/*
  * Copyright (c) 2017 Ronald S. Bultje <rsbultje@gmail.com>
  * Copyright (c) 2017 Ashish Pratap Singh <ashk43712@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 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
  */
 
 /**
  * @file
  * Calculate VMAF Motion score.
  */
 
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
 #include "drawutils.h"
 #include "formats.h"
 #include "internal.h"
 #include "vmaf_motion.h"
 
 #define BIT_SHIFT 15
 
 static const float FILTER_5[5] = {
     0.054488685,
     0.244201342,
     0.402619947,
     0.244201342,
     0.054488685
 };
 
 typedef struct VMAFMotionContext {
     const AVClass *class;
     VMAFMotionData data;
     FILE *stats_file;
     char *stats_file_str;
 } VMAFMotionContext;
 
 #define OFFSET(x) offsetof(VMAFMotionContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption vmafmotion_options[] = {
     {"stats_file", "Set file where to store per-frame difference information", OFFSET(stats_file_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(vmafmotion);
 
 static uint64_t image_sad(const uint16_t *img1, const uint16_t *img2, int w,
                           int h, ptrdiff_t _img1_stride, ptrdiff_t _img2_stride)
 {
     ptrdiff_t img1_stride = _img1_stride / sizeof(*img1);
     ptrdiff_t img2_stride = _img2_stride / sizeof(*img2);
     uint64_t sum = 0;
     int i, j;
 
     for (i = 0; i < h; i++) {
         for (j = 0; j < w; j++) {
             sum += abs(img1[j] - img2[j]);
         }
         img1 += img1_stride;
         img2 += img2_stride;
     }
 
     return sum;
 }
 
 static void convolution_x(const uint16_t *filter, int filt_w, const uint16_t *src,
                           uint16_t *dst, int w, int h, ptrdiff_t _src_stride,
                           ptrdiff_t _dst_stride)
 {
     ptrdiff_t src_stride = _src_stride / sizeof(*src);
     ptrdiff_t dst_stride = _dst_stride / sizeof(*dst);
     int radius = filt_w / 2;
     int borders_left = radius;
     int borders_right = w - (filt_w - radius);
     int i, j, k;
     int sum = 0;
 
     for (i = 0; i < h; i++) {
         for (j = 0; j < borders_left; j++) {
             sum = 0;
             for (k = 0; k < filt_w; k++) {
                 int j_tap = FFABS(j - radius + k);
                 if (j_tap >= w) {
                     j_tap = w - (j_tap - w + 1);
                 }
                 sum += filter[k] * src[i * src_stride + j_tap];
             }
             dst[i * dst_stride + j] = sum >> BIT_SHIFT;
         }
 
         for (j = borders_left; j < borders_right; j++) {
             int sum = 0;
             for (k = 0; k < filt_w; k++) {
                 sum += filter[k] * src[i * src_stride + j - radius + k];
             }
             dst[i * dst_stride + j] = sum >> BIT_SHIFT;
         }
 
         for (j = borders_right; j < w; j++) {
             sum = 0;
             for (k = 0; k < filt_w; k++) {
                 int j_tap = FFABS(j - radius + k);
                 if (j_tap >= w) {
                     j_tap = w - (j_tap - w + 1);
                 }
                 sum += filter[k] * src[i * src_stride + j_tap];
             }
             dst[i * dst_stride + j] = sum >> BIT_SHIFT;
         }
     }
 }
 
