@@ -382,6 +382,14 @@ static int decode_green_metadata(H264SEIGreenMetaData *h, GetBitContext *gb)
return 0;
}
+static int decode_alternative_transfer(H264SEIAlternativeTransfer *h,
+ GetBitContext *gb)
+{
+ h->present = 1;
+ h->preferred_transfer_characteristics = get_bits(gb, 8);
+ return 0;
+}
+
int ff_h264_sei_decode(H264SEIContext *h, GetBitContext *gb,
const H264ParamSets *ps, void *logctx)
{
@@ -437,6 +445,9 @@ int ff_h264_sei_decode(H264SEIContext *h, GetBitContext *gb,
case SEI_TYPE_GREEN_METADATA:
ret = decode_green_metadata(&h->green_metadata, gb);
break;
+ case SEI_TYPE_ALTERNATIVE_TRANSFER:
+ ret = decode_alternative_transfer(&h->alternative_transfer, gb);
+ break;
default:
av_log(logctx, AV_LOG_DEBUG, "unknown SEI type %d\n", type);
}
@@ -32,7 +32,8 @@ typedef enum {
SEI_TYPE_RECOVERY_POINT = 6, ///< recovery point (frame # to decoder sync)
SEI_TYPE_FRAME_PACKING = 45, ///< frame packing arrangement
SEI_TYPE_DISPLAY_ORIENTATION = 47, ///< display orientation
- SEI_TYPE_GREEN_METADATA = 56 ///< GreenMPEG information
+ SEI_TYPE_GREEN_METADATA = 56, ///< GreenMPEG information
+ SEI_TYPE_ALTERNATIVE_TRANSFER = 147, ///< alternative transfer
} SEI_Type;
/**
@@ -144,6 +145,11 @@ typedef struct H264SEIGreenMetaData {
uint16_t xsd_metric_value;
} H264SEIGreenMetaData;
+typedef struct H264SEIAlternativeTransfer {
+ int present;
+ int preferred_transfer_characteristics;
+} H264SEIAlternativeTransfer;
+
typedef struct H264SEIContext {
H264SEIPictureTiming picture_timing;
H264SEIAFD afd;
@@ -154,6 +160,7 @@ typedef struct H264SEIContext {
H264SEIFramePacking frame_packing;
H264SEIDisplayOrientation display_orientation;
H264SEIGreenMetaData green_metadata;
+ H264SEIAlternativeTransfer alternative_transfer;
} H264SEIContext;
struct H264ParamSets;
@@ -1287,6 +1287,12 @@ static int h264_export_frame_props(H264Context *h)
h->avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
}
+ if (h->sei.alternative_transfer.present &&
+ av_color_transfer_name(h->sei.alternative_transfer.preferred_transfer_characteristics) &&
+ h->sei.alternative_transfer.preferred_transfer_characteristics != AVCOL_TRC_UNSPECIFIED) {
+ h->avctx->color_trc = cur->f->color_trc = h->sei.alternative_transfer.preferred_transfer_characteristics;
+ }
+
return 0;
}
The use of this SEI is for backward compatibility in HLG HDR systems: older devices that cannot interpret the "arib-std-b67" transfer will get the compatible transfer (usually bt709 or bt2020) from the VUI, while newer devices that can interpret HDR will read the SEI and use its value instead. Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com> --- libavcodec/h264_sei.c | 11 +++++++++++ libavcodec/h264_sei.h | 9 ++++++++- libavcodec/h264_slice.c | 6 ++++++ 3 files changed, 25 insertions(+), 1 deletion(-)