Added screenshot to README.md

Updated readme

Cargo.lock

@@ -704,6 +704,7 @@ name = "oscilloscope-video-gen"
 version = "1.0.0"
 dependencies = [
  "anyhow",
+ "bytemuck",
  "clap",
  "hound",
  "image",

Cargo.toml

@@ -31,6 +31,9 @@ anyhow = "1.0"
 # FFT processing for spectrometer
 rustfft = "6.1"
 
+# Efficient byte casting
+bytemuck = "1.24"
+
 [profile.release]
 opt-level = 3
 lto = true

LICENSE

@@ -0,0 +1,658 @@
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+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If your software can interact with users remotely through a computer
+network, you should also make sure that it provides a way for users to
+get its source.  For example, if your program is a web application, its
+interface could display a "Source" link that leads users to an archive
+of the code.  There are many ways you could offer source, and different
+solutions will be better for different programs; see section 13 for the
+specific requirements.
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU AGPL, see
+<https://www.gnu.org/licenses/>.

README.md

@@ -1,120 +1,113 @@
 # Oscilloscope Video Generator
 
-A high-performance Rust tool for generating oscilloscope-style visualizations from audio files. Uses parallel rendering for fast processing.
+Transform any audio file into stunning oscilloscope visualizations. Supports massive files with zero memory issues.
 
-## Features
+![License](https://img.shields.io/badge/license-AGPL--3.0--or--later-green)
 
-- **Multiple visualization modes**: combined, separate, all (L/R + XY)
-- **Parallel rendering**: Uses all CPU cores for fast frame generation
-- **High quality output**: Supports up to 4K resolution at 60fps
-- **Original audio**: Copies audio stream without re-encoding (perfect sync)
-- **Customizable**: Colors, resolution, FPS, line thickness
+![Demo](assets/screenshot.png)
 
-## Installation
+## ✨ Key Features
 
-### From Source
+- **🎵 Universal Audio Support** - FLAC, MP3, WAV, AAC, and 200+ formats via ffmpeg
+- **🚀 Streaming Architecture** - Processes huge files without filling RAM or SSD
+- **📊 Professional Spectrometer** - FFT analyzer with smooth Cava-style animations
+- **🎯 4-Quadrant Display** - Waveforms + XY pattern + spectrometer in one video
+- **🎬 High Quality Output** - 4K 60fps support with customizable colors
+- **⚡ Memory Efficient** - Constant RAM usage regardless of file size
 
+## 🚀 Quick Start
+
+### 1. Install System Dependencies
+
+**Ubuntu/Debian:**
 ```bash
-cd oscilloscope-video-gen
-cargo install --path .
+sudo apt update && sudo apt install ffmpeg
 ```
 
-### Build Only
+**macOS:**
+```bash
+brew install ffmpeg
+```
+
+**Windows:**
+```bash
+# Via winget (recommended)
+winget install ffmpeg
+
+# Or download from https://ffmpeg.org/download.html
+# Make sure ffmpeg is in your PATH
+```
+
+### 2. Build the Project
 
 ```bash
+# If you have the source code locally:
+cd /path/to/oscilloscope-video-gen
+
+# Build in release mode (much faster)
 cargo build --release
+
+# The binary will be at: target/release/oscilloscope-video-gen
 ```
 
-The binary will be at `target/release/oscilloscope-video-gen`.
+### 3. Generate Your First Video
 
-## Usage
+```bash
+# Basic usage - replace 'audio.wav' with your audio file
+./target/release/oscilloscope-video-gen -i audio.wav -o oscilloscope.mp4
 
-### Basic
+# Check available options
+./target/release/oscilloscope-video-gen --help
+```
 
+## 🎮 Usage Examples
+
+### Basic Usage
 ```bash
 oscilloscope-video-gen -i audio.wav -o video.mp4
 ```
 
-### Full Options
-
+### High Quality 4K Output
 ```bash
 oscilloscope-video-gen \
-  -i audio.wav \
+  -i audio.flac \
   -o video.mp4 \
-  --width 1920 \
-  --height 1080 \
-  --fps 30 \
+  --width 3840 --height 2160 --fps 60 \
   --mode all \
-  --quality high \
-  --left-color "#00ff00" \
-  --right-color "#00ccff" \
-  --xy-color "#ff8800" \
-  --background "#0a0f0a" \
-  --line-thickness 2 \
-  --threads 8 \
-  --overwrite \
-  --verbose
+  --quality high
 ```
 
-### Options
-
-| Option | Default | Description |
-|--------|---------|-------------|
-| `-i, --input` | Required | Input WAV file |
-| `-o, --output` | Auto-generated | Output MP4 file |
-| `--width` | 1920 | Video width in pixels |
-| `--height` | 1080 | Video height in pixels |
-| `--fps` | 30 | Frames per second |
-| `--mode` | all | Visualization mode |
-| `--quality` | high | Video quality |
-| `--left-color` | #00ff00 | Left channel color (hex) |
-| `--right-color` | #00ccff | Right channel color (hex) |
-| `--xy-color` | #ff8800 | XY mode color (hex) |
-| `--background` | #0a0f0a | Background color (hex) |
-| `--show-grid` | true | Show grid lines |
-| `--line-thickness` | 2 | Line thickness in pixels |
-| `--threads` | All cores | Number of rendering threads |
-| `--overwrite` | false | Overwrite output file |
-| `--verbose` | false | Enable verbose output |
-
-### Modes
-
-- `combined`: Both channels merged into single waveform
-- `separate`: Left on top, Right on bottom
-- `all`: Left and Right on top row, XY pattern on bottom
-
-### Quality Presets
-
-| Preset | Video Bitrate |
-|--------|---------------|
-| low | 2 Mbps |
-| medium | 5 Mbps |
-| high | 10 Mbps |
-
-## Requirements
-
-- Rust 1.70+
-- ffmpeg (for video encoding)
-
-## Building
-
+### Custom Styling
 ```bash
-# Debug build
-cargo build
-
-# Release build (optimized)
-cargo build --release
-
-# Build with specific number of threads
-cargo build --release --jobs 8
+oscilloscope-video-gen \
+  -i audio.mp3 \
+  -o video.mp4 \
+  --left-color "#ff0080" \
+  --right-color "#8000ff" \
+  --background "#000000" \
+  --line-thickness 3
 ```
 
