add compression slider

app.py

@@ -157,11 +157,16 @@ def process_video():
         if mute_audio:
             cmd.extend(['-an'])  # Remove audio
         
+        # Get quality (CRF value)
+        quality = data.get('quality', 23)
+        # Ensure quality is within valid range (18-32)
+        quality = max(18, min(32, int(quality)))
+        
         # Output settings for H.264 MP4
         cmd.extend([
             '-c:v', 'libx264',
             '-preset', 'medium',
-            '-crf', '23',
+            '-crf', str(quality),
             '-c:a', 'aac',
             '-b:a', '128k',
             '-movflags', '+faststart',

templates/index.html

@@ -588,6 +588,28 @@
                     </div>
                 </div>
 
+                <!-- Compression Quality Controls -->
+                <div class="form-group">
+                    <label>💾 Compression Quality</label>
+                    <div class="scale-slider-container">
+                        <div class="scale-display">
+                            <span>Quality: <span class="scale-value" id="quality-value-display">High</span></span>
+                            <span style="color: #6c757d;">CRF: <strong id="crf-value-display">23</strong></span>
+                        </div>
+                        <input type="range" class="scale-slider" id="quality-slider" min="18" max="32" value="23" step="1">
+                        <div class="resolution-preview">
+                            <p style="margin: 0;">💡 <strong>Lower CRF</strong> = Better quality, larger file. <strong>Higher CRF</strong> = More compressed, smaller file.</p>
+                        </div>
+                        <div class="preset-resolutions" style="margin-top: 15px;">
+                            <button class="preset-btn" data-quality="18">Best Quality</button>
+                            <button class="preset-btn" data-quality="21">High</button>
+                            <button class="preset-btn" data-quality="23">Balanced</button>
+                            <button class="preset-btn" data-quality="26">Low</button>
+                            <button class="preset-btn" data-quality="30">Smallest File</button>
+                        </div>
+                    </div>
+                </div>
+
                 <!-- Quick Actions -->
                 <div class="form-group">
                     <label>⚡ Quick Actions</label>
@@ -632,6 +654,7 @@
         let scalePercentage = 100;
         let rotationDegrees = 0;
         let muteAudio = false;
+        let compressionQuality = 23;
 
         // Upload area handling
         const uploadArea = document.getElementById('upload-area');
@@ -935,6 +958,9 @@
         const scaleSlider = document.getElementById('scale-slider');
         const scaleValueDisplay = document.getElementById('scale-value-display');
         const outputResolution = document.getElementById('output-resolution');
+        const qualitySlider = document.getElementById('quality-slider');
+        const qualityValueDisplay = document.getElementById('quality-value-display');
+        const crfValueDisplay = document.getElementById('crf-value-display');
 
         function updateScaleDisplay() {
             scalePercentage = parseInt(scaleSlider.value);
@@ -953,14 +979,40 @@
 
         scaleSlider.addEventListener('input', updateScaleDisplay);
 
+        // Quality slider
+        function updateQualityDisplay() {
+            compressionQuality = parseInt(qualitySlider.value);
+            crfValueDisplay.textContent = compressionQuality;
+            
+            // Update quality label
+            let qualityLabel = 'Balanced';
+            if (compressionQuality <= 19) qualityLabel = 'Best Quality';
+            else if (compressionQuality <= 22) qualityLabel = 'High';
+            else if (compressionQuality <= 25) qualityLabel = 'Balanced';
+            else if (compressionQuality <= 28) qualityLabel = 'Low';
+            else qualityLabel = 'Smallest File';
+            
+            qualityValueDisplay.textContent = qualityLabel;
+        }
+
+        qualitySlider.addEventListener('input', updateQualityDisplay);
+        updateQualityDisplay();
+
         // Scale presets
         document.querySelectorAll('.preset-btn').forEach(btn => {
             btn.addEventListener('click', () => {
                 const scale = btn.dataset.scale;
+                const quality = btn.dataset.quality;
+                
                 if (scale) {
                     scaleSlider.value = scale;
                     updateScaleDisplay();
                 }
+                
+                if (quality) {
+                    qualitySlider.value = quality;
+                    updateQualityDisplay();
+                }
             });
         });
 
@@ -984,7 +1036,8 @@
                 end_time: endTime,
                 scale_percentage: scalePercentage,
                 rotation: rotationDegrees,
-                mute_audio: muteAudio
+                mute_audio: muteAudio,
+                quality: compressionQuality
             };
 
             if (cropWidth > 0 && cropHeight > 0) {
@@ -1048,8 +1101,9 @@
             rotationDegrees = 0;
             muteAudio = false;
             scalePercentage = 100;
+            compressionQuality = 23;
 
-            videoPreview.src = '';
+            videoPreview.src = '';;
             videoInput.value = '';
             clearCropCanvas();
             cropCanvas.classList.remove('active');
@@ -1065,6 +1119,8 @@
             document.getElementById('scale-value-display').textContent = '100%';
             document.getElementById('output-resolution').textContent = '--';
             document.getElementById('current-time-display').textContent = '0:00';
+            document.getElementById('quality-slider').value = '23';
+            updateQualityDisplay();
             
             // Reset quick actions
             document.getElementById('mute-audio-btn').classList.remove('active');