1 files changed, 99 insertions, 0 deletions
diff --git a/TOOLS/vf_dlopen/showqscale.c b/TOOLS/vf_dlopen/showqscale.c
new file mode 100644
index 0000000000..9bece60a4f
--- /dev/null
+++ b/TOOLS/vf_dlopen/showqscale.c
@@ -0,0 +1,99 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "vf_dlopen.h"
+
+/*
+ * qscale visualizer
+ *
+ * usage: -vf dlopen=./showqscale.so
+ *
+ * uses reddish colors for high QPs, and greenish colors for low QPs
+ */
+
+#define PLANE_Y 0
+#define PLANE_U 1
+#define PLANE_V 2
+
+static int qs_put_image(struct vf_dlopen_context *ctx)
+{
+    unsigned int x, y, p;
+
+    assert(ctx->inpic.planes == ctx->outpic[0].planes);
+
+    for (p = 0; p < ctx->outpic[0].planes; ++p) {
+        assert(ctx->inpic.planewidth[p] == ctx->outpic[0].planewidth[p]);
+        assert(ctx->inpic.planeheight[p] == ctx->outpic[0].planeheight[p]);
+        if ((p == PLANE_U || p == PLANE_V) && ctx->inpic_qscale)
+            continue;
+#if 0
+        // copy as is
+        for (y = 0; y < ctx->outpic[0].planeheight[p]; ++y)
+            memcpy(
+                &ctx->outpic[0].plane[p][ctx->outpic[0].planestride[p] * y],
+                &inpic[ctx->outpic[0].planeofs[p] + ctx->inpic.planestride[p] * y],
+                ctx->outpic[0].planewidth[p]
+                );
+#else
+        // reduce contrast
+        for (y = 0; y < ctx->outpic[0].planeheight[p]; ++y)
+            for (x = 0; x < ctx->outpic[0].planewidth[p]; ++x)
+                ctx->outpic[0].plane[p][ctx->outpic[0].planestride[p] * y + x] =
+                    0x20 + ((ctx->inpic.plane[p][ctx->inpic.planestride[p] * y + x] * 3) >> 2);
+#endif
+    }
+
+    if (ctx->inpic_qscale) {
+        int qmin = 255;
+        int qmax = -255;
+
+        // clear U plane
+        p = PLANE_U;
+        for (y = 0; y < ctx->outpic[0].planeheight[p]; ++y)
+            memset(
+                &ctx->outpic[0].plane[p][ctx->outpic[0].planestride[p] * y],
+                0x80,
+                ctx->outpic[0].planewidth[p]
+                );
+
+        // replace V by the qp (0 = green, 12 = red)
+        p = PLANE_V;
+        for (y = 0; y < ctx->outpic[0].planeheight[p]; ++y)
+            for (x = 0; x < ctx->outpic[0].planewidth[p]; ++x) {
+                int q = ctx->inpic_qscale[
+                    (x >> (ctx->inpic_qscaleshift - ctx->inpic.planexshift[p])) +
+                    (y >> (ctx->inpic_qscaleshift - ctx->inpic.planeyshift[p])) * ctx->inpic_qscalestride];
+                if (q < qmin)
+                    qmin = q;
+                if (q > qmax)
+                    qmax = q;
+                int v = 128 + 21 * (q - 6); // range: 0 = green, 12 = red
+                if (v < 0)
+                    v = 0;
+                if (v > 255)
+                    v = 255;
+                ctx->outpic[0].plane[p][ctx->outpic[0].planestride[p] * y + x] = v;
+            }
+
+        // printf("qscale range: %d .. %d\n", qmin, qmax);
+    }
+
+    ctx->outpic[0].pts = ctx->inpic.pts;
+    return 1;
+}
+
+int vf_dlopen_getcontext(struct vf_dlopen_context *ctx, int argc, const char **argv)
+{
+    VF_DLOPEN_CHECK_VERSION(ctx);
+    (void) argc;
+    (void) argv;
+    static struct vf_dlopen_formatpair map[] = {
+        { "yv12", "yv12" },
+        { NULL, NULL }
+    };
+    ctx->format_mapping = map;
+    ctx->put_image = qs_put_image;
+    return 1;
+}