use native player to speed up playback

src-tauri/Cargo.lock

@@ -136,6 +136,12 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
 
+[[package]]
+name = "ascii"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d92bec98840b8f03a5ff5413de5293bfcd8bf96467cf5452609f939ec6f5de16"
+
 [[package]]
 name = "ashpd"
 version = "0.10.2"
@@ -594,6 +600,12 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "chunked_transfer"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e4de3bc4ea267985becf712dc6d9eed8b04c953b3fcfb339ebc87acd9804901"
+
 [[package]]
 name = "clang-sys"
 version = "1.8.1"
@@ -1987,6 +1999,12 @@ version = "1.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7d71d3574edd2771538b901e6549113b4006ece66150fb69c0fb6d9a2adae946"
 
+[[package]]
+name = "httpdate"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
+
 [[package]]
 name = "hyper"
 version = "1.5.2"
@@ -2504,6 +2522,7 @@ dependencies = [
  "tauri-plugin-fs",
  "tauri-plugin-log",
  "tauri-plugin-shell",
+ "tiny_http",
  "tracing",
  "tracing-subscriber",
 ]
@@ -5191,6 +5210,18 @@ dependencies = [
  "time-core",
 ]
 
+[[package]]
+name = "tiny_http"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "389915df6413a2e74fb181895f933386023c71110878cd0825588928e64cdc82"
+dependencies = [
+ "ascii",
+ "chunked_transfer",
+ "httpdate",
+ "log",
+]
+
 [[package]]
 name = "tinystr"
 version = "0.7.6"

src-tauri/Cargo.toml

@@ -41,6 +41,9 @@ ffmpeg-next = "7.0"
 lru = "0.12"
 image = { version = "0.24", default-features = false, features = ["jpeg"] }
 
+# HTTP server for video streaming
+tiny_http = "0.12"
+
 [profile.dev]
 opt-level = 1  # Enable basic optimizations in debug mode for audio decoding performance
 

src-tauri/src/lib.rs

@@ -8,6 +8,7 @@ use tauri::{AppHandle, Manager, Url, WebviewUrl, WebviewWindowBuilder};
 
 mod audio;
 mod video;
+mod video_server;
 
 
 #[derive(Default)]
@@ -128,10 +129,16 @@ fn handle_file_associations(app: AppHandle, files: Vec<PathBuf>) {
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
     let pkg_name = env!("CARGO_PKG_NAME").to_string();
+    // Initialize video HTTP server
+    let video_server = video_server::VideoServer::new()
+        .expect("Failed to start video server");
+    eprintln!("[App] Video server started on port {}", video_server.port());
+
     tauri::Builder::default()
       .manage(Mutex::new(AppState::default()))
       .manage(Arc::new(Mutex::new(audio::AudioState::default())))
       .manage(Arc::new(Mutex::new(video::VideoState::default())))
+      .manage(Arc::new(Mutex::new(video_server)))
       .setup(|app| {
         #[cfg(any(windows, target_os = "linux"))] // Windows/Linux needs different handling from macOS
         {
@@ -255,8 +262,12 @@ pub fn run() {
         audio::audio_load_track_graph,
         video::video_load_file,
         video::video_get_frame,
+        video::video_get_frames_batch,
         video::video_set_cache_size,
         video::video_get_pool_info,
+        video::video_ipc_benchmark,
+        video::video_get_transcode_status,
+        video::video_allow_asset,
       ])
       // .manage(window_counter)
       .build(tauri::generate_context!())

src-tauri/src/video.rs

@@ -1,10 +1,10 @@
 use std::sync::{Arc, Mutex};
 use std::num::NonZeroUsize;
-use std::io::Cursor;
 use ffmpeg_next as ffmpeg;
 use lru::LruCache;
 use daw_backend::WaveformPeak;
-use image::{RgbaImage, ImageEncoder};
+use image::RgbaImage;
+use tauri::Manager;
 
 #[derive(serde::Serialize, Clone)]
 pub struct VideoFileMetadata {
@@ -19,6 +19,10 @@ pub struct VideoFileMetadata {
     pub audio_sample_rate: Option<u32>,
     pub audio_channels: Option<u32>,
     pub audio_waveform: Option<Vec<WaveformPeak>>,
+    pub codec_name: String,
+    pub is_browser_compatible: bool,
+    pub http_url: Option<String>,  // HTTP URL to stream video (if compatible or transcode complete)
+    pub transcoding: bool,  // True if currently transcoding
 }
 
 struct VideoDecoder {
@@ -119,7 +123,7 @@ impl VideoDecoder {
             return Ok(cached_frame.clone());
         }
 
-        let t_after_cache = Instant::now();
+        let _t_after_cache = Instant::now();
 
         // Determine if we need to seek
         // Seek if: no decoder open, going backwards, or jumping forward more than 2 seconds
@@ -240,10 +244,24 @@ impl VideoDecoder {
     }
 }
 
+use std::collections::HashMap;
+use std::path::PathBuf;
+
+#[derive(Clone)]
+pub struct TranscodeJob {
+    pub pool_index: usize,
+    pub input_path: String,
+    pub output_path: String,
+    pub http_url: Option<String>,  // HTTP URL when transcode completes
+    pub progress: f32,  // 0.0 to 1.0
+    pub completed: bool,
+}
+
 pub struct VideoState {
     pool: Vec<Arc<Mutex<VideoDecoder>>>,
     next_pool_index: usize,
     cache_size: usize,
+    transcode_jobs: Arc<Mutex<HashMap<usize, TranscodeJob>>>,  // pool_index -> job
 }
 
 impl Default for VideoState {
@@ -252,6 +270,7 @@ impl Default for VideoState {
             pool: Vec::new(),
             next_pool_index: 0,
             cache_size: 20, // Default cache size
+            transcode_jobs: Arc::new(Mutex::new(HashMap::new())),
         }
     }
 }
@@ -260,8 +279,11 @@ impl Default for VideoState {
 pub async fn video_load_file(
     video_state: tauri::State<'_, Arc<Mutex<VideoState>>>,
     audio_state: tauri::State<'_, Arc<Mutex<crate::audio::AudioState>>>,
+    video_server: tauri::State<'_, Arc<Mutex<crate::video_server::VideoServer>>>,
     path: String,
 ) -> Result<VideoFileMetadata, String> {
+    eprintln!("[Video] Loading file: {}", path);
+
     ffmpeg::init().map_err(|e| e.to_string())?;
 
     // Open input to check for audio stream
@@ -386,13 +408,45 @@ pub async fn video_load_file(
         (None, None, None, None, None)
     };
 
+    // Detect video codec
+    let video_stream = input.streams()
+        .best(ffmpeg::media::Type::Video)
+        .ok_or("No video stream found")?;
+
+    let codec_id = video_stream.parameters().id();
+    let codec_name = ffmpeg::codec::Id::name(&codec_id).to_string();
+
+    // Check if codec is browser-compatible (can play directly)
+    // Browsers support: H.264/AVC, VP8, VP9, AV1 (limited)
+    let is_browser_compatible = matches!(
+        codec_id,
+        ffmpeg::codec::Id::H264 |
+        ffmpeg::codec::Id::VP8 |
+        ffmpeg::codec::Id::VP9 |
+        ffmpeg::codec::Id::AV1
+    );
+
+    eprintln!("[Video Codec] {} - Browser compatible: {}", codec_name, is_browser_compatible);
+
     // Create video decoder with max dimensions for playback (800x600)
     // This scales down high-res videos to reduce data transfer
     let mut video_state_guard = video_state.lock().unwrap();
     let pool_index = video_state_guard.next_pool_index;
     video_state_guard.next_pool_index += 1;
 
