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authorBoris Brezillon <boris.brezillon@collabora.com>2020-04-04 00:13:41 +0200
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>2020-04-21 13:46:40 +0200
commit624922a2739b96b83aaf1655d0519b41d30140f7 (patch)
tree20159722c44c060221f94cc179adbd828dc0170a /include/media
parent45776c540f7fee193ab5a419d5e188cd220ce226 (diff)
media: v4l2-core: Add helpers to build the H264 P/B0/B1 reflists
Building those list is a standard procedure described in section '8.2.4 Decoding process for reference picture lists construction' of the H264 specification. We already have 2 drivers needing the same logic (hantro and rkvdec) and I suspect we will soon have more. Let's provide generic helpers to create those lists. Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'include/media')
-rw-r--r--include/media/h264-ctrls.h8
-rw-r--r--include/media/v4l2-h264.h85
2 files changed, 92 insertions, 1 deletions
diff --git a/include/media/h264-ctrls.h b/include/media/h264-ctrls.h
index 1c6ff7d63bca..080fd1293c42 100644
--- a/include/media/h264-ctrls.h
+++ b/include/media/h264-ctrls.h
@@ -13,6 +13,12 @@
#include <linux/videodev2.h>
+/*
+ * Maximum DPB size, as specified by section 'A.3.1 Level limits
+ * common to the Baseline, Main, and Extended profiles'.
+ */
+#define V4L2_H264_NUM_DPB_ENTRIES 16
+
/* Our pixel format isn't stable at the moment */
#define V4L2_PIX_FMT_H264_SLICE v4l2_fourcc('S', '2', '6', '4') /* H264 parsed slices */
@@ -201,7 +207,7 @@ struct v4l2_h264_dpb_entry {
#define V4L2_H264_DECODE_PARAM_FLAG_IDR_PIC 0x01
struct v4l2_ctrl_h264_decode_params {
- struct v4l2_h264_dpb_entry dpb[16];
+ struct v4l2_h264_dpb_entry dpb[V4L2_H264_NUM_DPB_ENTRIES];
__u16 num_slices;
__u16 nal_ref_idc;
__s32 top_field_order_cnt;
diff --git a/include/media/v4l2-h264.h b/include/media/v4l2-h264.h
new file mode 100644
index 000000000000..bc9ebb560ccf
--- /dev/null
+++ b/include/media/v4l2-h264.h
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Helper functions for H264 codecs.
+ *
+ * Copyright (c) 2019 Collabora, Ltd.
+ *
+ * Author: Boris Brezillon <boris.brezillon@collabora.com>
+ */
+
+#ifndef _MEDIA_V4L2_H264_H
+#define _MEDIA_V4L2_H264_H
+
+#include <media/h264-ctrls.h>
+
+/**
+ * struct v4l2_h264_reflist_builder - Reference list builder object
+ *
+ * @refs.pic_order_count: reference picture order count
+ * @refs.frame_num: reference frame number
+ * @refs.pic_num: reference picture number
+ * @refs.longterm: set to true for a long term reference
+ * @refs: array of references
+ * @cur_pic_order_count: picture order count of the frame being decoded
+ * @unordered_reflist: unordered list of references. Will be used to generate
+ * ordered P/B0/B1 lists
+ * @num_valid: number of valid references in the refs array
+ *
+ * This object stores the context of the P/B0/B1 reference list builder.
+ * This procedure is described in section '8.2.4 Decoding process for reference
+ * picture lists construction' of the H264 spec.
+ */
+struct v4l2_h264_reflist_builder {
+ struct {
+ s32 pic_order_count;
+ int frame_num;
+ u16 pic_num;
+ u16 longterm : 1;
+ } refs[V4L2_H264_NUM_DPB_ENTRIES];
+ s32 cur_pic_order_count;
+ u8 unordered_reflist[V4L2_H264_NUM_DPB_ENTRIES];
+ u8 num_valid;
+};
+
+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_slice_params *slice_params,
+ const struct v4l2_ctrl_h264_sps *sps,
+ const struct v4l2_h264_dpb_entry dpb[V4L2_H264_NUM_DPB_ENTRIES]);
+
+/**
+ * v4l2_h264_build_b_ref_lists() - Build the B0/B1 reference lists
+ *
+ * @builder: reference list builder context
+ * @b0_reflist: 16-bytes array used to store the B0 reference list. Each entry
+ * is an index in the DPB
+ * @b1_reflist: 16-bytes array used to store the B1 reference list. Each entry
+ * is an index in the DPB
+ *
+ * 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,
+ u8 *b0_reflist, u8 *b1_reflist);
+
+/**
+ * v4l2_h264_build_b_ref_lists() - Build the P reference list
+ *
+ * @builder: reference list builder context
+ * @p_reflist: 16-bytes array used to store the P reference list. Each entry
+ * is an index in the DPB
+ *
+ * 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,
+ u8 *reflist);
+
+#endif /* _MEDIA_V4L2_H264_H */