 #define conv_y_fn(type, bits) \
 static void convolution_y_##bits##bit(const uint16_t *filter, int filt_w, \
                                       const uint8_t *_src, uint16_t *dst, \
                                       int w, int h, ptrdiff_t _src_stride, \
                                       ptrdiff_t _dst_stride) \
 { \
     const type *src = (const type *) _src; \
     ptrdiff_t src_stride = _src_stride / sizeof(*src); \
     ptrdiff_t dst_stride = _dst_stride / sizeof(*dst); \
     int radius = filt_w / 2; \
     int borders_top = radius; \
     int borders_bottom = h - (filt_w - radius); \
     int i, j, k; \
     int sum = 0; \
     \
     for (i = 0; i < borders_top; i++) { \
         for (j = 0; j < w; j++) { \
             sum = 0; \
             for (k = 0; k < filt_w; k++) { \
                 int i_tap = FFABS(i - radius + k); \
                 if (i_tap >= h) { \
                     i_tap = h - (i_tap - h + 1); \
                 } \
                 sum += filter[k] * src[i_tap * src_stride + j]; \
             } \
             dst[i * dst_stride + j] = sum >> bits; \
         } \
     } \
     for (i = borders_top; i < borders_bottom; i++) { \
         for (j = 0; j < w; j++) { \
             sum = 0; \
             for (k = 0; k < filt_w; k++) { \
                 sum += filter[k] * src[(i - radius + k) * src_stride + j]; \
             } \
             dst[i * dst_stride + j] = sum >> bits; \
         } \
     } \
     for (i = borders_bottom; i < h; i++) { \
         for (j = 0; j < w; j++) { \
             sum = 0; \
             for (k = 0; k < filt_w; k++) { \
                 int i_tap = FFABS(i - radius + k); \
                 if (i_tap >= h) { \
                     i_tap = h - (i_tap - h + 1); \
                 } \
                 sum += filter[k] * src[i_tap * src_stride + j]; \
             } \
             dst[i * dst_stride + j] = sum >> bits; \
         } \
     } \
 }
 
 conv_y_fn(uint8_t, 8);
 conv_y_fn(uint16_t, 10);
 
 static void vmafmotiondsp_init(VMAFMotionDSPContext *dsp, int bpp) {
     dsp->convolution_x = convolution_x;
     dsp->convolution_y = bpp == 10 ? convolution_y_10bit : convolution_y_8bit;
     dsp->sad = image_sad;
 }
 
 double ff_vmafmotion_process(VMAFMotionData *s, AVFrame *ref)
 {
     double score;
 
     s->vmafdsp.convolution_y(s->filter, 5, ref->data[0], s->temp_data,
                              s->width, s->height, ref->linesize[0], s->stride);
     s->vmafdsp.convolution_x(s->filter, 5, s->temp_data, s->blur_data[0],
                              s->width, s->height, s->stride, s->stride);
 
     if (!s->nb_frames) {
         score = 0.0;
     } else {
         uint64_t sad = s->vmafdsp.sad(s->blur_data[1], s->blur_data[0],
                                       s->width, s->height, s->stride, s->stride);
         // the output score is always normalized to 8 bits
         score = (double) (sad * 1.0 / (s->width * s->height << (BIT_SHIFT - 8)));
     }
 
     FFSWAP(uint16_t *, s->blur_data[0], s->blur_data[1]);
     s->nb_frames++;
     s->motion_sum += score;
 
     return score;
 }
 
 static void set_meta(AVDictionary **metadata, const char *key, float d)
 {
     char value[128];
     snprintf(value, sizeof(value), "%0.2f", d);
     av_dict_set(metadata, key, value, 0);
 }
 
 static void do_vmafmotion(AVFilterContext *ctx, AVFrame *ref)
 {
     VMAFMotionContext *s = ctx->priv;
     double score;
 
     score = ff_vmafmotion_process(&s->data, ref);
     set_meta(&ref->metadata, "lavfi.vmafmotion.score", score);
     if (s->stats_file) {
         fprintf(s->stats_file,
                 "n:%"PRId64" motion:%0.2lf\n", s->data.nb_frames, score);
     }
 }
 
 
 int ff_vmafmotion_init(VMAFMotionData *s,
                        int w, int h, enum AVPixelFormat fmt)
 {
     size_t data_sz;
     int i;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
 
     s->width = w;
     s->height = h;
     s->stride = FFALIGN(w * sizeof(uint16_t), 32);
 