-    let decoder = VideoDecoder::new(path, video_state_guard.cache_size, Some(800), Some(600))?;
+    let decoder = VideoDecoder::new(path.clone(), video_state_guard.cache_size, Some(800), Some(600))?;
+
+    // Add file to HTTP server if browser-compatible
+    let http_url = if is_browser_compatible {
+        let server = video_server.lock().unwrap();
+        let url_path = format!("/video/{}", pool_index);
+        server.add_file(url_path.clone(), PathBuf::from(&path));
+        let http_url = server.get_url(&url_path);
+        eprintln!("[Video] Browser-compatible, serving at: {}", http_url);
+        Some(http_url)
+    } else {
+        None
+    };
 
     let metadata = VideoFileMetadata {
         pool_index,
@@ -406,13 +460,152 @@ pub async fn video_load_file(
         audio_sample_rate,
         audio_channels,
         audio_waveform,
+        codec_name,
+        is_browser_compatible,
+        http_url,
+        transcoding: !is_browser_compatible,
     };
 
     video_state_guard.pool.push(Arc::new(Mutex::new(decoder)));
 
+    // Start background transcoding if not browser-compatible
+    if !is_browser_compatible {
+        eprintln!("[Video Transcode] Starting background transcode for pool_index {}", pool_index);
+        let jobs = video_state_guard.transcode_jobs.clone();
+        let input_path = path.clone();
+        let pool_idx = pool_index;
+        let server = video_server.inner().clone();
+
+        tauri::async_runtime::spawn(async move {
+            if let Err(e) = start_transcode(jobs, pool_idx, input_path, server).await {
+                eprintln!("[Video Transcode] Failed: {}", e);
+            }
+        });
+    }
+
     Ok(metadata)
 }
 
+// Background transcode to WebM/VP9 for browser compatibility
+async fn start_transcode(
+    jobs: Arc<Mutex<HashMap<usize, TranscodeJob>>>,
+    pool_index: usize,
+    input_path: String,
+    video_server: Arc<Mutex<crate::video_server::VideoServer>>,
+) -> Result<(), String> {
+    use std::process::Command;
+
+    // Generate output path in system cache directory
+    let cache_dir = std::env::temp_dir().join("lightningbeam_transcoded");
+    std::fs::create_dir_all(&cache_dir).map_err(|e| e.to_string())?;
+
+    let input_file = PathBuf::from(&input_path);
+    let file_stem = input_file.file_stem()
+        .ok_or("Invalid input path")?
+        .to_string_lossy();
+    let output_path = cache_dir.join(format!("{}_{}.webm", file_stem, pool_index));
+
+    // Create job entry
+    {
+        let mut jobs_guard = jobs.lock().unwrap();
+        jobs_guard.insert(pool_index, TranscodeJob {
+            pool_index,
+            input_path: input_path.clone(),
+            output_path: output_path.to_string_lossy().to_string(),
+            http_url: None,
+            progress: 0.0,
+            completed: false,
+        });
+    }
+
+    eprintln!("[Video Transcode] Output: {}", output_path.display());
+
+    // Run FFmpeg transcode command
+    // Using VP9 codec with CRF 30 (good quality/size balance) and fast encoding
+    let output = Command::new("ffmpeg")
+        .args(&[
+            "-i", &input_path,
+            "-c:v", "libvpx-vp9",  // VP9 video codec
+            "-crf", "30",           // Quality (lower = better, 23-32 recommended)
+            "-b:v", "0",            // Use CRF mode
+            "-threads", "4",        // Use 4 threads
+            "-row-mt", "1",         // Enable row-based multithreading
+            "-speed", "4",          // Encoding speed (0=slowest/best, 4=good balance)
+            "-c:a", "libopus",      // Opus audio codec (best for WebM)
+            "-b:a", "128k",         // Audio bitrate
+            "-y",                   // Overwrite output
+            output_path.to_str().ok_or("Invalid output path")?,
+        ])
+        .output()
+        .map_err(|e| format!("Failed to spawn ffmpeg: {}", e))?;
+
+    if output.status.success() {
+        eprintln!("[Video Transcode] Completed: {}", output_path.display());
+
+        // Add transcoded file to HTTP server
+        let server = video_server.lock().unwrap();
+        let url_path = format!("/video/{}", pool_index);
+        server.add_file(url_path.clone(), output_path.clone());
+        let http_url = server.get_url(&url_path);
+        eprintln!("[Video Transcode] Serving at: {}", http_url);
+        drop(server);
+
+        // Mark as completed and store HTTP URL
+        let mut jobs_guard = jobs.lock().unwrap();
+        if let Some(job) = jobs_guard.get_mut(&pool_index) {
+            job.progress = 1.0;
+            job.completed = true;
+            job.http_url = Some(http_url);
+        }
+        eprintln!("[Video Transcode] Job completed for pool_index {}", pool_index);
+        Ok(())
+    } else {
+        let stderr = String::from_utf8_lossy(&output.stderr);
+        eprintln!("[Video Transcode] FFmpeg error: {}", stderr);
+        Err(format!("FFmpeg failed: {}", stderr))
+    }
+}
+
+// Get transcode status for a pool index
+#[tauri::command]
+pub async fn video_get_transcode_status(
+    video_state: tauri::State<'_, Arc<Mutex<VideoState>>>,
+    pool_index: usize,
+) -> Result<Option<(String, f32, bool, Option<String>)>, String> {
+    let state = video_state.lock().unwrap();
+    let jobs = state.transcode_jobs.lock().unwrap();
+
+    if let Some(job) = jobs.get(&pool_index) {
+        Ok(Some((job.output_path.clone(), job.progress, job.completed, job.http_url.clone())))
+    } else {
+        Ok(None)
+    }
+}
+
+// Add a video file to asset protocol scope so browser can access it
+#[tauri::command]
+pub async fn video_allow_asset(
+    app: tauri::AppHandle,
+    path: String,
+) -> Result<(), String> {
+    use tauri_plugin_fs::FsExt;
+
+    let file_path = PathBuf::from(&path);
+
+    // Add to FS scope
+    let fs_scope = app.fs_scope();
+    fs_scope.allow_file(&file_path)
+        .map_err(|e| format!("Failed to allow file in fs scope: {}", e))?;
+
+    // Add to asset protocol scope
+    let asset_scope = app.asset_protocol_scope();
+    asset_scope.allow_file(&file_path)
+        .map_err(|e| format!("Failed to allow file in asset scope: {}", e))?;
+
+    eprintln!("[Video] Added to asset scope: {}", path);
+    Ok(())
+}
+
 fn generate_waveform(audio_data: &[f32], channels: u32, target_peaks: usize) -> Vec<WaveformPeak> {
     let total_samples = audio_data.len();
     let samples_per_channel = total_samples / channels as usize;
@@ -465,6 +658,9 @@ pub async fn video_get_frame(
 ) -> Result<(), String> {
     use std::time::Instant;
 
+    let t_total_start = Instant::now();
+
+    let t_lock_start = Instant::now();
     let video_state = state.lock().unwrap();
 
     let decoder = video_state.pool.get(pool_index)
@@ -474,11 +670,14 @@ pub async fn video_get_frame(
     drop(video_state);
 
     let mut decoder = decoder.lock().unwrap();
+    let t_lock_end = Instant::now();
+
+    let t_decode_start = Instant::now();
     let frame_data = decoder.get_frame(timestamp)?;
+    let t_decode_end = Instant::now();
 
