Please see updated patch.
On Mon, Jan 25, 2016 at 11:39 PM, Neil Birkbeck <neil.birkb...@gmail.com> wrote:
> I guess png is another example; 100000 is the denominator for the 32-bit
> integer:
> https://github.com/FFmpeg/FFmpeg/blob/b58cfa616c169c90166938608e7135cdab5820e0/libavcodec/pngenc.c#L290
>
> In the standards, the primaries and white point coords are usually only
> referenced in 2-4 significant figures (ISO/IEC 23001-8:2013(E) has them all
> in one doc). The display primaries can be different from these, but I don't
> think you'd see them measured with any more precision (more precision is
> unlikely to matter for this metadata anyway).
>
> It seems that most are in favor of AVRational, so I'll change the avutil
> struct float internal fields to rational.
>
>
>
>
>
> On Mon, Jan 25, 2016 at 1:43 PM, Hendrik Leppkes <h.lepp...@gmail.com>
> wrote:
>>
>> On Mon, Jan 25, 2016 at 10:37 PM, Michael Niedermayer
>> <mich...@niedermayer.cc> wrote:
>> > On Fri, Jan 22, 2016 at 02:54:21PM -0800, Neil Birkbeck wrote:
>> >> Hmm. I don't have a good idea of how likely it is for this conversion
>> >> to
>> >> float (by dividing a constant) to not be bit-exact on different
>> >> architectures (compilers?) when there should not be any other math
>> >> transforming the metadata (other than the conversion back to the
>> >> integer
>> >> coding for cases like hevc, which for a given architecture is possible
>> >> without loss). The fact that this could happen at all does make it
>> >> annoying
>> >> in terms of bit-exact test expectations across arch, and this is the
>> >> main
>> >> concern, right? (for this type of metadata, it is really a hint to
>> >> TVs/algorithms, and some will ignore it altogether)
>> >
>> > bitexactness is one concern, also theres the issue with what is ideally
>> > correct.
>> > that is what are the ideal values dictated by various standards
>> > that hardware (cammeras, ...) aim at ?
>> > are these rational or float or what can represent them better ?
>> >
>>
>> Both HEVC and the HDMI Info Frames use fixed-point integers (the same
>> scales too, apparently), I do not know of the formats anything else
>> uses.
>> Maybe we should be using AVRationals?
>>
>> I would argue that MKV storing floats is a terrible idea, and someone
>> should bonk them over the head and store fixed point as well.
>>
>> - Hendrik
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
>
From 345db2caf7cac5c0acfb74501b6db9bd57e66f7d Mon Sep 17 00:00:00 2001
From: Neil Birkbeck <neil.birkb...@gmail.com>
Date: Thu, 21 Jan 2016 10:56:50 -0800
Subject: [PATCH] lavc/hevc Parse SEI_TYPE_MASTERING_DISPLAY_INFO and propagate
content into the AVMasteringDisplayMetadata side data.
Add support for parsing SEI_TYPE_MASTERING_DISPLAY_INFO and propagate contents into
the AVMasteringDisplayMetadata side data. Primaries are ordered in RGB order and
the values are converted to rationals ([0,1] for CEI 1931 Chroma coords,
and cd/m^2 for luma).
