Implemented the ffmpeg video compilation

frontend/src/App.svelte

@@ -39,6 +39,8 @@
   function closeGallery() {
     galleryFolder = null;
     currentView = 'main';
+    // Check for any running job (e.g., video compilation started from gallery)
+    checkAndPollProgress();
   }
 
   function handleConnectionChange(data) {

src/video/ffmpeg.rs

@@ -4,13 +4,13 @@ use crate::config::VideoConfig;
 use crate::error::{Error, Result};
 use std::path::Path;
 use std::process::Stdio;
-use tokio::io::{AsyncBufReadExt, BufReader};
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
 use tokio::process::Command;
 
 /// Compile images into a timelapse video.
 ///
 /// # Arguments
-/// * `input_dir` - Directory containing numbered JPEG images
+/// * `input_dir` - Directory containing JPEG images (sorted alphabetically for order)
 /// * `output_path` - Path for the output video file
 /// * `config` - Video configuration
 /// * `progress_callback` - Called with (current_frame, total_frames)
@@ -23,35 +23,65 @@ pub async fn compile_timelapse<F>(
 where
     F: FnMut(u32, u32),
 {
-    // Count input images
-    let mut image_count = 0u32;
+    // Collect and sort image files for reliable ordering.
+    // Filenames are timestamp-based, so alphabetical sort = chronological order.
+    let mut image_files: Vec<_> = Vec::new();
     let mut entries = tokio::fs::read_dir(input_dir).await?;
+
     while let Some(entry) = entries.next_entry().await? {
         let path = entry.path();
         if path.extension().map(|e| e == "jpg").unwrap_or(false) {
-            image_count += 1;
+            image_files.push(path);
         }
     }
 
-    if image_count == 0 {
+    if image_files.is_empty() {
         return Err(Error::VideoCompilation(
             "No images found in input directory".to_string(),
         ));
     }
 
+    // Sort alphabetically (timestamp-based names ensure chronological order)
+    image_files.sort();
+    let image_count = image_files.len() as u32;
+
     tracing::info!("Compiling {} images into video", image_count);
 
-    // Build ffmpeg command
-    let input_pattern = input_dir.join("*.jpg").to_string_lossy().to_string();
+    // Create concat file for ffmpeg (more reliable than glob pattern).
+    // Format: file '/path/to/image.jpg'\nduration 0.0667\n...
+    let frame_duration = 1.0 / config.framerate as f64;
+    let concat_path = input_dir.join(".concat.txt");
 
+    let mut concat_content = String::new();
+    for (i, path) in image_files.iter().enumerate() {
+        // Use just the filename since concat file is in the same directory as images
+        let filename = path
+            .file_name()
+            .map(|f| f.to_string_lossy())
+            .unwrap_or_default()
+            .replace('\'', "'\\''");
+        concat_content.push_str(&format!("file '{}'\n", filename));
+
+        // Don't add duration after the last frame
+        if i < image_files.len() - 1 {
+            concat_content.push_str(&format!("duration {:.6}\n", frame_duration));
+        }
+    }
+
+    // Write concat file
+    let mut file = tokio::fs::File::create(&concat_path).await?;
+    file.write_all(concat_content.as_bytes()).await?;
+    file.flush().await?;
+
+    // Build ffmpeg command using concat demuxer
     let mut cmd = Command::new("ffmpeg");
     cmd.arg("-y") // Overwrite output
-        .arg("-framerate")
-        .arg(config.framerate.to_string())
-        .arg("-pattern_type")
-        .arg("glob")
+        .arg("-f")
+        .arg("concat")
+        .arg("-safe")
+        .arg("0") // Allow absolute paths
         .arg("-i")
-        .arg(&input_pattern)
+        .arg(&concat_path)
         .arg("-c:v")
         .arg(&config.codec)
         .arg("-crf")
@@ -71,10 +101,29 @@ where
         ))
     })?;
 
-    // Parse progress from stdout
-    let stdout = child.stdout.take().unwrap();
-    let mut reader = BufReader::new(stdout).lines();
+    // Capture stdout for progress and stderr for errors
+    let stdout = child
+        .stdout
+        .take()
+        .ok_or_else(|| Error::FFmpeg("Failed to capture ffmpeg stdout".to_string()))?;
+    let stderr = child
+        .stderr
+        .take()
+        .ok_or_else(|| Error::FFmpeg("Failed to capture ffmpeg stderr".to_string()))?;
 