-    let data_to_send = if use_jpeg {
     let t_compress_start = Instant::now();
-
+    let data_to_send = if use_jpeg {
         // Get frame dimensions from decoder
         let width = decoder.output_width;
         let height = decoder.output_height;
@@ -500,23 +699,36 @@ pub async fn video_get_frame(
             image::ColorType::Rgb8
         ).map_err(|e| format!("JPEG encoding failed: {}", e))?;
 
-        let compress_time = t_compress_start.elapsed().as_millis();
-        let original_size = width as usize * height as usize * 4;
-        let compressed_size = jpeg_data.len();
-        let ratio = original_size as f32 / compressed_size as f32;
-
-        eprintln!("[Video JPEG] Compressed {}KB -> {}KB ({}x) in {}ms",
-            original_size / 1024, compressed_size / 1024, ratio, compress_time);
-
         jpeg_data
     } else {
         frame_data
     };
+    let t_compress_end = Instant::now();
 
+    // Drop decoder lock before sending to avoid blocking
+    drop(decoder);
+
+    let t_send_start = Instant::now();
     // Send binary data through channel (bypasses JSON serialization)
     // InvokeResponseBody::Raw sends raw binary data without JSON encoding
-    channel.send(tauri::ipc::InvokeResponseBody::Raw(data_to_send))
+    channel.send(tauri::ipc::InvokeResponseBody::Raw(data_to_send.clone()))
         .map_err(|e| format!("Channel send error: {}", e))?;
+    let t_send_end = Instant::now();
+
+    let t_total_end = Instant::now();
+
+    // Detailed profiling
+    let lock_time = t_lock_end.duration_since(t_lock_start).as_micros();
+    let decode_time = t_decode_end.duration_since(t_decode_start).as_micros();
+    let compress_time = t_compress_end.duration_since(t_compress_start).as_micros();
+    let send_time = t_send_end.duration_since(t_send_start).as_micros();
+    let total_time = t_total_end.duration_since(t_total_start).as_micros();
+
+    let size_kb = data_to_send.len() / 1024;
+    let mode = if use_jpeg { "JPEG" } else { "RAW" };
+
+    eprintln!("[Video Profile {}] Size: {}KB | Lock: {}μs | Decode: {}μs | Compress: {}μs | Send: {}μs | Total: {}μs",
+        mode, size_kb, lock_time, decode_time, compress_time, send_time, total_time);
 
     Ok(())
 }
@@ -547,3 +759,120 @@ pub async fn video_get_pool_info(
         decoder.fps
     ))
 }
+
+// Benchmark command to test IPC performance with various payload sizes
+#[tauri::command]
+pub async fn video_ipc_benchmark(
+    size_bytes: usize,
+    channel: tauri::ipc::Channel,
+) -> Result<(), String> {
+    use std::time::Instant;
+
+    let t_start = Instant::now();
+
+    // Create dummy data of requested size
+    let data = vec![0u8; size_bytes];
+
+    let t_after_alloc = Instant::now();
+
+    // Send through channel
+    channel.send(tauri::ipc::InvokeResponseBody::Raw(data))
+        .map_err(|e| format!("Channel send error: {}", e))?;
+
+    let t_after_send = Instant::now();
+
+    let alloc_time = t_after_alloc.duration_since(t_start).as_micros();
+    let send_time = t_after_send.duration_since(t_after_alloc).as_micros();
+    let total_time = t_after_send.duration_since(t_start).as_micros();
+
+    eprintln!("[IPC Benchmark Rust] Size: {}KB | Alloc: {}μs | Send: {}μs | Total: {}μs",
+        size_bytes / 1024, alloc_time, send_time, total_time);
+
+    Ok(())
+}
+
+// Batch frame request - get multiple frames in one IPC call
+#[tauri::command]
+pub async fn video_get_frames_batch(
+    state: tauri::State<'_, Arc<Mutex<VideoState>>>,
+    pool_index: usize,
+    timestamps: Vec<f64>,
+    use_jpeg: bool,
+    channel: tauri::ipc::Channel,
+) -> Result<(), String> {
+    use std::time::Instant;
+
+    let t_total_start = Instant::now();
+
+    let video_state = state.lock().unwrap();
+    let decoder = video_state.pool.get(pool_index)
+        .ok_or("Invalid pool index")?
+        .clone();
+    drop(video_state);
+
+    let mut decoder = decoder.lock().unwrap();
+
+    // Decode all frames
+    let mut all_frames = Vec::new();
+    let mut total_decode_time = 0u128;
+    let mut total_compress_time = 0u128;
+
+    for timestamp in &timestamps {
+        let t_decode_start = Instant::now();
+        let frame_data = decoder.get_frame(*timestamp)?;
+        let t_decode_end = Instant::now();
+        total_decode_time += t_decode_end.duration_since(t_decode_start).as_micros();
+
+        let t_compress_start = Instant::now();
+        let data = if use_jpeg {
+            let width = decoder.output_width;
+            let height = decoder.output_height;
+            let img = RgbaImage::from_raw(width, height, frame_data)
+                .ok_or("Failed to create image from frame data")?;
+            let rgb_img = image::DynamicImage::ImageRgba8(img).to_rgb8();
+            let mut jpeg_data = Vec::new();
+            let mut encoder = image::codecs::jpeg::JpegEncoder::new_with_quality(&mut jpeg_data, 85);
+            encoder.encode(
+                rgb_img.as_raw(),
+                rgb_img.width(),
+                rgb_img.height(),
+                image::ColorType::Rgb8
+            ).map_err(|e| format!("JPEG encoding failed: {}", e))?;
+            jpeg_data
+        } else {
+            frame_data
+        };
+        let t_compress_end = Instant::now();
+        total_compress_time += t_compress_end.duration_since(t_compress_start).as_micros();
+
+        all_frames.push(data);
+    }
+
+    drop(decoder);
+
+    // Pack all frames into one buffer with metadata
+    // Format: [frame_count: u32][frame1_size: u32][frame1_data...][frame2_size: u32][frame2_data...]
+    let mut packed_data = Vec::new();
+    packed_data.extend_from_slice(&(all_frames.len() as u32).to_le_bytes());
+
+    for frame in &all_frames {
+        packed_data.extend_from_slice(&(frame.len() as u32).to_le_bytes());
+        packed_data.extend_from_slice(frame);
+    }
+
+    let total_size_kb = packed_data.len() / 1024;
+
+    let t_send_start = Instant::now();
+    channel.send(tauri::ipc::InvokeResponseBody::Raw(packed_data))
+        .map_err(|e| format!("Channel send error: {}", e))?;
+    let t_send_end = Instant::now();
+
+    let send_time = t_send_end.duration_since(t_send_start).as_micros();
+    let total_time = t_send_end.duration_since(t_total_start).as_micros();
+
+    let mode = if use_jpeg { "JPEG" } else { "RAW" };
+    eprintln!("[Video Batch {}] Frames: {} | Size: {}KB | Decode: {}μs | Compress: {}μs | Send: {}μs | Total: {}μs",
+        mode, timestamps.len(), total_size_kb, total_decode_time, total_compress_time, send_time, total_time);
+
+    Ok(())
+}