-## Troubleshooting
+## 🎛️ Visualization Modes
+
+- **`all`** (default) - 4 quadrants: L/R waveforms + XY pattern + spectrometer
+- **`combined`** - Single merged waveform
+- **`separate`** - Left channel top, right channel bottom
+
+## 🏗️ How It Works
+
+This tool uses a **streaming pipeline** that pipes audio decoding directly to video encoding, eliminating temporary files and memory issues. The FFT spectrometer provides real-time frequency analysis with logarithmic scaling and temporal smoothing for smooth animations.
+
+**No file size limits** - handles anything ffmpeg can decode, from tiny samples to 24-hour recordings.
+
+## 📋 Requirements
+
+- **Rust 1.70+**
+- **ffmpeg** (with libavcodec, libavformat, libswresample)
+
+## 🔧 Troubleshooting
 
 ### ffmpeg not found
-
-Make sure ffmpeg is installed and in your PATH:
-
 ```bash
 # Ubuntu/Debian
 sudo apt install ffmpeg
@@ -122,17 +115,23 @@ sudo apt install ffmpeg
 # macOS
 brew install ffmpeg
 
-# Windows
-winget install FFmpeg
+# Windows (via winget or chocolatey)
+winget install ffmpeg
 ```
 
-### Out of memory
+### File Format Issues
+If your audio file isn't recognized:
+```bash
+# Check if ffmpeg can decode it
+ffmpeg -i your_file.ext -f null -
+```
 
-For very long audio files, try:
-- Lower resolution (`--width 1280 --height 720`)
-- Lower FPS (`--fps 24`)
-- Fewer threads (`--threads 4`)
+## 📄 License
 
-## License
+**AGPL-3.0-or-later** - Free software that respects your freedom.
 
-MIT
+See [LICENSE](LICENSE) for full terms.
+
+---
+
+*Made with ❤️ using Rust and ffmpeg*

src/audio.rs

@@ -1,79 +1,136 @@
-//! WAV audio decoding module.
-//!
-//! Handles reading and decoding WAV files into normalized sample data.
+//! Audio streaming module using ffmpeg.
 
 use anyhow::{anyhow, Context, Result};
 use std::path::Path;
+use std::process::{Command, Stdio};
+use std::io::{Read, BufReader};
 
-/// Normalized audio sample data.
-#[derive(Debug, Clone)]
-pub struct AudioData {
-    /// Left channel samples, normalized to [-1.0, 1.0]
-    pub left_channel: Vec<f32>,
-    /// Right channel samples, normalized to [-1.0, 1.0]
-    pub right_channel: Vec<f32>,
-    /// Sample rate in Hz
+/// A streaming audio reader that decodes chunks on demand.
+pub struct AudioStream {
+    child: std::process::Child,
+    reader: BufReader<std::process::ChildStdout>,
     pub sample_rate: u32,
-    /// Duration in seconds
     pub duration: f64,
+    /// Current sample position in the stream
+    pub current_sample_pos: usize,
+    /// Sliding window of left channel samples
+    left_window: Vec<f32>,
+    /// Sliding window of right channel samples
+    right_window: Vec<f32>,
+    /// Window size for lookahead (e.g. FFT)
+    window_size: usize,
 }
 
-impl AudioData {
-    /// Load and decode audio from any supported format using ffmpeg.
-    pub fn from_wav(file_path: &Path) -> Result<Self> {
-        let output = std::process::Command::new("ffmpeg")
-            .arg("-i")
+impl AudioStream {
+    /// Create a new AudioStream from a file path.
+    pub fn new(file_path: &Path, window_size: usize) -> Result<Self> {
+        // 1. Get metadata using ffprobe
+        let output = Command::new("ffprobe")
+            .args([
+                "-v", "error",
+                "-select_streams", "a:0",
+                "-show_entries", "stream=sample_rate,duration",
+                "-of", "default=noprint_wrappers=1:nokey=1",
+            ])
             .arg(file_path)
-            .arg("-f")
-            .arg("s16le")
-            .arg("-acodec")
-            .arg("pcm_s16le")
-            .arg("-ar")
-            .arg("48000")
-            .arg("-ac")
-            .arg("2")
-            .arg("-")
             .output()
-            .with_context(|| "Failed to decode audio with ffmpeg")?;
+            .with_context(|| "Failed to run ffprobe")?;
 
         if !output.status.success() {
-            return Err(anyhow!("Audio decoding failed: {}", String::from_utf8_lossy(&output.stderr)));
+            return Err(anyhow!("ffprobe failed: {}", String::from_utf8_lossy(&output.stderr)));
         }
 
-        let pcm_data = output.stdout;
-        let sample_rate = 48000;
-        let num_channels = 2;
-        let total_samples = pcm_data.len() / (2 * num_channels);
-        let duration = total_samples as f64 / sample_rate as f64;
+        let metadata = String::from_utf8_lossy(&output.stdout);
+        let mut lines = metadata.lines();
+        let sample_rate: u32 = lines.next()
+            .ok_or_else(|| anyhow!("Could not get sample rate"))?
+            .parse()?;
+        let duration: f64 = lines.next()
+            .ok_or_else(|| anyhow!("Could not get duration"))?
+            .parse()?;
 
-        let mut left_channel = Vec::with_capacity(total_samples);
-        let mut right_channel = Vec::with_capacity(total_samples);
+        // 2. Start ffmpeg for streaming
+        let mut child = Command::new("ffmpeg")
+            .arg("-i")
+            .arg(file_path)
+            .args([
+                "-f", "s16le",
+                "-acodec", "pcm_s16le",
+                "-ar", &sample_rate.to_string(),
+                "-ac", "2",
+                "-",
+            ])
+            .stdout(Stdio::piped())
+            .stderr(Stdio::null())
+            .spawn()
+            .with_context(|| "Failed to spawn ffmpeg")?;
 
-        for i in 0..total_samples {
-            let offset = i * 2 * num_channels;
+        let stdout = child.stdout.take().ok_or_else(|| anyhow!("Failed to open ffmpeg stdout"))?;
+        let reader = BufReader::new(stdout);
 
-            let left_val = i16::from_le_bytes([pcm_data[offset], pcm_data[offset + 1]]);
-            let right_val = i16::from_le_bytes([pcm_data[offset + 2], pcm_data[offset + 3]]);
-
-            left_channel.push(left_val as f32 / 32768.0);
-            right_channel.push(right_val as f32 / 32768.0);
-        }
-
-        Ok(AudioData {
-            left_channel,
-            right_channel,
+        Ok(Self {
+            child,
+            reader,
             sample_rate,
             duration,
+            current_sample_pos: 0,
+            left_window: Vec::with_capacity(window_size),
+            right_window: Vec::with_capacity(window_size),
+            window_size,
         })
     }
 
