/*
  * Copyright (c) 2016 Paul B Mahol
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg 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.
  *
  * 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser 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
  */
 
 #include "libavutil/attributes.h"
 #include "libavutil/common.h"
 #include "libavutil/eval.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
 #include "drawutils.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"

 #include "framesync.h"

 
 static const char *const var_names[] = {
     "w",        ///< width of the input video
     "h",        ///< height of the input video
     "x",        ///< input value for the pixel from input #1
     "y",        ///< input value for the pixel from input #2

     "bdx",      ///< input #1 video bitdepth
     "bdy",      ///< input #2 video bitdepth

     NULL
 };
 
 enum var_name {
     VAR_W,
     VAR_H,
     VAR_X,
     VAR_Y,

     VAR_BITDEPTHX,
     VAR_BITDEPTHY,

     VAR_VARS_NB
 };
 
 typedef struct LUT2Context {
     const AVClass *class;

     FFFrameSync fs;

 
     char   *comp_expr_str[4];
 
     AVExpr *comp_expr[4];
     double var_values[VAR_VARS_NB];
     uint16_t *lut[4];  ///< lookup table for each component
     int width[4], height[4];
     int nb_planes;
     int depth, depthx, depthy;

     int tlut2;
     AVFrame *prev_frame;        /* only used with tlut2 */

 
     void (*lut2)(struct LUT2Context *s, AVFrame *dst, AVFrame *srcx, AVFrame *srcy);
 
 } LUT2Context;
 
 #define OFFSET(x) offsetof(LUT2Context, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 

 static const AVOption options[] = {

     { "c0", "set component #0 expression", OFFSET(comp_expr_str[0]),  AV_OPT_TYPE_STRING, { .str = "x" }, .flags = FLAGS },
     { "c1", "set component #1 expression", OFFSET(comp_expr_str[1]),  AV_OPT_TYPE_STRING, { .str = "x" }, .flags = FLAGS },
     { "c2", "set component #2 expression", OFFSET(comp_expr_str[2]),  AV_OPT_TYPE_STRING, { .str = "x" }, .flags = FLAGS },
     { "c3", "set component #3 expression", OFFSET(comp_expr_str[3]),  AV_OPT_TYPE_STRING, { .str = "x" }, .flags = FLAGS },
     { NULL }
 };
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     LUT2Context *s = ctx->priv;
     int i;
 

     ff_framesync_uninit(&s->fs);

     av_frame_free(&s->prev_frame);
 

     for (i = 0; i < 4; i++) {
         av_expr_free(s->comp_expr[i]);
         s->comp_expr[i] = NULL;
         av_freep(&s->comp_expr_str[i]);
         av_freep(&s->lut[i]);
     }
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
         AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
         AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
         AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
         AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV440P12,
         AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
         AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
         AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
         AV_PIX_FMT_GBRP12,

         AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12,
         AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12,

         AV_PIX_FMT_NONE
     };
 
     return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
 }
 
 static int config_inputx(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     LUT2Context *s = ctx->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     int hsub = desc->log2_chroma_w;
     int vsub = desc->log2_chroma_h;
 
     s->nb_planes = av_pix_fmt_count_planes(inlink->format);
     s->height[1] = s->height[2] = AV_CEIL_RSHIFT(inlink->h, vsub);
     s->height[0] = s->height[3] = inlink->h;
     s->width[1]  = s->width[2]  = AV_CEIL_RSHIFT(inlink->w, hsub);
     s->width[0]  = s->width[3]  = inlink->w;
 
     s->var_values[VAR_W] = inlink->w;
     s->var_values[VAR_H] = inlink->h;
     s->depthx = desc->comp[0].depth;

     s->var_values[VAR_BITDEPTHX] = s->depthx;

     if (s->tlut2) {
         s->depthy = desc->comp[0].depth;
         s->var_values[VAR_BITDEPTHY] = s->depthy;
     }
 

     return 0;
 }
 
 static int config_inputy(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     LUT2Context *s = ctx->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
 
     s->depthy = desc->comp[0].depth;

     s->var_values[VAR_BITDEPTHY] = s->depthy;

 
     return 0;
 }
 
 static void lut2_8bit(struct LUT2Context *s, AVFrame *out, AVFrame *srcx, AVFrame *srcy)
 {
     int p, y, x;
 
     for (p = 0; p < s->nb_planes; p++) {
         const uint16_t *lut = s->lut[p];
         const uint8_t *srcxx, *srcyy;
         uint8_t *dst;
 
