lavu/imgutils: create misc functions for dealing with buffers

Move the lavc/imgconvert functions and rename them as follows:
avpicture_get_size -> av_image_get_buffer_size()
avpicture_fill     -> av_image_fill_arrays()
avpicture_layout   -> av_image_copy_to_buffer()

The new functions have an align parameter, which allows to define the
linesize alignment assumed in the buffer (which is set or read).

The names of the functions are consistent with the lavu/samples API
(av_samples_get_buffer_size(), av_samples_fill_arrays()).

3 files changed, 131 insertions, 1 deletions

diff --git a/libavutil/imgutils.c b/libavutil/imgutils.c
index ef7d4138ae..8ef92a50e3 100644
--- a/libavutil/imgutils.c
+++ b/libavutil/imgutils.c
@@ -23,6 +23,7 @@
 
 #include "imgutils.h"
 #include "internal.h"
+#include "intreadwrite.h"
 #include "log.h"
 #include "pixdesc.h"
 
@@ -276,3 +277,73 @@ void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
         }
     }
 }
+
+int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4],
+                         const uint8_t *src,
+                         enum PixelFormat pix_fmt, int width, int height, int align)
+{
+    int ret, i;
+
+    if ((ret = av_image_check_size(width, height, 0, NULL)) < 0)
+        return ret;
+
+    if ((ret = av_image_fill_linesizes(dst_linesize, pix_fmt, width)) < 0)
+        return ret;
+
+    for (i = 0; i < 4; i++)
+        dst_linesize[i] = FFALIGN(dst_linesize[i], align);
+
+    if ((ret = av_image_fill_pointers(dst_data, pix_fmt, width, NULL, dst_linesize)) < 0)
+        return ret;
+
+    return av_image_fill_pointers(dst_data, pix_fmt, height, src, dst_linesize);
+}
+
+int av_image_get_buffer_size(enum PixelFormat pix_fmt, int width, int height, int align)
+{
+    uint8_t *data[4];
+    int linesize[4];
+    if (av_image_check_size(width, height, 0, NULL) < 0)
+        return AVERROR(EINVAL);
+    if (av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_PSEUDOPAL)
+        // do not include palette for these pseudo-paletted formats
+        return width * height;
+    return av_image_fill_arrays(data, linesize, NULL, pix_fmt, width, height, align);
+}
+
+int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
+                            const uint8_t * const src_data[4], const int src_linesize[4],
+                            enum PixelFormat pix_fmt, int width, int height, int align)
+{
+    int i, j, nb_planes = 0, linesize[4];
+    const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[pix_fmt];
+    int size = av_image_get_buffer_size(pix_fmt, width, height, align);
+
+    if (size > dst_size || size < 0)
+        return AVERROR(EINVAL);
+
+    for (i = 0; i < desc->nb_components; i++)
+        nb_planes = FFMAX(desc->comp[i].plane, nb_planes);
+    nb_planes++;
+
+    av_image_fill_linesizes(linesize, pix_fmt, width);
+    for (i = 0; i < nb_planes; i++) {
+        int h, shift = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
+        const uint8_t *src = src_data[i];
+        h = (height + (1 << shift) - 1) >> shift;
+
+        for (j = 0; j < h; j++) {
+            memcpy(dst, src, linesize[i]);
+            dst += FFALIGN(linesize[i], align);
+            src += src_linesize[i];
+        }
+    }
+
+    if (desc->flags & PIX_FMT_PAL) {
+        uint32_t *d32 = (uint8_t *)(((size_t)dst + 3) & ~3);
+        for (i = 0; i<256; i++)
+            AV_WL32(d32 + i, AV_RN32(src_data[1] + 4*i));
+    }
+
+    return size;
+}
diff --git a/libavutil/imgutils.h b/libavutil/imgutils.h
index 9b53815fb6..3b1904bf3c 100644
--- a/libavutil/imgutils.h
+++ b/libavutil/imgutils.h
@@ -117,6 +117,65 @@ void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
                    enum PixelFormat pix_fmt, int width, int height);
 
 /**
+ * Setup the data pointers and linesizes based on the specified image
+ * parameters and the provided array.
+ *
+ * The fields of the given image are filled in by using the src
+ * address which points to the image data buffer. Depending on the
+ * specified pixel format, one or multiple image data pointers and
+ * line sizes will be set.  If a planar format is specified, several
+ * pointers will be set pointing to the different picture planes and
+ * the line sizes of the different planes will be stored in the
+ * lines_sizes array. Call with src == NULL to get the required
+ * size for the src buffer.
+ *
+ * To allocate the buffer and fill in the dst_data and dst_linesize in
+ * one call, use av_image_alloc().
+ *
+ * @param dst_data      data pointers to be filled in
+ * @param dst_linesizes linesizes for the image in dst_data to be filled in
+ * @param src           buffer which will contain or contains the actual image data, can be NULL
+ * @param pix_fmt       the pixel format of the image
+ * @param width         the width of the image in pixels
+ * @param height        the height of the image in pixels
+ * @param align         the value used in src for linesize alignment
+ * @return the size in bytes required for src, a negative error code
+ * in case of failure
+ */
+int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4],
+                         const uint8_t *src,
+                         enum PixelFormat pix_fmt, int width, int height, int align);
+
+/**
+ * Return the size in bytes of the amount of data required to store an
+ * image with the given parameters.
+ *
+ * @param[in] align the assumed linesize alignment
+ */
+int av_image_get_buffer_size(enum PixelFormat pix_fmt, int width, int height, int align);
+
+/**
+ * Copy image data from an image into a buffer.
+ *
+ * av_image_get_buffer_size() can be used to compute the required size
+ * for the buffer to fill.
+ *
+ * @param dst           a buffer into which picture data will be copied
+ * @param dst_size      the size in bytes of dst
+ * @param src_data      pointers containing the source image data
+ * @param src_linesizes linesizes for the image in src_data
+ * @param pix_fmt       the pixel format of the source image
+ * @param width         the width of the source image in pixels
+ * @param height        the height of the source image in pixels
+ * @param align         the assumed linesize alignment for dst
+ * @return the number of bytes written to dst, or a negative value
+ * (error code) on error
+ */
+int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
+                            const uint8_t * const src_data[4], const int src_linesize[4],
+                            enum PixelFormat pix_fmt, int width, int height, int align);
+
+/**
  * Check if the given dimension of an image is valid, meaning that all
  * bytes of the image can be addressed with a signed int.
  *
diff --git a/libavutil/version.h b/libavutil/version.h
index 1e05844c1e..9a0ac897b6 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -31,7 +31,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR 51
-#define LIBAVUTIL_VERSION_MINOR 62
+#define LIBAVUTIL_VERSION_MINOR 63
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \