[FFmpeg-devel] [PATCH v2] avcodec/h2645_sei: validate Mastering Display Colour Volume SEI values

* [FFmpeg-devel] [PATCH v2] avcodec/h2645_sei: validate Mastering Display Colour Volume SEI values
@ 2024-02-25  2:17 Kacper Michajłow
  2024-02-26 12:04 ` Niklas Haas
  0 siblings, 1 reply; 2+ messages in thread
From: Kacper Michajłow @ 2024-02-25  2:17 UTC (permalink / raw)
  To: ffmpeg-devel; +Cc: Kacper Michajłow

As we can read in ST 2086:

Values outside the specified ranges of luminance and chromaticity values
are not reserved by SMPTE, and can be used for purposes outside the
scope of this standard.

This is further acknowledged by ITU-T H.264 and ITU-T H.265. Which says
that values out of range are unknown or unspecified or specified by
other means not specified in this Specification.

Signed-off-by: Kacper Michajłow <kasper93@gmail.com>
---
 libavcodec/h2645_sei.c | 53 +++++++++++++++++++++++++++++-------------
 1 file changed, 37 insertions(+), 16 deletions(-)

diff --git a/libavcodec/h2645_sei.c b/libavcodec/h2645_sei.c
index cb6be0594b..e3581e8136 100644
--- a/libavcodec/h2645_sei.c
+++ b/libavcodec/h2645_sei.c
@@ -715,38 +715,59 @@ int ff_h2645_sei_to_frame(AVFrame *frame, H2645SEI *sei,
         if (!metadata)
             return AVERROR(ENOMEM);
 
+        metadata->has_luminance = 1;
+        metadata->has_primaries = 1;
+
         for (i = 0; i < 3; i++) {
             const int j = mapping[i];
             metadata->display_primaries[i][0].num = sei->mastering_display.display_primaries[j][0];
             metadata->display_primaries[i][0].den = chroma_den;
+            metadata->has_primaries &= sei->mastering_display.display_primaries[j][0] >= 5 &&
+                                       sei->mastering_display.display_primaries[j][0] <= 37000;
+
             metadata->display_primaries[i][1].num = sei->mastering_display.display_primaries[j][1];
             metadata->display_primaries[i][1].den = chroma_den;
+            metadata->has_primaries &= sei->mastering_display.display_primaries[j][1] >= 5 &&
+                                       sei->mastering_display.display_primaries[j][1] <= 42000;
         }
         metadata->white_point[0].num = sei->mastering_display.white_point[0];
         metadata->white_point[0].den = chroma_den;
+        metadata->has_primaries &= sei->mastering_display.white_point[0] >= 5 &&
+                                   sei->mastering_display.white_point[0] <= 37000;
+
         metadata->white_point[1].num = sei->mastering_display.white_point[1];
         metadata->white_point[1].den = chroma_den;
+        metadata->has_primaries &= sei->mastering_display.white_point[1] >= 5 &&
+                                   sei->mastering_display.white_point[1] <= 42000;
 
         metadata->max_luminance.num = sei->mastering_display.max_luminance;
         metadata->max_luminance.den = luma_den;
+        metadata->has_luminance &= sei->mastering_display.max_luminance >= 50000 &&
+                                   sei->mastering_display.max_luminance <= 100000000;
+
         metadata->min_luminance.num = sei->mastering_display.min_luminance;
         metadata->min_luminance.den = luma_den;
-        metadata->has_luminance = 1;
-        metadata->has_primaries = 1;
-
-        av_log(avctx, AV_LOG_DEBUG, "Mastering Display Metadata:\n");
-        av_log(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(avctx, AV_LOG_DEBUG,
-               "min_luminance=%f, max_luminance=%f\n",
-               av_q2d(metadata->min_luminance), av_q2d(metadata->max_luminance));
+        metadata->has_luminance &= sei->mastering_display.min_luminance >= 1 &&
+                                   sei->mastering_display.min_luminance <= 50000;
+
+        if (metadata->has_luminance || metadata->has_primaries)
+            av_log(avctx, AV_LOG_DEBUG, "Mastering Display Metadata:\n");
+        if (metadata->has_primaries) {
+            av_log(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]));
+        }
+        if (metadata->has_luminance) {
+            av_log(avctx, AV_LOG_DEBUG,
+                   "min_luminance=%f, max_luminance=%f\n",
+                   av_q2d(metadata->min_luminance), av_q2d(metadata->max_luminance));
+        }
     }
 
     if (sei->content_light.present) {
-- 
2.42.1

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