/*
 * Copyright (c) 2013 Jens Kuske <jenskuske@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <cedrus/cedrus.h>
#include <cedrus/cedrus_regs.h>
#include "vdpau_private.h"

static int find_startcode(const uint8_t *data, int len, int start)
{
	int pos, zeros = 0;
	for (pos = start; pos < len; pos++)
	{
		if (data[pos] == 0x00)
			zeros++;
		else if (data[pos] == 0x01 && zeros >= 2)
			return pos - 2;
		else
			zeros = 0;
	}

	return -1;
}

static uint32_t get_u(void *regs, int num)
{
	writel(0x00000002 | (num << 8), regs + VE_H264_TRIGGER);

	while (readl(regs + VE_H264_STATUS) & (1 << 8));

	return readl(regs + VE_H264_BASIC_BITS);
}

static uint32_t get_ue(void *regs)
{
	writel(0x00000005, regs + VE_H264_TRIGGER);

	while (readl(regs + VE_H264_STATUS) & (1 << 8));

	return readl(regs + VE_H264_BASIC_BITS);
}

static int32_t get_se(void *regs)
{
	writel(0x00000004, regs + VE_H264_TRIGGER);

	while (readl(regs + VE_H264_STATUS) & (1 << 8));

	return readl(regs + VE_H264_BASIC_BITS);
}

#define PIC_TOP_FIELD		0x1
#define PIC_BOTTOM_FIELD	0x2
#define PIC_FRAME		0x3

typedef struct
{
	video_surface_ctx_t *surface;
	uint16_t top_pic_order_cnt;
	uint16_t bottom_pic_order_cnt;
	uint16_t frame_idx;
	uint8_t field;
} h264_picture_t;


#define SLICE_TYPE_P	0
#define SLICE_TYPE_B	1
#define SLICE_TYPE_I	2
#define SLICE_TYPE_SP	3
#define SLICE_TYPE_SI	4

typedef struct
{
	uint8_t nal_unit_type;
	uint16_t first_mb_in_slice;
	uint8_t slice_type;
	uint8_t pic_parameter_set_id;
	uint16_t frame_num;
	uint8_t field_pic_flag;
	uint8_t bottom_field_flag;
	uint16_t idr_pic_id;
	uint32_t pic_order_cnt_lsb;
	int32_t delta_pic_order_cnt_bottom;
	int32_t delta_pic_order_cnt[2];
	uint8_t redundant_pic_cnt;
	uint8_t direct_spatial_mv_pred_flag;
	uint8_t num_ref_idx_active_override_flag;
	uint8_t num_ref_idx_l0_active_minus1;
	uint8_t num_ref_idx_l1_active_minus1;
	uint8_t cabac_init_idc;
	int8_t slice_qp_delta;
	uint8_t sp_for_switch_flag;
	int8_t slice_qs_delta;
	uint8_t disable_deblocking_filter_idc;
	int8_t slice_alpha_c0_offset_div2;
	int8_t slice_beta_offset_div2;

	uint8_t luma_log2_weight_denom;
	uint8_t chroma_log2_weight_denom;
	int8_t luma_weight_l0[32];
	int8_t luma_offset_l0[32];
	int8_t chroma_weight_l0[32][2];
	int8_t chroma_offset_l0[32][2];
	int8_t luma_weight_l1[32];
	int8_t luma_offset_l1[32];
	int8_t chroma_weight_l1[32][2];
	int8_t chroma_offset_l1[32][2];

	h264_picture_t RefPicList0[32];
	h264_picture_t RefPicList1[32];
} h264_header_t;

typedef struct
{
	void *regs;
	h264_header_t header;
	VdpPictureInfoH264 const *info;
	video_surface_ctx_t *output;
	uint8_t picture_width_in_mbs_minus1;
	uint8_t picture_height_in_mbs_minus1;
	uint8_t default_scaling_lists;
	int video_extra_data_len;

	int ref_count;
	h264_picture_t ref_pic[16];
} h264_context_t;

typedef struct
{
	cedrus_mem_t *extra_data;
} h264_private_t;

static void h264_private_free(decoder_ctx_t *decoder)
{
	h264_private_t *decoder_p = (h264_private_t *)decoder->private;
	cedrus_mem_free(decoder_p->extra_data);
	free(decoder_p);
}

