wip: callback wiring

2026-05-26 07:02:29 +02:00
parent 972a79dde2
commit c4c0dce098
2 changed files with 114 additions and 3 deletions
@@ -175,7 +175,31 @@ target_compile_options(bench_flush_frame PRIVATE -O2)
 # 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)
+    # Optional path to a private FFmpeg install carrying the per-MB
+    # inspection callback (marfrit-packages patch 0016).  When set,
+    # the CLI links against it instead of the system FFmpeg and the
+    # inspection-callback code path is compiled in.
+    set(DAEDALUS_FFMPEG_PREFIX "" CACHE PATH
+        "Path to a patched FFmpeg install (with 0016 mb-inspect-callback) for daedalus_decode_h264. Empty = use system pkg-config FFmpeg.")
+
+    if(DAEDALUS_FFMPEG_PREFIX)
+        message(STATUS "daedalus_decode_h264: patched FFmpeg at ${DAEDALUS_FFMPEG_PREFIX}")
+        set(FFMPEG_INCLUDE_DIRS ${DAEDALUS_FFMPEG_PREFIX}/include)
+        set(FFMPEG_LIBRARY_DIRS ${DAEDALUS_FFMPEG_PREFIX}/lib)
+        # Patched libavcodec is built static (no shared libs in the private prefix).
+        # System pull-ins are still needed for libav* dependencies.
+        set(FFMPEG_LIBRARIES
+            ${DAEDALUS_FFMPEG_PREFIX}/lib/libavformat.a
+            ${DAEDALUS_FFMPEG_PREFIX}/lib/libavcodec.a
+            ${DAEDALUS_FFMPEG_PREFIX}/lib/libavutil.a
+            ${DAEDALUS_FFMPEG_PREFIX}/lib/libswresample.a
+            m z pthread)
+        set(FFMPEG_CFLAGS_OTHER "-DDAEDALUS_HAVE_H264_MB_INSPECT_CB=1")
+    else()
        pkg_check_modules(FFMPEG REQUIRED libavcodec libavformat libavutil)
+        message(STATUS "daedalus_decode_h264: system FFmpeg (no inspection callback)")
+    endif()
+
    add_executable(daedalus_decode_h264 tools/daedalus_decode_h264.c)
    target_link_libraries(daedalus_decode_h264
        PRIVATE daedalus_decoder ${FFMPEG_LIBRARIES})
@@ -50,6 +50,22 @@
 #include <libavformat/avformat.h>
 #include <libavutil/imgutils.h>

+/* Per-MB inspection callback API — provided by the patched FFmpeg
+ * fork via marfrit-packages 0016.  The H264Context struct itself
+ * remains internal (declared in libavcodec/h264dec.h which isn't
+ * installed), so we only forward-declare it here and use it
+ * opaquely through the callback signature.  Real per-MB state
+ * extraction (sl->mb coefficients, mb_type, etc.) will land in
+ * PR-A3 alongside an internal-header include path. */
+#ifdef DAEDALUS_HAVE_H264_MB_INSPECT_CB
+struct H264Context;
+typedef void (*ff_h264_mb_inspect_cb)(void *opaque,
+                                       const struct H264Context *h,
+                                       int mb_x, int mb_y);
+void ff_h264_set_mb_inspect_cb(AVCodecContext *avctx,
+                                ff_h264_mb_inspect_cb cb, void *opaque);
+#endif
+
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -59,6 +75,37 @@
 static const char *substrate_str = "auto";
 static int   max_frames = -1;

+/* Inspection-callback state: per-frame counter + raster-order check.
+ * Reset at end of each frame by the main loop. */
+#ifdef DAEDALUS_HAVE_H264_MB_INSPECT_CB
+struct inspect_state {
+    int      n_cbs_this_frame;
+    int      expected_mb_w;
+    int      raster_violations;
+    int      last_mb_x, last_mb_y;  /* for raster-order detection */
+};
+
+static void inspect_cb(void *opaque,
+                        const struct H264Context *h,
+                        int mb_x, int mb_y)
+{
+    (void) h;
+    struct inspect_state *st = opaque;
+
+    /* Raster order check: each subsequent (mb_x, mb_y) should be the
+     * raster successor of the previous one within the frame. */
+    if (st->n_cbs_this_frame > 0) {
+        int expected_x = (st->last_mb_x + 1) % st->expected_mb_w;
+        int expected_y = st->last_mb_y + (st->last_mb_x + 1 == st->expected_mb_w ? 1 : 0);
+        if (mb_x != expected_x || mb_y != expected_y)
+            st->raster_violations++;
+    }
+    st->last_mb_x = mb_x;
+    st->last_mb_y = mb_y;
+    st->n_cbs_this_frame++;
+}
+#endif
+
 /* Extract one MB's predicted-samples block from a YUV420P AVFrame
 * (stock libavcodec) and pack it into the 384-byte mb_input.predicted
 * layout: 16x16 luma raster, then 8x8 Cb raster, then 8x8 Cr raster.
@@ -206,6 +253,13 @@ int main(int argc, char **argv)
    AVPacket *pkt = av_packet_alloc();
    AVFrame  *fr  = av_frame_alloc();