         dst   = out->data[p];
         srcxx = srcx->data[p];
         srcyy = srcy->data[p];
 
         for (y = 0; y < s->height[p]; y++) {
             for (x = 0; x < s->width[p]; x++) {
                 dst[x] = lut[(srcyy[x] << s->depthx) | srcxx[x]];
             }
 
             dst   += out->linesize[p];
             srcxx += srcx->linesize[p];
             srcyy += srcy->linesize[p];
         }
     }
 }
 
 static void lut2_16bit(struct LUT2Context *s, AVFrame *out, AVFrame *srcx, AVFrame *srcy)
 {
     int p, y, x;
 
     for (p = 0; p < s->nb_planes; p++) {
         const uint16_t *lut = s->lut[p];
         const uint16_t *srcxx, *srcyy;
         uint16_t *dst;
 
         dst   = (uint16_t *)out->data[p];
         srcxx = (uint16_t *)srcx->data[p];
         srcyy = (uint16_t *)srcy->data[p];
 
         for (y = 0; y < s->height[p]; y++) {
             for (x = 0; x < s->width[p]; x++) {
                 dst[x] = lut[(srcyy[x] << s->depthx) | srcxx[x]];
             }
 
             dst   += out->linesize[p]  / 2;
             srcxx += srcx->linesize[p] / 2;
             srcyy += srcy->linesize[p] / 2;
         }
     }
 }
 
 static int process_frame(FFFrameSync *fs)
 {
     AVFilterContext *ctx = fs->parent;
     LUT2Context *s = fs->opaque;
     AVFilterLink *outlink = ctx->outputs[0];

     AVFrame *out, *srcx = NULL, *srcy = NULL;

     int ret;
 

     if ((ret = ff_framesync_get_frame(&s->fs, 0, &srcx, 0)) < 0 ||
         (ret = ff_framesync_get_frame(&s->fs, 1, &srcy, 0)) < 0)

         return ret;
 

     if (ctx->is_disabled || !srcy) {

         out = av_frame_clone(srcx);
         if (!out)
             return AVERROR(ENOMEM);
     } else {
         out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!out)
             return AVERROR(ENOMEM);
         av_frame_copy_props(out, srcx);
 
         s->lut2(s, out, srcx, srcy);
     }
 
     out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, outlink->time_base);
 
     return ff_filter_frame(outlink, out);
 }
 
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     LUT2Context *s = ctx->priv;
     int p, ret;
 
     s->depth = s->depthx + s->depthy;
 

     s->lut2 = s->depth > 16 ? lut2_16bit : lut2_8bit;
 
     for (p = 0; p < s->nb_planes; p++) {
         s->lut[p] = av_malloc_array(1 << s->depth, sizeof(uint16_t));
         if (!s->lut[p])
             return AVERROR(ENOMEM);
     }
 
     for (p = 0; p < s->nb_planes; p++) {
         double res;
         int x, y;
 
         /* create the parsed expression */
         av_expr_free(s->comp_expr[p]);
         s->comp_expr[p] = NULL;
         ret = av_expr_parse(&s->comp_expr[p], s->comp_expr_str[p],
                             var_names, NULL, NULL, NULL, NULL, 0, ctx);
         if (ret < 0) {
             av_log(ctx, AV_LOG_ERROR,
                    "Error when parsing the expression '%s' for the component %d.\n",
                    s->comp_expr_str[p], p);
             return AVERROR(EINVAL);
         }
 
         /* compute the lut */
         for (y = 0; y < (1 << s->depthx); y++) {
             s->var_values[VAR_Y] = y;
             for (x = 0; x < (1 << s->depthx); x++) {
                 s->var_values[VAR_X] = x;
                 res = av_expr_eval(s->comp_expr[p], s->var_values, s);
                 if (isnan(res)) {
                     av_log(ctx, AV_LOG_ERROR,
                            "Error when evaluating the expression '%s' for the values %d and %d for the component %d.\n",
                            s->comp_expr_str[p], x, y, p);
                     return AVERROR(EINVAL);
                 }
 
                 s->lut[p][(y << s->depthx) + x] = res;
             }
         }
     }
 
     return 0;
 }
 
 static int lut2_config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     LUT2Context *s = ctx->priv;
     AVFilterLink *srcx = ctx->inputs[0];
     AVFilterLink *srcy = ctx->inputs[1];
     FFFrameSyncIn *in;
     int ret;
 

     if (srcx->format != srcy->format) {
         av_log(ctx, AV_LOG_ERROR, "inputs must be of same pixel format\n");
         return AVERROR(EINVAL);
     }

     if (srcx->w != srcy->w || srcx->h != srcy->h) {

         av_log(ctx, AV_LOG_ERROR, "First input link %s parameters "

