/*
  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>

  * Copyright (c) 2013 Clément Bœsch <u pkh me>

  *
  * 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
  * Simple post processing filter
  *
  * This implementation is based on an algorithm described in
  * "Aria Nosratinia Embedded Post-Processing for
  * Enhancement of Compressed Images (1999)"
  *
  * Originally written by Michael Niedermayer for the MPlayer project, and
  * ported by Clément Bœsch for FFmpeg.
  */
 
 #include "libavutil/avassert.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "internal.h"
 #include "vf_spp.h"
 
 enum mode {
     MODE_HARD,
     MODE_SOFT,
     NB_MODES
 };
 

 static const AVClass *child_class_next(const AVClass *prev)
 {
     return prev ? NULL : avcodec_dct_get_class();
 }
 
 static void *child_next(void *obj, void *prev)
 {
     SPPContext *s = obj;
     return prev ? NULL : s->dct;
 }
 

 #define OFFSET(x) offsetof(SPPContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 static const AVOption spp_options[] = {
     { "quality", "set quality", OFFSET(log2_count), AV_OPT_TYPE_INT, {.i64 = 3}, 0, MAX_LEVEL, FLAGS },
     { "qp", "force a constant quantizer parameter", OFFSET(qp), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 63, FLAGS },
     { "mode", "set thresholding mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = MODE_HARD}, 0, NB_MODES - 1, 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" },

     { "use_bframe_qp", "use B-frames' QP", OFFSET(use_bframe_qp), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, FLAGS },

     { NULL }
 };
 

 static const AVClass spp_class = {
     .class_name       = "spp",
     .item_name        = av_default_item_name,
     .option           = spp_options,
     .version          = LIBAVUTIL_VERSION_INT,
     .category         = AV_CLASS_CATEGORY_FILTER,
     .child_class_next = child_class_next,
     .child_next       = child_next,
 };

 
 // XXX: share between filters?
 DECLARE_ALIGNED(8, static const uint8_t, ldither)[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 },
 };
 
 static const uint8_t offset[127][2] = {
     {0,0},
     {0,0}, {4,4},                                           // quality = 1
     {0,0}, {2,2}, {6,4}, {4,6},                             // quality = 2
     {0,0}, {5,1}, {2,2}, {7,3}, {4,4}, {1,5}, {6,6}, {3,7}, // quality = 3
 
     {0,0}, {4,0}, {1,1}, {5,1}, {3,2}, {7,2}, {2,3}, {6,3}, // quality = 4
     {0,4}, {4,4}, {1,5}, {5,5}, {3,6}, {7,6}, {2,7}, {6,7},
 
     {0,0}, {0,2}, {0,4}, {0,6}, {1,1}, {1,3}, {1,5}, {1,7}, // quality = 5
     {2,0}, {2,2}, {2,4}, {2,6}, {3,1}, {3,3}, {3,5}, {3,7},
     {4,0}, {4,2}, {4,4}, {4,6}, {5,1}, {5,3}, {5,5}, {5,7},
     {6,0}, {6,2}, {6,4}, {6,6}, {7,1}, {7,3}, {7,5}, {7,7},
 
     {0,0}, {4,4}, {0,4}, {4,0}, {2,2}, {6,6}, {2,6}, {6,2}, // quality = 6
     {0,2}, {4,6}, {0,6}, {4,2}, {2,0}, {6,4}, {2,4}, {6,0},
     {1,1}, {5,5}, {1,5}, {5,1}, {3,3}, {7,7}, {3,7}, {7,3},
     {1,3}, {5,7}, {1,7}, {5,3}, {3,1}, {7,5}, {3,5}, {7,1},
     {0,1}, {4,5}, {0,5}, {4,1}, {2,3}, {6,7}, {2,7}, {6,3},
     {0,3}, {4,7}, {0,7}, {4,3}, {2,1}, {6,5}, {2,5}, {6,1},
     {1,0}, {5,4}, {1,4}, {5,0}, {3,2}, {7,6}, {3,6}, {7,2},
     {1,2}, {5,6}, {1,6}, {5,2}, {3,0}, {7,4}, {3,4}, {7,0},
 };
 
 static void hardthresh_c(int16_t dst[64], const int16_t src[64],
                          int qp, const uint8_t *permutation)
 {
     int i;
     int bias = 0; // FIXME
 