+#ifdef DAEDALUS_HAVE_H264_MB_INSPECT_CB
+    struct inspect_state inspect_st = {0};
+    ff_h264_set_mb_inspect_cb(avctx, inspect_cb, &inspect_st);
+    int inspect_total_cbs = 0;
+    int inspect_total_violations = 0;
+#endif
+
    /* ---- Create daedalus_decoder.  Coded width/height come from
     * the bitstream's SPS via libavcodec (after the first packet
     * is decoded — defer creation until then). ---- */
@@ -269,6 +323,12 @@ int main(int argc, char **argv)
                }
                printf("daedalus_decode_h264: %dx%d, substrate=%s\n",
                       W, H, substrate_str);
+#ifdef DAEDALUS_HAVE_H264_MB_INSPECT_CB
+                inspect_st.expected_mb_w = W / 16;
+                printf("  inspection callback: ACTIVE (patched libavcodec)\n");
+#else
+                printf("  inspection callback: not built in (stock libavcodec)\n");
+#endif
            }

            /* Pack each MB's predicted samples from the AVFrame.
@@ -320,6 +380,24 @@ int main(int argc, char **argv)
                if (out_uv_dadec[i] != out_uv_ref[i]) uv_diffs++;
            total_y_diffs  += y_diffs;
            total_uv_diffs += uv_diffs;
+#ifdef DAEDALUS_HAVE_H264_MB_INSPECT_CB
+            {
+                const int expected = mb_w * mb_h;
+                if (inspect_st.n_cbs_this_frame != expected) {
+                    fprintf(stderr,
+                        "  frame %d: callback fired %d times, expected %d (mb_w*mb_h)\n",
+                        n_frames, inspect_st.n_cbs_this_frame, expected);
+                    rc = 4; /* treat as bit-exact failure */
+                }
+                inspect_total_cbs        += inspect_st.n_cbs_this_frame;
+                inspect_total_violations += inspect_st.raster_violations;
+                /* Reset for next frame. */
+                inspect_st.n_cbs_this_frame = 0;
+                inspect_st.raster_violations = 0;
+                inspect_st.last_mb_x = 0;
+                inspect_st.last_mb_y = 0;
+            }
+#endif
            printf("  frame %d: Y diff %zu/%zu  UV diff %zu/%zu%s\n",
                   n_frames, y_diffs, y_size, uv_diffs, uv_size,
                   (y_diffs || uv_diffs) ? "  ***" : "");
@@ -348,11 +426,20 @@ int main(int argc, char **argv)
 drained:
    printf("\n%d frames decoded; total Y diff %zu, UV diff %zu\n",
           n_frames, total_y_diffs, total_uv_diffs);
-    if (total_y_diffs || total_uv_diffs) {
+#ifdef DAEDALUS_HAVE_H264_MB_INSPECT_CB
+    printf("inspection callback: %d total invocations, %d raster-order violations\n",
+           inspect_total_cbs, inspect_total_violations);
+    if (inspect_total_violations) rc = 4;
+#endif
+    if (rc == 0 && (total_y_diffs || total_uv_diffs)) {
        printf("FAIL: daedalus-decoder output does NOT match libavcodec reference byte-for-byte\n");
        rc = 4;
-    } else {
+    } else if (rc == 0) {
        printf("PASS: byte-exact identity-passthrough across %d frames\n", n_frames);
+    } else {
+        printf("FAIL: %s\n",
+               (total_y_diffs || total_uv_diffs) ? "byte-exact comparison failed"
+                                                   : "inspection callback invariants violated");
    }

 cleanup: