* [FFmpeg-devel] [PATCH v5] avcodec/h2645_sei: validate Mastering Display Colour Volume SEI values
@ 2024-04-13 15:21 Kacper Michajłow
2024-04-13 15:53 ` Niklas Haas
0 siblings, 1 reply; 2+ messages in thread
From: Kacper Michajłow @ 2024-04-13 15:21 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 | 55 ++++++++++++++++++++++++++++++------------
1 file changed, 39 insertions(+), 16 deletions(-)
diff --git a/libavcodec/h2645_sei.c b/libavcodec/h2645_sei.c
index 933975f076..96a22e7cf6 100644
--- a/libavcodec/h2645_sei.c
+++ b/libavcodec/h2645_sei.c
@@ -587,38 +587,61 @@ static int h2645_sei_to_side_data(AVCodecContext *avctx, H2645SEI *sei,
return ret;
if (metadata) {
+ 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 &&
+ sei->mastering_display.min_luminance <
+ sei->mastering_display.max_luminance;
+
+ 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));
+ }
}
}
--
2.43.0
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^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [FFmpeg-devel] [PATCH v5] avcodec/h2645_sei: validate Mastering Display Colour Volume SEI values
2024-04-13 15:21 [FFmpeg-devel] [PATCH v5] avcodec/h2645_sei: validate Mastering Display Colour Volume SEI values Kacper Michajłow
@ 2024-04-13 15:53 ` Niklas Haas
0 siblings, 0 replies; 2+ messages in thread
From: Niklas Haas @ 2024-04-13 15:53 UTC (permalink / raw)
To: ffmpeg-devel; +Cc: Kacper Michajłow
On Sat, 13 Apr 2024 17:21:08 +0200 Kacper Michajłow <kasper93@gmail.com> wrote:
> 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 | 55 ++++++++++++++++++++++++++++++------------
> 1 file changed, 39 insertions(+), 16 deletions(-)
>
> diff --git a/libavcodec/h2645_sei.c b/libavcodec/h2645_sei.c
> index 933975f076..96a22e7cf6 100644
> --- a/libavcodec/h2645_sei.c
> +++ b/libavcodec/h2645_sei.c
> @@ -587,38 +587,61 @@ static int h2645_sei_to_side_data(AVCodecContext *avctx, H2645SEI *sei,
> return ret;
>
> if (metadata) {
> + 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 &&
> + sei->mastering_display.min_luminance <
> + sei->mastering_display.max_luminance;
> +
> + 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));
> + }
> }
> }
>
> --
> 2.43.0
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
LGTM.
As was discussed on IRC, this validation logic strictly follows the
wording of SMPTE ST 2086 and H.264/H.265. While we may wish to handle
invalid metadata in a different layer, there is no similar bitstream
conformance requirements in AV1 etc. (And who's to say what brightness
ranges for the min/max *should* be considered "valid"?)
Merged as 1c45104f74e59beb25ce7451c98527f7a3c518f6
_______________________________________________
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https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
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2024-04-13 15:21 [FFmpeg-devel] [PATCH v5] avcodec/h2645_sei: validate Mastering Display Colour Volume SEI values Kacper Michajłow
2024-04-13 15:53 ` Niklas Haas
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