#define PIC_TYPE_FRAME	0x0
#define PIC_TYPE_FIELD	0x1
#define PIC_TYPE_MBAFF	0x2

typedef struct
{
	cedrus_mem_t *extra_data;
	uint8_t pos;
	uint8_t pic_type;
} h264_video_private_t;

static void h264_video_private_free(video_surface_ctx_t *surface)
{
	h264_video_private_t *surface_p = (h264_video_private_t *)surface->decoder_private;
	cedrus_mem_free(surface_p->extra_data);
	free(surface_p);
}

static h264_video_private_t *get_surface_priv(h264_context_t *c, video_surface_ctx_t *surface)
{
	h264_video_private_t *surface_p = surface->decoder_private;

	if (!surface_p)
	{
		surface_p = calloc(1, sizeof(h264_video_private_t));
		if (!surface_p)
			return NULL;

		surface_p->extra_data = cedrus_mem_alloc(surface->device->cedrus, c->video_extra_data_len * 2);
		if (!surface_p->extra_data)
		{
			free(surface_p);
			return NULL;
		}

		surface->decoder_private = surface_p;
		surface->decoder_private_free = h264_video_private_free;
	}

	return surface_p;
}

static void ref_pic_list_modification(h264_context_t *c)
{
	h264_header_t *h = &c->header;
	VdpPictureInfoH264 const *info = c->info;
	const int MaxFrameNum = 1 << (info->log2_max_frame_num_minus4 + 4);
	const int MaxPicNum = (info->field_pic_flag) ? 2 * MaxFrameNum : MaxFrameNum;

	if (h->slice_type != SLICE_TYPE_I && h->slice_type != SLICE_TYPE_SI)
	{
		int ref_pic_list_modification_flag_l0 = get_u(c->regs, 1);
		if (ref_pic_list_modification_flag_l0)
		{
			unsigned int modification_of_pic_nums_idc;
			int refIdxL0 = 0;
			unsigned int picNumL0 = info->frame_num;
			if (h->field_pic_flag)
				picNumL0 = picNumL0 * 2 + 1;

			do
			{
				modification_of_pic_nums_idc = get_ue(c->regs);
				if (modification_of_pic_nums_idc == 0 || modification_of_pic_nums_idc == 1)
				{
					unsigned int abs_diff_pic_num_minus1 = get_ue(c->regs);

					if (modification_of_pic_nums_idc == 0)
						picNumL0 -= (abs_diff_pic_num_minus1 + 1);
					else
						picNumL0 += (abs_diff_pic_num_minus1 + 1);

					picNumL0 &= (MaxPicNum - 1);

					int frame_num = picNumL0;
					int field = PIC_FRAME;

					if (h->field_pic_flag)
					{
						field = h->bottom_field_flag ? PIC_BOTTOM_FIELD : PIC_TOP_FIELD;
						if (!(frame_num & 1))
							field ^= PIC_FRAME;

						frame_num /= 2;
					}

					int i, j;
					for (i = 0; i < c->ref_count; i++)
					{
						if (c->ref_pic[i].frame_idx == frame_num)
							break;
					}

					for (j = h->num_ref_idx_l0_active_minus1 + 1; j > refIdxL0; j--)
						h->RefPicList0[j] = h->RefPicList0[j - 1];
					h->RefPicList0[refIdxL0] = c->ref_pic[i];
					if (h->field_pic_flag)
						h->RefPicList0[refIdxL0].field = field;
					i = ++refIdxL0;
					for (j = refIdxL0; j <= h->num_ref_idx_l0_active_minus1 + 1; j++)
						if (h->RefPicList0[j].frame_idx != frame_num || h->RefPicList0[j].field != field)
							h->RefPicList0[i++] = h->RefPicList0[j];
				}
				else if (modification_of_pic_nums_idc == 2)
				{
					VDPAU_DBG("NOT IMPLEMENTED: modification_of_pic_nums_idc == 2");
					unsigned int long_term_pic_num = get_ue(c->regs);
				}
			} while (modification_of_pic_nums_idc != 3);
		}
	}

	if (h->slice_type == SLICE_TYPE_B)
	{
		int ref_pic_list_modification_flag_l1 = get_u(c->regs, 1);
		if (ref_pic_list_modification_flag_l1)
		{
			VDPAU_DBG("NOT IMPLEMENTED: ref_pic_list_modification_flag_l1 == 1");
			unsigned int modification_of_pic_nums_idc;
			do
			{
				modification_of_pic_nums_idc = get_ue(c->regs);
				if (modification_of_pic_nums_idc == 0 || modification_of_pic_nums_idc == 1)
				{
					unsigned int abs_diff_pic_num_minus1 = get_ue(c->regs);
				}
				else if (modification_of_pic_nums_idc == 2)
				{
					unsigned int long_term_pic_num = get_ue(c->regs);
				}
			} while (modification_of_pic_nums_idc != 3);
		}
	}
}

static void pred_weight_table(h264_context_t *c)
{
	h264_header_t *h = &c->header;
	int i, j, ChromaArrayType = 1;

	h->luma_log2_weight_denom = get_ue(c->regs);
	if (ChromaArrayType != 0)
		h->chroma_log2_weight_denom = get_ue(c->regs);

	for (i = 0; i < 32; i++)
	{
		h->luma_weight_l0[i] = (1 << h->luma_log2_weight_denom);
		h->luma_weight_l1[i] = (1 << h->luma_log2_weight_denom);
		h->chroma_weight_l0[i][0] = (1 << h->chroma_log2_weight_denom);
		h->chroma_weight_l1[i][0] = (1 << h->chroma_log2_weight_denom);
		h->chroma_weight_l0[i][1] = (1 << h->chroma_log2_weight_denom);
		h->chroma_weight_l1[i][1] = (1 << h->chroma_log2_weight_denom);
	}

