[FFmpeg-devel] [PATCH] avcodec/hevc: Extract Content light level from HEVC SEI prefix message

[Nikola Kolarović]

From: Nikola Kolarović <Nikola.Kolarovic at rt-rk.com>

Extract max_content_light_level and max_frame_average_light_level
which are used in HEVC Main 10 (HDR10) for luminosity adjustment.

Based on ISO/IEC 23008-2:2015 section D.2.35.
---
 libavcodec/hevc.h     |  4 ++++
 libavcodec/hevc_sei.c | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/libavcodec/hevc.h b/libavcodec/hevc.h
index 6a3c7506c2..d5970b61b6 100644
--- a/libavcodec/hevc.h
+++ b/libavcodec/hevc.h
@@ -931,6 +931,10 @@ typedef struct HEVCContext {
     uint32_t max_mastering_luminance;
     uint32_t min_mastering_luminance;
 
+    /** content light level */
+    uint16_t max_content_light_level;
+    uint16_t max_frame_average_light_level;
+
 } HEVCContext;
 
 int ff_hevc_decode_short_term_rps(GetBitContext *gb, AVCodecContext *avctx,
diff --git a/libavcodec/hevc_sei.c b/libavcodec/hevc_sei.c
index 148f246df1..13ecc67173 100644
--- a/libavcodec/hevc_sei.c
+++ b/libavcodec/hevc_sei.c
@@ -102,6 +102,16 @@ static int decode_nal_sei_mastering_display_info(HEVCContext *s)
     return 0;
 }
 
+static int decode_nal_sei_content_light_level_info(HEVCContext *s)
+{
+    GetBitContext *gb = &s->HEVClc->gb;
+
+    s->max_content_light_level = get_bits(gb, 16);
+    s->max_frame_average_light_level = get_bits(gb, 16);
+
+    return 0;
+}
+
 static int decode_nal_sei_frame_packing_arrangement(HEVCContext *s)
 {
     GetBitContext *gb = &s->HEVClc->gb;
@@ -304,6 +314,8 @@ static int decode_nal_sei_prefix(HEVCContext *s, int type, int size)
         }
     case SEI_TYPE_MASTERING_DISPLAY_INFO:
         return decode_nal_sei_mastering_display_info(s);
+    case SEI_TYPE_CONTENT_LIGHT_LEVEL_INFO:
+        return decode_nal_sei_content_light_level_info(s);
     case SEI_TYPE_ACTIVE_PARAMETER_SETS:
         active_parameter_sets(s);
         av_log(s->avctx, AV_LOG_DEBUG, "Skipped PREFIX SEI %d\n", type);
-- 
2.11.0