     unsigned threshold1 = qp * ((1<<4) - bias) - 1;
     unsigned threshold2 = threshold1 << 1;
 
     memset(dst, 0, 64 * sizeof(dst[0]));
     dst[0] = (src[0] + 4) >> 3;
 
     for (i = 1; i < 64; i++) {
         int level = src[i];
         if (((unsigned)(level + threshold1)) > threshold2) {
             const int j = permutation[i];
             dst[j] = (level + 4) >> 3;
         }
     }
 }
 
 static void softthresh_c(int16_t dst[64], const int16_t src[64],
                          int qp, const uint8_t *permutation)
 {
     int i;
     int bias = 0; //FIXME
 
     unsigned threshold1 = qp * ((1<<4) - bias) - 1;
     unsigned threshold2 = threshold1 << 1;
 
     memset(dst, 0, 64 * sizeof(dst[0]));
     dst[0] = (src[0] + 4) >> 3;
 
     for (i = 1; i < 64; i++) {
         int level = src[i];
         if (((unsigned)(level + threshold1)) > threshold2) {
             const int j = permutation[i];
             if (level > 0) dst[j] = (level - threshold1 + 4) >> 3;
             else           dst[j] = (level + threshold1 + 4) >> 3;
         }
     }
 }
 

 static void store_slice_c(uint8_t *dst, const int16_t *src,

                           int dst_linesize, int src_linesize,
                           int width, int height, int log2_scale,
                           const uint8_t dither[8][8])
 {
     int y, x;
 
 #define STORE(pos) do {                                                     \
     temp = ((src[x + y*src_linesize + pos] << log2_scale) + d[pos]) >> 6;   \
     if (temp & 0x100)                                                       \
         temp = ~(temp >> 31);                                               \
     dst[x + y*dst_linesize + pos] = temp;                                   \
 } while (0)
 
     for (y = 0; y < height; y++) {
         const uint8_t *d = dither[y];
         for (x = 0; x < width; x += 8) {
             int temp;
             STORE(0);
             STORE(1);
             STORE(2);
             STORE(3);
             STORE(4);
             STORE(5);
             STORE(6);
             STORE(7);
         }
     }
 }
 

 static void store_slice16_c(uint16_t *dst, const int16_t *src,

                             int dst_linesize, int src_linesize,
                             int width, int height, int log2_scale,

                             const uint8_t dither[8][8], int depth)

 {
     int y, x;

     unsigned int mask = -1<<depth;

 
 #define STORE16(pos) do {                                                   \
     temp = ((src[x + y*src_linesize + pos] << log2_scale) + (d[pos]>>1)) >> 5;   \

     if (temp & mask )                                                       \

         temp = ~(temp >> 31);                                               \
     dst[x + y*dst_linesize + pos] = temp;                                   \
 } while (0)
 
     for (y = 0; y < height; y++) {
         const uint8_t *d = dither[y];
         for (x = 0; x < width; x += 8) {
             int temp;
             STORE16(0);
             STORE16(1);
             STORE16(2);
             STORE16(3);
             STORE16(4);
             STORE16(5);
             STORE16(6);
             STORE16(7);
         }
     }
 }
 

 static inline void add_block(uint16_t *dst, int linesize, const int16_t block[64])

 {
     int y;
 
     for (y = 0; y < 8; y++) {
         *(uint32_t *)&dst[0 + y*linesize] += *(uint32_t *)&block[0 + y*8];
         *(uint32_t *)&dst[2 + y*linesize] += *(uint32_t *)&block[2 + y*8];
         *(uint32_t *)&dst[4 + y*linesize] += *(uint32_t *)&block[4 + y*8];
         *(uint32_t *)&dst[6 + y*linesize] += *(uint32_t *)&block[6 + y*8];
     }
 }
 
 static void filter(SPPContext *p, uint8_t *dst, uint8_t *src,
                    int dst_linesize, int src_linesize, int width, int height,

                    const uint8_t *qp_table, int qp_stride, int is_luma, int depth)