	for (i = 0; i <= h->num_ref_idx_l0_active_minus1; i++)
	{
		int luma_weight_l0_flag = get_u(c->regs, 1);
		if (luma_weight_l0_flag)
		{
			h->luma_weight_l0[i] = get_se(c->regs);
			h->luma_offset_l0[i] = get_se(c->regs);
		}
		if (ChromaArrayType != 0)
		{
			int chroma_weight_l0_flag = get_u(c->regs, 1);
			if (chroma_weight_l0_flag)
				for (j = 0; j < 2; j++)
				{
					h->chroma_weight_l0[i][j] = get_se(c->regs);
					h->chroma_offset_l0[i][j] = get_se(c->regs);
				}
		}
	}

	if (h->slice_type == SLICE_TYPE_B)
		for (i = 0; i <= h->num_ref_idx_l1_active_minus1; i++)
		{
			int luma_weight_l1_flag = get_u(c->regs, 1);
			if (luma_weight_l1_flag)
			{
				h->luma_weight_l1[i] = get_se(c->regs);
				h->luma_offset_l1[i] = get_se(c->regs);
			}
			if (ChromaArrayType != 0)
			{
				int chroma_weight_l1_flag = get_u(c->regs, 1);
				if (chroma_weight_l1_flag)
					for (j = 0; j < 2; j++)
					{
						h->chroma_weight_l1[i][j] = get_se(c->regs);
						h->chroma_offset_l1[i][j] = get_se(c->regs);
					}
			}
		}

	writel(((h->chroma_log2_weight_denom & 0xf) << 4)
		| ((h->luma_log2_weight_denom & 0xf) << 0)
		, c->regs + VE_H264_PRED_WEIGHT);

	writel(VE_SRAM_H264_PRED_WEIGHT_TABLE, c->regs + VE_H264_RAM_WRITE_PTR);
	for (i = 0; i < 32; i++)
		writel(((h->luma_offset_l0[i] & 0x1ff) << 16)
			| (h->luma_weight_l0[i] & 0xff), c->regs + VE_H264_RAM_WRITE_DATA);
	for (i = 0; i < 32; i++)
		for (j = 0; j < 2; j++)
			writel(((h->chroma_offset_l0[i][j] & 0x1ff) << 16)
				| (h->chroma_weight_l0[i][j] & 0xff), c->regs + VE_H264_RAM_WRITE_DATA);
	for (i = 0; i < 32; i++)
		writel(((h->luma_offset_l1[i] & 0x1ff) << 16)
			| (h->luma_weight_l1[i] & 0xff), c->regs + VE_H264_RAM_WRITE_DATA);
	for (i = 0; i < 32; i++)
		for (j = 0; j < 2; j++)
			writel(((h->chroma_offset_l1[i][j] & 0x1ff) << 16)
				| (h->chroma_weight_l1[i][j] & 0xff), c->regs + VE_H264_RAM_WRITE_DATA);
}

static void dec_ref_pic_marking(h264_context_t *c)
{
	h264_header_t *h = &c->header;
	// only reads bits to allow decoding, doesn't mark anything
	if (h->nal_unit_type == 5)
	{
		get_u(c->regs, 1);
		get_u(c->regs, 1);
	}
	else
	{
		int adaptive_ref_pic_marking_mode_flag = get_u(c->regs, 1);
		if (adaptive_ref_pic_marking_mode_flag)
		{
			unsigned int memory_management_control_operation;
			do
			{
				memory_management_control_operation = get_ue(c->regs);
				if (memory_management_control_operation == 1 || memory_management_control_operation == 3)
				{
					get_ue(c->regs);
				}
				if (memory_management_control_operation == 2)
				{
					get_ue(c->regs);
				}
				if (memory_management_control_operation == 3 || memory_management_control_operation == 6)
				{
					get_ue(c->regs);
				}
				if (memory_management_control_operation == 4)
				{
					get_ue(c->regs);
				}
			} while (memory_management_control_operation != 0);
		}
	}
}

static int pic_order_cnt(const h264_picture_t *pic)
{
	if (pic->field == PIC_FRAME)
		return min(pic->top_pic_order_cnt, pic->bottom_pic_order_cnt);
	else if (pic->field == PIC_TOP_FIELD)
		return pic->top_pic_order_cnt;
	else
		return pic->bottom_pic_order_cnt;
}

static int sort_ref_pics_by_poc(const void *p1, const void *p2)
{
	const h264_picture_t *r1 = p1;
	const h264_picture_t *r2 = p2;

	return pic_order_cnt(r1) - pic_order_cnt(r2);
}

static int sort_ref_pics_by_frame_num(const void *p1, const void *p2)
{
	const h264_picture_t *r1 = p1;
	const h264_picture_t *r2 = p2;

	return r1->frame_idx - r2->frame_idx;
}

static void split_ref_fields(h264_picture_t *out, h264_picture_t **in, int len, int cur_field)
{
	int even = 0, odd = 0;
	int index = 0;

