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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/media/platform/allegro-dvt/nal-rbsp.c | |
parent | Initial commit. (diff) | |
download | linux-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.c | 310 |
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); +} |