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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/media/platform/allegro-dvt/nal-rbsp.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/media/platform/allegro-dvt/nal-rbsp.c310
1 files changed, 310 insertions, 0 deletions
diff --git a/drivers/media/platform/allegro-dvt/nal-rbsp.c b/drivers/media/platform/allegro-dvt/nal-rbsp.c
new file mode 100644
index 000000000..d911322d0
--- /dev/null
+++ b/drivers/media/platform/allegro-dvt/nal-rbsp.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019-2020 Pengutronix, Michael Tretter <kernel@pengutronix.de>
+ *
+ * Helper functions to generate a raw byte sequence payload from values.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/v4l2-controls.h>
+
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/log2.h>
+
+#include "nal-rbsp.h"
+
+void rbsp_init(struct rbsp *rbsp, void *addr, size_t size,
+ struct nal_rbsp_ops *ops)
+{
+ if (!rbsp)
+ return;
+
+ rbsp->data = addr;
+ rbsp->size = size;
+ rbsp->pos = 0;
+ rbsp->ops = ops;
+ rbsp->error = 0;
+}
+
+void rbsp_unsupported(struct rbsp *rbsp)
+{
+ rbsp->error = -EINVAL;
+}
+
+static int rbsp_read_bits(struct rbsp *rbsp, int n, unsigned int *value);
+static int rbsp_write_bits(struct rbsp *rbsp, int n, unsigned int value);
+
+/*
+ * When reading or writing, the emulation_prevention_three_byte is detected
+ * only when the 2 one bits need to be inserted. Therefore, we are not
+ * actually adding the 0x3 byte, but the 2 one bits and the six 0 bits of the
+ * next byte.
+ */
+#define EMULATION_PREVENTION_THREE_BYTE (0x3 << 6)
+
+static int add_emulation_prevention_three_byte(struct rbsp *rbsp)
+{
+ rbsp->num_consecutive_zeros = 0;
+ rbsp_write_bits(rbsp, 8, EMULATION_PREVENTION_THREE_BYTE);
+
+ return 0;
+}
+
+static int discard_emulation_prevention_three_byte(struct rbsp *rbsp)
+{
+ unsigned int tmp = 0;
+
+ rbsp->num_consecutive_zeros = 0;
+ rbsp_read_bits(rbsp, 8, &tmp);
+ if (tmp != EMULATION_PREVENTION_THREE_BYTE)
+ return -EINVAL;
+
+ return 0;
+}
+
+static inline int rbsp_read_bit(struct rbsp *rbsp)
+{
+ int shift;
+ int ofs;
+ int bit;
+ int err;
+
+ if (rbsp->num_consecutive_zeros == 22) {
+ err = discard_emulation_prevention_three_byte(rbsp);
+ if (err)
+ return err;
+ }
+
+ shift = 7 - (rbsp->pos % 8);
+ ofs = rbsp->pos / 8;
+ if (ofs >= rbsp->size)
+ return -EINVAL;
+
+ bit = (rbsp->data[ofs] >> shift) & 1;
+
+ rbsp->pos++;
+
+ if (bit == 1 ||
+ (rbsp->num_consecutive_zeros < 7 && (rbsp->pos % 8 == 0)))
+ rbsp->num_consecutive_zeros = 0;
+ else
+ rbsp->num_consecutive_zeros++;
+
+ return bit;
+}
+
+static inline int rbsp_write_bit(struct rbsp *rbsp, bool value)
+{
+ int shift;
+ int ofs;
+
+ if (rbsp->num_consecutive_zeros == 22)
+ add_emulation_prevention_three_byte(rbsp);
+
+ shift = 7 - (rbsp->pos % 8);
+ ofs = rbsp->pos / 8;
+ if (ofs >= rbsp->size)
+ return -EINVAL;
+
+ rbsp->data[ofs] &= ~(1 << shift);
+ rbsp->data[ofs] |= value << shift;
+
+ rbsp->pos++;
+
+ if (value ||
+ (rbsp->num_consecutive_zeros < 7 && (rbsp->pos % 8 == 0))) {
+ rbsp->num_consecutive_zeros = 0;
+ } else {
+ rbsp->num_consecutive_zeros++;
+ }
+
+ return 0;
+}
+
+static inline int rbsp_read_bits(struct rbsp *rbsp, int n, unsigned int *value)
+{
+ int i;
+ int bit;