 {
     int x, y, i;
     const int count = 1 << p->log2_count;
     const int linesize = is_luma ? p->temp_linesize : FFALIGN(width+16, 16);
     DECLARE_ALIGNED(16, uint64_t, block_align)[32];
     int16_t *block  = (int16_t *)block_align;
     int16_t *block2 = (int16_t *)(block_align + 16);

     uint16_t *psrc16 = (uint16_t*)p->src;

     const int sample_bytes = (depth+7) / 8;

 
     for (y = 0; y < height; y++) {
         int index = 8 + 8*linesize + y*linesize;

         memcpy(p->src + index*sample_bytes, src + y*src_linesize, width*sample_bytes);
         if (sample_bytes == 1) {
             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];
             }
         } else {
             for (x = 0; x < 8; x++) {
                 psrc16[index         - x - 1] = psrc16[index +         x    ];
                 psrc16[index + width + x    ] = psrc16[index + width - x - 1];
             }

         }
     }
     for (y = 0; y < 8; y++) {

         memcpy(p->src + (       7-y)*linesize * sample_bytes, p->src + (       y+8)*linesize * sample_bytes, linesize * sample_bytes);
         memcpy(p->src + (height+8+y)*linesize * sample_bytes, p->src + (height-y+7)*linesize * sample_bytes, linesize * sample_bytes);

     }
 
     for (y = 0; y < height + 8; y += 8) {
         memset(p->temp + (8 + y) * linesize, 0, 8 * linesize * sizeof(*p->temp));
         for (x = 0; x < width + 8; x += 8) {
             int qp;
 
             if (p->qp) {
                 qp = p->qp;
             } else{
                 const int qps = 3 + is_luma;
                 qp = qp_table[(FFMIN(x, width - 1) >> qps) + (FFMIN(y, height - 1) >> qps) * qp_stride];

                 qp = FFMAX(1, ff_norm_qscale(qp, p->qscale_type));

             }
             for (i = 0; i < count; i++) {
                 const int x1 = x + offset[i + count - 1][0];
                 const int y1 = y + offset[i + count - 1][1];
                 const int index = x1 + y1*linesize;

                 p->dct->get_pixels(block, p->src + sample_bytes*index, sample_bytes*linesize);

                 p->dct->fdct(block);
                 p->requantize(block2, block, qp, p->dct->idct_permutation);
                 p->dct->idct(block2);

                 add_block(p->temp + index, linesize, block2);
             }
         }

         if (y) {
             if (sample_bytes == 1) {
                 p->store_slice(dst + (y - 8) * dst_linesize, p->temp + 8 + y*linesize,
                                dst_linesize, linesize, width,
                                FFMIN(8, height + 8 - y), MAX_LEVEL - p->log2_count,
                                ldither);
             } else {

                 store_slice16_c((uint16_t*)(dst + (y - 8) * dst_linesize), p->temp + 8 + y*linesize,

                                 dst_linesize/2, linesize, width,
                                 FFMIN(8, height + 8 - y), MAX_LEVEL - p->log2_count,

                                 ldither, depth);

             }
         }

     }
 }
 
 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_YUV444P10,  AV_PIX_FMT_YUV422P10,
         AV_PIX_FMT_YUV420P10,

         AV_PIX_FMT_YUV444P9,  AV_PIX_FMT_YUV422P9,
         AV_PIX_FMT_YUV420P9,

         AV_PIX_FMT_GRAY8,

         AV_PIX_FMT_GBRP,

         AV_PIX_FMT_GBRP9,
         AV_PIX_FMT_GBRP10,

         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)
 {

     SPPContext *s = inlink->dst->priv;

     const int h = FFALIGN(inlink->h + 16, 16);
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

     const int bps = desc->comp[0].depth;

     av_opt_set_int(s->dct, "bits_per_sample", bps, 0);
     avcodec_dct_init(s->dct);

 
     if (ARCH_X86)

         ff_spp_init_x86(s);

     s->hsub = desc->log2_chroma_w;
     s->vsub = desc->log2_chroma_h;
     s->temp_linesize = FFALIGN(inlink->w + 16, 16);
     s->temp = av_malloc_array(s->temp_linesize, h * sizeof(*s->temp));
     s->src  = av_malloc_array(s->temp_linesize, h * sizeof(*s->src) * 2);

     if (!s->temp || !s->src)

         return AVERROR(ENOMEM);
     return 0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     AVFilterContext *ctx = inlink->dst;

     SPPContext *s = ctx->priv;

