From 33050939ff2eebb34610e9ccd53992fc693cf315 Mon Sep 17 00:00:00 2001
From: Nicolas Dufresne <nicolas.dufresne@collabora.co.uk>
Date: Sat, 28 Feb 2015 11:55:26 -0500
Subject: [PATCH] glmemory: Use fallback for partial copy

When the memory is partial copy, the texture size and videoinfo no
longer make sense. As we cannot guess what the application wants, we
safely copy into a sysmem memory.

https://bugzilla.gnome.org/show_bug.cgi?id=744246
---
 gst-libs/gst/gl/gstglmemory.c | 21 ++++++++++++++++++---
 gst-libs/gst/gl/gstglmemory.h |  1 +
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/gst-libs/gst/gl/gstglmemory.c b/gst-libs/gst/gl/gstglmemory.c
index 2a6f5f4505..47467f8e67 100644
--- a/gst-libs/gst/gl/gstglmemory.c
+++ b/gst-libs/gst/gl/gstglmemory.c
@@ -1038,12 +1038,18 @@ error:
 static GstMemory *
 _gl_mem_copy (GstGLMemory * src, gssize offset, gssize size)
 {
-  GstGLMemory *dest;
+  GstGLAllocator *allocator = (GstGLAllocator *) src->mem.allocator;
+  GstMemory *ret = NULL;
 
   g_mutex_lock (&((GstGLMemory *) src)->lock);
 
-  if (GST_GL_MEMORY_FLAG_IS_SET (src, GST_GL_MEMORY_FLAG_NEED_UPLOAD)) {
+  /* If not doing a full copy, then copy to sysmem, the 2D represention of the
+   * texture would become wrong */
+  if (offset > 0 || size < src->mem.size) {
+    ret = allocator->fallback_mem_copy (&src->mem, offset, size);
+  } else if (GST_GL_MEMORY_FLAG_IS_SET (src, GST_GL_MEMORY_FLAG_NEED_UPLOAD)) {
     GstAllocationParams params = { 0, src->mem.align, 0, 0 };
+    GstGLMemory *dest;
 
     dest = _gl_mem_new (src->mem.allocator, NULL, src->context, &params,
         &src->info, &src->valign, src->plane, NULL, NULL);
@@ -1057,9 +1063,11 @@ _gl_mem_copy (GstGLMemory * src, gssize offset, gssize size)
 
     memcpy (dest->data, (guint8 *) src->data + src->mem.offset, src->mem.size);
     GST_GL_MEMORY_FLAG_SET (dest, GST_GL_MEMORY_FLAG_NEED_UPLOAD);
+    ret = (GstMemory *) dest;
   } else {
     GstAllocationParams params = { 0, src->mem.align, 0, 0 };
     GstGLMemoryCopyParams copy_params;
+    GstGLMemory *dest;
 
     copy_params.src = src;
     copy_params.tex_id = 0;
@@ -1085,12 +1093,13 @@ _gl_mem_copy (GstGLMemory * src, gssize offset, gssize size)
     dest->tex_target = copy_params.tex_target;
     dest = _gl_mem_alloc_data (dest);
     GST_GL_MEMORY_FLAG_SET (dest, GST_GL_MEMORY_FLAG_NEED_DOWNLOAD);
+    ret = (GstMemory *) dest;
   }
 
 done:
   g_mutex_unlock (&((GstGLMemory *) src)->lock);
 
-  return (GstMemory *) dest;
+  return ret;
 }
 
 static GstMemory *
@@ -1331,12 +1340,18 @@ gst_gl_allocator_init (GstGLAllocator * allocator)
 {
   GstAllocator *alloc = GST_ALLOCATOR_CAST (allocator);
 
+  /* Keep the fallback copy function around, we will need it when copying with
+   * at an offset or smaller size */
+  allocator->fallback_mem_copy = alloc->mem_copy;
+
   alloc->mem_type = GST_GL_MEMORY_ALLOCATOR;
   alloc->mem_map = (GstMemoryMapFunction) _gl_mem_map;
   alloc->mem_unmap = (GstMemoryUnmapFunction) _gl_mem_unmap;
   alloc->mem_copy = (GstMemoryCopyFunction) _gl_mem_copy;
   alloc->mem_share = (GstMemoryShareFunction) _gl_mem_share;
   alloc->mem_is_span = (GstMemoryIsSpanFunction) _gl_mem_is_span;
+
+  GST_OBJECT_FLAG_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC);
 }
 
 /**
diff --git a/gst-libs/gst/gl/gstglmemory.h b/gst-libs/gst/gl/gstglmemory.h
index 0d745e4218..87033c0f56 100644
--- a/gst-libs/gst/gl/gstglmemory.h
+++ b/gst-libs/gst/gl/gstglmemory.h
@@ -190,6 +190,7 @@ void gst_gl_memory_download_transfer (GstGLMemory * gl_mem);
 struct _GstGLAllocator
 {
   GstAllocator parent;
+  GstMemoryCopyFunction fallback_mem_copy;
 };
 
 /**