	while (even < len || odd < len)
	{
		while (even < len && !(in[even]->field & cur_field))
			even++;
		if (even < len)
		{
			out[index] = *in[even++];
			out[index].field = cur_field;
			index++;
		}

		while (odd < len && !(in[odd]->field & (cur_field ^ PIC_FRAME)))
			odd++;
		if (odd < len)
		{
			out[index] = *in[odd++];
			out[index].field = cur_field ^ PIC_FRAME;
			index++;
		}
	}
}

static void fill_default_ref_pic_list(h264_context_t *c)
{
	h264_header_t *h = &c->header;
	VdpPictureInfoH264 const *info = c->info;
	int cur_field = h->field_pic_flag ? (h->bottom_field_flag ? PIC_BOTTOM_FIELD : PIC_TOP_FIELD) : PIC_FRAME;

	if (h->slice_type == SLICE_TYPE_P)
	{
		qsort(c->ref_pic, c->ref_count, sizeof(c->ref_pic[0]), &sort_ref_pics_by_frame_num);

		int i;
		int ptr0 = 0;
		h264_picture_t *sorted[16];
		for (i = 0; i < c->ref_count; i++)
		{
			if (c->ref_pic[c->ref_count - 1 - i].frame_idx <= info->frame_num)
				sorted[ptr0++] = &c->ref_pic[c->ref_count - 1 - i];
		}
		for (i = 0; i < c->ref_count; i++)
		{
			if (c->ref_pic[c->ref_count - 1 - i].frame_idx > info->frame_num)
				sorted[ptr0++] = &c->ref_pic[c->ref_count - 1 - i];
		}

		split_ref_fields(h->RefPicList0, sorted, c->ref_count, cur_field);
	}
	else if (h->slice_type == SLICE_TYPE_B)
	{
		qsort(c->ref_pic, c->ref_count, sizeof(c->ref_pic[0]), &sort_ref_pics_by_poc);

		int cur_poc;
		if (h->field_pic_flag)
			cur_poc = (uint16_t)info->field_order_cnt[cur_field == PIC_BOTTOM_FIELD];
		else
			cur_poc = min((uint16_t)info->field_order_cnt[0], (uint16_t)info->field_order_cnt[1]);

		int i;
		int ptr0 = 0, ptr1 = 0;
		h264_picture_t *sorted[2][16];
		for (i = 0; i < c->ref_count; i++)
		{
			if (pic_order_cnt(&c->ref_pic[c->ref_count - 1 - i]) <= cur_poc)
				sorted[0][ptr0++] = &c->ref_pic[c->ref_count - 1  - i];

			if (pic_order_cnt(&c->ref_pic[i]) > cur_poc)
				sorted[1][ptr1++] = &c->ref_pic[i];
		}
		for (i = 0; i < c->ref_count; i++)
		{
			if (pic_order_cnt(&c->ref_pic[i]) > cur_poc)
				sorted[0][ptr0++] = &c->ref_pic[i];

			if (pic_order_cnt(&c->ref_pic[c->ref_count - 1 - i]) <= cur_poc)
				sorted[1][ptr1++] = &c->ref_pic[c->ref_count - 1 - i];
		}

		split_ref_fields(h->RefPicList0, sorted[0], c->ref_count, cur_field);
		split_ref_fields(h->RefPicList1, sorted[1], c->ref_count, cur_field);
	}
}

static void decode_slice_header(h264_context_t *c)
{
	h264_header_t *h = &c->header;
	VdpPictureInfoH264 const *info = c->info;
	h->num_ref_idx_l0_active_minus1 = info->num_ref_idx_l0_active_minus1;
	h->num_ref_idx_l1_active_minus1 = info->num_ref_idx_l1_active_minus1;

	h->first_mb_in_slice = get_ue(c->regs);
	h->slice_type = get_ue(c->regs);
	if (h->slice_type >= 5)
		h->slice_type -= 5;
	h->pic_parameter_set_id = get_ue(c->regs);

	// separate_colour_plane_flag isn't available in VDPAU
	/*if (separate_colour_plane_flag == 1)
		colour_plane_id u(2)*/

	h->frame_num = get_u(c->regs, info->log2_max_frame_num_minus4 + 4);

	if (!info->frame_mbs_only_flag)
	{
		h->field_pic_flag = get_u(c->regs, 1);
		if (h->field_pic_flag)
			h->bottom_field_flag = get_u(c->regs, 1);
	}

	if (h->nal_unit_type == 5)
		h->idr_pic_id = get_ue(c->regs);

	if (info->pic_order_cnt_type == 0)
	{
		h->pic_order_cnt_lsb = get_u(c->regs, info->log2_max_pic_order_cnt_lsb_minus4 + 4);
		if (info->pic_order_present_flag && !info->field_pic_flag)
			h->delta_pic_order_cnt_bottom = get_se(c->regs);
	}

