feat: video renderer adapter w/ slides + charts + ffmpeg

crates/adapters/wrapup-renderer/src/ffmpeg.rs

@@ -0,0 +1,56 @@
+use domain::errors::DomainError;
+use domain::ports::VideoRenderConfig;
+use tokio::process::Command;
+
+pub async fn stitch_slides(
+    slides: &[Vec<u8>],
+    config: &VideoRenderConfig,
+) -> Result<Vec<u8>, DomainError> {
+    let dir =
+        tempfile::tempdir().map_err(|e| DomainError::InfrastructureError(e.to_string()))?;
+
+    // Write slide PNGs
+    for (i, png) in slides.iter().enumerate() {
+        let path = dir.path().join(format!("slide_{:04}.png", i));
+        std::fs::write(&path, png)
+            .map_err(|e| DomainError::InfrastructureError(e.to_string()))?;
+    }
+
+    let output_path = dir.path().join("output.mp4");
+
+    // -framerate 1/N makes each image last N seconds
+    let framerate = format!("1/{}", config.slide_duration_secs);
+    let (w, h) = config.resolution;
+
+    let status = Command::new(&config.ffmpeg_path)
+        .args([
+            "-y",
+            "-framerate",
+            &framerate,
+            "-i",
+            &dir.path().join("slide_%04d.png").to_string_lossy(),
+            "-vf",
+            &format!("scale={}:{},format=yuv420p", w, h),
+            "-c:v",
+            "libx264",
+            "-preset",
+            "fast",
+            "-crf",
+            "23",
+            "-movflags",
+            "+faststart",
+            &output_path.to_string_lossy(),
+        ])
+        .output()
+        .await
+        .map_err(|e| DomainError::InfrastructureError(format!("ffmpeg failed: {e}")))?;
+
+    if !status.status.success() {
+        let stderr = String::from_utf8_lossy(&status.stderr);
+        return Err(DomainError::InfrastructureError(format!(
+            "ffmpeg error: {stderr}"
+        )));
+    }
+
+    std::fs::read(&output_path).map_err(|e| DomainError::InfrastructureError(e.to_string()))
+}