src-tauri/src/video_server.rs

@@ -0,0 +1,203 @@
+use std::sync::{Arc, Mutex};
+use std::collections::HashMap;
+use std::fs::File;
+use std::io::{Read, Seek, SeekFrom};
+use std::path::PathBuf;
+use tiny_http::{Server, Response, Request, Header, StatusCode};
+
+pub struct VideoServer {
+    port: u16,
+    allowed_files: Arc<Mutex<HashMap<String, PathBuf>>>, // URL path -> file path
+}
+
+impl VideoServer {
+    pub fn new() -> Result<Self, String> {
+        // Bind to localhost on a random available port
+        let server = Server::http("127.0.0.1:0")
+            .map_err(|e| format!("Failed to create HTTP server: {}", e))?;
+
+        let port = match server.server_addr() {
+            tiny_http::ListenAddr::IP(addr) => addr.port(),
+            _ => return Err("Unexpected server address type".to_string()),
+        };
+        let allowed_files = Arc::new(Mutex::new(HashMap::new()));
+
+        eprintln!("[Video Server] Started on port {}", port);
+
+        // Spawn server thread
+        let files = allowed_files.clone();
+        std::thread::spawn(move || {
+            for request in server.incoming_requests() {
+                handle_request(request, &files);
+            }
+        });
+
+        Ok(Self {
+            port,
+            allowed_files,
+        })
+    }
+
+    pub fn port(&self) -> u16 {
+        self.port
+    }
+
+    pub fn add_file(&self, url_path: String, file_path: PathBuf) {
+        eprintln!("[Video Server] Adding file: {} -> {:?}", url_path, file_path);
+        let mut files = self.allowed_files.lock().unwrap();
+        files.insert(url_path, file_path);
+    }
+
+    pub fn get_url(&self, url_path: &str) -> String {
+        format!("http://127.0.0.1:{}{}", self.port, url_path)
+    }
+}
+
+fn handle_request(request: Request, allowed_files: &Arc<Mutex<HashMap<String, PathBuf>>>) {
+    let url = request.url();
+    let method = request.method();
+
+    eprintln!("[Video Server] {} {}", method, url);
+
+    // Get file path
+    let files = allowed_files.lock().unwrap();
+    let file_path = match files.get(url) {
+        Some(path) => path.clone(),
+        None => {
+            eprintln!("[Video Server] File not found: {}", url);
+            let response = Response::from_string("Not Found")
+                .with_status_code(StatusCode(404));
+            let _ = request.respond(response);
+            return;
+        }
+    };
+    drop(files);
+
+    // Open file
+    let mut file = match File::open(&file_path) {
+        Ok(f) => f,
+        Err(e) => {
+            eprintln!("[Video Server] Failed to open file: {}", e);
+            let response = Response::from_string("Internal Server Error")
+                .with_status_code(StatusCode(500));
+            let _ = request.respond(response);
+            return;
+        }
+    };
+
+    // Get file size
+    let file_size = match file.metadata() {
+        Ok(meta) => meta.len(),
+        Err(e) => {
+            eprintln!("[Video Server] Failed to get file metadata: {}", e);
+            let response = Response::from_string("Internal Server Error")
+                .with_status_code(StatusCode(500));
+            let _ = request.respond(response);
+            return;
+        }
+    };
+
+    // Check for Range header - convert to owned String to avoid borrow issues
+    let range_header = request.headers().iter()
+        .find(|h| h.field.equiv("Range"))
+        .map(|h| h.value.as_str().to_string());
+
+    match range_header {
+        Some(range) if range.starts_with("bytes=") => {
+            // Parse range request
+            eprintln!("[Video Server] Range request: {}", range);
+            handle_range_request(request, file, file_size, &range, &file_path);
+        }
+        _ => {
+            // Serve entire file
+            eprintln!("[Video Server] Full file request");
+            handle_full_request(request, file, file_size, &file_path);
+        }
+    }
+}
+
+fn handle_range_request(
+    request: Request,
+    mut file: File,
+    file_size: u64,
+    range: &str,
+    file_path: &PathBuf,
+) {
+    // Parse "bytes=start-end"
+    let range = range.trim_start_matches("bytes=");
+    let parts: Vec<&str> = range.split('-').collect();
+
+    let start = parts[0].parse::<u64>().unwrap_or(0);
+    let end = if parts.len() > 1 && !parts[1].is_empty() {
+        parts[1].parse::<u64>().unwrap_or(file_size - 1)
+    } else {
+        file_size - 1
+    };
+
+    let length = end - start + 1;
+
+    // Seek to start position
+    if let Err(e) = file.seek(SeekFrom::Start(start)) {
+        eprintln!("[Video Server] Failed to seek: {}", e);
+        let response = Response::from_string("Internal Server Error")
+            .with_status_code(StatusCode(500));
+        let _ = request.respond(response);
+        return;
+    }
+
+    // Read the requested range
+    let mut buffer = vec![0u8; length as usize];
+    if let Err(e) = file.read_exact(&mut buffer) {
+        eprintln!("[Video Server] Failed to read range: {}", e);
+        let response = Response::from_string("Internal Server Error")
+            .with_status_code(StatusCode(500));
+        let _ = request.respond(response);
+        return;
+    }
+
+    // Determine content type
+    let content_type = get_content_type(file_path);
+
+    // Send 206 Partial Content response
+    let content_range = format!("bytes {}-{}/{}", start, end, file_size);
+    let response = Response::from_data(buffer)
+        .with_status_code(StatusCode(206))
+        .with_header(Header::from_bytes(&b"Content-Type"[..], content_type.as_bytes()).unwrap())
+        .with_header(Header::from_bytes(&b"Content-Length"[..], length.to_string().as_bytes()).unwrap())
+        .with_header(Header::from_bytes(&b"Content-Range"[..], content_range.as_bytes()).unwrap())
+        .with_header(Header::from_bytes(&b"Accept-Ranges"[..], &b"bytes"[..]).unwrap())
+        .with_header(Header::from_bytes(&b"Access-Control-Allow-Origin"[..], &b"*"[..]).unwrap());
+
+    let _ = request.respond(response);
+}
+
+fn handle_full_request(
+    request: Request,
+    file: File,
+    file_size: u64,
+    file_path: &PathBuf,
+) {
+    // Determine content type
+    let content_type = get_content_type(file_path);
+
+    // Send 200 OK response using from_file to avoid chunked encoding
+    let response = Response::from_file(file)
+        .with_status_code(StatusCode(200))
+        .with_chunked_threshold(usize::MAX)  // Force Content-Length instead of chunked
+        .with_header(Header::from_bytes(&b"Content-Type"[..], content_type.as_bytes()).unwrap())
+        .with_header(Header::from_bytes(&b"Accept-Ranges"[..], &b"bytes"[..]).unwrap())
+        .with_header(Header::from_bytes(&b"Access-Control-Allow-Origin"[..], &b"*"[..]).unwrap());
+
+    let _ = request.respond(response);
+}
+
+fn get_content_type(path: &PathBuf) -> String {
+    match path.extension().and_then(|s| s.to_str()) {
+        Some("webm") => "video/webm".to_string(),
+        Some("mp4") => "video/mp4".to_string(),
+        Some("mkv") => "video/x-matroska".to_string(),
+        Some("avi") => "video/x-msvideo".to_string(),
+        Some("mov") => "video/quicktime".to_string(),
+        _ => "application/octet-stream".to_string(),
+    }
+}

src/actions/index.js

@@ -629,7 +629,8 @@ export const actions = {
           metadata.duration,
           0, // offset
           action.videoname,
-          metadata.duration // sourceDuration
+          metadata.duration, // sourceDuration
+          metadata  // Pass full metadata for browser playback support
         );
 
