File 0003-stridetransform-implement-transform-function.patch of Package gst-plugins-base

From 4819a17561e36a6bb01ff0062b364c607cb5ea14 Mon Sep 17 00:00:00 2001
From: Rob Clark <rob@ti.com>
Date: Fri, 31 Jul 2009 17:39:47 -0500
Subject: [PATCH] stridetransform: implement transform function

Still needed are a few details, like conversion from one stride to another (instead of just strided->nonstrided or visa versa), and support for RGB and more YUV color formats.
---
 gst/stride/gststridetransform.c |  163 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 157 insertions(+), 6 deletions(-)

diff --git a/gst/stride/gststridetransform.c b/gst/stride/gststridetransform.c
index e31bf11..a911cd0 100644
--- a/gst/stride/gststridetransform.c
+++ b/gst/stride/gststridetransform.c
@@ -187,7 +187,7 @@ add_all_fields (GstCaps *caps, const gchar *name, GstStructure *s, gboolean rows
   GstStructure *new_s = gst_structure_new (name, NULL);
 
   if (rowstride) {
-    gst_structure_set (new_s, "rowstride", GST_TYPE_INT_RANGE, 1, 1000, NULL);  // XXX
+    gst_structure_set (new_s, "rowstride", GST_TYPE_INT_RANGE, 1, 1000, NULL);  // TODO
   }
 
   idx = gst_structure_n_fields (s) - 1;
@@ -253,6 +253,8 @@ gst_stride_transform_set_caps (GstBaseTransform *base,
     GstCaps *incaps, GstCaps *outcaps)
 {
   GstStrideTransform *self = GST_STRIDE_TRANSFORM (base);
+  GstVideoFormat format;
+  gint width, height;
 
   LOG_CAPS (self, incaps);
   LOG_CAPS (self, outcaps);
@@ -260,17 +262,166 @@ gst_stride_transform_set_caps (GstBaseTransform *base,
   g_return_val_if_fail (gst_video_format_parse_caps_strided (incaps,
       &self->format, &self->width, &self->height, &self->in_rowstride), FALSE);
   g_return_val_if_fail (gst_video_format_parse_caps_strided (outcaps,
-      NULL, NULL, NULL, &self->out_rowstride), FALSE);
+      &format, &width, &height, &self->out_rowstride), FALSE);
+
+  g_return_val_if_fail (self->format == format, FALSE);
+  g_return_val_if_fail (self->width  == width,  FALSE);
+  g_return_val_if_fail (self->height == height, FALSE);
 
