Playbin2 has a bug that removes allocation meta in the pipeline
causing most of video decoders to copy frames. Workaround this
bug by explicitly advertising support for video meta.

WARNING: This is meant only for sinks which supports this.
Not every sink does. Do not upstream!
---
diff --git a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codech264dec.c b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codech264dec.c
index 9c7260b85a..d0a14e3c5e 100644
--- a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codech264dec.c
+++ b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codech264dec.c
@@ -403,8 +403,7 @@ gst_v4l2_codec_h264_dec_decide_allocation (GstVideoDecoder * decoder,
   GstV4l2CodecH264Dec *self = GST_V4L2_CODEC_H264_DEC (decoder);
   guint min = 0, num_bitstream;
 
-  self->has_videometa = gst_query_find_allocation_meta (query,
-      GST_VIDEO_META_API_TYPE, NULL);
+  self->has_videometa = TRUE;
 
   g_clear_object (&self->src_pool);
   g_clear_object (&self->src_allocator);
diff --git a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecmpeg2dec.c b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecmpeg2dec.c
index e3a31dab53..a095e64ed4 100644
--- a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecmpeg2dec.c
+++ b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecmpeg2dec.c
@@ -327,8 +327,7 @@ gst_v4l2_codec_mpeg2_dec_decide_allocation (GstVideoDecoder * decoder,
   GstV4l2CodecMpeg2Dec *self = GST_V4L2_CODEC_MPEG2_DEC (decoder);
   guint min = 0, num_bitstream;
 
-  self->has_videometa = gst_query_find_allocation_meta (query,
-      GST_VIDEO_META_API_TYPE, NULL);
+  self->has_videometa = TRUE;
 
   g_clear_object (&self->src_pool);
   g_clear_object (&self->src_allocator);
diff --git a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp8dec.c b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp8dec.c
index 6d547c565a..a90e39c89b 100644
--- a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp8dec.c
+++ b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp8dec.c
@@ -273,8 +273,7 @@ gst_v4l2_codec_vp8_dec_decide_allocation (GstVideoDecoder * decoder,
   guint min = 0;
   guint num_bitstream;
 
-  self->has_videometa = gst_query_find_allocation_meta (query,
-      GST_VIDEO_META_API_TYPE, NULL);
+  self->has_videometa = TRUE;
 
   g_clear_object (&self->src_pool);
   g_clear_object (&self->src_allocator);
diff --git a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp9dec.c b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp9dec.c
index 19cd0a71a2..5ee20fe4fa 100644
--- a/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp9dec.c
+++ b/subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp9dec.c
@@ -521,8 +521,7 @@ gst_v4l2_codec_vp9_dec_decide_allocation (GstVideoDecoder * decoder,
   guint min = 0;
   guint num_bitstream;
 
-  self->has_videometa = gst_query_find_allocation_meta (query,
-      GST_VIDEO_META_API_TYPE, NULL);
+  self->has_videometa = TRUE;
 
   g_clear_object (&self->src_pool);
   g_clear_object (&self->src_allocator);
diff --git a/subprojects/gst-plugins-bad/sys/va/gstvabasedec.c b/subprojects/gst-plugins-bad/sys/va/gstvabasedec.c
index 8414ecb2ee..323ee80c55 100644
--- a/subprojects/gst-plugins-bad/sys/va/gstvabasedec.c
+++ b/subprojects/gst-plugins-bad/sys/va/gstvabasedec.c
@@ -466,8 +466,7 @@ gst_va_base_dec_decide_allocation (GstVideoDecoder * decoder, GstQuery * query)
   if (!(caps && gst_video_info_from_caps (&info, caps)))
     goto wrong_caps;
 
-  has_videometa = gst_query_find_allocation_meta (query,
-      GST_VIDEO_META_API_TYPE, NULL);
+  has_videometa = TRUE;
   has_video_crop_meta = has_videometa && gst_query_find_allocation_meta (query,
       GST_VIDEO_CROP_META_API_TYPE, NULL);
 
diff --git a/subprojects/gst-plugins-bad/sys/va/gstvabasetransform.c b/subprojects/gst-plugins-bad/sys/va/gstvabasetransform.c
index f9cef373ff..c62cd97d33 100644
--- a/subprojects/gst-plugins-bad/sys/va/gstvabasetransform.c
+++ b/subprojects/gst-plugins-bad/sys/va/gstvabasetransform.c
@@ -389,8 +389,7 @@ gst_va_base_transform_decide_allocation (GstBaseTransform * trans,
   else
     gst_query_add_allocation_pool (query, pool, size, min, max);
 
-  has_videometa = gst_query_find_allocation_meta (query,
-      GST_VIDEO_META_API_TYPE, NULL);
+  has_videometa = TRUE;
 
   copy_frames = (!has_videometa && gst_va_pool_requires_video_meta (pool)
       && gst_caps_is_raw (outcaps));