Implement av_get_image_linesize() and use it in

ff_get_plane_bytewidth().

The new implementation is more generic, more compact and more correct.

Originally committed as revision 24786 to svn://svn.ffmpeg.org/ffmpeg/trunk

3 files changed, 33 insertions, 1 deletions

diff --git a/libavcore/avcore.h b/libavcore/avcore.h
index cba074ec54..4c45225b48 100644
--- a/libavcore/avcore.h
+++ b/libavcore/avcore.h
@@ -27,7 +27,7 @@
 #include <libavutil/avutil.h>
 
 #define LIBAVCORE_VERSION_MAJOR  0
-#define LIBAVCORE_VERSION_MINOR  3
+#define LIBAVCORE_VERSION_MINOR  4
 #define LIBAVCORE_VERSION_MICRO  0
 
 #define LIBAVCORE_VERSION_INT   AV_VERSION_INT(LIBAVCORE_VERSION_MAJOR, \
diff --git a/libavcore/imgutils.c b/libavcore/imgutils.c
index f3d75eecb2..84db01ae77 100644
--- a/libavcore/imgutils.c
+++ b/libavcore/imgutils.c
@@ -24,6 +24,30 @@
 #include "imgutils.h"
 #include "libavutil/pixdesc.h"
 
+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;
+
+    if (desc->flags & PIX_FMT_BITSTREAM)
+        return (width * (desc->comp[0].step_minus1+1) + 7) >> 3;
+
+    memset(max_step     , 0, sizeof(max_step     ));
+    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);
+}
+
 int av_fill_image_linesizes(int linesizes[4], enum PixelFormat pix_fmt, int width)
 {
     int i;
diff --git a/libavcore/imgutils.h b/libavcore/imgutils.h
index be6886c38e..c2cf6eb53e 100644
--- a/libavcore/imgutils.h
+++ b/libavcore/imgutils.h
@@ -28,6 +28,14 @@
 #include "avcore.h"
 
 /**
+ * Compute the size of an image line with format pix_fmt and width
+ * width for the plane plane.
+ *
+ * @return the computed size in bytes
+ */
+int av_get_image_linesize(enum PixelFormat pix_fmt, int width, int plane);
+
+/**
  * Fill plane linesizes for an image with pixel format pix_fmt and
  * width width.
  *