fix(media-proxy): bound animated transforms by output pixels (#3402)

fluxer_media_proxy/src/media_process/animated_transform.rs

@@ -182,7 +182,7 @@ impl GifResizeDims {
         (self.width as usize)
             .saturating_mul(self.height as usize)
             .saturating_mul(frames.max(1) as usize)
-            <= constants::MAX_GIF_RESIZE_OUTPUT_PIXELS
+            <= constants::MAX_ANIMATED_OUTPUT_PIXELS
     }
 }
 

fluxer_media_proxy/src/media_process/transform.rs

@@ -13,8 +13,8 @@ use super::image_probe::{
 };
 use super::loaded_image::{
     normalize_vips_image_to_uchar, page_height, resize_loaded_image, resize_loaded_image_by_scale,
-    validate_dimensions_u32, validate_jxl_decode_pixels, validate_static_output_pixels,
-    validate_vips_image,
+    static_output_pixels, validate_dimensions_u32, validate_jxl_decode_pixels,
+    validate_static_output_pixels, validate_vips_image,
 };
 use super::native_runtime::{clear_vips_error, ensure_vips_init, last_vips_error};
 use super::transform_plan::{
@@ -128,6 +128,31 @@ fn ensure_decode_cost_admissible(
     admitted
 }
 
+fn ensure_animated_output_admissible(
+    input: &[u8],
+    options: &ImageOptions,
+    media_limits: &MediaLimits,
+) -> Result<(), MediaError> {
+    let dims = probe_image_dims(media_limits, input)?;
+    if dims.pages <= 1 {
+        return Ok(());
+    }
+    let output_pixels = static_output_pixels(options, dims).saturating_mul(dims.pages as usize);
+    if output_pixels <= constants::MAX_ANIMATED_OUTPUT_PIXELS {
+        return Ok(());
+    }
+    tracing::warn!(
+        input_bytes = input.len(),
+        width = dims.width,
+        height = dims.height,
+        pages = dims.pages,
+        out_width = options.width.unwrap_or(0),
+        out_height = options.height.unwrap_or(0),
+        "animated transform refused by the output work budget"
+    );
+    Err(MediaError::TooLargeToProcess)
+}
+
 pub fn transform_image(
     input: &[u8],
     options: &ImageOptions,
@@ -184,6 +209,9 @@ pub fn transform_image(
             content_type: "image/gif",
         });
     }
+    if animated {
+        ensure_animated_output_admissible(input, options, media_limits)?;
+    }
     if should_transform_animated_webp_direct(sniffed, options, format) {
         validate_dimensions_u32(media_limits, sniffed.width, sniffed.height)?;
         let resolved = resolve_auto_quality(