   return TRUE;
 }
 
+/* ************************************************************************* */
+
+/**
+ * Convert from one stride to another... like memmove, but can convert stride in
+ * the process.  This function is not aware of pixels, only of bytes.  So widths
+ * are given in bytes, not pixels.  The new_buf and orig_buf can point to the
+ * same buffers to do an in-place conversion, but the buffer should be large
+ * enough.
+ */
+static void
+stridemove (guchar *new_buf, guchar *orig_buf, gint new_width, gint orig_width, gint height)
+{
+  int row;
+
+  GST_DEBUG ("new_buf=%p, orig_buf=%p, new_width=%d, orig_width=%d, height=%d",
+      new_buf, orig_buf, new_width, orig_width, height);
+  /* if increasing the stride, work from bottom-up to avoid overwriting data
+   * that has not been moved yet.. otherwise, work in the opposite order,
+   * for the same reason.
+   */
+  if (new_width > orig_width) {
+    for (row=height-1; row>=0; row--) {
+      memmove (new_buf+(new_width*row), orig_buf+(orig_width*row), orig_width);
+    }
+  } else {
+    for (row=0; row<height; row++) {
+      memmove (new_buf+(new_width*row), orig_buf+(orig_width*row), orig_width);
+    }
+  }
+}
+
+
+/**
+ * Convert from a non-strided buffer to strided.  The two buffer pointers could
+ * be pointing to the same memory block for in-place transform.. assuming that
+ * the buffer is large enough
+ *
+ * @strided:    the pointer to the resulting strided buffer
+ * @unstrided:  the pointer to the initial unstrided buffer
+ * @fourcc:     the color format
+ * @stride:     the stride, in bytes
+ * @width:      the width in pixels
+ * @height:     the height in pixels
+ */
+static GstFlowReturn
+stridify (GstStrideTransform *self, guchar *strided, guchar *unstrided)
+{
+  gint width  = self->width;
+  gint height = self->height;
+  gint stride = self->out_rowstride;
+
+  switch (self->format) {
+#if 0 /* TODO */
+    case GST_VIDEO_FORMAT_NV12:
+      g_return_val_if_fail (stride >= width, GST_FLOW_ERROR);
+      stridemove (strided, unstrided, stride, width, height * 1.5);
+      return GST_FLOW_OK;
+#endif
+    case GST_VIDEO_FORMAT_I420:
+    case GST_VIDEO_FORMAT_YV12:
+      g_return_val_if_fail (stride >= width, GST_FLOW_ERROR);
+      stridemove (
+          strided + (int)(height*stride*1.5),
+          unstrided + (int)(height*width*1.5),
+          stride, width/2, height);                             /* move U/V */
+      stridemove (
+          strided + (height*stride),
+          unstrided + (height*width),
+          stride, width/2, height);                             /* move V/U */
+      stridemove (strided, unstrided, stride, width, height);   /* move Y */
+      return GST_FLOW_OK;
+    case GST_VIDEO_FORMAT_YUY2:
+    case GST_VIDEO_FORMAT_UYVY:
+      g_return_val_if_fail (stride >= (width*2), GST_FLOW_ERROR);
+      stridemove (strided, unstrided, stride, width*2, height);
+      return GST_FLOW_OK;
+    default:
+      GST_WARNING ("unknown color format!\n");
+      return GST_FLOW_ERROR;
+  }
+}
+
+
+/**
+ * Convert from a strided buffer to non-strided.  The two buffer pointers could
+ * be pointing to the same memory block for in-place transform..
+ *
+ * @unstrided:  the pointer to the resulting unstrided buffer
+ * @strided:    the pointer to the initial strided buffer
+ */
+static GstFlowReturn
+unstridify (GstStrideTransform *self, guchar *unstrided, guchar *strided)
+{
+  gint width  = self->width;
+  gint height = self->height;
+  gint stride = self->in_rowstride;
+
+  switch (self->format) {
+#if 0 /* TODO */
+    case GST_VIDEO_FORMAT_NV12:
+      g_return_val_if_fail (stride >= width, GST_FLOW_ERROR);
+      stridemove (unstrided, strided, width, stride, height * 1.5);
+      return GST_FLOW_OK;
+#endif
+    case GST_VIDEO_FORMAT_I420:
+    case GST_VIDEO_FORMAT_YV12:
+      g_return_val_if_fail (stride >= width, GST_FLOW_ERROR);
+      stridemove (unstrided, strided, width, stride, height);   /* move Y */
+      stridemove (
+          unstrided + (height*width),
+          strided + (height*stride),
+          width/2, stride, height);                             /* move V/U */
+      stridemove (
+          unstrided + (int)(height*width*1.5),
+          strided + (int)(height*stride*1.5),
+          width/2, stride, height);                             /* move U/V */
+      return GST_FLOW_OK;
+    case GST_VIDEO_FORMAT_YUY2:
+    case GST_VIDEO_FORMAT_UYVY:
+      g_return_val_if_fail (stride >= (width*2), GST_FLOW_ERROR);
+      stridemove (unstrided, strided, width*2, stride, height);
+      return GST_FLOW_OK;
+    default:
+      GST_WARNING ("unknown color format!\n");
+      return GST_FLOW_ERROR;
+  }
+}
+
+
 static GstFlowReturn
 gst_stride_transform_transform (GstBaseTransform *base,
     GstBuffer *inbuf, GstBuffer *outbuf)
 {
   GstStrideTransform *self = GST_STRIDE_TRANSFORM (base);
-  GST_DEBUG_OBJECT (self, "not implemented");
+
+  GST_DEBUG_OBJECT (self, "inbuf=%p, outbuf=%p", inbuf, outbuf);
+
+  if (self->in_rowstride && self->out_rowstride) {
+    GST_DEBUG_OBJECT (self, "not implemented");  // TODO
+    return GST_FLOW_ERROR;
+  } else if (self->in_rowstride) {
+    return unstridify (self,
+        GST_BUFFER_DATA (outbuf), GST_BUFFER_DATA (inbuf));
+  } else if (self->out_rowstride) {
+    return stridify (self,
+        GST_BUFFER_DATA (outbuf), GST_BUFFER_DATA (inbuf));
+  }
+
+  GST_DEBUG_OBJECT (self, "this shouldn't happen!  in_rowstride=%d, out_rowstride=%d",
+      self->in_rowstride, self->out_rowstride);
+
   return GST_FLOW_ERROR;
 }
 
@@ -278,7 +429,7 @@ static GstFlowReturn
 gst_stride_transform_transform_ip (GstBaseTransform *base,
     GstBuffer *buf)
 {
-  GstStrideTransform *self = GST_STRIDE_TRANSFORM (base);
-  GST_DEBUG_OBJECT (self, "not implemented");
-  return GST_FLOW_ERROR;
+  /* transform function is safe to call with same buffer ptr:
+   */
+  return gst_stride_transform_transform (base, buf, buf);
 }
-- 
1.7.9.5