wip: tools/daedalus_decode_h264 cli

CMakeLists.txt

@@ -162,6 +162,31 @@ add_executable(bench_flush_frame tests/bench_flush_frame.c)
 target_link_libraries(bench_flush_frame PRIVATE daedalus_decoder)
 target_compile_options(bench_flush_frame PRIVATE -O2)
 
+# ---- Tools (not gated by ctest; opt-in via DAEDALUS_BUILD_TOOLS) ----
+#
+# daedalus_decode_h264 — option A standalone test harness that
+# wraps libavcodec + daedalus-decoder and bit-exact-compares their
+# outputs on real H.264 streams.  Identity-passthrough mode in this
+# first iteration (predicted = AVFrame pixels, coeffs = 0, no
+# deblock edges); follow-up PRs use the per-MB inspection callback
+# (marfrit-packages patch 0016) to feed REAL per-MB state.
+#
+# Requires libavcodec + libavformat headers + libs.  Off by default
+# so the standard ctest build doesn't pull in FFmpeg as a hard dep.
+option(DAEDALUS_BUILD_TOOLS "Build daedalus-decoder CLI tools (requires libavcodec)" OFF)
+if(DAEDALUS_BUILD_TOOLS)
+    pkg_check_modules(FFMPEG REQUIRED libavcodec libavformat libavutil)
+    add_executable(daedalus_decode_h264 tools/daedalus_decode_h264.c)
+    target_link_libraries(daedalus_decode_h264
+        PRIVATE daedalus_decoder ${FFMPEG_LIBRARIES})
+    target_include_directories(daedalus_decode_h264
+        PRIVATE ${FFMPEG_INCLUDE_DIRS})
+    target_link_directories(daedalus_decode_h264
+        PRIVATE ${FFMPEG_LIBRARY_DIRS})
+    target_compile_options(daedalus_decode_h264
+        PRIVATE -O2 ${FFMPEG_CFLAGS_OTHER})
+endif()
+
 # ---- Install ------------------------------------------------------
 #
 # Library + public header.  Stage 2/3 will add a pkg-config file and