     data_sz = (size_t) s->stride * h;
     if (!(s->blur_data[0] = av_malloc(data_sz)) ||
         !(s->blur_data[1] = av_malloc(data_sz)) ||
         !(s->temp_data    = av_malloc(data_sz))) {
         return AVERROR(ENOMEM);
     }
 
     for (i = 0; i < 5; i++) {
         s->filter[i] = lrint(FILTER_5[i] * (1 << BIT_SHIFT));
     }
 
     vmafmotiondsp_init(&s->vmafdsp, desc->comp[0].depth);
 
     return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {

     AVFilterFormats *fmts_list = NULL;
     int format, ret;
 
     for (format = 0; av_pix_fmt_desc_get(format); format++) {
         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(format);
         if (!(desc->flags & (AV_PIX_FMT_FLAG_RGB | AV_PIX_FMT_FLAG_HWACCEL | AV_PIX_FMT_FLAG_BITSTREAM | AV_PIX_FMT_FLAG_PAL)) &&
             (desc->flags & AV_PIX_FMT_FLAG_PLANAR || desc->nb_components == 1) &&
             (!(desc->flags & AV_PIX_FMT_FLAG_BE) == !HAVE_BIGENDIAN || desc->comp[0].depth == 8) &&
             (desc->comp[0].depth == 8 || desc->comp[0].depth == 10) &&
             (ret = ff_add_format(&fmts_list, format)) < 0)
             return ret;
     }
 

     return ff_set_common_formats(ctx, fmts_list);
 }
 
 static int config_input_ref(AVFilterLink *inlink)
 {
     AVFilterContext *ctx  = inlink->dst;
     VMAFMotionContext *s = ctx->priv;
 
     return ff_vmafmotion_init(&s->data, ctx->inputs[0]->w,
                               ctx->inputs[0]->h, ctx->inputs[0]->format);
 }
 
 double ff_vmafmotion_uninit(VMAFMotionData *s)
 {
     av_free(s->blur_data[0]);
     av_free(s->blur_data[1]);
     av_free(s->temp_data);
 
     return s->nb_frames > 0 ? s->motion_sum / s->nb_frames : 0.0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *ref)
 {
     AVFilterContext *ctx = inlink->dst;
     do_vmafmotion(ctx, ref);
     return ff_filter_frame(ctx->outputs[0], ref);
 }
 
 static av_cold int init(AVFilterContext *ctx)
 {
     VMAFMotionContext *s = ctx->priv;
 
     if (s->stats_file_str) {
         if (!strcmp(s->stats_file_str, "-")) {
             s->stats_file = stdout;
         } else {
             s->stats_file = fopen(s->stats_file_str, "w");
             if (!s->stats_file) {
                 int err = AVERROR(errno);
                 char buf[128];
                 av_strerror(err, buf, sizeof(buf));
                 av_log(ctx, AV_LOG_ERROR, "Could not open stats file %s: %s\n",
                        s->stats_file_str, buf);
                 return err;
             }
         }
     }
 
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     VMAFMotionContext *s = ctx->priv;
     double avg_motion = ff_vmafmotion_uninit(&s->data);
 
     if (s->data.nb_frames > 0) {
         av_log(ctx, AV_LOG_INFO, "VMAF Motion avg: %.3f\n", avg_motion);
     }
 
     if (s->stats_file && s->stats_file != stdout)
         fclose(s->stats_file);
 }
 
 static const AVFilterPad vmafmotion_inputs[] = {
     {
         .name         = "reference",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
         .config_props = config_input_ref,
     },
     { NULL }
 };
 
 static const AVFilterPad vmafmotion_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 
 AVFilter ff_vf_vmafmotion = {
     .name          = "vmafmotion",
     .description   = NULL_IF_CONFIG_SMALL("Calculate the VMAF Motion score."),
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
     .priv_size     = sizeof(VMAFMotionContext),
     .priv_class    = &vmafmotion_class,
     .inputs        = vmafmotion_inputs,
     .outputs       = vmafmotion_outputs,
 };