	if (info->pic_order_cnt_type == 1 && !info->delta_pic_order_always_zero_flag)
	{
		h->delta_pic_order_cnt[0] = get_se(c->regs);
		if (info->pic_order_present_flag && !info->field_pic_flag)
			h->delta_pic_order_cnt[1] = get_se(c->regs);
	}

	if (info->redundant_pic_cnt_present_flag)
		h->redundant_pic_cnt = get_ue(c->regs);

	if (h->slice_type == SLICE_TYPE_B)
		h->direct_spatial_mv_pred_flag = get_u(c->regs, 1);

	if (h->slice_type == SLICE_TYPE_P || h->slice_type == SLICE_TYPE_SP || h->slice_type == SLICE_TYPE_B)
	{
		h->num_ref_idx_active_override_flag = get_u(c->regs, 1);
		if (h->num_ref_idx_active_override_flag)
		{
			h->num_ref_idx_l0_active_minus1 = get_ue(c->regs);
			if (h->slice_type == SLICE_TYPE_B)
				h->num_ref_idx_l1_active_minus1 = get_ue(c->regs);
		}
	}

	fill_default_ref_pic_list(c);

	if (h->nal_unit_type == 20)
		{}//ref_pic_list_mvc_modification(); // specified in Annex H
	else
		ref_pic_list_modification(c);

	if ((info->weighted_pred_flag && (h->slice_type == SLICE_TYPE_P || h->slice_type == SLICE_TYPE_SP)) || (info->weighted_bipred_idc == 1 && h->slice_type == SLICE_TYPE_B))
		pred_weight_table(c);

	if (info->is_reference)
		dec_ref_pic_marking(c);

	if (info->entropy_coding_mode_flag && h->slice_type != SLICE_TYPE_I && h->slice_type != SLICE_TYPE_SI)
		h->cabac_init_idc = get_ue(c->regs);

	h->slice_qp_delta = get_se(c->regs);

	if (h->slice_type == SLICE_TYPE_SP || h->slice_type == SLICE_TYPE_SI)
	{
		if (h->slice_type == SLICE_TYPE_SP)
			h->sp_for_switch_flag = get_u(c->regs, 1);
		h->slice_qs_delta = get_se(c->regs);
	}

	if (info->deblocking_filter_control_present_flag)
	{
		h->disable_deblocking_filter_idc = get_ue(c->regs);
		if (h->disable_deblocking_filter_idc != 1)
		{
			h->slice_alpha_c0_offset_div2 = get_se(c->regs);
			h->slice_beta_offset_div2 = get_se(c->regs);
		}
	}

	// num_slice_groups_minus1, slice_group_map_type, slice_group_map_type aren't available in VDPAU
	/*if (num_slice_groups_minus1 > 0 && slice_group_map_type >= 3 && slice_group_map_type <= 5)
		slice_group_change_cycle u(v)*/
}


static int fill_frame_lists(h264_context_t *c)
{
	int i;
	h264_video_private_t *output_p = (h264_video_private_t *)c->output->decoder_private;

	// collect reference frames
	h264_picture_t *frame_list[18];
	memset(frame_list, 0, sizeof(frame_list));

	int output_placed = 0;

	for (i = 0; i < 16; i++)
	{
		const VdpReferenceFrameH264 *rf = &(c->info->referenceFrames[i]);
		if (rf->surface != VDP_INVALID_HANDLE)
		{
			if (rf->is_long_term)
				VDPAU_DBG("NOT IMPLEMENTED: We got a longterm reference!");

			video_surface_ctx_t *surface = handle_get(rf->surface);
			h264_video_private_t *surface_p = get_surface_priv(c, surface);
			if (!surface_p)
				return 0;

			if (surface == c->output)
				output_placed = 1;

			c->ref_pic[c->ref_count].surface = surface;
			c->ref_pic[c->ref_count].top_pic_order_cnt = rf->field_order_cnt[0];
			c->ref_pic[c->ref_count].bottom_pic_order_cnt = rf->field_order_cnt[1];
			c->ref_pic[c->ref_count].frame_idx = rf->frame_idx;
			c->ref_pic[c->ref_count].field =
				(rf->top_is_reference ? PIC_TOP_FIELD : 0) |
				(rf->bottom_is_reference ? PIC_BOTTOM_FIELD : 0);

			frame_list[surface_p->pos] = &c->ref_pic[c->ref_count];
			c->ref_count++;
		}
	}