         // If video has audio, create linked AudioTrack

src/main.js

@@ -220,7 +220,6 @@ let fileExportPath = undefined;
 
 let state = "normal";
 
-let playing = false;
 let lastFrameTime;
 
 let uiDirty = false;
@@ -347,6 +346,65 @@ window.actions = actions;
 window.addKeyframeAtPlayhead = addKeyframeAtPlayhead;
 window.updateVideoFrames = null; // Will be set after function is defined
 
+// IPC Benchmark function - run from console: testIPCBenchmark()
+window.testIPCBenchmark = async function() {
+  const { invoke, Channel } = window.__TAURI__.core;
+
+  // Test sizes: 1KB, 10KB, 50KB, 100KB, 500KB, 1MB, 2MB, 5MB
+  const testSizes = [
+    1024,           // 1 KB
+    10 * 1024,      // 10 KB
+    50 * 1024,      // 50 KB
+    100 * 1024,     // 100 KB
+    500 * 1024,     // 500 KB
+    1024 * 1024,    // 1 MB
+    2 * 1024 * 1024,  // 2 MB
+    5 * 1024 * 1024   // 5 MB
+  ];
+
+  console.log('\n=== IPC Benchmark Starting ===\n');
+  console.log('Size (KB)\tJS Total (ms)\tJS IPC (ms)\tJS Recv (ms)\tThroughput (MB/s)');
+  console.log('─'.repeat(80));
+
+  for (const sizeBytes of testSizes) {
+    const t_start = performance.now();
+
+    let receivedData = null;
+    const dataPromise = new Promise((resolve, reject) => {
+      const channel = new Channel();
+
+      channel.onmessage = (data) => {
+        const t_recv_start = performance.now();
+        receivedData = data;
+        const t_recv_end = performance.now();
+        resolve(t_recv_end - t_recv_start);
+      };
+
+      invoke('video_ipc_benchmark', {
+        sizeBytes: sizeBytes,
+        channel: channel
+      }).catch(reject);
+    });
+
+    const recv_time = await dataPromise;
+    const t_after_ipc = performance.now();
+
+    const total_time = t_after_ipc - t_start;
+    const ipc_time = total_time - recv_time;
+    const size_kb = sizeBytes / 1024;
+    const size_mb = sizeBytes / (1024 * 1024);
+    const throughput = size_mb / (total_time / 1000);
+
+    console.log(`${size_kb.toFixed(0)}\t\t${total_time.toFixed(2)}\t\t${ipc_time.toFixed(2)}\t\t${recv_time.toFixed(2)}\t\t${throughput.toFixed(2)}`);
+
+    // Small delay between tests
+    await new Promise(resolve => setTimeout(resolve, 100));
+  }
+
+  console.log('\n=== IPC Benchmark Complete ===\n');
+  console.log('Run again with: testIPCBenchmark()');
+};
+
 function uuidv4() {
   return "10000000-1000-4000-8000-100000000000".replace(/[018]/g, (c) =>
     (
@@ -907,8 +965,8 @@ window.addEventListener("keydown", (e) => {
 });
 
 async function playPause() {
-  playing = !playing;
+  context.playing = !context.playing;
-  if (playing) {
+  if (context.playing) {
     // Reset to start if we're at the end
     const duration = context.activeObject.duration;
     if (duration > 0 && context.activeObject.currentTime >= duration) {
@@ -966,8 +1024,8 @@ async function playPause() {
 
   // Update play/pause button appearance if it exists
   if (context.playPauseButton) {
-    context.playPauseButton.className = playing ? "playback-btn playback-btn-pause" : "playback-btn playback-btn-play";
+    context.playPauseButton.className = context.playing ? "playback-btn playback-btn-pause" : "playback-btn playback-btn-play";
-    context.playPauseButton.title = playing ? "Pause" : "Play";
+    context.playPauseButton.title = context.playing ? "Pause" : "Play";
   }
 }
 
@@ -980,7 +1038,7 @@ function playbackLoop() {
     context.timelineWidget.requestRedraw();
   }
 
-  if (playing) {
+  if (context.playing) {
     const duration = context.activeObject.duration;
 
     // Check if we've reached the end (but allow infinite playback when recording)
@@ -989,7 +1047,7 @@ function playbackLoop() {
       requestAnimationFrame(playbackLoop);
     } else {
       // Animation finished
-      playing = false;
+      context.playing = false;
 
       // Stop DAW backend audio playback
       invoke('audio_stop').catch(error => {
@@ -1136,7 +1194,7 @@ async function handleAudioEvent(event) {
   switch (event.type) {
     case 'PlaybackPosition':
       // Sync frontend time with DAW time
-      if (playing) {
+      if (context.playing) {
         // Quantize time to framerate for animation playback
         const framerate = context.activeObject.frameRate;
         const frameDuration = 1 / framerate;
@@ -1565,7 +1623,7 @@ async function toggleRecording() {
         console.log('[FRONTEND] MIDI recording started successfully');
 
         // Start playback so the timeline moves (if not already playing)
-        if (!playing) {
+        if (!context.playing) {
           await playPause();
         }
       } catch (error) {
@@ -1585,7 +1643,7 @@ async function toggleRecording() {
         console.log('[FRONTEND] Audio recording started successfully, waiting for RecordingStarted event');
 
         // Start playback so the timeline moves (if not already playing)
-        if (!playing) {
+        if (!context.playing) {
           await playPause();
         }
       } catch (error) {
@@ -4528,8 +4586,8 @@ function timelineV2() {
 
     // Play/Pause button
     const playPauseButton = document.createElement("button");
-    playPauseButton.className = playing ? "playback-btn playback-btn-pause" : "playback-btn playback-btn-play";
+    playPauseButton.className = context.playing ? "playback-btn playback-btn-pause" : "playback-btn playback-btn-play";
-    playPauseButton.title = playing ? "Pause" : "Play";
+    playPauseButton.title = context.playing ? "Pause" : "Play";
     playPauseButton.addEventListener("click", playPause);
 
     // Store reference so playPause() can update it
@@ -6709,7 +6767,7 @@ async function renderMenu() {
       },
       {
         text: "Play",
-        enabled: !playing,
+        enabled: !context.playing,
         action: playPause,
         accelerator: getShortcut("playAnimation"),
       },
@@ -10916,7 +10974,7 @@ async function renderAll() {
     renderInProgress = false;
 
     // FPS logging (only when playing)
-    if (playing) {
+    if (context.playing) {
       frameCount++;
       const now = performance.now();
       const renderTime = now - renderStartTime;

src/models/layer.js

@@ -1281,7 +1281,8 @@ class VideoLayer extends Widget {
     this.linkedAudioTrack = null;  // Reference to AudioTrack
 
     // Performance settings
-    this.useJpegCompression = true;  // Enable JPEG compression for faster transfer (default: true)
+    this.useJpegCompression = false;  // JPEG compression adds more overhead than it saves (default: false)
+    this.prefetchCount = 3;  // Number of frames to prefetch ahead of playhead
 
     // Timeline display
     this.collapsed = false;
@@ -1291,12 +1292,12 @@ class VideoLayer extends Widget {
     pointerList[this.idx] = this;
   }
 
-  async addClip(poolIndex, startTime, duration, offset = 0.0, name = '', sourceDuration = null) {
+  async addClip(poolIndex, startTime, duration, offset = 0.0, name = '', sourceDuration = null, metadata = null) {
     const poolInfo = await invoke('video_get_pool_info', { poolIndex });
     // poolInfo is [width, height, fps] tuple from Rust
     const [width, height, fps] = poolInfo;
 
