diff --git a/src/output.zig b/src/output.zig
index 3bd687b..3d1e3ef 100644
--- a/src/output.zig
+++ b/src/output.zig
@@ -57,12 +57,18 @@ const Scan = struct {
     }
 };
 
-fn parse_block(block: *util.BlockQuantized, dc_diff: *i16, dc_rle: *RLE_Seq, dc_freqs: []u32, ac_freqs: []u32) !void {
+inline fn get_size(v: i16) u8 {
+    _ = v;
+}
+
+fn parse_block(block: *util.BlockQuantized, dc_diff: *i16, rle: *RLE_Seq, dc_freqs: []u32, ac_freqs: []u32) !void {
     _ = ac_freqs;
     _ = dc_freqs;
-    _ = dc_rle;
-    _ = dc_diff;
-    _ = block;
+    const diff = block[0] - dc_diff.*;
+    try rle.append(RLE_Unit{
+        .symbol = get_size(diff),
+        .value = diff,
+    });
 }
 
 pub fn generate_jpg(buff: util.Buffers, alloc: std.mem.Allocator) !void {