	// write picture buffer list
	writel(VE_SRAM_H264_FRAMEBUFFER_LIST, c->regs + VE_H264_RAM_WRITE_PTR);

	for (i = 0; i < 18; i++)
	{
		if (!output_placed && !frame_list[i])
		{
			writel((uint16_t)c->info->field_order_cnt[0], c->regs + VE_H264_RAM_WRITE_DATA);
			writel((uint16_t)c->info->field_order_cnt[1], c->regs + VE_H264_RAM_WRITE_DATA);
			writel(output_p->pic_type << 8, c->regs + VE_H264_RAM_WRITE_DATA);
			writel(cedrus_mem_get_bus_addr(c->output->rec), c->regs + VE_H264_RAM_WRITE_DATA);
			writel(cedrus_mem_get_bus_addr(c->output->rec) + c->output->luma_size, c->regs + VE_H264_RAM_WRITE_DATA);
			writel(cedrus_mem_get_bus_addr(output_p->extra_data), c->regs + VE_H264_RAM_WRITE_DATA);
			writel(cedrus_mem_get_bus_addr(output_p->extra_data) + c->video_extra_data_len, c->regs + VE_H264_RAM_WRITE_DATA);
			writel(0, c->regs + VE_H264_RAM_WRITE_DATA);

			output_p->pos = i;
			output_placed = 1;
		}
		else if (!frame_list[i])
		{
			int j;
			for (j = 0; j < 8; j++)
				writel(0x0, c->regs + VE_H264_RAM_WRITE_DATA);
		}
		else
		{
			video_surface_ctx_t *surface = frame_list[i]->surface;
			h264_video_private_t *surface_p = (h264_video_private_t *)surface->decoder_private;

			writel(frame_list[i]->top_pic_order_cnt, c->regs + VE_H264_RAM_WRITE_DATA);
			writel(frame_list[i]->bottom_pic_order_cnt, c->regs + VE_H264_RAM_WRITE_DATA);
			writel(surface_p->pic_type << 8, c->regs + VE_H264_RAM_WRITE_DATA);
			writel(cedrus_mem_get_bus_addr(surface->rec), c->regs + VE_H264_RAM_WRITE_DATA);
			writel(cedrus_mem_get_bus_addr(surface->rec) + surface->luma_size, c->regs + VE_H264_RAM_WRITE_DATA);
			writel(cedrus_mem_get_bus_addr(surface_p->extra_data), c->regs + VE_H264_RAM_WRITE_DATA);
			writel(cedrus_mem_get_bus_addr(surface_p->extra_data) + c->video_extra_data_len, c->regs + VE_H264_RAM_WRITE_DATA);
			writel(0, c->regs + VE_H264_RAM_WRITE_DATA);
		}
	}

	// output index
	writel(output_p->pos, c->regs + VE_H264_OUTPUT_FRAME_IDX);

	return 1;
}

// VDPAU does not tell us if the scaling lists are default or custom
static int check_scaling_lists(h264_context_t *c)
{
	const uint32_t *sl4 = (uint32_t *)&c->info->scaling_lists_4x4[0][0];
	const uint32_t *sl8 = (uint32_t *)&c->info->scaling_lists_8x8[0][0];

	int i;
	for (i = 0; i < 6 * 16 / 4; i++)
		if (sl4[i] != 0x10101010)
			return 0;

	for (i = 0; i < 2 * 64 / 4; i++)
		if (sl8[i] != 0x10101010)
			return 0;

	return 1;
}

static VdpStatus h264_decode(decoder_ctx_t *decoder,
                             VdpPictureInfo const *_info,
                             const int len,
                             video_surface_ctx_t *output)
{
	h264_private_t *decoder_p = (h264_private_t *)decoder->private;
	VdpPictureInfoH264 const *info = (VdpPictureInfoH264 const *)_info;

	VdpStatus ret = yuv_prepare(output);
	if (ret != VDP_STATUS_OK)
		return ret;

	ret = rec_prepare(output);
	if (ret != VDP_STATUS_OK)
		return ret;

	h264_context_t *c = calloc(1, sizeof(h264_context_t));
	c->picture_width_in_mbs_minus1 = (decoder->width - 1) / 16;
	if (!info->frame_mbs_only_flag)
		c->picture_height_in_mbs_minus1 = ((decoder->height / 2) - 1) / 16;
	else
		c->picture_height_in_mbs_minus1 = (decoder->height - 1) / 16;
	c->info = info;
	c->output = output;
	c->video_extra_data_len = ((decoder->width + 15) / 16) * ((decoder->height + 15) / 16) * 32;

	h264_video_private_t *output_p = get_surface_priv(c, output);
	if (!output_p)
	{
		ret = VDP_STATUS_RESOURCES;
		goto err_free;
	}

	if (info->field_pic_flag)
		output_p->pic_type = PIC_TYPE_FIELD;
	else if (info->mb_adaptive_frame_field_flag)
		output_p->pic_type = PIC_TYPE_MBAFF;
	else
		output_p->pic_type = PIC_TYPE_FRAME;

	// activate H264 engine
	c->regs = cedrus_ve_get(decoder->device->cedrus, CEDRUS_ENGINE_H264, (decoder->width >= 2048 ? 0x1 : 0x0) << 21);

