Implement inline function av_fill_image_max_pixstep() and use it for

factorizing code.

Originally committed as revision 24827 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcore/avcore.h

@@ -27,7 +27,7 @@
 #include <libavutil/avutil.h>
 
 #define LIBAVCORE_VERSION_MAJOR  0
-#define LIBAVCORE_VERSION_MINOR  4
+#define LIBAVCORE_VERSION_MINOR  5
 #define LIBAVCORE_VERSION_MICRO  0
 
 #define LIBAVCORE_VERSION_INT   AV_VERSION_INT(LIBAVCORE_VERSION_MAJOR, \

libavcore/imgutils.c

@@ -29,21 +29,12 @@ int av_get_image_linesize(enum PixelFormat pix_fmt, int width, int plane)
     const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[pix_fmt];
     int max_step     [4];       /* max pixel step for each plane */
     int max_step_comp[4];       /* the component for each plane which has the max pixel step */
-    int s, i;
+    int s;
 
     if (desc->flags & PIX_FMT_BITSTREAM)
         return (width * (desc->comp[0].step_minus1+1) + 7) >> 3;
 
-    memset(max_step     , 0, sizeof(max_step     ));
+    av_fill_image_max_pixstep(max_step, max_step_comp, desc);
-    memset(max_step_comp, 0, sizeof(max_step_comp));
-    for (i = 0; i < 4; i++) {
-        const AVComponentDescriptor *comp = &(desc->comp[i]);
-        if ((comp->step_minus1+1) > max_step[comp->plane]) {
-            max_step     [comp->plane] = comp->step_minus1+1;
-            max_step_comp[comp->plane] = i;
-        }
-    }
-
     s = (max_step_comp[plane] == 1 || max_step_comp[plane] == 2) ? desc->log2_chroma_w : 0;
     return max_step[plane] * (((width + (1 << s) - 1)) >> s);
 }
@@ -65,16 +56,7 @@ int av_fill_image_linesizes(int linesizes[4], enum PixelFormat pix_fmt, int widt
         return 0;
     }
 
-    memset(max_step     , 0, sizeof(max_step     ));
+    av_fill_image_max_pixstep(max_step, max_step_comp, desc);
-    memset(max_step_comp, 0, sizeof(max_step_comp));
-    for (i = 0; i < 4; i++) {
-        const AVComponentDescriptor *comp = &(desc->comp[i]);
-        if ((comp->step_minus1+1) > max_step[comp->plane]) {
-            max_step     [comp->plane] = comp->step_minus1+1;
-            max_step_comp[comp->plane] = i;
-        }
-    }
-
     for (i = 0; i < 4; i++) {
         int s = (max_step_comp[i] == 1 || max_step_comp[i] == 2) ? desc->log2_chroma_w : 0;
         linesizes[i] = max_step[i] * (((width + (1 << s) - 1)) >> s);

libavcore/imgutils.h

@@ -24,9 +24,43 @@
  * misc image utilities
  */
 
-#include "libavutil/pixfmt.h"
+#include "libavutil/pixdesc.h"
 #include "avcore.h"
 
+/**
+ * Compute the max pixel step for each plane of an image with a
+ * format described by pixdesc
+ *
+ * The pixel step is the distance in bytes between the first byte of
+ * the group of bytes which describe a pixel component and the first
+ * byte of the successive group in the same plane for the same
+ * component.
+ *
+ * @param max_pixstep an array which is filled with the max pixel step
+ * for each plane. Since a plane may contain different pixel
+ * components, the computed max_pixstep[plane] is relative to the
+ * component in the plane with the max pixel step.
+ * @param max_pixstep_comp an array which is filled with the component
+ * for each plane which has the max pixel step. May be NULL.
+ */
+static inline void av_fill_image_max_pixstep(int max_pixstep[4], int max_pixstep_comp[4],
+                                             const AVPixFmtDescriptor *pixdesc)
+{
+    int i;
+    memset(max_pixstep, 0, 4*sizeof(max_pixstep[0]));
+    if (max_pixstep_comp)
+        memset(max_pixstep_comp, 0, 4*sizeof(max_pixstep_comp[0]));
+
+    for (i = 0; i < 4; i++) {
+        const AVComponentDescriptor *comp = &(pixdesc->comp[i]);
+        if ((comp->step_minus1+1) > max_pixstep[comp->plane]) {
+            max_pixstep[comp->plane] = comp->step_minus1+1;
+            if (max_pixstep_comp)
+                max_pixstep_comp[comp->plane] = i;
+        }
+    }
+}
+
 /**
  * Compute the size of an image line with format pix_fmt and width
  * width for the plane plane.

libavfilter/vf_crop.c

@@ -24,7 +24,7 @@
  */
 
 #include "avfilter.h"
-#include "libavutil/pixdesc.h"
+#include "libavcore/imgutils.h"
 
 typedef struct {
     int  x;             ///< x offset of the non-cropped area with respect to the input area
@@ -83,15 +83,8 @@ static int config_input(AVFilterLink *link)
     AVFilterContext *ctx = link->dst;
     CropContext *crop = ctx->priv;
     const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[link->format];
-    int i;
-
-    memset(crop->max_step, 0, sizeof(crop->max_step));
-    for (i = 0; i < 4; i++) {
-        const AVComponentDescriptor *comp = &(pix_desc->comp[i]);
-        if ((comp->step_minus1+1) > crop->max_step[comp->plane])
-            crop->max_step[comp->plane] = comp->step_minus1+1;
-    }
 
+    av_fill_image_max_pixstep(crop->max_step, NULL, pix_desc);
     crop->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
     crop->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
 

libavfilter/vf_hflip.c

@@ -27,6 +27,7 @@
 #include "avfilter.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/intreadwrite.h"
+#include "libavcore/imgutils.h"
 
 typedef struct {
     int max_step[4];    ///< max pixel step for each plane, expressed as a number of bytes
@@ -68,15 +69,8 @@ static int config_props(AVFilterLink *inlink)
 {
     FlipContext *flip = inlink->dst->priv;
     const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
-    int i;
-
-    memset(flip->max_step, 0, sizeof(flip->max_step));
-    for (i = 0; i < 4; i++) {
-        const AVComponentDescriptor *comp = &(pix_desc->comp[i]);
-        if ((comp->step_minus1+1) > flip->max_step[comp->plane])
-            flip->max_step[comp->plane] = comp->step_minus1+1;
-    }
 
+    av_fill_image_max_pixstep(flip->max_step, NULL, pix_desc);
     flip->hsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
     flip->vsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_h;