Module debug_rect 

Spatial decision logging for encoder debugging.

When the debug-rect feature is enabled, the debug_rect! macro logs every encoder decision alongside the rectangle it affects. Logs are collected in a global buffer and flushed to a sidecar CSV when the frame is complete.

When the feature is disabled, the macro compiles to nothing.

CSV format

stage,x,y,w,h,message

Query workflow

1. Encode with --features debug-rect → produces output.jxl.debug_rect.csv
2. Decode both our JXL and cjxl’s JXL, diff the pixels to find divergent regions
3. Call query_overlapping (or grep the CSV) for rectangles touching that region
4. Read the message column to understand every decision that affected those pixels

Functions

clear

diff_and_query

find_worst_block

find_worst_blocks

flush

query_overlapping