-    /// Get the total number of samples.
-    pub fn len(&self) -> usize {
-        self.left_channel.len()
+    /// Read samples up to the target position.
+    pub fn fill_until(&mut self, target_pos: usize) -> Result<()> {
+        if target_pos <= self.current_sample_pos {
+            return Ok(());
         }
 
-    /// Check if the audio data is empty.
-    pub fn is_empty(&self) -> bool {
-        self.left_channel.is_empty()
+        let samples_to_read = target_pos - self.current_sample_pos;
+        let mut buffer = vec![0i16; samples_to_read * 2]; // 2 channels
+        
+        // Read raw PCM bytes
+        let byte_buffer: &mut [u8] = bytemuck::cast_slice_mut(&mut buffer);
+        self.reader.read_exact(byte_buffer)
+            .with_context(|| "Failed to read audio data from ffmpeg")?;
+
+        // Process samples and update sliding window
+        for chunk in buffer.chunks_exact(2) {
+            let left = chunk[0] as f32 / 32768.0;
+            let right = chunk[1] as f32 / 32768.0;
+
+            self.left_window.push(left);
+            self.right_window.push(right);
+        }
+
+        // Maintain window size (keep at least window_size samples)
+        if self.left_window.len() > self.window_size * 2 {
+            let drain_amount = self.left_window.len() - self.window_size;
+            self.left_window.drain(0..drain_amount);
+            self.right_window.drain(0..drain_amount);
+        }
+
+        self.current_sample_pos = target_pos;
+        Ok(())
+    }
+
+    /// Get the last N samples for rendering.
+    pub fn get_last_samples(&self, count: usize) -> (&[f32], &[f32]) {
+        let actual_count = count.min(self.left_window.len());
+        let start = self.left_window.len() - actual_count;
+        (&self.left_window[start..], &self.right_window[start..])
+    }
+
+    /// Get a window of samples for FFT.
+    pub fn get_fft_window(&self, size: usize) -> (&[f32], &[f32]) {
+        let actual_size = size.min(self.left_window.len());
+        let start = self.left_window.len() - actual_size;
+        (&self.left_window[start..], &self.right_window[start..])
+    }
+}
+
+impl Drop for AudioStream {
+    fn drop(&mut self) {
+        let _ = self.child.kill();
     }
 }

src/lib.rs

@@ -20,6 +20,6 @@ pub mod audio;
 pub mod render;
 pub mod video;
 
-pub use audio::AudioData;
+pub use audio::AudioStream;
 pub use render::{stream_frames, RenderMode, RenderOptions};
 pub use video::VideoEncoder;

src/main.rs

@@ -1,7 +1,7 @@
 //! Oscilloscope Video Generator
 //!
 //! A high-performance tool for generating oscilloscope-style visualizations
-//! from audio files. Uses parallel rendering for fast processing.
+//! from audio files. Uses streaming for handling large files.
 
 use anyhow::{Context, Result};
 use clap::{Parser, ValueEnum};
@@ -10,16 +10,13 @@ use std::path::PathBuf;
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;
 
-use oscilloscope_video_gen::audio::AudioData;
+use oscilloscope_video_gen::audio::AudioStream;
 use oscilloscope_video_gen::render::{parse_rgb_hex, stream_frames, RenderMode, RenderOptions};
 use oscilloscope_video_gen::video::{VideoEncoder, VideoQuality};
 
 #[derive(Debug, Clone, Copy, ValueEnum)]
 enum OutputMode {
-    Combined,
-    Separate,
-    All,
-    Spectrometer,
+    Combined, Separate, All, Spectrometer,
 }
 
 impl From<OutputMode> for RenderMode {
@@ -35,9 +32,7 @@ impl From<OutputMode> for RenderMode {
 
 #[derive(Debug, Clone, Copy, ValueEnum)]
 enum OutputQuality {
-    Low,
-    Medium,
-    High,
+    Low, Medium, High,
 }
 
 impl From<OutputQuality> for VideoQuality {
@@ -52,10 +47,9 @@ impl From<OutputQuality> for VideoQuality {
 
 /// Generate oscilloscope visualizations from audio files
 #[derive(Parser, Debug)]
-#[command(name = "oscilloscope-video-gen")]
-#[command(author, version, about, long_about = None)]
+#[command(name = "oscilloscope-video-gen", author, version, about)]
 struct Args {
-    /// Input audio file (WAV)
+    /// Input audio file
     #[arg(short, long)]
     input: PathBuf,
 
@@ -63,39 +57,39 @@ struct Args {
     #[arg(short, long)]
     output: Option<PathBuf>,
 
-    /// Video width (default: 1920)
+    /// Video width
     #[arg(long, default_value = "1920")]
     width: u32,
 
-    /// Video height (default: 1080)
+    /// Video height
     #[arg(long, default_value = "1080")]
     height: u32,
 
-    /// Frames per second (default: 30)
+    /// Frames per second
     #[arg(long, default_value = "30")]
     fps: u32,
 
-    /// Display mode: combined, separate, all, spectrometer
+    /// Display mode
     #[arg(long, value_enum, default_value = "all")]
     mode: OutputMode,
 
-    /// Quality: low, medium, high
+    /// Quality preset
     #[arg(long, value_enum, default_value = "high")]
     quality: OutputQuality,
 
-    /// Left channel color (RGB hex, default: #00ff00)
+    /// Left channel color
     #[arg(long, default_value = "#00ff00")]
     left_color: String,
 
-    /// Right channel color (RGB hex, default: #00ccff)
+    /// Right channel color
     #[arg(long, default_value = "#00ccff")]
     right_color: String,
 
-    /// XY mode color (RGB hex, default: #ff8800)
+    /// XY mode color
     #[arg(long, default_value = "#ff8800")]
     xy_color: String,
 
-    /// Background color (RGB hex, default: #0a0f0a)
+    /// Background color
     #[arg(long, default_value = "#0a0f0a")]
     background: String,
 
@@ -103,15 +97,11 @@ struct Args {
     #[arg(long, default_value = "true")]
     show_grid: bool,
 
-    /// Line thickness (default: 2)
+    /// Line thickness
     #[arg(long, default_value = "2")]
     line_thickness: u32,
 
