libavutil: add mastering display metadata sidedata

Adding mastering display metadata struct to avutil. The mastering display metadata contains information
about the mastering display color volume (SMPTE 2086:2014).

This info comes from HEVC in the SEI_TYPE_MASTERING_DISPLAY_INFO and is soon to be included in MKV:
https://mailarchive.ietf.org/arch/search/?email_list=cellar&gbt=1&index=sZyfPTM-QY69P-0omfOIiTN622o
so it is similar to SEI FPA / stereo_mode in MKV and as such this patch follows how AVStereo3D is implemented.

I'll add support to HEVC in a follow-up (and MKV when spec is approved).

Signed-off-by: Neil Birkbeck <neil.birkbeck@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 87 insertions, 0 deletions

diff --git a/libavutil/mastering_display_metadata.h b/libavutil/mastering_display_metadata.h
new file mode 100644
index 0000000000..781c1fd3b2
--- /dev/null
+++ b/libavutil/mastering_display_metadata.h
@@ -0,0 +1,87 @@
+/**
+ * Copyright (c) 2016 Neil Birkbeck <neil.birkbeck@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_MASTERING_DISPLAY_METADATA_H
+#define AVUTIL_MASTERING_DISPLAY_METADATA_H
+
+#include "frame.h"
+
+/**
+ * Mastering display metadata capable of representing the color volume of
+ * the display used to master the content (SMPTE 2086:2014).
+ *
+ * To be used as payload of a AVFrameSideData or AVPacketSideData with the
+ * appropriate type.
+ *
+ * @note The struct should be allocated with av_mastering_display_metadata_alloc()
+ *       and its size is not a part of the public ABI.
+ */
+typedef struct AVMasteringDisplayMetadata {
+    /**
+     * CIE 1931 xy chromaticity coords of color primaries (r, g, b order).
+     */
+    float display_primaries[3][2];
+
+    /**
+     * CIE 1931 xy chromaticity coords of white point.
+     */
+    float white_point[2];
+
+    /**
+     * Min luminance of mastering display (cd/m^2).
+     */
+    float min_luminance;
+
+    /**
+     * Max luminance of mastering display (cd/m^2).
+     */
+    float max_luminance;
+
+    /**
+     * Flag indicating whether the display primaries (and white point) are set.
+     */
+    int has_primaries;
+
+    /**
+     * Flag indicating whether the luminance (min_ and max_) have been set.
+     */
+    int has_luminance;
+
+} AVMasteringDisplayMetadata;
+
+/**
+ * Allocate an AVMasteringDisplayMetadata structure and set its fields to
+ * default values. The resulting struct can be freed using av_freep().
+ *
+ * @return An AVMasteringDisplayMetadata filled with default values or NULL
+ *         on failure.
+ */
+AVMasteringDisplayMetadata *av_mastering_display_metadata_alloc(void);
+
+/**
+ * Allocate a complete AVMasteringDisplayMetadata and add it to the frame.
+ *
+ * @param frame The frame which side data is added to.
+ *
+ * @return The AVMasteringDisplayMetadata structure to be filled by caller.
+ */
+AVMasteringDisplayMetadata *av_mastering_display_metadata_create_side_data(AVFrame *frame);
+
+#endif /* AVUTIL_MASTERING_DISPLAY_METADATA_H */