/*
  * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
  * Copyright (c) 2014 Arwa Arif <arwaarif1994@gmail.com>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * FFmpeg 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 General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along
  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 /**
  * @file
  * Postprocessing filter - 7
  *
  * Originally written by Michael Niedermayer for the MPlayer
  * project, and ported by Arwa Arif for FFmpeg.
  */
 
 #include "libavutil/avassert.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "internal.h"
 #include "vf_pp7.h"
 
 enum mode {
     MODE_HARD,
     MODE_SOFT,
     MODE_MEDIUM
 };
 
 #define OFFSET(x) offsetof(PP7Context, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 static const AVOption pp7_options[] = {
     { "qp", "force a constant quantizer parameter", OFFSET(qp), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 64, FLAGS },
     { "mode", "set thresholding mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = MODE_MEDIUM}, 0, 2, FLAGS, "mode" },
         { "hard",   "hard thresholding",   0, AV_OPT_TYPE_CONST, {.i64 = MODE_HARD},   INT_MIN, INT_MAX, FLAGS, "mode" },
         { "soft",   "soft thresholding",   0, AV_OPT_TYPE_CONST, {.i64 = MODE_SOFT},   INT_MIN, INT_MAX, FLAGS, "mode" },
         { "medium", "medium thresholding", 0, AV_OPT_TYPE_CONST, {.i64 = MODE_MEDIUM}, INT_MIN, INT_MAX, FLAGS, "mode" },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(pp7);
 
 DECLARE_ALIGNED(8, static const uint8_t, dither)[8][8] = {
     {  0,  48,  12,  60,   3,  51,  15,  63, },
     { 32,  16,  44,  28,  35,  19,  47,  31, },
     {  8,  56,   4,  52,  11,  59,   7,  55, },
     { 40,  24,  36,  20,  43,  27,  39,  23, },
     {  2,  50,  14,  62,   1,  49,  13,  61, },
     { 34,  18,  46,  30,  33,  17,  45,  29, },
     { 10,  58,   6,  54,   9,  57,   5,  53, },
     { 42,  26,  38,  22,  41,  25,  37,  21, },
 };
 
 #define N0 4
 #define N1 5
 #define N2 10
 #define SN0 2
 #define SN1 2.2360679775
 #define SN2 3.16227766017
 #define N (1 << 16)
 
 static const int factor[16] = {
     N / (N0 * N0), N / (N0 * N1), N / (N0 * N0), N / (N0 * N2),
     N / (N1 * N0), N / (N1 * N1), N / (N1 * N0), N / (N1 * N2),
     N / (N0 * N0), N / (N0 * N1), N / (N0 * N0), N / (N0 * N2),
     N / (N2 * N0), N / (N2 * N1), N / (N2 * N0), N / (N2 * N2),
 };
 
 static void init_thres2(PP7Context *p)
 {
     int qp, i;
     int bias = 0; //FIXME
 
     for (qp = 0; qp < 99; qp++) {
         for (i = 0; i < 16; i++) {
             p->thres2[qp][i] = ((i&1) ? SN2 : SN0) * ((i&4) ? SN2 : SN0) * FFMAX(1, qp) * (1<<2) - 1 - bias;
         }
     }
 }
 
 static inline void dctA_c(int16_t *dst, uint8_t *src, int stride)
 {
     int i;
 
     for (i = 0; i < 4; i++) {
         int s0 = src[0 * stride] + src[6 * stride];
         int s1 = src[1 * stride] + src[5 * stride];
         int s2 = src[2 * stride] + src[4 * stride];
         int s3 = src[3 * stride];
         int s = s3 + s3;
         s3 = s  - s0;
         s0 = s  + s0;
         s  = s2 + s1;
         s2 = s2 - s1;
         dst[0] = s0 + s;
         dst[2] = s0 - s;
         dst[1] = 2 * s3 +     s2;
         dst[3] =     s3 - 2 * s2;
         src++;
         dst += 4;
     }
 }
 
 static void dctB_c(int16_t *dst, int16_t *src)
 {
     int i;
 
     for (i = 0; i < 4; i++) {
         int s0 = src[0 * 4] + src[6 * 4];
         int s1 = src[1 * 4] + src[5 * 4];
         int s2 = src[2 * 4] + src[4 * 4];
         int s3 = src[3 * 4];
         int s = s3 + s3;
         s3 = s  - s0;
         s0 = s  + s0;
         s  = s2 + s1;
         s2 = s2 - s1;
         dst[0 * 4] = s0 + s;
         dst[2 * 4] = s0 - s;
         dst[1 * 4] = 2 * s3 +     s2;
         dst[3 * 4] =     s3 - 2 * s2;
         src++;
         dst++;
     }
 }
 