	// some buffers
	uint32_t extra_buffers = cedrus_mem_get_bus_addr(decoder_p->extra_data);
	writel(extra_buffers, c->regs + VE_H264_EXTRA_BUFFER1);
	writel(extra_buffers + 0x48000, c->regs + VE_H264_EXTRA_BUFFER2);
	if (cedrus_get_ve_version(decoder->device->cedrus) == 0x1625 || decoder->width >= 2048)
	{
		int size = (c->picture_width_in_mbs_minus1 + 32) * 192;
		size = (size + 4095) & ~4095;
		writel(decoder->width >= 2048 ? 0x5 : 0xa, c->regs + 0x50);
		writel(extra_buffers + 0x50000, c->regs + 0x54);
		writel(extra_buffers + 0x50000 + size, c->regs + 0x58);
	}

	// write custom scaling lists
	if (!(c->default_scaling_lists = check_scaling_lists(c)))
	{
		const uint32_t *sl4 = (uint32_t *)&c->info->scaling_lists_4x4[0][0];
		const uint32_t *sl8 = (uint32_t *)&c->info->scaling_lists_8x8[0][0];

		writel(VE_SRAM_H264_SCALING_LISTS, c->regs + VE_H264_RAM_WRITE_PTR);

		int i;
		for (i = 0; i < 2 * 64 / 4; i++)
			writel(sl8[i], c->regs + VE_H264_RAM_WRITE_DATA);

		for (i = 0; i < 6 * 16 / 4; i++)
			writel(sl4[i], c->regs + VE_H264_RAM_WRITE_DATA);
	}

	// sdctrl
	writel(0x00000000, c->regs + VE_H264_SDROT_CTRL);
	if (cedrus_get_ve_version(decoder->device->cedrus) >= 0x1680)
	{
		writel(cedrus_mem_get_bus_addr(c->output->yuv->data), c->regs + VE_H264_SDROT_LUMA);
		writel(cedrus_mem_get_bus_addr(c->output->yuv->data) + c->output->luma_size, c->regs + VE_H264_SDROT_CHROMA);
		writel((0x2 << 30) | (0x1 << 28) | (c->output->chroma_size / 2), c->regs + VE_EXTRA_OUT_FMT_OFFSET);
	}

	if (!fill_frame_lists(c))
	{
		ret = VDP_STATUS_ERROR;
		goto err_ve_put;
	}

	unsigned int slice, pos = 0;
	for (slice = 0; slice < info->slice_count; slice++)
	{
		h264_header_t *h = &c->header;
		memset(h, 0, sizeof(h264_header_t));

		pos = find_startcode(cedrus_mem_get_pointer(decoder->data), len, pos) + 3;

		h->nal_unit_type = ((uint8_t *)cedrus_mem_get_pointer(decoder->data))[pos++] & 0x1f;

		if (h->nal_unit_type != 5 && h->nal_unit_type != 1)
		{
			ret = VDP_STATUS_ERROR;
			goto err_ve_put;
		}

		// Enable startcode detect and ??
		writel((0x1 << 25) | (0x1 << 10) | ((cedrus_get_ve_version(decoder->device->cedrus) >= 0x1680) << 9), c->regs + VE_H264_CTRL);

		// input buffer
		writel((len - pos) * 8, c->regs + VE_H264_VLD_LEN);
		writel(pos * 8, c->regs + VE_H264_VLD_OFFSET);
		uint32_t input_addr = cedrus_mem_get_bus_addr(decoder->data);
		writel(input_addr + VBV_SIZE - 1, c->regs + VE_H264_VLD_END);
		writel((input_addr & 0x0ffffff0) | (input_addr >> 28) | (0x7 << 28), c->regs + VE_H264_VLD_ADDR);

		// ?? some sort of reset maybe
		writel(0x7, c->regs + VE_H264_TRIGGER);

		int i;

		decode_slice_header(c);

		// write RefPicLists
		if (h->slice_type != SLICE_TYPE_I && h->slice_type != SLICE_TYPE_SI)
		{
			writel(VE_SRAM_H264_REF_LIST0, c->regs + VE_H264_RAM_WRITE_PTR);
			for (i = 0; i < h->num_ref_idx_l0_active_minus1 + 1; i += 4)
			{
				int j;
				uint32_t list = 0;
				for (j = 0; j < 4; j++)
					if (h->RefPicList0[i + j].surface)
					{
						h264_video_private_t *surface_p = (h264_video_private_t *)h->RefPicList0[i + j].surface->decoder_private;
						list |= ((surface_p->pos * 2 + (h->RefPicList0[i + j].field == PIC_BOTTOM_FIELD)) << (j * 8));
					}
				writel(list, c->regs + VE_H264_RAM_WRITE_DATA);
			}
		}
		if (h->slice_type == SLICE_TYPE_B)
		{
			writel(VE_SRAM_H264_REF_LIST1, c->regs + VE_H264_RAM_WRITE_PTR);
			for (i = 0; i < h->num_ref_idx_l1_active_minus1 + 1; i += 4)
			{
				int j;
				uint32_t list = 0;
				for (j = 0; j < 4; j++)
					if (h->RefPicList1[i + j].surface)
					{
						h264_video_private_t *surface_p = (h264_video_private_t *)h->RefPicList1[i + j].surface->decoder_private;
						list |= ((surface_p->pos * 2 + (h->RefPicList1[i + j].field  == PIC_BOTTOM_FIELD)) << (j * 8));
					}
				writel(list, c->regs + VE_H264_RAM_WRITE_DATA);
			}
		}