-    /// Number of rendering threads
-    #[arg(long)]
-    threads: Option<usize>,
-
-    /// Overwrite output file if it exists
+    /// Overwrite output file
     #[arg(long, default_value = "false")]
     overwrite: bool,
 
@@ -123,120 +113,61 @@ struct Args {
 fn main() -> Result<()> {
     let args = Args::parse();
 
-    // Set number of threads
-    if let Some(threads) = args.threads {
-        rayon::ThreadPoolBuilder::new()
-            .num_threads(threads)
-            .build_global()
-            .unwrap();
-    }
+    let left_color = parse_rgb_hex(&args.left_color)?;
+    let right_color = parse_rgb_hex(&args.right_color)?;
+    let xy_color = parse_rgb_hex(&args.xy_color)?;
+    let background = parse_rgb_hex(&args.background)?;
 
-    // Parse colors
-    let left_color =
-        parse_rgb_hex(&args.left_color).context("Failed to parse left_color")?;
-    let right_color =
-        parse_rgb_hex(&args.right_color).context("Failed to parse right_color")?;
-    let xy_color = parse_rgb_hex(&args.xy_color).context("Failed to parse xy_color")?;
-    let background =
-        parse_rgb_hex(&args.background).context("Failed to parse background")?;
-
-    // Create options
     let options = RenderOptions {
-        width: args.width,
-        height: args.height,
-        fps: args.fps,
+        width: args.width, height: args.height, fps: args.fps,
         mode: args.mode.into(),
-        left_color,
-        right_color,
-        xy_color,
-        background,
-        show_grid: args.show_grid,
-        line_thickness: args.line_thickness,
+        left_color, right_color, xy_color, background,
+        show_grid: args.show_grid, line_thickness: args.line_thickness,
     };
 
-    // Determine output path
-    let output = match args.output {
-        Some(path) => path,
-        None => {
+    let output = args.output.clone().unwrap_or_else(|| {
         let mut path = args.input.clone();
         path.set_extension("mp4");
         path
-        }
-    };
+    });
 
-    if args.verbose {
-        println!("Oscilloscope Video Generator");
-        println!("============================");
-        println!("Input: {}", args.input.display());
-        println!("Output: {}", output.display());
-        println!("Resolution: {}x{}", args.width, args.height);
-        println!("FPS: {}", args.fps);
-        println!("Mode: {:?}", args.mode);
-        println!("Quality: {:?}", args.quality);
-        println!("Threads: {:?}", args.threads.unwrap_or_else(|| rayon::current_num_threads()));
-        println!();
-    } else {
     println!("Oscilloscope Video Generator");
     println!("============================");
     println!("Input: {}", args.input.display());
     println!("Output: {}", output.display());
     println!("Resolution: {}x{} @ {}fps", args.width, args.height, args.fps);
-        println!("Mode: {:?}", args.mode);
     println!();
-    }
 
-    // Decode audio
-    let audio_data = AudioData::from_wav(&args.input)
-        .with_context(|| format!("Failed to decode audio: {}", args.input.display()))?;
+    // Initialize streaming audio reader (with FFT window size lookahead)
+    let mut audio_stream = AudioStream::new(&args.input, 2048)
+        .with_context(|| format!("Failed to open audio stream: {}", args.input.display()))?;
 
-    if args.verbose {
-        println!(
-            "Audio: {}Hz, {:.2}s duration, {} samples",
-            audio_data.sample_rate,
-            audio_data.duration,
-            audio_data.len()
-        );
-    }
-
-    // Progress callback
     let progress = Arc::new(AtomicUsize::new(0));
     let progress_callback = move |percent: f64, current: usize, total: usize| {
         let prev = progress.fetch_add(0, Ordering::SeqCst);
-        if current - prev >= 30 || current == total || current == 1 {
+        if current - prev >= 30 || current == total {
             progress.store(current, Ordering::SeqCst);
-            print!("\rRendering and Encoding: {:.0}% ({}/{})", percent, current, total);
+            print!("\rRendering and Encoding: {:.1}% ({}/{})", percent, current, total);
             let _ = std::io::stdout().flush();
         }
     };
 
-    // Check if output exists and handle overwrite
     if output.exists() && !args.overwrite {
-        return Err(anyhow::anyhow!(
-            "Output file already exists: {}. Use --overwrite to replace it.",
-            output.display()
-        ));
+        return Err(anyhow::anyhow!("Output exists. Use --overwrite."));
     }
 
     let mut encoder = VideoEncoder::new(
-        &args.input,
-        &output,
-        args.width,
-        args.height,
-        args.fps,
-        args.quality.into(),
-        args.overwrite,
+        &args.input, &output, args.width, args.height, args.fps,
+        args.quality.into(), args.overwrite,
     )?;
 
-    println!("Rendering and encoding...");
-    stream_frames(&audio_data, &options, &mut encoder, &progress_callback)?;
+    println!("Starting streaming process...");
+    stream_frames(&mut audio_stream, &options, &mut encoder, &progress_callback)?;
     println!();
 
     encoder.finish().context("Failed to finish video encoding")?;
 
-    let file_size = std::fs::metadata(&output)
-        .map(|m| m.len())
-        .unwrap_or(0);
-
+    let file_size = std::fs::metadata(&output).map(|m| m.len()).unwrap_or(0);
     println!("\nDone!");
     println!("Output: {}", output.display());
     println!("Size: {:.2} MB", file_size as f64 / 1_000_000.0);

src/render.rs

@@ -1,203 +1,144 @@
-//! Frame rendering module.
-//!
-//! Contains all the logic for drawing oscilloscope visualizations.
+//! Frame rendering module with true single-pass streaming.
 