 static int hardthresh_c(PP7Context *p, int16_t *src, int qp)
 {
     int i;
     int a;
 
     a = src[0] * factor[0];
     for (i = 1; i < 16; i++) {
         unsigned int threshold1 = p->thres2[qp][i];
         unsigned int threshold2 = threshold1 << 1;
         int level = src[i];
         if (((unsigned)(level + threshold1)) > threshold2)
             a += level * factor[i];
     }
     return (a + (1 << 11)) >> 12;
 }
 
 static int mediumthresh_c(PP7Context *p, int16_t *src, int qp)
 {
     int i;
     int a;
 
     a = src[0] * factor[0];
     for (i = 1; i < 16; i++) {
         unsigned int threshold1 = p->thres2[qp][i];
         unsigned int threshold2 = threshold1 << 1;
         int level = src[i];
         if (((unsigned)(level + threshold1)) > threshold2) {
             if (((unsigned)(level + 2 * threshold1)) > 2 * threshold2)
                 a += level * factor[i];
             else {
                 if (level > 0)
                     a += 2 * (level - (int)threshold1) * factor[i];
                 else
                     a += 2 * (level + (int)threshold1) * factor[i];
             }
         }
     }
     return (a + (1 << 11)) >> 12;
 }
 
 static int softthresh_c(PP7Context *p, int16_t *src, int qp)
 {
     int i;
     int a;
 
     a = src[0] * factor[0];
     for (i = 1; i < 16; i++) {
         unsigned int threshold1 = p->thres2[qp][i];
         unsigned int threshold2 = threshold1 << 1;
         int level = src[i];
         if (((unsigned)(level + threshold1)) > threshold2) {
             if (level > 0)
                 a += (level - (int)threshold1) * factor[i];
             else
                 a += (level + (int)threshold1) * factor[i];
         }
     }
     return (a + (1 << 11)) >> 12;
 }
 
 static void filter(PP7Context *p, uint8_t *dst, uint8_t *src,
                    int dst_stride, int src_stride,
                    int width, int height,
                    uint8_t *qp_store, int qp_stride, int is_luma)
 {
     int x, y;
     const int stride = is_luma ? p->temp_stride : ((width + 16 + 15) & (~15));
     uint8_t *p_src = p->src + 8 * stride;
     int16_t *block = (int16_t *)p->src;
     int16_t *temp  = (int16_t *)(p->src + 32);
 
     if (!src || !dst) return;
     for (y = 0; y < height; y++) {
         int index = 8 + 8 * stride + y * stride;
         memcpy(p_src + index, src + y * src_stride, width);
         for (x = 0; x < 8; x++) {
             p_src[index         - x - 1]= p_src[index +         x    ];
             p_src[index + width + x    ]= p_src[index + width - x - 1];
         }
     }
     for (y = 0; y < 8; y++) {
         memcpy(p_src + (    7 - y     ) * stride, p_src + (    y + 8     ) * stride, stride);
         memcpy(p_src + (height + 8 + y) * stride, p_src + (height - y + 7) * stride, stride);
     }
     //FIXME (try edge emu)
 
     for (y = 0; y < height; y++) {
         for (x = -8; x < 0; x += 4) {
             const int index = x + y * stride + (8 - 3) * (1 + stride) + 8; //FIXME silly offset
             uint8_t *src  = p_src + index;
             int16_t *tp   = temp + 4 * x;
 
             dctA_c(tp + 4 * 8, src, stride);
         }
         for (x = 0; x < width; ) {
             const int qps = 3 + is_luma;
             int qp;
             int end = FFMIN(x + 8, width);
 
             if (p->qp)
                 qp = p->qp;
             else {
                 qp = qp_store[ (FFMIN(x, width - 1) >> qps) + (FFMIN(y, height - 1) >> qps) * qp_stride];

                 qp = ff_norm_qscale(qp, p->qscale_type);