Signed-off-by: Neil Birkbeck <neil.birkb...@gmail.com>
---
libavcodec/hevc.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
libavcodec/hevc.h | 7 +++++++
libavcodec/hevc_sei.c | 22 ++++++++++++++++++++++
libavcodec/version.h | 2 +-
4 files changed, 76 insertions(+), 1 deletion(-)
diff --git a/libavcodec/hevc.c b/libavcodec/hevc.c
index c245d3b..e475f94 100644
--- a/libavcodec/hevc.c
+++ b/libavcodec/hevc.c
@@ -28,6 +28,7 @@
#include "libavutil/common.h"
#include "libavutil/display.h"
#include "libavutil/internal.h"
+#include "libavutil/mastering_display_metadata.h"
#include "libavutil/md5.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
@@ -2580,6 +2581,51 @@ static int set_side_data(HEVCContext *s)
s->sei_hflip, s->sei_vflip);
}
+ if (s->sei_mastering_display_info_present) {
+ // HEVC uses a g,b,r ordering, which we convert to a more natural r,g,b
+ const int mapping[3] = {2, 0, 1};
+ const int chroma_den = 50000;
+ const int luma_den = 10000;
+ int i;
+ AVMasteringDisplayMetadata *metadata =
+ av_mastering_display_metadata_create_side_data(out);
+ if (!metadata)
+ return AVERROR(ENOMEM);
+
+ for (i = 0; i < 3; i++) {
+ const int j = mapping[i];
+ metadata->display_primaries[i][0].num = s->display_primaries[j][0];
+ metadata->display_primaries[i][0].den = chroma_den;
+ metadata->display_primaries[i][1].num = s->display_primaries[j][1];
+ metadata->display_primaries[i][1].den = chroma_den;
+ }
+ metadata->white_point[0].num = s->white_point[0];
+ metadata->white_point[0].den = chroma_den;
+ metadata->white_point[1].num = s->white_point[1];
+ metadata->white_point[1].den = chroma_den;
+
+ metadata->max_luminance.num = s->max_mastering_luminance;
+ metadata->max_luminance.den = luma_den;
+ metadata->min_luminance.num = s->min_mastering_luminance;
+ metadata->min_luminance.den = luma_den;
+ metadata->has_luminance = 1;
+ metadata->has_primaries = 1;
+
+ av_log(s->avctx, AV_LOG_DEBUG, "Mastering Display Metadata:\n");
+ av_log(s->avctx, AV_LOG_DEBUG,
+ "r(%5.4f,%5.4f) g(%5.4f,%5.4f) b(%5.4f %5.4f) wp(%5.4f, %5.4f)\n",
+ av_q2d(metadata->display_primaries[0][0]),
+ av_q2d(metadata->display_primaries[0][1]),
+ av_q2d(metadata->display_primaries[1][0]),
+ av_q2d(metadata->display_primaries[1][1]),
+ av_q2d(metadata->display_primaries[2][0]),
+ av_q2d(metadata->display_primaries[2][1]),
+ av_q2d(metadata->white_point[0]), av_q2d(metadata->white_point[1]));
+ av_log(s->avctx, AV_LOG_DEBUG,
+ "min_luminance=%f, max_luminance=%f\n",
+ av_q2d(metadata->min_luminance), av_q2d(metadata->max_luminance));
+ }
+
if (s->a53_caption) {
AVFrameSideData* sd = av_frame_new_side_data(out,
AV_FRAME_DATA_A53_CC,
diff --git a/libavcodec/hevc.h b/libavcodec/hevc.h
index 9d72555..c91f815 100644
--- a/libavcodec/hevc.h
+++ b/libavcodec/hevc.h
@@ -941,6 +941,13 @@ typedef struct HEVCContext {
uint8_t* a53_caption;
int a53_caption_size;
+ /** mastering display */
+ int sei_mastering_display_info_present;
+ uint16_t display_primaries[3][2];
+ uint16_t white_point[2];
+ uint32_t max_mastering_luminance;
+ uint32_t min_mastering_luminance;
+
} 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 07856f2..d33530b 100644
--- a/libavcodec/hevc_sei.c
+++ b/libavcodec/hevc_sei.c
@@ -78,6 +78,26 @@ static int decode_nal_sei_decoded_picture_hash(HEVCContext *s)
return 0;
}
+static int decode_nal_sei_mastering_display_info(HEVCContext *s)
+{
+ GetBitContext *gb = &s->HEVClc->gb;
+ int i;
+ // Mastering primaries
+ for (i = 0; i < 3; i++) {
+ s->display_primaries[i][0] = get_bits(gb, 16);
+ s->display_primaries[i][1] = get_bits(gb, 16);
+ }
+ // White point (x, y)
+ s->white_point[0] = get_bits(gb, 16);
+ s->white_point[1] = get_bits(gb, 16);
+
+ // Max and min luminance of mastering display
+ s->max_mastering_luminance = get_bits_long(gb, 32);
+ s->min_mastering_luminance = get_bits_long(gb, 32);
+ s->sei_mastering_display_info_present = 1;
+ return 0;
+}
+
static int decode_nal_sei_frame_packing_arrangement(HEVCContext *s)
{
GetBitContext *gb = &s->HEVClc->gb;
@@ -278,6 +298,8 @@ static int decode_nal_sei_prefix(HEVCContext *s, int type, int size)
skip_bits(gb, 8 * size);
return ret;
}
+ case SEI_TYPE_MASTERING_DISPLAY_INFO:
+ return decode_nal_sei_mastering_display_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);
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 02063c8..37a35e0 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -30,7 +30,7 @@
#define LIBAVCODEC_VERSION_MAJOR 57
#define LIBAVCODEC_VERSION_MINOR 24
-#define LIBAVCODEC_VERSION_MICRO 101
+#define LIBAVCODEC_VERSION_MICRO 102
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \
--
2.7.0.rc3.207.g0ac5344
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