+    // Read stderr in background to avoid blocking
+    let stderr_handle = tokio::spawn(async move {
+        let mut stderr_reader = BufReader::new(stderr).lines();
+        let mut stderr_output = String::new();
+        while let Ok(Some(line)) = stderr_reader.next_line().await {
+            stderr_output.push_str(&line);
+            stderr_output.push('\n');
+        }
+        stderr_output
+    });
+
+    // Parse progress from stdout
+    let mut reader = BufReader::new(stdout).lines();
     while let Some(line) = reader.next_line().await? {
         if line.starts_with("frame=") {
             if let Some(frame_str) = line.strip_prefix("frame=") {
@@ -86,11 +135,20 @@ where
     }
 
     let status = child.wait().await?;
+    let stderr_output = stderr_handle.await.unwrap_or_default();
+
+    // Clean up concat file
+    let _ = tokio::fs::remove_file(&concat_path).await;
 
     if !status.success() {
+        // Get last few lines of stderr for the error message
+        let error_lines: Vec<&str> = stderr_output.lines().rev().take(10).collect();
+        let error_detail = error_lines.into_iter().rev().collect::<Vec<_>>().join("\n");
+
         return Err(Error::FFmpeg(format!(
-            "ffmpeg exited with status {}",
-            status
+            "ffmpeg exited with status {}\n{}",
+            status,
+            error_detail
         )));
     }
 

src/web/handlers.rs

@@ -942,7 +942,6 @@ async fn compile_folder_video(
         // Update final status
         match result {
             Ok(_) => {
-                tracing::info!("Video compilation complete for folder: {}", folder_name_clone);
                 job_state
                     .update_progress(Progress {
                         status: JobStatus::Completed,

src/web/state.rs

@@ -17,6 +17,14 @@ pub enum JobStatus {
     Error(String),
 }
 
+impl JobStatus {
+    /// Returns true if this is a terminal status (job has finished).
+    /// Terminal statuses should not be overwritten by non-terminal statuses.
+    pub fn is_terminal(&self) -> bool {
+        matches!(self, JobStatus::Completed | JobStatus::Cancelled | JobStatus::Error(_))
+    }
+}
+
 /// Detailed statistics for skipped images.
 #[derive(Debug, Clone, Default)]
 pub struct SkipStats {
@@ -102,8 +110,26 @@ impl AppState {
     }
 
     /// Update progress and broadcast to all listeners.
+    ///
+    /// Note: This method prevents non-terminal statuses (Running, CompilingVideo)
+    /// from overwriting terminal statuses (Completed, Cancelled, Error). This
+    /// avoids race conditions where fire-and-forget progress updates arrive after
+    /// the job has finished.
     pub async fn update_progress(&self, progress: Progress) {
-        *self.progress.write().await = progress.clone();
+        let mut current = self.progress.write().await;
+
+        // Don't allow non-terminal statuses to overwrite terminal statuses.
+        // This prevents race conditions from fire-and-forget progress callbacks.
+        if current.status.is_terminal() && !progress.status.is_terminal() {
+            tracing::debug!(
+                "Ignoring progress update: current status {:?} is terminal, incoming {:?} is not",
+                current.status,
+                progress.status
+            );
+            return;
+        }
+
+        *current = progress.clone();
         let _ = self.progress_tx.send(progress);
     }
 
@@ -112,9 +138,11 @@ impl AppState {
         let cancel_token = self.cancel_token.read().await;
         if let Some(token) = cancel_token.as_ref() {
             token.cancel();
-            // Update progress to show cancelling state immediately
+            // Update progress to show cancelling state immediately.
+            // Only change to Cancelling if in an active (non-terminal) state.
             let mut progress = self.progress.write().await;
-            if progress.status == JobStatus::Running || progress.status == JobStatus::CompilingVideo
+            if progress.status == JobStatus::Running
+                || progress.status == JobStatus::CompilingVideo
             {
                 progress.status = JobStatus::Cancelling;
                 progress.message = Some("Cancelling...".to_string());