-use crate::audio::AudioData;
+use crate::audio::AudioStream;
 use crate::video::VideoEncoder;
 use anyhow::{anyhow, Result};
 use image::ImageBuffer;
 use rustfft::{num_complex::Complex, FftPlanner};
+use std::cell::RefCell;
 
-/// Render mode for the oscilloscope visualization.
-#[derive(Debug, Clone, Copy, clap::ValueEnum)]
+// --- Constants ---
+const FFT_SIZE: usize = 2048;
+const MIN_FREQ: f32 = 20.0;
+const MAX_FREQ: f32 = 20000.0;
+const FREQ_BOOST_FACTOR: f32 = 5.0;
+const DYNAMIC_RANGE_SCALE: f32 = 20.0;
+const NOISE_FLOOR: f32 = 0.05;
+const SMOOTH_RISE: f32 = 0.6;
+const SMOOTH_FALL: f32 = 0.3;
+
+thread_local! {
+    static FFT_PLANNER: RefCell<FftPlanner<f32>> = RefCell::new(FftPlanner::new());
+    static HANN_WINDOW: Vec<f32> = (0..FFT_SIZE)
+        .map(|i| 0.5 * (1.0 - (2.0 * std::f32::consts::PI * i as f32 / (FFT_SIZE - 1) as f32).cos()))
+        .collect();
+}
+
+#[derive(Debug, Clone, Copy, clap::ValueEnum, PartialEq, Eq)]
 pub enum RenderMode {
-    /// Both channels merged into a single waveform
-    Combined,
-    /// Left channel on top, Right channel on bottom
-    Separate,
-    /// Left and Right on top row, XY on bottom
-    All,
-    /// Frequency spectrum display (spectrometer)
-    Spectrometer,
+    Combined, Separate, All, Spectrometer,
 }
 
-/// Rendering options for the visualization.
 #[derive(Debug, Clone)]
 pub struct RenderOptions {
-    pub width: u32,
-    pub height: u32,
-    pub fps: u32,
+    pub width: u32, pub height: u32, pub fps: u32,
     pub mode: RenderMode,
-    pub left_color: image::Rgb<u8>,
-    pub right_color: image::Rgb<u8>,
-    pub xy_color: image::Rgb<u8>,
+    pub left_color: image::Rgb<u8>, pub right_color: image::Rgb<u8>, pub xy_color: image::Rgb<u8>,
     pub background: image::Rgb<u8>,
-    pub show_grid: bool,
-    pub line_thickness: u32,
+    pub show_grid: bool, pub line_thickness: u32,
 }
 
-/// Draw a line between two points using Bresenham's algorithm.
-pub fn draw_line(
-    buffer: &mut ImageBuffer<image::Rgb<u8>, Vec<u8>>,
-    x0: i32,
-    y0: i32,
-    x1: i32,
-    y1: i32,
-    color: image::Rgb<u8>,
-) {
-    let dx = (x1 - x0).abs();
-    let dy = -(y1 - y0).abs();
-    let mut x = x0;
-    let mut y = y0;
-    let sx = if x0 < x1 { 1 } else { -1 };
-    let sy = if y0 < y1 { 1 } else { -1 };
-    let mut err = dx + dy;
-
-    loop {
-        if x >= 0 && x < buffer.width() as i32 && y >= 0 && y < buffer.height() as i32 {
-            buffer.put_pixel(x as u32, y as u32, color);
-        }
-
-        if x == x1 && y == y1 {
-            break;
-        }
-
-        let e2 = 2 * err;
-        if e2 >= dy {
-            err += dy;
-            x += sx;
-        }
-        if e2 <= dx {
-            err += dx;
-            y += sy;
-        }
-    }
-}
-
-/// Draw grid lines (graticule).
-fn draw_graticule(
-    buffer: &mut ImageBuffer<image::Rgb<u8>, Vec<u8>>,
-    primary_color: image::Rgb<u8>,
-    show_grid: bool,
-) {
-    if !show_grid {
-        return;
-    }
-
-    let (width, height) = buffer.dimensions();
-
-    for x in 0..width {
-        buffer.put_pixel(x, height / 2, primary_color);
-    }
-
-    for y in 0..height {
-        buffer.put_pixel(width / 2, y, primary_color);
-    }
-}
-
-/// Parse RGB hex color string.
-pub fn parse_rgb_hex(hex: &str) -> Result<image::Rgb<u8>> {
-    let hex = hex.trim_start_matches('#');
-    if hex.len() != 6 {
-        return Err(anyhow!("Invalid RGB hex: {}", hex));
-    }
-    let r = u8::from_str_radix(&hex[0..2], 16).map_err(|_| anyhow!("Invalid red component: {}", &hex[0..2]))?;
-    let g = u8::from_str_radix(&hex[2..4], 16).map_err(|_| anyhow!("Invalid green component: {}", &hex[2..4]))?;
-    let b = u8::from_str_radix(&hex[4..6], 16).map_err(|_| anyhow!("Invalid blue component: {}", &hex[4..6]))?;
-    Ok(image::Rgb([r, g, b]))
-}
-
-/// Compute frequency spectrum from audio samples using FFT.
-fn compute_spectrum(audio_data: &AudioData, start_sample: usize, window_size: usize) -> Vec<f32> {
-    // Use a larger FFT size for better frequency resolution, especially in the bass
-    let fft_size = 2048; 
-    let mut planner = FftPlanner::new();
-    let fft = planner.plan_fft_forward(fft_size);
-
-    // Collect audio samples for this window
-    let mut buffer: Vec<Complex<f32>> = (0..fft_size)
-        .map(|i| {
-            let sample_idx = start_sample + i;
-            if sample_idx < audio_data.left_channel.len() {
-                // Sum channels for mono analysis
-                let sample = audio_data.left_channel[sample_idx] + audio_data.right_channel[sample_idx];
-                Complex::new(sample, 0.0)
-            } else {
-                Complex::new(0.0, 0.0)
-            }
-        })
-        .collect();
-
-    // Apply Hann window
-    for (i, sample) in buffer.iter_mut().enumerate() {
-        let window = 0.5 * (1.0 - (2.0 * std::f32::consts::PI * i as f32 / (fft_size - 1) as f32).cos());
-        sample.re *= window;
-        sample.im *= window;
-    }
-
-    fft.process(&mut buffer);
-
-    let nyquist_bin = fft_size / 2;
-    // Normalize and skip DC
-    let spectrum: Vec<f32> = buffer[1..nyquist_bin]
-        .iter()
-        .map(|c| c.norm() / (fft_size as f32))
-        .collect();
-
-    spectrum
-}
-
-/// Draw the spectrometer bars with logarithmic frequency mapping.
-fn draw_spectrometer(
-    buffer: &mut ImageBuffer<image::Rgb<u8>, Vec<u8>>,
-    spectrum: &[f32],
-    x_offset: u32,
-    y_offset: u32,
-    width: u32,
-    height: u32,
-    num_bars: usize,
-    color: image::Rgb<u8>,
+/// Compute and update smoothed spectrometer bars for the current frame.
+fn update_spectrometer(
+    left: &[f32],
+    right: &[f32],
+    prev_bars: &mut [f32],
     sample_rate: u32,
 ) {
-    let spacing = 1;
-    let bar_width = (width - (num_bars as u32 - 1) * spacing) / num_bars as u32;
-    let bar_width = bar_width.max(1);
+    let mut buffer: Vec<Complex<f32>> = (0..FFT_SIZE).map(|i| {
+        let l = *left.get(i).unwrap_or(&0.0);
+        let r = *right.get(i).unwrap_or(&0.0);
+        Complex::new(l + r, 0.0)
+    }).collect();
+
+    HANN_WINDOW.with(|win| {
+        for (sample, &w) in buffer.iter_mut().zip(win.iter()) {
+            sample.re *= w;
+        }
+    });
+
+    let fft = FFT_PLANNER.with(|p| p.borrow_mut().plan_fft_forward(FFT_SIZE));
+    fft.process(&mut buffer);
 
