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Diffstat (limited to 'drivers/media/v4l2-core/v4l2-h264.c')
-rw-r--r--drivers/media/v4l2-core/v4l2-h264.c453
1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-h264.c b/drivers/media/v4l2-core/v4l2-h264.c
new file mode 100644
index 0000000000..c00197d095
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-h264.c
@@ -0,0 +1,453 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * V4L2 H264 helpers.
+ *
+ * Copyright (C) 2019 Collabora, Ltd.
+ *
+ * Author: Boris Brezillon <boris.brezillon@collabora.com>
+ */
+
+#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 = 1024;
+
+/**
+ * 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])
+{
+ int cur_frame_num, max_frame_num;
+ unsigned int i;
+
+ max_frame_num = 1 << (sps->log2_max_frame_num_minus4 + 4);
+ cur_frame_num = dec_params->frame_num;
+
+ memset(b, 0, sizeof(*b));
+ if (!(dec_params->flags & V4L2_H264_DECODE_PARAM_FLAG_FIELD_PIC)) {
+ b->cur_pic_order_count = min(dec_params->bottom_field_order_cnt,
+ dec_params->top_field_order_cnt);
+ b->cur_pic_fields = V4L2_H264_FRAME_REF;
+ } else if (dec_params->flags & V4L2_H264_DECODE_PARAM_FLAG_BOTTOM_FIELD) {
+ b->cur_pic_order_count = dec_params->bottom_field_order_cnt;
+ b->cur_pic_fields = V4L2_H264_BOTTOM_FIELD_REF;
+ } else {
+ b->cur_pic_order_count = dec_params->top_field_order_cnt;
+ b->cur_pic_fields = V4L2_H264_TOP_FIELD_REF;
+ }
+
+ for (i = 0; i < V4L2_H264_NUM_DPB_ENTRIES; i++) {
+ if (!(dpb[i].flags & V4L2_H264_DPB_ENTRY_FLAG_ACTIVE))
+ continue;
+
+ if (dpb[i].flags & V4L2_H264_DPB_ENTRY_FLAG_LONG_TERM)
+ b->refs[i].longterm = true;
+
+ /*
+ * Handle frame_num wraparound as described in section
+ * '8.2.4.1 Decoding process for picture numbers' of the spec.
+ * For long term references, frame_num is set to
+ * long_term_frame_idx which requires no wrapping.
+ */
+ if (!b->refs[i].longterm && dpb[i].frame_num > cur_frame_num)
+ b->refs[i].frame_num = (int)dpb[i].frame_num -
+ max_frame_num;
+ else
+ b->refs[i].frame_num = dpb[i].frame_num;
+
+ b->refs[i].top_field_order_cnt = dpb[i].top_field_order_cnt;
+ b->refs[i].bottom_field_order_cnt = dpb[i].bottom_field_order_cnt;
+
+ if (b->cur_pic_fields == V4L2_H264_FRAME_REF) {
+ u8 fields = V4L2_H264_FRAME_REF;
+
+ b->unordered_reflist[b->num_valid].index = i;
+ b->unordered_reflist[b->num_valid].fields = fields;
+ b->num_valid++;
+ continue;
+ }
+
+ if (dpb[i].fields & V4L2_H264_TOP_FIELD_REF) {
+ u8 fields = V4L2_H264_TOP_FIELD_REF;
+
+ b->unordered_reflist[b->num_valid].index = i;
+ b->unordered_reflist[b->num_valid].fields = fields;
+ b->num_valid++;
+ }
+
+ if (dpb[i].fields & V4L2_H264_BOTTOM_FIELD_REF) {
+ u8 fields = V4L2_H264_BOTTOM_FIELD_REF;
+
+ b->unordered_reflist[b->num_valid].index = i;
+ b->unordered_reflist[b->num_valid].fields = fields;