-    this.clips.push({
+    const clip = {
       clipId: this.clips.length,
       poolIndex,
       name: name || `Video ${this.clips.length + 1}`,
@@ -1305,10 +1306,124 @@ class VideoLayer extends Widget {
       offset,
       width,
       height,
-      sourceDuration: sourceDuration || duration  // Store original file duration
+      sourceDuration: sourceDuration || duration,  // Store original file duration
+      httpUrl: metadata?.http_url || null,
+      isBrowserCompatible: metadata?.is_browser_compatible || false,
+      transcoding: metadata?.transcoding || false,
+      videoElement: null,  // Will hold HTML5 video element if using browser playback
+      useBrowserVideo: false,  // Switch to true when video element is ready
+      isPlaying: false,  // Track if video element is actively playing
+    };
+
+    this.clips.push(clip);
+
+    console.log(`Video clip added: ${name}, ${width}x${height}, duration: ${duration}s, browser-compatible: ${clip.isBrowserCompatible}, http_url: ${clip.httpUrl}`);
+
+    // If HTTP URL is available, create video element immediately
+    if (clip.httpUrl) {
+      await this._createVideoElement(clip);
+      clip.useBrowserVideo = true;
+    }
+    // If transcoding is in progress, start polling
+    else if (clip.transcoding) {
+      console.log(`[Video] Starting transcode polling for ${clip.name}`);
+      this._pollTranscodeStatus(clip);
+    }
+  }
+
+  async _createVideoElement(clip) {
+    // Create hidden video element for hardware-accelerated decoding
+    const video = document.createElement('video');
+    // DEBUG: Make video visible on top of everything
+    video.style.position = 'fixed';
+    video.style.top = '10px';
+    video.style.right = '10px';
+    video.style.width = '400px';
+    video.style.height = '225px';
+    video.style.zIndex = '99999';
+    video.style.border = '3px solid red';
+    video.controls = true;  // DEBUG: Add controls
+    video.preload = 'auto';
+    video.muted = true;  // Mute video element (audio plays separately)
+    video.playsInline = true;
+    video.autoplay = false;
+    video.crossOrigin = 'anonymous';  // Required for canvas drawing - prevent CORS taint
+
+    // Add event listeners for debugging
+    video.addEventListener('loadedmetadata', () => {
+      console.log(`[Video] Loaded metadata for ${clip.name}: ${video.videoWidth}x${video.videoHeight}, duration: ${video.duration}s`);
     });
 
-    console.log(`Video clip added: ${name}, ${width}x${height}, duration: ${duration}s`);
+    video.addEventListener('loadeddata', () => {
+      console.log(`[Video] Loaded data for ${clip.name}, readyState: ${video.readyState}`);
+    });
+
+    video.addEventListener('canplay', () => {
+      console.log(`[Video] Can play ${clip.name}, duration: ${video.duration}s`);
+      // Mark video as ready for seeking once we can play AND have valid duration
+      if (video.duration > 0 && !isNaN(video.duration) && video.duration !== Infinity) {
+        clip.videoReady = true;
+        console.log(`[Video] Video is ready for seeking`);
+      }
+    });
+
+    // When seek completes, trigger UI redraw to show the new frame
+    video.addEventListener('seeked', () => {
+      if (updateUI) {
+        updateUI();
+      }
+    });
+
+    video.addEventListener('error', (e) => {
+      const error = video.error;
+      const errorMessages = {
+        1: 'MEDIA_ERR_ABORTED - Fetching aborted',
+        2: 'MEDIA_ERR_NETWORK - Network error',
+        3: 'MEDIA_ERR_DECODE - Decoding error',
+        4: 'MEDIA_ERR_SRC_NOT_SUPPORTED - Format not supported or file not accessible'
+      };
+      const errorMsg = errorMessages[error?.code] || 'Unknown error';
+      console.error(`[Video] Error loading ${clip.name}: ${errorMsg}`, error?.message);
+    });
+
+    // Use HTTP URL from local server (supports range requests for seeking)
+    video.src = clip.httpUrl;
+
+    // Try to load the video
+    video.load();
+
+    document.body.appendChild(video);
+    clip.videoElement = video;
+
+    console.log(`[Video] Created video element for clip ${clip.name}: ${clip.httpUrl}`);
+  }
+
+  async _pollTranscodeStatus(clip) {
+    // Poll transcode status every 2 seconds
+    const pollInterval = setInterval(async () => {
+      try {
+        const status = await invoke('video_get_transcode_status', { poolIndex: clip.poolIndex });
+
+        if (status && status[2]) {  // [path, progress, completed, httpUrl]
+          // Transcode complete!
+          clearInterval(pollInterval);
+          const [outputPath, progress, completed, httpUrl] = status;
+
+          clip.transcodedPath = outputPath;
+          clip.httpUrl = httpUrl;
+          clip.transcoding = false;
+          clip.useBrowserVideo = true;
+
+          console.log(`[Video] Transcode complete for ${clip.name}, switching to browser playback: ${httpUrl}`);
+
+          // Create video element for browser playback
+          await this._createVideoElement(clip);
+        }
+      } catch (error) {
+        console.error('Failed to poll transcode status:', error);
+        clearInterval(pollInterval);
+      }
+    }, 2000);
   }
 
   // Pre-fetch frames for current time (call before draw)
@@ -1325,88 +1440,172 @@ class VideoLayer extends Widget {
         if (currentTime < clip.startTime ||
             currentTime >= clip.startTime + clip.duration) {
           clip.currentFrame = null;
+
+          // Pause video element if we left its time range
+          if (clip.videoElement && clip.isPlaying) {
+            clip.videoElement.pause();
+            clip.isPlaying = false;
+          }
+
           continue;
         }
 
-        // Calculate video timestamp from clip time
+        // If using browser video element
-        const clipTime = currentTime - clip.startTime;
+        if (clip.useBrowserVideo && clip.videoElement) {
-        const videoTimestamp = clip.offset + clipTime;
+          const videoTime = clip.offset + (currentTime - clip.startTime);
 
-        // Only fetch if timestamp changed
+          // Don't do anything until video is fully ready
-        if (clip.lastFetchedTimestamp === videoTimestamp && clip.currentFrame) {
+          if (!clip.videoReady) {
+            if (!clip._notReadyWarned) {
+              console.warn(`[Video updateFrame] Video not ready yet (duration=${clip.videoElement.duration})`);
+              clip._notReadyWarned = true;
+            }
             continue;
           }
 