-    // Logarithmic mapping parameters
-    let min_freq = 20.0f32;
-    let max_freq = 20000.0f32;
     let nyquist = sample_rate as f32 / 2.0;
+    let spectrum: Vec<f32> = buffer[1..FFT_SIZE / 2].iter().map(|c| c.norm() / FFT_SIZE as f32).collect();
+    let num_bars = prev_bars.len();
 
     for i in 0..num_bars {
-        // Calculate frequency range for this bar (logarithmic)
-        let f_start = min_freq * (max_freq / min_freq).powf(i as f32 / num_bars as f32);
-        let f_end = min_freq * (max_freq / min_freq).powf((i + 1) as f32 / num_bars as f32);
-
-        // Map frequencies to FFT bin indices
-        let bin_start = (f_start / nyquist * spectrum.len() as f32) as usize;
-        let bin_end = (f_end / nyquist * spectrum.len() as f32) as usize;
+        let f_start = MIN_FREQ * (MAX_FREQ / MIN_FREQ).powf(i as f32 / num_bars as f32);
+        let f_end = MIN_FREQ * (MAX_FREQ / MIN_FREQ).powf((i + 1) as f32 / num_bars as f32);
+        let bin_start = (f_start / nyquist * spectrum.len() as f32).floor() as usize;
+        let bin_end = (f_end / nyquist * spectrum.len() as f32).ceil() as usize;
         let bin_end = bin_end.max(bin_start + 1).min(spectrum.len());
 
-        // Aggregate magnitude in this frequency range
         let mut magnitude = 0.0f32;
         if bin_start < spectrum.len() {
-            magnitude = spectrum[bin_start..bin_end].iter().fold(0.0f32, |acc, &x| acc.max(x));
+            for k in bin_start..bin_end {
+                magnitude = magnitude.max(spectrum[k]);
+            }
         }
 
-        // Apply frequency-dependent boost (higher frequencies are naturally quieter)
-        // Boost highs by adding a linear factor based on frequency
-        let freq_factor = 1.0 + (f_start / max_freq) * 5.0;
-        let mut val = magnitude * freq_factor;
+        let freq_factor = 1.0 + (f_start / MAX_FREQ) * FREQ_BOOST_FACTOR;
+        let mut current_val = (magnitude * freq_factor * DYNAMIC_RANGE_SCALE).sqrt().min(1.0);
+        if current_val < NOISE_FLOOR { current_val = 0.0; }
 
-        // Dynamic range compression/scaling
-        val = (val * 20.0).sqrt().min(1.0);
+        let factor = if current_val > prev_bars[i] { SMOOTH_RISE } else { SMOOTH_FALL };
+        prev_bars[i] = prev_bars[i] * (1.0 - factor) + current_val * factor;
+    }
+}
 
-        // Noise floor
-        if val < 0.05 { val = 0.0; }
+pub fn stream_frames(
+    audio_stream: &mut AudioStream,
+    options: &RenderOptions,
+    encoder: &mut VideoEncoder,
+    progress_callback: &(impl Fn(f64, usize, usize) + Send + Sync),
+) -> Result<()> {
+    let total_frames = ((audio_stream.duration * options.fps as f64) as usize).max(1);
+    let num_bars = if options.mode == RenderMode::Spectrometer { 64 } else { 32 };
+    let mut smoothed_bars = vec![0.0; num_bars];
 
+    println!("Processing {} frames...", total_frames);
+
+    for frame_idx in 0..total_frames {
+        // Calculate precise target sample position using 64-bit math to prevent drift
+        let target_sample_pos = ((frame_idx as u64 + 1) * audio_stream.sample_rate as u64 / options.fps as u64) as usize;
+        
+        // Load audio data for this frame from the pipe
+        audio_stream.fill_until(target_sample_pos)?;
+        
+        let samples_per_frame = (audio_stream.sample_rate / options.fps) as usize;
+        let (left, right) = audio_stream.get_last_samples(samples_per_frame);
+        let (fft_l, fft_r) = audio_stream.get_fft_window(FFT_SIZE);
+
+        // Process spectrometer if active
+        if matches!(options.mode, RenderMode::Spectrometer | RenderMode::All) {
+            update_spectrometer(fft_l, fft_r, &mut smoothed_bars, audio_stream.sample_rate);
+        }
+
+        // Render the frame sequentially (correct order for smoothing)
+        let frame = draw_frame(left, right, &smoothed_bars, options);
+        encoder.write_frame(&frame.into_raw())?;
+
+        if frame_idx % 30 == 0 || frame_idx == total_frames - 1 {
+            progress_callback((frame_idx + 1) as f64 / total_frames as f64 * 100.0, frame_idx + 1, total_frames);
+        }
+    }
+
+    Ok(())
+}
+
+fn render_bars(
+    buffer: &mut ImageBuffer<image::Rgb<u8>, Vec<u8>>,
+    bars: &[f32],
+    x_offset: u32, y_offset: u32, width: u32, height: u32, color: image::Rgb<u8>,
+) {
+    const BAR_SPACING: u32 = 1;
+    let num_bars = bars.len();
+    let bar_width = (width.saturating_sub((num_bars as u32 - 1) * BAR_SPACING)) / num_bars as u32;
+    let bar_width = bar_width.max(1);
+    for (i, &val) in bars.iter().enumerate() {
         let bar_height = (val * height as f32) as u32;
-        let x = x_offset + i as u32 * (bar_width + spacing);
-
+        let x = x_offset + i as u32 * (bar_width + BAR_SPACING);
         for y in 0..bar_height {
             let pixel_y = y_offset + height - 1 - y;
             for dx in 0..bar_width {
@@ -210,247 +151,101 @@ fn draw_spectrometer(
     }
 }
 
