[PATCH] winegstreamer: Check whether transforms are supported at creation time.

[Rémi Bernon]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52908
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52914
Signed-off-by: Rémi Bernon <rbernon(a)codeweavers.com>
---
 dlls/winegstreamer/h264_decoder.c | 10 ++++++++++
 dlls/winegstreamer/wg_transform.c | 13 +++++++++----
 dlls/winegstreamer/wma_decoder.c  | 10 ++++++++++
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/dlls/winegstreamer/h264_decoder.c b/dlls/winegstreamer/h264_decoder.c
index 8bfa15529db..778729f576c 100644
--- a/dlls/winegstreamer/h264_decoder.c
+++ b/dlls/winegstreamer/h264_decoder.c
@@ -585,10 +585,20 @@ static const IMFTransformVtbl transform_vtbl =
 
 HRESULT h264_decoder_create(REFIID riid, void **ret)
 {
+    struct wg_format output_format = {.major_type = WG_MAJOR_TYPE_UNKNOWN};
+    struct wg_format input_format = {.major_type = WG_MAJOR_TYPE_H264};
+    struct wg_transform *transform;
     struct h264_decoder *decoder;
 
     TRACE("riid %s, ret %p.\n", debugstr_guid(riid), ret);
 
+    if (!(transform = wg_transform_create(&input_format, &output_format)))
+    {
+        FIXME("GStreamer doesn't support H264 decoding, please install appropriate plugins\n");
+        return E_FAIL;
+    }
+    wg_transform_destroy(transform);
+
     if (!(decoder = calloc(1, sizeof(*decoder))))
         return E_OUTOFMEMORY;
 
diff --git a/dlls/winegstreamer/wg_transform.c b/dlls/winegstreamer/wg_transform.c
index 49c7bfaa927..0b975a8210e 100644
--- a/dlls/winegstreamer/wg_transform.c
+++ b/dlls/winegstreamer/wg_transform.c
@@ -169,7 +169,6 @@ NTSTATUS wg_transform_create(void *args)
     NTSTATUS status = STATUS_UNSUCCESSFUL;
     GstPadTemplate *template = NULL;
     struct wg_transform *transform;
-    const gchar *media_type;
     GstEvent *event;
 
     if (!init_gstreamer())
@@ -210,9 +209,13 @@ NTSTATUS wg_transform_create(void *args)
      * based on the actual output caps now. Matching decoders with the
      * raw output media type should be enough.
      */
-    media_type = gst_structure_get_name(gst_caps_get_structure(sink_caps, 0));
-    if (!(raw_caps = gst_caps_new_empty_simple(media_type)))
+    if (!(raw_caps = gst_caps_new_any()))
         goto out;
+    if (gst_caps_get_size(sink_caps))
+    {
+        const gchar *media_type = gst_structure_get_name(gst_caps_get_structure(sink_caps, 0));
+        gst_caps_append_structure(raw_caps, gst_structure_new_empty(media_type));
+    }
 
     switch (input_format.major_type)
     {
@@ -268,9 +271,11 @@ NTSTATUS wg_transform_create(void *args)
 
         case WG_MAJOR_TYPE_H264:
         case WG_MAJOR_TYPE_WMA:
-        case WG_MAJOR_TYPE_UNKNOWN:
             GST_FIXME("Format %u not implemented!", output_format.major_type);
             goto out;
+
+        case WG_MAJOR_TYPE_UNKNOWN:
+            break;
     }
 
     if (!(transform->their_sink = gst_element_get_static_pad(first, "sink")))
diff --git a/dlls/winegstreamer/wma_decoder.c b/dlls/winegstreamer/wma_decoder.c
index 57b0f204f9e..9d1ad20fba7 100644
--- a/dlls/winegstreamer/wma_decoder.c
+++ b/dlls/winegstreamer/wma_decoder.c
@@ -853,10 +853,20 @@ static const IPropertyBagVtbl property_bag_vtbl =
 
 HRESULT wma_decoder_create(IUnknown *outer, IUnknown **out)
 {
+    struct wg_format output_format = {.major_type = WG_MAJOR_TYPE_UNKNOWN};
+    struct wg_format input_format = {.major_type = WG_MAJOR_TYPE_WMA};
+    struct wg_transform *transform;
     struct wma_decoder *decoder;
 
     TRACE("outer %p, out %p.\n", outer, out);
 
+    if (!(transform = wg_transform_create(&input_format, &output_format)))
+    {
+        FIXME("GStreamer doesn't support WMA decoding, please install appropriate plugins\n");
+        return E_FAIL;
+    }
+    wg_transform_destroy(transform);
+
     if (!(decoder = calloc(1, sizeof(*decoder))))
         return E_OUTOFMEMORY;
 
-- 
2.35.1

[Zebediah Figura]

On 4/27/22 12:50, Rémi Bernon wrote:
> diff --git a/dlls/winegstreamer/h264_decoder.c b/dlls/winegstreamer/h264_decoder.c
> index 8bfa15529db..778729f576c 100644
> --- a/dlls/winegstreamer/h264_decoder.c
> +++ b/dlls/winegstreamer/h264_decoder.c
> @@ -585,10 +585,20 @@ static const IMFTransformVtbl transform_vtbl =
>
> HRESULT h264_decoder_create(REFIID riid, void **ret)
>   {
> +    struct wg_format output_format = {.major_type = WG_MAJOR_TYPE_UNKNOWN};
> +    struct wg_format input_format = {.major_type = WG_MAJOR_TYPE_H264};

This feels a bit awkward. input_format is somewhat ill-formed [not that 
struct wg_format is highly formalized, but wg_format_to_caps_h264() at 
least expects the profile and level to be set], but output_format has a 
major type of UNKNOWN, presumably to avoid passing an ill-formed type.
> @@ -210,9 +209,13 @@ NTSTATUS wg_transform_create(void *args)
>        * based on the actual output caps now. Matching decoders with the
>        * raw output media type should be enough.
>        */
> -    media_type = gst_structure_get_name(gst_caps_get_structure(sink_caps, 0));
> -    if (!(raw_caps = gst_caps_new_empty_simple(media_type)))
> +    if (!(raw_caps = gst_caps_new_any()))
>           goto out;
> +    if (gst_caps_get_size(sink_caps))
> +    {
> +        const gchar *media_type = gst_structure_get_name(gst_caps_get_structure(sink_caps, 0));
> +        gst_caps_append_structure(raw_caps, gst_structure_new_empty(media_type));
> +    }

And this will end up checking whether H.264 or WMA can decode to 
*anything*, which, while probably sufficient in practice, is less useful 
in theory than checking whether it can decode to, say, NV12 or PCM 
respectively.

I don't think that wg_format structs need to be fully specified (e.g. 
just enough to calculate the GstStructure name seems sufficient), 
although it'd be nice to avoid generating GStreamer FIXMEs under normal 
operation.