-        // Skip if already fetching this frame
+          // During playback: let video play naturally
-        if (clip.fetchInProgress === videoTimestamp) {
+          if (context.playing) {
+            // Check if we just entered this clip (need to start playing)
+            if (!clip.isPlaying) {
+              // Start playing one frame ahead to compensate for canvas drawing lag
+              const frameDuration = 1 / (clip.fps || 30); // Use clip's actual framerate
+              const startTime = videoTime + frameDuration;
+              console.log(`[Video updateFrame] Starting playback at ${startTime.toFixed(3)}s (compensated by ${frameDuration.toFixed(3)}s for ${clip.fps}fps)`);
+              clip.videoElement.currentTime = startTime;
+              clip.videoElement.play().catch(e => console.error('Failed to play video:', e));
+              clip.isPlaying = true;
+            }
+            // Otherwise, let it play naturally - don't seek!
+          }
+          // When scrubbing (not playing): seek to exact position and pause
+          else {
+            if (clip.isPlaying) {
+              clip.videoElement.pause();
+              clip.isPlaying = false;
+            }
+
+            // Only seek if the time is actually different
+            if (!clip.videoElement.seeking) {
+              const timeDiff = Math.abs(clip.videoElement.currentTime - videoTime);
+              if (timeDiff > 0.016) { // ~1 frame tolerance at 60fps
+                clip.videoElement.currentTime = videoTime;
+              }
+            }
+          }
+
+          continue;  // Skip frame fetching
+        }
+
+        // Use frame batching for frame-based playback
+
+        // Initialize frame cache if needed
+        if (!clip.frameCache) {
+          clip.frameCache = new Map();
+        }
+
+        // Check if current frame is already cached
+        if (clip.frameCache.has(currentVideoTimestamp)) {
+          clip.currentFrame = clip.frameCache.get(currentVideoTimestamp);
+          clip.lastFetchedTimestamp = currentVideoTimestamp;
           continue;
         }
 
-        clip.fetchInProgress = videoTimestamp;
+        // Skip if already fetching
-        clip.lastFetchedTimestamp = videoTimestamp;
+        if (clip.fetchInProgress) {
+          continue;
+        }
+
+        clip.fetchInProgress = true;
 
         try {
-          // Request frame from Rust backend using IPC Channel for efficient binary transfer
+          // Calculate timestamps to prefetch (current + next N frames)
+          const frameDuration = 1 / 30; // Assume 30fps for now, could get from clip metadata
+          const timestamps = [];
+          for (let i = 0; i < this.prefetchCount; i++) {
+            const ts = currentVideoTimestamp + (i * frameDuration);
+            // Don't exceed clip duration
+            if (ts <= clip.offset + clip.sourceDuration) {
+              timestamps.push(ts);
+            }
+          }
+
+          if (timestamps.length === 0) {
+            continue;
+          }
+
           const t_start = performance.now();
 
-          // Create a promise that resolves when channel receives data
+          // Request batch of frames using IPC Channel
-          const frameDataPromise = new Promise((resolve, reject) => {
+          const batchDataPromise = new Promise((resolve, reject) => {
             const channel = new Channel();
 
             channel.onmessage = (data) => {
               resolve(data);
             };
 
-            // Invoke command with channel
+            invoke('video_get_frames_batch', {
-            invoke('video_get_frame', {
               poolIndex: clip.poolIndex,
-              timestamp: videoTimestamp,
+              timestamps: timestamps,
               useJpeg: this.useJpegCompression,
               channel: channel
             }).catch(reject);
           });
 
-          // Wait for the frame data
+          let batchData = await batchDataPromise;
-          let frameData = await frameDataPromise;
           const t_after_ipc = performance.now();
 
           // Ensure data is Uint8Array
-          if (!(frameData instanceof Uint8Array)) {
+          if (!(batchData instanceof Uint8Array)) {
-            frameData = new Uint8Array(frameData);
+            batchData = new Uint8Array(batchData);
+          }
+
+          // Unpack the batch format: [frame_count: u32][frame1_size: u32][frame1_data...][frame2_size: u32][frame2_data...]...
+          const view = new DataView(batchData.buffer, batchData.byteOffset, batchData.byteLength);
+          let offset = 0;
+
+          // Read frame count
+          const frameCount = view.getUint32(offset, true); // little-endian
+          offset += 4;
+
+          if (frameCount !== timestamps.length) {
+            console.warn(`Expected ${timestamps.length} frames, got ${frameCount}`);
           }
 
-          let imageData;
           const t_before_conversion = performance.now();
 
-          if (this.useJpegCompression) {
+          // Process each frame
-            // Decode JPEG data
+          for (let i = 0; i < frameCount; i++) {
-            const blob = new Blob([frameData], { type: 'image/jpeg' });
+            // Read frame size
-            const imageUrl = URL.createObjectURL(blob);
+            const frameSize = view.getUint32(offset, true);
+            offset += 4;
 
-            // Load and decode JPEG
+            // Extract frame data
-            const img = new Image();
+            const frameData = new Uint8Array(batchData.buffer, batchData.byteOffset + offset, frameSize);
-            await new Promise((resolve, reject) => {
+            offset += frameSize;
-              img.onload = resolve;
+
-              img.onerror = reject;
+            let imageData;
-              img.src = imageUrl;
+
-            });
+            if (this.useJpegCompression) {
+              // Decode JPEG using createImageBitmap
+              const blob = new Blob([frameData], { type: 'image/jpeg' });
+              const imageBitmap = await createImageBitmap(blob);
 
               // Create temporary canvas to extract ImageData
               const tempCanvas = document.createElement('canvas');
               tempCanvas.width = clip.width;
               tempCanvas.height = clip.height;
               const tempCtx = tempCanvas.getContext('2d');
-            tempCtx.drawImage(img, 0, 0);
+              tempCtx.drawImage(imageBitmap, 0, 0);
               imageData = tempCtx.getImageData(0, 0, clip.width, clip.height);
 
-            // Cleanup
+              imageBitmap.close();
-            URL.revokeObjectURL(imageUrl);
             } else {
               // Raw RGBA data
-            const expectedSize = clip.width * clip.height * 4; // RGBA = 4 bytes per pixel
+              const expectedSize = clip.width * clip.height * 4;
 
               if (frameData.length !== expectedSize) {
-              throw new Error(`Invalid frame data size: got ${frameData.length}, expected ${expectedSize}`);
+                console.error(`Invalid frame ${i} data size: got ${frameData.length}, expected ${expectedSize}`);
+                continue;
               }
 
               imageData = new ImageData(
@@ -1416,35 +1615,49 @@ class VideoLayer extends Widget {
               );
             }
 
-          const t_after_conversion = performance.now();
+            // Create canvas for this frame
+            const frameCanvas = document.createElement('canvas');
+            frameCanvas.width = clip.width;
+            frameCanvas.height = clip.height;
+            const frameCtx = frameCanvas.getContext('2d');
+            frameCtx.putImageData(imageData, 0, 0);
 
-          // Create or reuse temp canvas
+            // Cache the frame
-          if (!clip.frameCanvas) {
+            clip.frameCache.set(timestamps[i], frameCanvas);
-            clip.frameCanvas = document.createElement('canvas');
+
-            clip.frameCanvas.width = clip.width;
+            // Set as current frame if it's the first one
-            clip.frameCanvas.height = clip.height;
+            if (i === 0) {
+              clip.currentFrame = frameCanvas;
+              clip.lastFetchedTimestamp = timestamps[i];
+            }
           }
 
-          const tempCtx = clip.frameCanvas.getContext('2d');
+          const t_after_conversion = performance.now();
-          const t_before_putimage = performance.now();
-          tempCtx.putImageData(imageData, 0, 0);
-          const t_after_putimage = performance.now();
 
-          clip.currentFrame = clip.frameCanvas;
+          // Limit cache size to avoid memory issues
+          const maxCacheSize = this.prefetchCount * 2;
+          if (clip.frameCache.size > maxCacheSize) {
+            // Remove oldest entries (simple LRU by keeping only recent timestamps)
+            const sortedKeys = Array.from(clip.frameCache.keys()).sort((a, b) => a - b);
+            const toRemove = sortedKeys.slice(0, sortedKeys.length - maxCacheSize);
+            for (let key of toRemove) {
+              clip.frameCache.delete(key);
+            }
+          }
 