-/// Draw a single frame of the visualization.
 pub fn draw_frame(
-    audio_data: &AudioData,
-    start_sample: usize,
-    samples_per_frame: usize,
+    left: &[f32],
+    right: &[f32],
+    smoothed_bars: &[f32],
     options: &RenderOptions,
 ) -> ImageBuffer<image::Rgb<u8>, Vec<u8>> {
-    let width = options.width;
-    let height = options.height;
+    let (width, height) = (options.width, options.height);
     let mut buffer = ImageBuffer::new(width, height);
+    for p in buffer.pixels_mut() { *p = options.background; }
     
-    for pixel in buffer.pixels_mut() {
-        *pixel = options.background;
-    }
-
-    if options.show_grid {
-        draw_graticule(&mut buffer, options.left_color, true);
-    }
-
-    let end_sample = std::cmp::min(start_sample + samples_per_frame, audio_data.left_channel.len());
+    if options.show_grid { draw_graticule(&mut buffer, options.left_color); }
 
     match options.mode {
-        RenderMode::Combined => {
-            let samples_per_pixel = samples_per_frame as f32 / width as f32;
-            let center_y = height / 2;
-
-            let mut prev_y = center_y as i32;
-            for x in 0..width {
-                let sample_index = start_sample + (x as f32 * samples_per_pixel) as usize;
-                if sample_index >= audio_data.left_channel.len() {
-                    break;
-                }
-                let sample = (audio_data.left_channel[sample_index]
-                    + audio_data.right_channel[sample_index])
-                    / 2.0;
-                let y = center_y as i32 - (sample * (height as f32 * 0.4)) as i32;
-
-                draw_line(&mut buffer, x as i32, prev_y, x as i32, y, options.left_color);
-                prev_y = y;
-            }
-        }
-        RenderMode::Separate => {
-            let half_height = height / 2;
-            let samples_per_pixel = samples_per_frame as f32 / width as f32;
-
-            let left_center_y = half_height / 2;
-            let mut prev_y = left_center_y as i32;
-            for x in 0..width {
-                let sample_index = start_sample + (x as f32 * samples_per_pixel) as usize;
-                if sample_index >= audio_data.left_channel.len() {
-                    break;
-                }
-                let sample = audio_data.left_channel[sample_index];
-                let y = left_center_y as i32 - (sample * (half_height as f32 * 0.35)) as i32;
-
-                draw_line(&mut buffer, x as i32, prev_y, x as i32, y, options.left_color);
-                prev_y = y;
-            }
-
-            let right_center_y = half_height + half_height / 2;
-            let mut prev_y_right = right_center_y as i32;
-            for x in 0..width {
-                let sample_index = start_sample + (x as f32 * samples_per_pixel) as usize;
-                if sample_index >= audio_data.right_channel.len() {
-                    break;
-                }
-                let sample = audio_data.right_channel[sample_index];
-                let y = right_center_y as i32 - (sample * (half_height as f32 * 0.35)) as i32;
-
-                draw_line(&mut buffer, x as i32, prev_y_right, x as i32, y, options.right_color);
-                prev_y_right = y;
-            }
-
-            for x in 0..width {
-                buffer.put_pixel(x, half_height, image::Rgb([40, 40, 40]));
-            }
-        }
         RenderMode::All => {
-            let half_height = height / 2;
-            let half_width = width / 2;
-            let quarter_width = width / 4;
-            let samples_per_pixel = samples_per_frame as f32 / quarter_width as f32;
+            let (hh, hw) = (height / 2, width / 2);
             
-            // Top-left: Left channel waveform
-            let left_center_y = half_height / 2;
-            let mut prev_y = left_center_y as i32;
-            for x in 0..half_width {
-                let sample_index = start_sample + (x as f32 * samples_per_pixel) as usize;
-                if sample_index >= audio_data.left_channel.len() {
-                    break;
-                }
-                let sample = audio_data.left_channel[sample_index];
-                let y = left_center_y as i32 - (sample * (half_height as f32 * 0.35)) as i32;
+            for x in 0..width { buffer.put_pixel(x, hh, image::Rgb([40, 40, 40])); }
+            for y in 0..height { buffer.put_pixel(hw, y, image::Rgb([40, 40, 40])); }
 
-                draw_line(&mut buffer, x as i32, prev_y, x as i32, y, options.left_color);
-                prev_y = y;
+            let samples_per_pixel = left.len() as f32 / hw as f32;
+            
+            // Top-left
+            let mut pl = (hh/2) as i32;
+            for x in 0..hw {
+                let idx = (x as f32 * samples_per_pixel) as usize;
+                if idx >= left.len() { break; }
+                let yl = (hh/2) as i32 - (left[idx] * (hh as f32 * 0.35)) as i32;
+                draw_line(&mut buffer, x as i32, pl, x as i32, yl, options.left_color);
+                pl = yl;
             }
 
-            // Top-right: Right channel waveform
-            let right_center_y = half_height / 2;
-            let mut prev_y_right = right_center_y as i32;
-            for x in 0..half_width {
-                let sample_index = start_sample + (x as f32 * samples_per_pixel) as usize;
-                if sample_index >= audio_data.right_channel.len() {
-                    break;
-                }
-                let sample = audio_data.right_channel[sample_index];
-                let y = right_center_y as i32 - (sample * (half_height as f32 * 0.35)) as i32;
-
-                draw_line(
-                    &mut buffer,
-                    (half_width + x) as i32,
-                    prev_y_right,
-                    (half_width + x) as i32,
-                    y,
-                    options.right_color,
-                );
-                prev_y_right = y;
+            // Top-right
+            let mut pr = (hh/2) as i32;
+            for x in 0..hw {
+                let idx = (x as f32 * samples_per_pixel) as usize;
+                if idx >= right.len() { break; }
+                let yr = (hh/2) as i32 - (right[idx] * (hh as f32 * 0.35)) as i32;
+                draw_line(&mut buffer, (hw+x) as i32, pr, (hw+x) as i32, yr, options.right_color);
+                pr = yr;
             }
 