     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *out = in;
     int qp_stride = 0;
     const int8_t *qp_table = NULL;

     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

     const int depth = desc->comp[0].depth;

 
     /* if we are not in a constant user quantizer mode and we don't want to use
      * the quantizers from the B-frames (B-frames often have a higher QP), we
      * need to save the qp table from the last non B-frame; this is what the
      * following code block does */

     if (!s->qp) {
         qp_table = av_frame_get_qp_table(in, &qp_stride, &s->qscale_type);

         if (qp_table && !s->use_bframe_qp && in->pict_type != AV_PICTURE_TYPE_B) {

             int w, h;
 
             /* if the qp stride is not set, it means the QP are only defined on
              * a line basis */
             if (!qp_stride) {

                 w = AV_CEIL_RSHIFT(inlink->w, 4);

                 h = 1;
             } else {

                 w = qp_stride;

                 h = AV_CEIL_RSHIFT(inlink->h, 4);

             }

             if (w * h > s->non_b_qp_alloc_size) {
                 int ret = av_reallocp_array(&s->non_b_qp_table, w, h);

                 if (ret < 0) {

                     s->non_b_qp_alloc_size = 0;

                     return ret;
                 }

                 s->non_b_qp_alloc_size = w * h;

             }
 

             av_assert0(w * h <= s->non_b_qp_alloc_size);
             memcpy(s->non_b_qp_table, qp_table, w * h);

         }
     }
 

     if (s->log2_count && !ctx->is_disabled) {
         if (!s->use_bframe_qp && s->non_b_qp_table)
             qp_table = s->non_b_qp_table;

         if (qp_table || s->qp) {

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

             filter(s, out->data[0], in->data[0], out->linesize[0], in->linesize[0], inlink->w, inlink->h, qp_table, qp_stride, 1, depth);

 
             if (out->data[2]) {

                 filter(s, out->data[1], in->data[1], out->linesize[1], in->linesize[1], cw,        ch,        qp_table, qp_stride, 0, depth);
                 filter(s, out->data[2], in->data[2], out->linesize[2], in->linesize[2], cw,        ch,        qp_table, qp_stride, 0, depth);

             }

             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 int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
                            char *res, int res_len, int flags)
 {

     SPPContext *s = ctx->priv;

 
     if (!strcmp(cmd, "level")) {
         if (!strcmp(args, "max"))

             s->log2_count = MAX_LEVEL;

         else

             s->log2_count = av_clip(strtol(args, NULL, 10), 0, MAX_LEVEL);

         return 0;
     }
     return AVERROR(ENOSYS);
 }
 

 static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)

 {

     SPPContext *s = ctx->priv;

     int ret;

     s->avctx = avcodec_alloc_context3(NULL);
     s->dct = avcodec_dct_alloc();
     if (!s->avctx || !s->dct)

         return AVERROR(ENOMEM);

 
     if (opts) {
         AVDictionaryEntry *e = NULL;
 
         while ((e = av_dict_get(*opts, "", e, AV_DICT_IGNORE_SUFFIX))) {

             if ((ret = av_opt_set(s->dct, e->key, e->value, 0)) < 0)

                 return ret;
         }
         av_dict_free(opts);
     }
 

     s->store_slice = store_slice_c;
     switch (s->mode) {
     case MODE_HARD: s->requantize = hardthresh_c; break;
     case MODE_SOFT: s->requantize = softthresh_c; break;

     }
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {

     SPPContext *s = ctx->priv;

     av_freep(&s->temp);
     av_freep(&s->src);
     if (s->avctx) {
         avcodec_close(s->avctx);
         av_freep(&s->avctx);

     }

     av_freep(&s->dct);
     av_freep(&s->non_b_qp_table);

 }
 
 static const AVFilterPad spp_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_input,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad spp_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter ff_vf_spp = {

     .name            = "spp",

     .description     = NULL_IF_CONFIG_SMALL("Apply a simple post processing filter."),

     .priv_size       = sizeof(SPPContext),

     .init_dict       = init_dict,

     .uninit          = uninit,
     .query_formats   = query_formats,
     .inputs          = spp_inputs,
     .outputs         = spp_outputs,
     .process_command = process_command,
     .priv_class      = &spp_class,
     .flags           = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
 };