+ b->num_valid++;
+ }
+ }
+
+ for (i = b->num_valid; i < ARRAY_SIZE(b->unordered_reflist); i++)
+ b->unordered_reflist[i].index = i;
+}
+EXPORT_SYMBOL_GPL(v4l2_h264_init_reflist_builder);
+
+static s32 v4l2_h264_get_poc(const struct v4l2_h264_reflist_builder *b,
+ const struct v4l2_h264_reference *ref)
+{
+ switch (ref->fields) {
+ case V4L2_H264_FRAME_REF:
+ return min(b->refs[ref->index].top_field_order_cnt,
+ b->refs[ref->index].bottom_field_order_cnt);
+ case V4L2_H264_TOP_FIELD_REF:
+ return b->refs[ref->index].top_field_order_cnt;
+ case V4L2_H264_BOTTOM_FIELD_REF:
+ return b->refs[ref->index].bottom_field_order_cnt;
+ }
+
+ /* not reached */
+ return 0;
+}
+
+static int v4l2_h264_p_ref_list_cmp(const void *ptra, const void *ptrb,
+ const void *data)
+{
+ const struct v4l2_h264_reflist_builder *builder = data;
+ u8 idxa, idxb;
+
+ idxa = ((struct v4l2_h264_reference *)ptra)->index;
+ idxb = ((struct v4l2_h264_reference *)ptrb)->index;
+
+ if (WARN_ON(idxa >= V4L2_H264_NUM_DPB_ENTRIES ||
+ idxb >= V4L2_H264_NUM_DPB_ENTRIES))
+ return 1;
+
+ if (builder->refs[idxa].longterm != builder->refs[idxb].longterm) {
+ /* Short term pics first. */
+ if (!builder->refs[idxa].longterm)
+ return -1;
+ else
+ return 1;
+ }
+
+ /*
+ * For frames, short term pics are in descending pic num order and long
+ * term ones in ascending order. For fields, the same direction is used
+ * but with frame_num (wrapped). For frames, the value of pic_num and
+ * frame_num are the same (see formula (8-28) and (8-29)). For this
+ * reason we can use frame_num only and share this function between
+ * frames and fields reflist.
+ */
+ if (!builder->refs[idxa].longterm)
+ return builder->refs[idxb].frame_num <
+ builder->refs[idxa].frame_num ?
+ -1 : 1;
+
+ return builder->refs[idxa].frame_num < builder->refs[idxb].frame_num ?
+ -1 : 1;
+}
+
+static int v4l2_h264_b0_ref_list_cmp(const void *ptra, const void *ptrb,
+ const void *data)
+{
+ const struct v4l2_h264_reflist_builder *builder = data;
+ s32 poca, pocb;
+ u8 idxa, idxb;
+
+ idxa = ((struct v4l2_h264_reference *)ptra)->index;
+ idxb = ((struct v4l2_h264_reference *)ptrb)->index;
+
+ if (WARN_ON(idxa >= V4L2_H264_NUM_DPB_ENTRIES ||
+ idxb >= V4L2_H264_NUM_DPB_ENTRIES))
+ return 1;
+
+ if (builder->refs[idxa].longterm != builder->refs[idxb].longterm) {
+ /* Short term pics first. */
+ if (!builder->refs[idxa].longterm)
+ return -1;
+ else
+ return 1;
+ }
+
+ /* Long term pics in ascending frame num order. */
+ if (builder->refs[idxa].longterm)
+ return builder->refs[idxa].frame_num <
+ builder->refs[idxb].frame_num ?
+ -1 : 1;
+
+ poca = v4l2_h264_get_poc(builder, ptra);
+ pocb = v4l2_h264_get_poc(builder, ptrb);
+
+ /*
+ * Short term pics with POC < cur POC first in POC descending order
+ * followed by short term pics with POC > cur POC in POC ascending
+ * order.