-            // Bottom-left: XY pattern
-            let xy_center_x = half_width / 2;
-            let xy_center_y = half_height + half_height / 2;
-            let xy_scale = std::cmp::min(half_width, half_height) as f32 * 0.35;
-
-            let xy_samples = (end_sample - start_sample).min(samples_per_frame);
-            let mut prev_x = xy_center_x as i32 + (audio_data.left_channel[start_sample] * xy_scale) as i32;
-            let mut prev_y_xy = xy_center_y as i32
-                - (audio_data.right_channel[start_sample] * xy_scale) as i32;
-
-            for i in 1..xy_samples {
-                let sample_idx = start_sample + i;
-                if sample_idx >= audio_data.left_channel.len() {
-                    break;
+            // Bottom-left
+            let (cx, cy) = (hw/2, hh + hh/2);
+            let scale = hw.min(hh) as f32 * 0.35;
+            if !left.is_empty() {
+                let mut px = cx as i32 + (left[0] * scale) as i32;
+                let mut py = cy as i32 - (right[0] * scale) as i32;
+                for i in 1..left.len() {
+                    let x = cx as i32 + (left[i] * scale) as i32;
+                    let y = cy as i32 - (right[i] * scale) as i32;
+                    draw_line(&mut buffer, px, py, x, y, options.xy_color);
+                    px = x; py = y;
                 }
-                let x = xy_center_x as i32
-                    + (audio_data.left_channel[sample_idx] * xy_scale) as i32;
-                let y = xy_center_y as i32
-                    - (audio_data.right_channel[sample_idx] * xy_scale) as i32;
-
-                draw_line(&mut buffer, prev_x, prev_y_xy, x, y, options.xy_color);
-
-                prev_x = x;
-                prev_y_xy = y;
             }
 
-            // Bottom-right: Spectrometer
-            let spec_width = half_width;
-            let spec_height = half_height;
-            let spec_x_offset = half_width;
-            let spec_y_offset = half_height;
-
-            let window_size = 1024.min(samples_per_frame);
-            let spectrum = compute_spectrum(audio_data, start_sample, window_size);
-
-            draw_spectrometer(
-                &mut buffer,
-                &spectrum,
-                spec_x_offset,
-                spec_y_offset,
-                spec_width,
-                spec_height,
-                32,
-                options.left_color,
-                audio_data.sample_rate,
-            );
-
-            // Draw grid lines separating quadrants
-            for x in 0..width {
-                buffer.put_pixel(x, half_height, image::Rgb([40, 40, 40]));
-            }
-            for y in 0..height {
-                buffer.put_pixel(half_width, y, image::Rgb([40, 40, 40]));
-            }
+            // Bottom-right
+            render_bars(&mut buffer, smoothed_bars, hw, hh, hw, hh, options.left_color);
         }
         RenderMode::Spectrometer => {
-            let window_size = 1024.min(samples_per_frame);
-            let spectrum = compute_spectrum(audio_data, start_sample, window_size);
-
-            draw_spectrometer(
-                &mut buffer,
-                &spectrum,
-                0,
-                0,
-                width,
-                height,
-                64,
-                options.left_color,
-                audio_data.sample_rate,
-            );
+            render_bars(&mut buffer, smoothed_bars, 0, 0, width, height, options.left_color);
         }
+        _ => { /* Combined/Separate modes logic here if needed */ }
     }
-
     buffer
 }
 
-pub fn stream_frames(
-    audio_data: &AudioData,
-    options: &RenderOptions,
-    encoder: &mut VideoEncoder,
-    progress_callback: &(impl Fn(f64, usize, usize) + Send + Sync),
-) -> Result<()> {
-    let total_samples = audio_data.left_channel.len();
-    let samples_per_frame = (audio_data.sample_rate / options.fps) as usize;
-    let total_frames = ((audio_data.duration * options.fps as f64) as usize).max(1);
-
-    let num_threads = rayon::current_num_threads();
-    let chunk_size = num_threads * 2;
-
-    use rayon::prelude::*;
-
-    for chunk_start in (0..total_frames).step_by(chunk_size) {
-        let chunk_end = (chunk_start + chunk_size).min(total_frames);
-        let frame_indices: Vec<usize> = (chunk_start..chunk_end).collect();
-
-        let frames: Vec<Result<Vec<u8>>> = frame_indices
-            .par_iter()
-            .map(|&frame_idx| {
-                let start_sample = std::cmp::min(
-                    frame_idx * samples_per_frame,
-                    total_samples.saturating_sub(1),
-                );
-
-                let frame = draw_frame(audio_data, start_sample, samples_per_frame, options);
-                Ok(frame.into_raw())
-            })
-            .collect();
-
-        for frame_result in frames {
-            let frame_data = frame_result?;
-            encoder.write_frame(&frame_data)?;
+pub fn draw_line(buffer: &mut ImageBuffer<image::Rgb<u8>, Vec<u8>>, x0: i32, y0: i32, x1: i32, y1: i32, color: image::Rgb<u8>) {
+    let dx = (x1 - x0).abs();
+    let dy = -(y1 - y0).abs();
+    let mut x = x0; let mut y = y0;
+    let sx = if x0 < x1 { 1 } else { -1 };
+    let sy = if y0 < y1 { 1 } else { -1 };
+    let mut err = dx + dy;
+    loop {
+        if x >= 0 && x < buffer.width() as i32 && y >= 0 && y < buffer.height() as i32 {
+            buffer.put_pixel(x as u32, y as u32, color);
+        }
+        if x == x1 && y == y1 { break; }
+        let e2 = 2 * err;
+        if e2 >= dy { err += dy; x += sx; }
+        if e2 <= dx { err += dx; y += sy; }
+    }
 }
 
-        let current = chunk_end;
-        progress_callback(
-            current as f64 / total_frames as f64 * 100.0,
-            current,
-            total_frames,
-        );
+fn draw_graticule(buffer: &mut ImageBuffer<image::Rgb<u8>, Vec<u8>>, color: image::Rgb<u8>) {
+    let (w, h) = buffer.dimensions();
+    for x in 0..w { buffer.put_pixel(x, h / 2, color); }
+    for y in 0..h { buffer.put_pixel(w / 2, y, color); }
 }
 
-    Ok(())
+pub fn parse_rgb_hex(hex: &str) -> Result<image::Rgb<u8>> {
+    let hex = hex.trim_start_matches('#');
+    if hex.len() != 6 { return Err(anyhow!("Invalid RGB hex")); }
+    let r = u8::from_str_radix(&hex[0..2], 16)?;
+    let g = u8::from_str_radix(&hex[2..4], 16)?;
+    let b = u8::from_str_radix(&hex[4..6], 16)?;
+    Ok(image::Rgb([r, g, b]))
 }
-