		// picture parameters
		writel(((info->entropy_coding_mode_flag & 0x1) << 15)
			| ((info->num_ref_idx_l0_active_minus1 & 0x1f) << 10)
			| ((info->num_ref_idx_l1_active_minus1 & 0x1f) << 5)
			| ((info->weighted_pred_flag & 0x1) << 4)
			| ((info->weighted_bipred_idc & 0x3) << 2)
			| ((info->constrained_intra_pred_flag & 0x1) << 1)
			| ((info->transform_8x8_mode_flag & 0x1) << 0)
			, c->regs + VE_H264_PIC_HDR);

		// sequence parameters
		writel((0x1 << 19)
			| ((c->info->frame_mbs_only_flag & 0x1) << 18)
			| ((c->info->mb_adaptive_frame_field_flag & 0x1) << 17)
			| ((c->info->direct_8x8_inference_flag & 0x1) << 16)
			| ((c->picture_width_in_mbs_minus1 & 0xff) << 8)
			| ((c->picture_height_in_mbs_minus1 & 0xff) << 0)
			, c->regs + VE_H264_FRAME_SIZE);

		// slice parameters
		writel((((h->first_mb_in_slice % (c->picture_width_in_mbs_minus1 + 1)) & 0xff) << 24)
			| (((h->first_mb_in_slice / (c->picture_width_in_mbs_minus1 + 1)) & 0xff) *
				(output_p->pic_type == PIC_TYPE_MBAFF ? 2 : 1) << 16)
			| ((info->is_reference & 0x1) << 12)
			| ((h->slice_type & 0xf) << 8)
			| ((slice == 0 ? 0x1 : 0x0) << 5)
			| ((info->field_pic_flag & 0x1) << 4)
			| ((info->bottom_field_flag & 0x1) << 3)
			| ((h->direct_spatial_mv_pred_flag & 0x1) << 2)
			| ((h->cabac_init_idc & 0x3) << 0)
			, c->regs + VE_H264_SLICE_HDR);

		writel(((h->num_ref_idx_l0_active_minus1 & 0x1f) << 24)
			| ((h->num_ref_idx_l1_active_minus1 & 0x1f) << 16)
			| ((h->num_ref_idx_active_override_flag & 0x1) << 12)
			| ((h->disable_deblocking_filter_idc & 0x3) << 8)
			| ((h->slice_alpha_c0_offset_div2 & 0xf) << 4)
			| ((h->slice_beta_offset_div2 & 0xf) << 0)
			, c->regs + VE_H264_SLICE_HDR2);

		writel(((c->default_scaling_lists & 0x1) << 24)
			| ((info->second_chroma_qp_index_offset & 0x3f) << 16)
			| ((info->chroma_qp_index_offset & 0x3f) << 8)
			| (((info->pic_init_qp_minus26 + 26 + h->slice_qp_delta) & 0x3f) << 0)
			, c->regs + VE_H264_QP_PARAM);

		// clear status flags
		writel(readl(c->regs + VE_H264_STATUS), c->regs + VE_H264_STATUS);

		// enable int
		writel(readl(c->regs + VE_H264_CTRL) | 0x7, c->regs + VE_H264_CTRL);

		// SHOWTIME
		writel(0x8, c->regs + VE_H264_TRIGGER);

		cedrus_ve_wait(decoder->device->cedrus, 1);

		// clear status flags
		writel(readl(c->regs + VE_H264_STATUS), c->regs + VE_H264_STATUS);

		pos = (readl(c->regs + VE_H264_VLD_OFFSET) / 8) - 3;
	}

	ret = VDP_STATUS_OK;

err_ve_put:
	// stop H264 engine
	cedrus_ve_put(decoder->device->cedrus);
err_free:
	free(c);
	return ret;
}

VdpStatus new_decoder_h264(decoder_ctx_t *decoder)
{
	h264_private_t *decoder_p = calloc(1, sizeof(h264_private_t));
	if (!decoder_p)
		return VDP_STATUS_RESOURCES;

	int extra_data_size = 320 * 1024;
	if (cedrus_get_ve_version(decoder->device->cedrus) == 0x1625 || decoder->width >= 2048)
	{
		// Engine version 0x1625 needs two extra buffers
		extra_data_size += ((decoder->width - 1) / 16 + 32) * 192;
		extra_data_size = (extra_data_size + 4095) & ~4095;
		extra_data_size += ((decoder->width - 1) / 16 + 64) * 80;
	}

	decoder_p->extra_data = cedrus_mem_alloc(decoder->device->cedrus, extra_data_size);
	if (!decoder_p->extra_data)
	{
		free(decoder_p);
		return VDP_STATUS_RESOURCES;
	}

	decoder->decode = h264_decode;
	decoder->private = decoder_p;
	decoder->private_free = h264_private_free;
	return VDP_STATUS_OK;
}