+ */
+ if ((poca < builder->cur_pic_order_count) !=
+ (pocb < builder->cur_pic_order_count))
+ return poca < pocb ? -1 : 1;
+ else if (poca < builder->cur_pic_order_count)
+ return pocb < poca ? -1 : 1;
+
+ return poca < pocb ? -1 : 1;
+}
+
+static int v4l2_h264_b1_ref_list_cmp(const void *ptra, const void *ptrb,
+ const void *data)
+{
+ const struct v4l2_h264_reflist_builder *builder = data;
+ s32 poca, pocb;
+ u8 idxa, idxb;
+
+ idxa = ((struct v4l2_h264_reference *)ptra)->index;
+ idxb = ((struct v4l2_h264_reference *)ptrb)->index;
+
+ if (WARN_ON(idxa >= V4L2_H264_NUM_DPB_ENTRIES ||
+ idxb >= V4L2_H264_NUM_DPB_ENTRIES))
+ return 1;
+
+ if (builder->refs[idxa].longterm != builder->refs[idxb].longterm) {
+ /* Short term pics first. */
+ if (!builder->refs[idxa].longterm)
+ return -1;
+ else
+ return 1;
+ }
+
+ /* Long term pics in ascending frame num order. */
+ if (builder->refs[idxa].longterm)
+ return builder->refs[idxa].frame_num <
+ builder->refs[idxb].frame_num ?
+ -1 : 1;
+
+ poca = v4l2_h264_get_poc(builder, ptra);
+ pocb = v4l2_h264_get_poc(builder, ptrb);
+
+ /*
+ * Short term pics with POC > cur POC first in POC ascending order
+ * followed by short term pics with POC < cur POC in POC descending
+ * order.
+ */
+ if ((poca < builder->cur_pic_order_count) !=
+ (pocb < builder->cur_pic_order_count))
+ return pocb < poca ? -1 : 1;
+ else if (poca < builder->cur_pic_order_count)
+ return pocb < poca ? -1 : 1;
+
+ return poca < pocb ? -1 : 1;
+}
+
+/*
+ * 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)
+{
+ struct v4l2_h264_reference tmplist[V4L2_H264_REF_LIST_LEN];
+ u8 lt, i = 0, j = 0, k = 0;
+
+ memcpy(tmplist, reflist, sizeof(tmplist[0]) * b->num_valid);
+
+ for (lt = 0; lt <= 1; lt++) {
+ do {
+ for (; i < b->num_valid && b->refs[tmplist[i].index].longterm == lt; i++) {
+ if (tmplist[i].fields == b->cur_pic_fields) {
+ reflist[k++] = tmplist[i++];
+ break;
+ }
+ }
+
+ for (; j < b->num_valid && b->refs[tmplist[j].index].longterm == lt; j++) {
+ if (tmplist[j].fields != b->cur_pic_fields) {
+ reflist[k++] = tmplist[j++];
+ break;
+ }
+ }
+ } while ((i < b->num_valid && b->refs[tmplist[i].index].longterm == lt) ||
+ (j < b->num_valid && b->refs[tmplist[j].index].longterm == lt));
+ }
+}
+
+static char ref_type_to_char(u8 ref_type)
+{
+ switch (ref_type) {
+ case V4L2_H264_FRAME_REF:
+ return 'f';
+ case V4L2_H264_TOP_FIELD_REF:
+ return 't';
+ case V4L2_H264_BOTTOM_FIELD_REF:
+ return 'b';
+ }
+
+ return '?';
+}
+
+static const char *format_ref_list_p(const struct v4l2_h264_reflist_builder *builder,
+ struct v4l2_h264_reference *reflist,
+ char **out_str)
+{
+ int n = 0, i;
+
+ *out_str = kmalloc(tmp_str_size, GFP_KERNEL);
+ if (!(*out_str))
+ return NULL;
+
+ n += snprintf(*out_str + n, tmp_str_size - n, "|");
+
+ for (i = 0; i < builder->num_valid; i++) {
+ /* this is pic_num for frame and frame_num (wrapped) for field,
+ * but for frame pic_num is equal to frame_num (wrapped).