-          // Log detailed timing breakdown
+          // Log timing breakdown
-          const total_time = t_after_putimage - t_start;
+          const total_time = t_after_conversion - t_start;
           const ipc_time = t_after_ipc - t_start;
           const conversion_time = t_after_conversion - t_before_conversion;
-          const putimage_time = t_after_putimage - t_before_putimage;
           const compression_mode = this.useJpegCompression ? 'JPEG' : 'RAW';
+          const avg_per_frame = total_time / frameCount;
 
-          console.log(`[JS Video Timing ${compression_mode}] ts=${videoTimestamp.toFixed(3)}s | Total: ${total_time.toFixed(1)}ms | IPC: ${ipc_time.toFixed(1)}ms (${(ipc_time/total_time*100).toFixed(0)}%) | Convert: ${conversion_time.toFixed(1)}ms | PutImage: ${putimage_time.toFixed(1)}ms | Size: ${(frameData.length/1024/1024).toFixed(2)}MB`);
+          console.log(`[JS Video Batch ${compression_mode}] Fetched ${frameCount} frames | Total: ${total_time.toFixed(1)}ms | IPC: ${ipc_time.toFixed(1)}ms (${(ipc_time/total_time*100).toFixed(0)}%) | Convert: ${conversion_time.toFixed(1)}ms | Avg/frame: ${avg_per_frame.toFixed(1)}ms | Size: ${(batchData.length/1024/1024).toFixed(2)}MB`);
         } catch (error) {
-          console.error('Failed to get video frame:', error);
+          console.error('Failed to get video frames batch:', error);
           clip.currentFrame = null;
         } finally {
-          clip.fetchInProgress = null;
+          clip.fetchInProgress = false;
         }
       }
     } finally {
@@ -1472,8 +1685,89 @@ class VideoLayer extends Widget {
         continue;
       }
 
-      // Draw cached frame if available
+      // Debug: log what path we're taking
-      if (clip.currentFrame) {
+      if (!clip._drawPathLogged) {
+        console.log(`[Video Draw] useBrowserVideo=${clip.useBrowserVideo}, videoElement=${!!clip.videoElement}, currentFrame=${!!clip.currentFrame}`);
+        clip._drawPathLogged = true;
+      }
+
+      // Prefer browser video element if available
+      if (clip.useBrowserVideo && clip.videoElement) {
+        // Debug: log readyState issues
+        if (clip.videoElement.readyState < 2) {
+          if (!clip._readyStateWarned) {
+            console.warn(`[Video] Video not ready: readyState=${clip.videoElement.readyState}, src=${clip.videoElement.src}`);
+            clip._readyStateWarned = true;
+          }
+        }
+
+        // Draw if video is ready (shows last frame while seeking, updates when seek completes)
+        if (clip.videoElement.readyState >= 2) {
+          try {
+            // Calculate expected video time
+            const expectedVideoTime = clip.offset + (currentTime - clip.startTime);
+            const actualVideoTime = clip.videoElement.currentTime;
+            const timeDiff = Math.abs(expectedVideoTime - actualVideoTime);
+
+            // Debug: log if time is significantly different
+            if (timeDiff > 0.1 && (!clip._lastTimeDiffWarning || Date.now() - clip._lastTimeDiffWarning > 1000)) {
+              console.warn(`[Video Draw] Time mismatch: expected ${expectedVideoTime.toFixed(2)}s, actual ${actualVideoTime.toFixed(2)}s, diff=${timeDiff.toFixed(2)}s`);
+              clip._lastTimeDiffWarning = Date.now();
+            }
+
+            // Debug: log successful draw periodically
+            if (!clip._lastDrawLog || Date.now() - clip._lastDrawLog > 1000) {
+              console.log(`[Video Draw] Drawing at currentTime=${actualVideoTime.toFixed(2)}s (expected ${expectedVideoTime.toFixed(2)}s)`);
+              clip._lastDrawLog = Date.now();
+            }
+
+            // Scale to fit canvas while maintaining aspect ratio
+            const canvasWidth = config.fileWidth;
+            const canvasHeight = config.fileHeight;
+            const scale = Math.min(
+              canvasWidth / clip.videoElement.videoWidth,
+              canvasHeight / clip.videoElement.videoHeight
+            );
+            const scaledWidth = clip.videoElement.videoWidth * scale;
+            const scaledHeight = clip.videoElement.videoHeight * scale;
+            const x = (canvasWidth - scaledWidth) / 2;
+            const y = (canvasHeight - scaledHeight) / 2;
+
+            // Debug: draw a test rectangle to verify canvas is working
+            if (!clip._canvasTestDone) {
+              ctx.save();
+              ctx.fillStyle = 'red';
+              ctx.fillRect(10, 10, 100, 100);
+              ctx.restore();
+              console.log(`[Video Draw] Drew test rectangle at (10, 10, 100, 100)`);
+              console.log(`[Video Draw] Canvas dimensions: ${canvasWidth}x${canvasHeight}`);
+              console.log(`[Video Draw] Scaled video dimensions: ${scaledWidth}x${scaledHeight} at (${x}, ${y})`);
+              clip._canvasTestDone = true;
+            }
+
+            // Debug: Check if video element has dimensions
+            if (!clip._videoDimensionsLogged) {
+              console.log(`[Video Draw] Video element dimensions: videoWidth=${clip.videoElement.videoWidth}, videoHeight=${clip.videoElement.videoHeight}, naturalWidth=${clip.videoElement.videoWidth}, naturalHeight=${clip.videoElement.videoHeight}`);
+              console.log(`[Video Draw] Video element state: paused=${clip.videoElement.paused}, ended=${clip.videoElement.ended}, seeking=${clip.videoElement.seeking}, readyState=${clip.videoElement.readyState}`);
+              clip._videoDimensionsLogged = true;
+            }
+
+            ctx.drawImage(clip.videoElement, x, y, scaledWidth, scaledHeight);
+
+            // Debug: Sample a pixel to see if video is actually drawing
+            if (!clip._pixelTestDone) {
+              const imageData = ctx.getImageData(canvasWidth / 2, canvasHeight / 2, 1, 1);
+              const pixel = imageData.data;
+              console.log(`[Video Draw] Center pixel after drawImage: R=${pixel[0]}, G=${pixel[1]}, B=${pixel[2]}, A=${pixel[3]}`);
+              clip._pixelTestDone = true;
+            }
+          } catch (error) {
+            console.error('Failed to draw video element:', error);
+          }
+        }
+      }
+      // Fall back to cached frame if available
+      else if (clip.currentFrame) {
         try {
           // Scale to fit canvas while maintaining aspect ratio
           const canvasWidth = config.fileWidth;
@@ -1500,7 +1794,8 @@ class VideoLayer extends Widget {
         ctx.font = '24px sans-serif';
         ctx.textAlign = 'center';
         ctx.textBaseline = 'middle';
-        ctx.fillText('Loading...', config.fileWidth / 2, config.fileHeight / 2);
+        const msg = clip.transcoding ? 'Transcoding...' : 'Loading...';
+        ctx.fillText(msg, config.fileWidth / 2, config.fileHeight / 2);
         ctx.restore();
       }
     }

src/state.js

@@ -36,7 +36,8 @@ export let context = {
   timelineWidget: null, // Reference to TimelineWindowV2 widget for zoom controls
   config: null, // Reference to config object (set after config is initialized)
   mode: "select", // Current tool mode
-  // Recording state
+  // Playback and recording state
+  playing: false,
   isRecording: false,
   recordingTrackId: null,
   recordingClipId: null,