feat(png): Add handler for tRNS ancillary chunk in PNG processing

2 files changed, 10 insertions, 2 deletions

diff --git a/include/tinyff/image/png.h b/include/tinyff/image/png.h
index 0b0bb3b..3d68fec 100644
--- a/include/tinyff/image/png.h
+++ b/include/tinyff/image/png.h
@@ -82,6 +82,9 @@ ff_result ff_png_palette_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); //
 ff_result ff_png_data_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // IDAT
 ff_result ff_png_end_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // IEND
 
+// Ancillary chunks
+ff_result ff_png_trans_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // tRNS
+
 
 const ff_png_chunk_handler ff_png_chunk_handlers[] = {
     {"IHDR", ff_png_header_handler},
@@ -90,7 +93,7 @@ const ff_png_chunk_handler ff_png_chunk_handlers[] = {
     {"PLTE", ff_png_palette_handler},   
 
     // From now on, the handlers will be for ancillary chunks
-
+    {"tRNS", ff_png_trans_handler},
 
     {NULL, NULL} // Terminator
 }; 
diff --git a/src/format/image/png.c b/src/format/image/png.c
index 162d5ee..d883863 100644
--- a/src/format/image/png.c
+++ b/src/format/image/png.c
@@ -309,4 +309,9 @@ ff_result ff_png_end_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
     ff_dprintf("png: all chunks received\n");
 
     return FF_RESULT_OK;
-}
\ No newline at end of file
+}
+
+ff_result ff_png_trans_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
+{
+    ff_dprintf("png: PLTE chunk received (len=%zu)\n", len);
+}