             }
             for (; x < end; x++) {
                 const int index = x + y * stride + (8 - 3) * (1 + stride) + 8; //FIXME silly offset
                 uint8_t *src = p_src + index;
                 int16_t *tp  = temp + 4 * x;
                 int v;
 
                 if ((x & 3) == 0)
                     dctA_c(tp + 4 * 8, src, stride);
 
                 p->dctB(block, tp);
 
                 v = p->requantize(p, block, qp);
                 v = (v + dither[y & 7][x & 7]) >> 6;
                 if ((unsigned)v > 255)
                     v = (-v) >> 31;
                 dst[x + y * dst_stride] = v;
             }
         }
     }
 }
 
 static int query_formats(AVFilterContext *ctx)
 {

     static const enum AVPixelFormat pix_fmts[] = {

         AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_YUV420P,  AV_PIX_FMT_YUV411P,
         AV_PIX_FMT_YUV410P,  AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P,
         AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ440P,

         AV_PIX_FMT_GBRP,

         AV_PIX_FMT_GRAY8,    AV_PIX_FMT_NONE
     };

 
     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
     if (!fmts_list)
         return AVERROR(ENOMEM);
     return ff_set_common_formats(ctx, fmts_list);

 }
 
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     PP7Context *pp7 = ctx->priv;
     const int h = FFALIGN(inlink->h + 16, 16);
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
 
     pp7->hsub = desc->log2_chroma_w;
     pp7->vsub = desc->log2_chroma_h;
 
     pp7->temp_stride = FFALIGN(inlink->w + 16, 16);

     pp7->src = av_malloc_array(pp7->temp_stride,  (h + 8) * sizeof(uint8_t));

 
     if (!pp7->src)
         return AVERROR(ENOMEM);
 
     init_thres2(pp7);
 
     switch (pp7->mode) {
         case 0: pp7->requantize = hardthresh_c; break;
         case 1: pp7->requantize = softthresh_c; break;
         default:
         case 2: pp7->requantize = mediumthresh_c; break;
     }
 
     pp7->dctB = dctB_c;
 
     if (ARCH_X86)
         ff_pp7_init_x86(pp7);
 
     return 0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     AVFilterContext *ctx = inlink->dst;
     PP7Context *pp7 = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *out = in;
 
     int qp_stride = 0;
     uint8_t *qp_table = NULL;
 
     if (!pp7->qp)
         qp_table = av_frame_get_qp_table(in, &qp_stride, &pp7->qscale_type);
 
     if (!ctx->is_disabled) {

         const int cw = AV_CEIL_RSHIFT(inlink->w, pp7->hsub);
         const int ch = AV_CEIL_RSHIFT(inlink->h, pp7->vsub);

 
         /* get a new frame if in-place is not possible or if the dimensions
         * are not multiple of 8 */
         if (!av_frame_is_writable(in) || (inlink->w & 7) || (inlink->h & 7)) {
             const int aligned_w = FFALIGN(inlink->w, 8);
             const int aligned_h = FFALIGN(inlink->h, 8);
 
             out = ff_get_video_buffer(outlink, aligned_w, aligned_h);
             if (!out) {
                 av_frame_free(&in);
                 return AVERROR(ENOMEM);
             }
             av_frame_copy_props(out, in);

             out->width = in->width;
             out->height = in->height;

         }
 
         if (qp_table || pp7->qp) {
 
             filter(pp7, out->data[0], in->data[0], out->linesize[0], in->linesize[0],
                    inlink->w, inlink->h, qp_table, qp_stride, 1);
             filter(pp7, out->data[1], in->data[1], out->linesize[1], in->linesize[1],
                    cw,        ch,        qp_table, qp_stride, 0);
             filter(pp7, out->data[2], in->data[2], out->linesize[2], in->linesize[2],
                    cw,        ch,        qp_table, qp_stride, 0);
             emms_c();
         }
     }
 
     if (in != out) {
         if (in->data[3])
             av_image_copy_plane(out->data[3], out->linesize[3],
                                 in ->data[3], in ->linesize[3],
                                 inlink->w, inlink->h);
         av_frame_free(&in);
     }
     return ff_filter_frame(outlink, out);
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     PP7Context *pp7 = ctx->priv;
     av_freep(&pp7->src);
 }
 
 static const AVFilterPad pp7_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_input,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad pp7_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 
 AVFilter ff_vf_pp7 = {
     .name            = "pp7",
     .description     = NULL_IF_CONFIG_SMALL("Apply Postprocessing 7 filter."),
     .priv_size       = sizeof(PP7Context),
     .uninit          = uninit,
     .query_formats   = query_formats,
     .inputs          = pp7_inputs,
     .outputs         = pp7_outputs,
     .priv_class      = &pp7_class,
     .flags           = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
 };