From 2134fa4e6b1287b493a6bc65392ec17854a92d5d Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Thu, 18 Jul 2013 13:37:24 +0200
Subject: [PATCH] vf: make sure less important image params are set
 before/after filters

Image parameters like colorspace, color levels, and chroma location are
generally less important, and many filters don't set them correctly.
Force them instead in the generic VF code, which is probably better and
more convenient over all. So we designate this is a proper solution,
instead of a dirty hack.
---
 video/filter/vf.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/video/filter/vf.c b/video/filter/vf.c
index 8946aeb801..eaa19bbdb8 100644
--- a/video/filter/vf.c
+++ b/video/filter/vf.c
@@ -128,13 +128,29 @@ int vf_control(struct vf_instance *vf, int cmd, void *arg)
     return vf->control(vf, cmd, arg);
 }
 
+static void vf_fix_img_params(struct mp_image *img, struct mp_image_params *p)
+{
+    // Filters must absolutely set these correctly.
+    assert(img->w == p->w && img->h == p->h);
+    assert(img->imgfmt == p->imgfmt);
+    // Too many things don't set this correctly.
+    // If --colormatrix is used, decoder and filter chain disagree too.
+    // In general, it's probably more convenient to force these here,
+    // instead of requiring filters to set these correctly.
+    img->colorspace = p->colorspace;
+    img->levels = p->colorlevels;
+    img->chroma_location = p->chroma_location;
+}
+
 // Get a new image for filter output, with size and pixel format according to
 // the last vf_config call.
 struct mp_image *vf_alloc_out_image(struct vf_instance *vf)
 {
-    struct mp_image_params *p = &vf->fmt_out.params;
     assert(vf->fmt_out.configured);
-    return mp_image_pool_get(vf->out_pool, p->imgfmt, p->w, p->h);
+    struct mp_image_params *p = &vf->fmt_out.params;
+    struct mp_image *img = mp_image_pool_get(vf->out_pool, p->imgfmt, p->w, p->h);
+    vf_fix_img_params(img, p);
+    return img;
 }
 
 void vf_make_out_image_writeable(struct vf_instance *vf, struct mp_image *img)
@@ -360,16 +376,9 @@ unsigned int vf_match_csp(vf_instance_t **vfp, const unsigned int *list,
 void vf_add_output_frame(struct vf_instance *vf, struct mp_image *img)
 {
     if (img) {
-        struct mp_image_params *p = &vf->fmt_out.params;
         // vf_vo doesn't have output config
-        if (vf->fmt_out.configured) {
-            assert(p->imgfmt == img->imgfmt);
-            assert(p->w == img->w && p->h == img->h);
-            // Too many filters which don't set these correctly
-            img->colorspace = p->colorspace;
-            img->levels = p->colorlevels;
-            img->chroma_location = p->chroma_location;
-        }
+        if (vf->fmt_out.configured)
+            vf_fix_img_params(img, &vf->fmt_out.params);
         MP_TARRAY_APPEND(vf, vf->out_queued, vf->num_out_queued, img);
     }
 }
@@ -388,10 +397,8 @@ static struct mp_image *vf_dequeue_output_frame(struct vf_instance *vf)
 // Return >= 0 on success, < 0 on failure (even if output frames were produced)
 int vf_filter_frame(struct vf_instance *vf, struct mp_image *img)
 {
-    struct mp_image_params *p = &vf->fmt_in.params;
     assert(vf->fmt_in.configured);
-    assert(img->w == p->w && img->h == p->h);
-    assert(img->imgfmt == p->imgfmt);
+    vf_fix_img_params(img, &vf->fmt_in.params);
 
     if (vf->filter_ext) {
         return vf->filter_ext(vf, img);