                "(size %dx%d) do not match the corresponding "
                "second input link %s parameters (size %dx%d)\n",

                ctx->input_pads[0].name, srcx->w, srcx->h,
                ctx->input_pads[1].name,

                srcy->w, srcy->h);

         return AVERROR(EINVAL);
     }
 
     outlink->w = srcx->w;
     outlink->h = srcx->h;
     outlink->time_base = srcx->time_base;
     outlink->sample_aspect_ratio = srcx->sample_aspect_ratio;
     outlink->frame_rate = srcx->frame_rate;
 

     if ((ret = ff_framesync_init(&s->fs, ctx, 2)) < 0)

         return ret;
 
     in = s->fs.in;
     in[0].time_base = srcx->time_base;
     in[1].time_base = srcy->time_base;

     in[0].sync   = 2;

     in[0].before = EXT_STOP;
     in[0].after  = EXT_INFINITY;
     in[1].sync   = 1;
     in[1].before = EXT_STOP;
     in[1].after  = EXT_INFINITY;
     s->fs.opaque   = s;
     s->fs.on_event = process_frame;
 

     if ((ret = config_output(outlink)) < 0)
         return ret;

     return ff_framesync_configure(&s->fs);

 }
 

 static int activate(AVFilterContext *ctx)

 {

     LUT2Context *s = ctx->priv;

     return ff_framesync_activate(&s->fs);

 }
 
 static const AVFilterPad inputs[] = {
     {
         .name         = "srcx",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_inputx,
     },
     {
         .name         = "srcy",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_inputy,
     },
     { NULL }
 };
 
 static const AVFilterPad outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,

         .config_props  = lut2_config_output,

     },
     { NULL }
 };
 

 #define lut2_options options
 

 FRAMESYNC_DEFINE_CLASS(lut2, LUT2Context, fs);

 
 AVFilter ff_vf_lut2 = {
     .name          = "lut2",
     .description   = NULL_IF_CONFIG_SMALL("Compute and apply a lookup table from two video inputs."),

     .preinit       = lut2_framesync_preinit,

     .priv_size     = sizeof(LUT2Context),
     .priv_class    = &lut2_class,
     .uninit        = uninit,
     .query_formats = query_formats,

     .activate      = activate,

     .inputs        = inputs,
     .outputs       = outputs,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
 };

 
 #if CONFIG_TLUT2_FILTER
 
 static av_cold int init(AVFilterContext *ctx)
 {
     LUT2Context *s = ctx->priv;
 
     s->tlut2 = !strcmp(ctx->filter->name, "tlut2");
 
     return 0;
 }
 
 static int tlut2_filter_frame(AVFilterLink *inlink, AVFrame *frame)
 {
     LUT2Context *s = inlink->dst->priv;
     AVFilterLink *outlink = inlink->dst->outputs[0];
 
     if (s->prev_frame) {
         AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!out) {
             av_frame_free(&s->prev_frame);
             s->prev_frame = frame;
             return AVERROR(ENOMEM);
         }
         av_frame_copy_props(out, frame);
         s->lut2(s, out, frame, s->prev_frame);
         av_frame_free(&s->prev_frame);
         s->prev_frame = frame;
         return ff_filter_frame(outlink, out);
     }
     s->prev_frame = frame;
     return 0;
 }
 
 #define tlut2_options options
 
 AVFILTER_DEFINE_CLASS(tlut2);
 
 static const AVFilterPad tlut2_inputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .filter_frame  = tlut2_filter_frame,
         .config_props  = config_inputx,
     },
     { NULL }
 };
 
 static const AVFilterPad tlut2_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = config_output,
     },
     { NULL }
 };
 
 AVFilter ff_vf_tlut2 = {
     .name          = "tlut2",
     .description   = NULL_IF_CONFIG_SMALL("Compute and apply a lookup table from two successive frames."),
     .priv_size     = sizeof(LUT2Context),
     .priv_class    = &tlut2_class,
     .query_formats = query_formats,
     .init          = init,
     .uninit        = uninit,
     .inputs        = tlut2_inputs,
     .outputs       = tlut2_outputs,
 };
 
 #endif