gstreamer/subprojects/gst-plugins-bad/sys/kms/gstkmsedid.c

112 lines
3.9 KiB
C
Raw Normal View History

/*
* Copyright © 2008-2011 Kristian Høgsberg
* Copyright © 2011 Intel Corporation
* Copyright © 2017, 2018 Collabora, Ltd.
* Copyright © 2017, 2018 General Electric Company
* Copyright (c) 2018 DisplayLink (UK) Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <math.h>
#include "gstkmsedid.h"
/* from libweston/backend-drm/modes.c unaccepted merge, modified slightly to
remove non HDR stuff, return -1 if no HDR in EDID.
https://gitlab.freedesktop.org/jcline/weston/-/commit/b3fa65d19ca60a45d0cc0fc1bfa68eea970344ee
*/
#define EDID_OFFSET_EXT_COUNT 0x7E
#define EDID_EXTENSION_SIZE 0x80
// Indicates the EDID extension is a CTA extension
#define EDID_CTA_EXTENSION_TAG 0x02
// Indicates the data block uses the extended tag field
#define EDID_CTA_EXTENDED_TAG 0x07
// Value of the extended tag field for HDR static metadata blocks
#define EDID_CTA_STATIC_HDR_TAG 0x06
/* Extract the HDR static metadata from a CTA EDID extension. */
static int
gst_kms_parse_hdr_metadata (const uint8_t * cta_ext_data,
struct gst_kms_hdr_static_metadata *metadata)
{
int i, block_len;
uint8_t cta_revision = cta_ext_data[1];
uint8_t dtd_offset = cta_ext_data[2];
const uint8_t *data_blocks = cta_ext_data + 4;
if (cta_revision != 3) {
return -1;
}
// The data block collection ranges from byte 4 to the dtd_offset; each
// block begins with the block size (in bytes) in bits 0-4 of the first byte.
for (i = 0; i < dtd_offset; i += (data_blocks[i] & 0x1f) + 1) {
if ((data_blocks[i] & 0xe0) >> 5 == EDID_CTA_EXTENDED_TAG) {
block_len = data_blocks[i] & 0x1f;
if (data_blocks[i + 1] == EDID_CTA_STATIC_HDR_TAG) {
if (block_len < 2)
continue;
metadata->eotf = data_blocks[i + 2];
metadata->metadata_type = data_blocks[i + 3];
if (block_len > 3 && data_blocks[i + 4])
metadata->max_cll = 50.0 * pow (2, data_blocks[i + 4] / 32.0);
if (block_len > 4 && data_blocks[i + 5])
metadata->max_fall = 50.0 * pow (2, data_blocks[i + 5] / 32.0);
if (block_len > 5)
metadata->min_cll =
metadata->max_cll * pow (data_blocks[i + 6] / 255.0, 2) / 100.0;
return 0;
}
}
}
return -1;
}
int
gst_kms_edid_parse (struct gst_kms_hdr_static_metadata *metadata,
const uint8_t * data, size_t length)
{
int i;
const uint8_t *edid_extension;
/* check header */
if (length < 128 || length < ((size_t) data[EDID_OFFSET_EXT_COUNT] + 1) * 128)
return -1;
if (data[0] != 0x00 || data[1] != 0xff)
return -1;
edid_extension = data + 128;
for (i = 0; i < data[EDID_OFFSET_EXT_COUNT]; i++) {
switch (edid_extension[0]) {
case EDID_CTA_EXTENSION_TAG:
return gst_kms_parse_hdr_metadata (edid_extension, metadata);
}
edid_extension += 128;
}
return 0;
}
/* END from libweston/backend-drm/modes.c unaccepted merge */