linux/drivers/media/v4l2-core/v4l2-h264.c

// SPDX-License-Identifier: GPL-2.0
/*
 * V4L2 H264 helpers.
 *
 * Copyright (C) 2019 Collabora, Ltd.
 *
 * Author: Boris Brezillon <[email protected]>
 */

#include <linux/module.h>
#include <linux/sort.h>

#include <media/v4l2-h264.h>

/*
 * Size of the tempory buffer allocated when printing reference lists. The
 * output will be truncated if the size is too small.
 */
static const int tmp_str_size = …;

/**
 * v4l2_h264_init_reflist_builder() - Initialize a P/B0/B1 reference list
 *				      builder
 *
 * @b: the builder context to initialize
 * @dec_params: decode parameters control
 * @sps: SPS control
 * @dpb: DPB to use when creating the reference list
 */
void
v4l2_h264_init_reflist_builder(struct v4l2_h264_reflist_builder *b,
		const struct v4l2_ctrl_h264_decode_params *dec_params,
		const struct v4l2_ctrl_h264_sps *sps,
		const struct v4l2_h264_dpb_entry dpb[V4L2_H264_NUM_DPB_ENTRIES])
{ … }
EXPORT_SYMBOL_GPL(…);

static s32 v4l2_h264_get_poc(const struct v4l2_h264_reflist_builder *b,
			     const struct v4l2_h264_reference *ref)
{ … }

static int v4l2_h264_p_ref_list_cmp(const void *ptra, const void *ptrb,
				    const void *data)
{ … }

static int v4l2_h264_b0_ref_list_cmp(const void *ptra, const void *ptrb,
				     const void *data)
{ … }

static int v4l2_h264_b1_ref_list_cmp(const void *ptra, const void *ptrb,
				     const void *data)
{ … }

/*
 * The references need to be reordered so that references are alternating
 * between top and bottom field references starting with the current picture
 * parity. This has to be done for short term and long term references
 * separately.
 */
static void reorder_field_reflist(const struct v4l2_h264_reflist_builder *b,
				  struct v4l2_h264_reference *reflist)
{ … }

static char ref_type_to_char(u8 ref_type)
{ … }

static const char *format_ref_list_p(const struct v4l2_h264_reflist_builder *builder,
				     struct v4l2_h264_reference *reflist,
				     char **out_str)
{ … }

static void print_ref_list_p(const struct v4l2_h264_reflist_builder *builder,
			     struct v4l2_h264_reference *reflist)
{ … }

static const char *format_ref_list_b(const struct v4l2_h264_reflist_builder *builder,
				     struct v4l2_h264_reference *reflist,
				     char **out_str)
{ … }

static void print_ref_list_b(const struct v4l2_h264_reflist_builder *builder,
			     struct v4l2_h264_reference *reflist, u8 list_num)
{ … }

/**
 * v4l2_h264_build_p_ref_list() - Build the P reference list
 *
 * @builder: reference list builder context
 * @reflist: 32 sized array used to store the P reference list. Each entry
 *	     is a v4l2_h264_reference structure
 *
 * This functions builds the P reference lists. This procedure is describe in
 * section '8.2.4 Decoding process for reference picture lists construction'
 * of the H264 spec. This function can be used by H264 decoder drivers that
 * need to pass a P reference list to the hardware.
 */
void
v4l2_h264_build_p_ref_list(const struct v4l2_h264_reflist_builder *builder,
			   struct v4l2_h264_reference *reflist)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * v4l2_h264_build_b_ref_lists() - Build the B0/B1 reference lists
 *
 * @builder: reference list builder context
 * @b0_reflist: 32 sized array used to store the B0 reference list. Each entry
 *		is a v4l2_h264_reference structure
 * @b1_reflist: 32 sized array used to store the B1 reference list. Each entry
 *		is a v4l2_h264_reference structure
 *
 * This functions builds the B0/B1 reference lists. This procedure is described
 * in section '8.2.4 Decoding process for reference picture lists construction'
 * of the H264 spec. This function can be used by H264 decoder drivers that
 * need to pass B0/B1 reference lists to the hardware.
 */
void
v4l2_h264_build_b_ref_lists(const struct v4l2_h264_reflist_builder *builder,
			    struct v4l2_h264_reference *b0_reflist,
			    struct v4l2_h264_reference *b1_reflist)
{ … }
EXPORT_SYMBOL_GPL(…);

MODULE_LICENSE(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_AUTHOR(…) …;