+ */
+ int frame_num = builder->refs[reflist[i].index].frame_num;
+ bool longterm = builder->refs[reflist[i].index].longterm;
+
+ n += scnprintf(*out_str + n, tmp_str_size - n, "%i%c%c|",
+ frame_num, longterm ? 'l' : 's',
+ ref_type_to_char(reflist[i].fields));
+ }
+
+ return *out_str;
+}
+
+static void print_ref_list_p(const struct v4l2_h264_reflist_builder *builder,
+ struct v4l2_h264_reference *reflist)
+{
+ char *buf = NULL;
+
+ pr_debug("ref_pic_list_p (cur_poc %u%c) %s\n",
+ builder->cur_pic_order_count,
+ ref_type_to_char(builder->cur_pic_fields),
+ format_ref_list_p(builder, reflist, &buf));
+
+ kfree(buf);
+}
+
+static const char *format_ref_list_b(const struct v4l2_h264_reflist_builder *builder,
+ struct v4l2_h264_reference *reflist,
+ char **out_str)
+{
+ int n = 0, i;
+
+ *out_str = kmalloc(tmp_str_size, GFP_KERNEL);
+ if (!(*out_str))
+ return NULL;
+
+ n += snprintf(*out_str + n, tmp_str_size - n, "|");
+
+ for (i = 0; i < builder->num_valid; i++) {
+ int frame_num = builder->refs[reflist[i].index].frame_num;
+ u32 poc = v4l2_h264_get_poc(builder, reflist + i);
+ bool longterm = builder->refs[reflist[i].index].longterm;
+
+ n += scnprintf(*out_str + n, tmp_str_size - n, "%i%c%c|",
+ longterm ? frame_num : poc,
+ longterm ? 'l' : 's',
+ ref_type_to_char(reflist[i].fields));
+ }
+
+ return *out_str;
+}
+
+static void print_ref_list_b(const struct v4l2_h264_reflist_builder *builder,
+ struct v4l2_h264_reference *reflist, u8 list_num)
+{
+ char *buf = NULL;
+
+ pr_debug("ref_pic_list_b%u (cur_poc %u%c) %s",
+ list_num, builder->cur_pic_order_count,
+ ref_type_to_char(builder->cur_pic_fields),
+ format_ref_list_b(builder, reflist, &buf));
+
+ kfree(buf);
+}
+
+/**
+ * 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)
+{
+ memcpy(reflist, builder->unordered_reflist,
+ sizeof(builder->unordered_reflist[0]) * builder->num_valid);
+ sort_r(reflist, builder->num_valid, sizeof(*reflist),
+ v4l2_h264_p_ref_list_cmp, NULL, builder);
+
+ if (builder->cur_pic_fields != V4L2_H264_FRAME_REF)
+ reorder_field_reflist(builder, reflist);
+
+ print_ref_list_p(builder, reflist);
+}
+EXPORT_SYMBOL_GPL(v4l2_h264_build_p_ref_list);
+
+/**
+ * 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)
+{
+ memcpy(b0_reflist, builder->unordered_reflist,
+ sizeof(builder->unordered_reflist[0]) * builder->num_valid);
+ sort_r(b0_reflist, builder->num_valid, sizeof(*b0_reflist),
+ v4l2_h264_b0_ref_list_cmp, NULL, builder);
+
+ memcpy(b1_reflist, builder->unordered_reflist,
+ sizeof(builder->unordered_reflist[0]) * builder->num_valid);
+ sort_r(b1_reflist, builder->num_valid, sizeof(*b1_reflist),
+ v4l2_h264_b1_ref_list_cmp, NULL, builder);
+
+ if (builder->cur_pic_fields != V4L2_H264_FRAME_REF) {
+ reorder_field_reflist(builder, b0_reflist);
+ reorder_field_reflist(builder, b1_reflist);
+ }
+
+ if (builder->num_valid > 1 &&
+ !memcmp(b1_reflist, b0_reflist, builder->num_valid))
+ swap(b1_reflist[0], b1_reflist[1]);
+
+ print_ref_list_b(builder, b0_reflist, 0);
+ print_ref_list_b(builder, b1_reflist, 1);
+}
+EXPORT_SYMBOL_GPL(v4l2_h264_build_b_ref_lists);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("V4L2 H264 Helpers");
+MODULE_AUTHOR("Boris Brezillon <boris.brezillon@collabora.com>");
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-15 09:37:37 +0000