[PATCH v2 0/1] MR8758: winegstreamer: Use a stride alignment of 2 for NV12 in align_video_info_planes().

[Conor McCarthy (＠cmccarthy)]

Fixes the todos in !8034.

--
  v2: winegstreamer: Use a stride alignment of 2 for NV12 in align_video_info_planes().

https://gitlab.winehq.org/wine/wine/-/merge_requests/8758

[PATCH v2 1/1] winegstreamer: Use a stride alignment of 2 for NV12 in align_video_info_planes().

[Conor McCarthy]

From: Conor McCarthy

---
 dlls/mf/tests/transform.c         |  3 +--
 dlls/winegstreamer/wg_transform.c | 28 ++++++++++++++++++++++++----
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/dlls/mf/tests/transform.c b/dlls/mf/tests/transform.c
index 9bac63779b8..f82dfa1b090 100644
--- a/dlls/mf/tests/transform.c
+++ b/dlls/mf/tests/transform.c
@@ -9333,7 +9333,7 @@ static void test_video_processor(BOOL use_2d_buffer)
             .output_buffer_desc = use_2d_buffer ? nv12_crop : NULL,
             .output_sample_desc = &nv12_crop_sample_desc, .output_sample_2d_desc = &nv12_crop_sample_2d_desc,
             .delta = 2, /* Windows returns 1, Wine needs 2 */
-            .todo = TRUE, /* Would need special handling to convert gstreamer NV12 buffer to Windows alignment */
+            .todo = use_2d_buffer,
         },
     };

@@ -9773,7 +9773,6 @@ static void test_video_processor(BOOL use_2d_buffer)
         output_sample = create_sample_(NULL, output_info.cbSize, test->output_buffer_desc);
         hr = check_mft_process_output(transform, output_sample, &output_status);

-        todo_wine_if(test->output_sample_desc == &nv12_crop_sample_desc)
         ok(hr == S_OK || broken(hr == MF_E_SHUTDOWN) /* w8 */, "ProcessOutput returned %#lx\n", hr);
         if (hr != S_OK)
         {
diff --git a/dlls/winegstreamer/wg_transform.c b/dlls/winegstreamer/wg_transform.c
index 9ca3368ecb9..4171db272b7 100644
--- a/dlls/winegstreamer/wg_transform.c
+++ b/dlls/winegstreamer/wg_transform.c
@@ -107,6 +107,7 @@ static struct wg_transform *get_transform(wg_transform_t trans)
 static void align_video_info_planes(MFVideoInfo *video_info, gsize plane_align,
         GstVideoInfo *info, GstVideoAlignment *align)
 {
+    bool fix_nv12 = !plane_align && info->finfo->format == GST_VIDEO_FORMAT_NV12 && (info->width & 3) && (info->width & 3) != 3;
     const MFVideoArea *aperture = &video_info->MinimumDisplayAperture;

gst_video_alignment_reset(align);
@@ -129,9 +130,24 @@ static void align_video_info_planes(MFVideoInfo *video_info, gsize plane_align,
         align->padding_bottom = top;
     }

-    align->stride_align[0] = plane_align;
-
-    gst_video_info_align(info, align);
+    /* TODO: set NV12 GstVideoInfo correctly when padding is present */
+    if (fix_nv12 && !align->padding_left && !align->padding_top && !align->padding_right && !align->padding_bottom)
+    {
+        /* NV12 minimum stride alignment is 2, and Windows expects 2,
+         * but gst_video_info_align() imposes a minimum of 4. */
+        gint aligned_height = GST_ROUND_UP_2(info->height);
+        info->stride[0] = GST_ROUND_UP_2(info->width);
+        info->stride[1] = info->stride[0];
+        info->offset[0] = 0;
+        info->offset[1] = info->stride[0] * aligned_height;
+        info->size = info->offset[1] + info->stride[0] * aligned_height / 2;
+        align->stride_align[0] = 1;
+    }
+    else
+    {
+        align->stride_align[0] = plane_align;
+        gst_video_info_align(info, align);
+    }

if (video_info->VideoFlags & MFVideoFlag_BottomUpLinearRep)
     {
@@ -206,12 +222,16 @@ static WgVideoBufferPool *wg_video_buffer_pool_create(GstCaps *caps, gsize plane
 {
     WgVideoBufferPool *pool;
     GstStructure *config;
+    gsize max_size;

if (!(pool = g_object_new(wg_video_buffer_pool_get_type(), NULL)))
         return NULL;

gst_video_info_from_caps(&pool->info, caps);
+    max_size = pool->info.size;
     align_video_info_planes(video_info, plane_align, &pool->info, align);
+    /* GStreamer assumes NV12 pools must accommodate a stride alignment of 4, but we use 2 */
+    max_size = max(max_size, pool->info.size);

if (!(config = gst_buffer_pool_get_config(GST_BUFFER_POOL(pool))))
         GST_ERROR("Failed to get %"GST_PTR_FORMAT" config.", pool);
@@ -221,7 +241,7 @@ static WgVideoBufferPool *wg_video_buffer_pool_create(GstCaps *caps, gsize plane
         gst_buffer_pool_config_add_option(config, GST_BUFFER_POOL_OPTION_VIDEO_ALIGNMENT);
         gst_buffer_pool_config_set_video_alignment(config, align);

-        gst_buffer_pool_config_set_params(config, caps, pool->info.size, 0, 0);
+        gst_buffer_pool_config_set_params(config, caps, max_size, 0, 0);
         gst_buffer_pool_config_set_allocator(config, allocator, NULL);
         if (!gst_buffer_pool_set_config(GST_BUFFER_POOL(pool), config))
             GST_ERROR("Failed to set %"GST_PTR_FORMAT" config.", pool);

[Conor McCarthy (＠cmccarthy)]

On Tue Aug 19 05:43:37 2025 +0000, Conor McCarthy wrote:
> GStreamer has an internal check of the pool size which assumes a minimum
> 4-byte alignment for NV12. We must increase `max_size` even though the
> extra is unused.

Edited the code comment to improve clarity.

[PATCH v2 0/1] MR8758: winegstreamer: Use a stride alignment of 2 for NV12 in align_video_info_planes(). - approved

[Elizabeth Figura (＠zfigura)]

This merge request was approved by Elizabeth Figura.