events.EventEmitter {
     constructor(opts, channel) {
@@ -9,7 +10,7 @@ class FFMPEG extends events.EventEmitter {
         this.opts = opts;
         this.errorPicturePath = `http://localhost:${process.env.PORT}/images/generic-error-screen.png`;
         if (! this.opts.enableFFMPEGTranscoding) {
-            //this ensures transcoding is completely disabled even if 
+            //this ensures transcoding is completely disabled even if
             // some settings are true
             this.opts.normalizeAudio = false;
             this.opts.normalizeAudioCodec = false;
@@ -17,6 +18,7 @@ class FFMPEG extends events.EventEmitter {
             this.opts.errorScreen = 'kill';
             this.opts.normalizeResolution = false;
             this.opts.audioVolumePercent = 100;
+            this.opts.maxFPS = REALLY_RIDICULOUSLY_HIGH_FPS_FOR_DIZQUETVS_USECASE;
         }
         this.channel = channel
         this.ffmpegPath = opts.ffmpegPath
@@ -129,6 +131,11 @@ class FFMPEG extends events.EventEmitter {
             // When adding filters, make sure that
             // videoComplex always begins wiht ; and doesn't end with ;
 
+            if ( streamStats.videoFramerate >= this.opts.maxFPS + 0.000001 ) {
+                videoComplex += `;${currentVideo}fps=${this.opts.maxFPS}[fpchange]`;
+                currentVideo ="[fpchange]";
+            }
+
             // prepare input streams
             if ( typeof(streamUrl.errorTitle) !== 'undefined') {
                 doOverlay = false; //never show icon in the error screen
@@ -263,7 +270,7 @@ class FFMPEG extends events.EventEmitter {
                     currentVideo = "blackpadded";
                 }
                 let name = "siz";
-                if (! this.ensureResolution) {
+                if (! this.ensureResolution && (beforeSizeChange != '[fpchange]') ) {
                     name = "minsiz";
                 }
                 videoComplex += `;[${currentVideo}]setsar=1[${name}]`;

web/directives/ffmpeg-settings.js

@@ -59,6 +59,17 @@
                 {value:"sine", description:"Beep"},
                 {value:"silent", description:"No Audio"},
             ]
+            scope.fpsOptions = [
+                {id: 23.976, description: "23.976 frames per second"},
+                {id: 24, description: "24 frames per second"},
+                {id: 25, description: "25 frames per second"},
+                {id: 29.97, description: "29.97 frames per second"},
+                {id: 30, description: "30 frames per second"},
+                {id: 50, description: "50 frames per second"},
+                {id: 59.94, description: "59.94 frames per second"},
+                {id: 60, description: "60 frames per second"},
+                {id: 120, description: "120 frames per second"},
+            ];
         }
     }
 }

web/public/templates/ffmpeg-settings.html

@@ -91,6 +91,10 @@
             <br />
             <label>Video Buffer Size (k)</label>
             <input type="number" class="form-control form-control-sm" ng-model="settings.videoBufSize"/>
+            <label>Max Frame Rate</label>
+            <select class='form-control custom-select'  ng-model="settings.maxFPS" ria-describedby="fpsHelp"
+            ng-options="o.id as o.description for o in fpsOptions" ></select>
+            <small id='fpsHelp' class='form-text text-muted'>Will transcode videos that have FPS higher than this.</small>
         </div>
 
         <div class="form-group">