+ unsigned int tmp = 0;
+
+ if (n > 8 * sizeof(*value))
+ return -EINVAL;
+
+ for (i = n; i > 0; i--) {
+ bit = rbsp_read_bit(rbsp);
+ if (bit < 0)
+ return bit;
+ tmp |= bit << (i - 1);
+ }
+
+ if (value)
+ *value = tmp;
+
+ return 0;
+}
+
+static int rbsp_write_bits(struct rbsp *rbsp, int n, unsigned int value)
+{
+ int ret;
+
+ if (n > 8 * sizeof(value))
+ return -EINVAL;
+
+ while (n--) {
+ ret = rbsp_write_bit(rbsp, (value >> n) & 1);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int rbsp_read_uev(struct rbsp *rbsp, unsigned int *value)
+{
+ int leading_zero_bits = 0;
+ unsigned int tmp = 0;
+ int ret;
+
+ while ((ret = rbsp_read_bit(rbsp)) == 0)
+ leading_zero_bits++;
+ if (ret < 0)
+ return ret;
+
+ if (leading_zero_bits > 0) {
+ ret = rbsp_read_bits(rbsp, leading_zero_bits, &tmp);
+ if (ret)
+ return ret;
+ }
+
+ if (value)
+ *value = (1 << leading_zero_bits) - 1 + tmp;
+
+ return 0;
+}
+
+static int rbsp_write_uev(struct rbsp *rbsp, unsigned int *value)
+{
+ int ret;
+ int leading_zero_bits;
+
+ if (!value)
+ return -EINVAL;
+
+ leading_zero_bits = ilog2(*value + 1);
+
+ ret = rbsp_write_bits(rbsp, leading_zero_bits, 0);
+ if (ret)
+ return ret;
+
+ return rbsp_write_bits(rbsp, leading_zero_bits + 1, *value + 1);
+}
+
+static int rbsp_read_sev(struct rbsp *rbsp, int *value)
+{
+ int ret;
+ unsigned int tmp;
+
+ ret = rbsp_read_uev(rbsp, &tmp);
+ if (ret)
+ return ret;
+
+ if (value) {
+ if (tmp & 1)
+ *value = (tmp + 1) / 2;
+ else
+ *value = -(tmp / 2);
+ }
+
+ return 0;
+}
+
+static int rbsp_write_sev(struct rbsp *rbsp, int *value)
+{
+ unsigned int tmp;
+
+ if (!value)
+ return -EINVAL;
+
+ if (*value > 0)
+ tmp = (2 * (*value)) | 1;
+ else
+ tmp = -2 * (*value);
+
+ return rbsp_write_uev(rbsp, &tmp);
+}
+
+static int __rbsp_write_bit(struct rbsp *rbsp, int *value)
+{
+ return rbsp_write_bit(rbsp, *value);
+}
+
+static int __rbsp_write_bits(struct rbsp *rbsp, int n, unsigned int *value)
+{
+ return rbsp_write_bits(rbsp, n, *value);
+}
+
+struct nal_rbsp_ops write = {
+ .rbsp_bit = __rbsp_write_bit,
+ .rbsp_bits = __rbsp_write_bits,
+ .rbsp_uev = rbsp_write_uev,
+ .rbsp_sev = rbsp_write_sev,
+};
+
+static int __rbsp_read_bit(struct rbsp *rbsp, int *value)
+{
+ int tmp = rbsp_read_bit(rbsp);
+
+ if (tmp < 0)
+ return tmp;
+ *value = tmp;
+
+ return 0;
+}
+
+struct nal_rbsp_ops read = {
+ .rbsp_bit = __rbsp_read_bit,
+ .rbsp_bits = rbsp_read_bits,
+ .rbsp_uev = rbsp_read_uev,
+ .rbsp_sev = rbsp_read_sev,
+};
+
+void rbsp_bit(struct rbsp *rbsp, int *value)
+{
+ if (rbsp->error)
+ return;
+ rbsp->error = rbsp->ops->rbsp_bit(rbsp, value);
+}
+
+void rbsp_bits(struct rbsp *rbsp, int n, int *value)
+{
+ if (rbsp->error)
+ return;
+ rbsp->error = rbsp->ops->rbsp_bits(rbsp, n, value);
+}
+
+void rbsp_uev(struct rbsp *rbsp, unsigned int *value)
+{
+ if (rbsp->error)
+ return;
+ rbsp->error = rbsp->ops->rbsp_uev(rbsp, value);
+}
+
+void rbsp_sev(struct rbsp *rbsp, int *value)
+{
+ if (rbsp->error)
+ return;
+ rbsp->error = rbsp->ops->rbsp_sev(rbsp, value);
+}
+
+void rbsp_trailing_bits(struct rbsp *rbsp)
+{
+ unsigned int rbsp_stop_one_bit = 1;
+ unsigned int rbsp_alignment_zero_bit = 0;
+
+ rbsp_bit(rbsp, &rbsp_stop_one_bit);
+ rbsp_bits(rbsp, round_up(rbsp->pos, 8) - rbsp->pos,
+ &rbsp_alignment_zero_bit);
+}