[FFmpeg-devel] [PATCH 3/4] avformat/mov: add support for reading Mastering Display Metadata Box

[James Almer]

As defined in "VP Codec ISO Media File Format Binding v1.0"
https://github.com/webmproject/vp9-dash/blob/master/VPCodecISOMediaFileFormatBinding.md

Partially based on Matroska decoder code.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavformat/isom.h |  2 ++
 libavformat/mov.c  | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/libavformat/isom.h b/libavformat/isom.h
index d9956cf63a..426f732247 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -27,6 +27,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "libavutil/mastering_display_metadata.h"
 #include "libavutil/spherical.h"
 #include "libavutil/stereo3d.h"
 
@@ -194,6 +195,7 @@ typedef struct MOVStreamContext {
     AVStereo3D *stereo3d;
     AVSphericalMapping *spherical;
     size_t spherical_size;
+    AVMasteringDisplayMetadata *mastering;
 
     uint32_t format;
 
diff --git a/libavformat/mov.c b/libavformat/mov.c
index afef53b79a..0b5fd849f3 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -4612,6 +4612,60 @@ static int mov_read_tmcd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     return 0;
 }
 
+static int mov_read_smdm(MOVContext *c, AVIOContext *pb, MOVAtom atom)
+{
+    MOVStreamContext *sc;
+    const int chroma_den = 50000;
+    const int luma_den = 10000;
+    int version;
+
+    if (c->fc->nb_streams < 1)
+        return AVERROR_INVALIDDATA;
+
+    sc = c->fc->streams[c->fc->nb_streams - 1]->priv_data;
+
+    if (atom.size < 5) {
+        av_log(c->fc, AV_LOG_ERROR, "Empty Mastering Display Metadata box\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    version = avio_r8(pb);
+    if (version) {
+        av_log(c->fc, AV_LOG_WARNING, "Unsupported Mastering Display Metadata box version %d\n", version);
+        return 0;
+    }
+    avio_skip(pb, 3); /* flags */
+
+    sc->mastering = av_mastering_display_metadata_alloc();
+    if (!sc->mastering)
+        return AVERROR(ENOMEM);
+
+    sc->mastering->display_primaries[0][0] =
+        av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), chroma_den);
+    sc->mastering->display_primaries[0][1] =
+        av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), chroma_den);
+    sc->mastering->display_primaries[1][0] =
+        av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), chroma_den);
+    sc->mastering->display_primaries[1][1] =
+        av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), chroma_den);
+    sc->mastering->display_primaries[2][0] =
+        av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), chroma_den);
+    sc->mastering->display_primaries[2][1] =
+        av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), chroma_den);
+    sc->mastering->white_point[0]          =
+        av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), chroma_den);
+    sc->mastering->white_point[1]          =
+        av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), chroma_den);
+    sc->mastering->max_luminance           =
+        av_make_q(lrint(((double)avio_rb32(pb) / (1 <<  8)) *   luma_den),   luma_den);
+    sc->mastering->min_luminance           =
+        av_make_q(lrint(((double)avio_rb32(pb) / (1 << 14)) *   luma_den),   luma_den);
+    sc->mastering->has_primaries = 1;
+    sc->mastering->has_luminance = 1;
+
+    return 0;
+}
+
 static int mov_read_st3d(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
     AVStream *st;
@@ -5398,6 +5452,7 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
 { MKTAG('s','t','3','d'), mov_read_st3d }, /* stereoscopic 3D video box */
 { MKTAG('s','v','3','d'), mov_read_sv3d }, /* spherical video box */
 { MKTAG('d','O','p','s'), mov_read_dops },
+{ MKTAG('S','m','D','m'), mov_read_smdm },
 { 0, NULL }
 };
 
@@ -5822,6 +5877,7 @@ static int mov_read_close(AVFormatContext *s)
 
         av_freep(&sc->stereo3d);
         av_freep(&sc->spherical);
+        av_freep(&sc->mastering);
     }
 
     if (mov->dv_demux) {
@@ -6172,6 +6228,15 @@ static int mov_read_header(AVFormatContext *s)
 
                 sc->spherical = NULL;
             }
+            if (sc->mastering) {
+                err = av_stream_add_side_data(st, AV_PKT_DATA_MASTERING_DISPLAY_METADATA,
+                                              (uint8_t *)sc->mastering,
+                                              sizeof(*sc->mastering));
+                if (err < 0)
+                    return err;
+
+                sc->mastering = NULL;
+            }
             break;
         }
     }
-- 
2.12.1