/*
  * Copyright (C) 2006-2010 Michael Niedermayer <michaelni@gmx.at>

  *               2010      James Darnley <james.darnley@gmail.com>

  *
  * 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.
  */
 
 #include "libavutil/cpu.h"
 #include "libavutil/common.h"

 #include "libavutil/pixdesc.h"

 #include "avfilter.h"
 #include "yadif.h"
 
 #undef NDEBUG
 #include <assert.h>
 
 typedef struct {
     /**
      * 0: send 1 frame for each frame
      * 1: send 1 frame for each field
      * 2: like 0 but skips spatial interlacing check
      * 3: like 1 but skips spatial interlacing check
      */
     int mode;
 
     /**
      *  0: bottom field first
      *  1: top field first
      * -1: auto-detection
      */
     int parity;
 
     int frame_pending;
 
     AVFilterBufferRef *cur;
     AVFilterBufferRef *next;
     AVFilterBufferRef *prev;
     AVFilterBufferRef *out;
     void (*filter_line)(uint8_t *dst,
                         uint8_t *prev, uint8_t *cur, uint8_t *next,

                         int w, int prefs, int mrefs, int parity, int mode);

 
     const AVPixFmtDescriptor *csp;

 } YADIFContext;
 
 #define CHECK(j)\

     {   int score = FFABS(cur[mrefs-1+(j)] - cur[prefs-1-(j)])\
                   + FFABS(cur[mrefs  +(j)] - cur[prefs  -(j)])\
                   + FFABS(cur[mrefs+1+(j)] - cur[prefs+1-(j)]);\

         if (score < spatial_score) {\
             spatial_score= score;\

             spatial_pred= (cur[mrefs  +(j)] + cur[prefs  -(j)])>>1;\

 #define FILTER \
     for (x = 0;  x < w; x++) { \
         int c = cur[mrefs]; \
         int d = (prev2[0] + next2[0])>>1; \
         int e = cur[prefs]; \
         int temporal_diff0 = FFABS(prev2[0] - next2[0]); \
         int temporal_diff1 =(FFABS(prev[mrefs] - c) + FFABS(prev[prefs] - e) )>>1; \
         int temporal_diff2 =(FFABS(next[mrefs] - c) + FFABS(next[prefs] - e) )>>1; \
         int diff = FFMAX3(temporal_diff0>>1, temporal_diff1, temporal_diff2); \
         int spatial_pred = (c+e)>>1; \
         int spatial_score = FFABS(cur[mrefs-1] - cur[prefs-1]) + FFABS(c-e) \
                           + FFABS(cur[mrefs+1] - cur[prefs+1]) - 1; \
  \
         CHECK(-1) CHECK(-2) }} }} \
         CHECK( 1) CHECK( 2) }} }} \
  \
         if (mode < 2) { \
             int b = (prev2[2*mrefs] + next2[2*mrefs])>>1; \
             int f = (prev2[2*prefs] + next2[2*prefs])>>1; \
             int max = FFMAX3(d-e, d-c, FFMIN(b-c, f-e)); \
             int min = FFMIN3(d-e, d-c, FFMAX(b-c, f-e)); \
  \
             diff = FFMAX3(diff, min, -max); \
         } \
  \
         if (spatial_pred > d + diff) \
            spatial_pred = d + diff; \
         else if (spatial_pred < d - diff) \
            spatial_pred = d - diff; \
  \
         dst[0] = spatial_pred; \
  \
         dst++; \
         cur++; \
         prev++; \
         next++; \
         prev2++; \
         next2++; \
     }

 static void filter_line_c(uint8_t *dst,
                           uint8_t *prev, uint8_t *cur, uint8_t *next,
                           int w, int prefs, int mrefs, int parity, int mode)
 {
     int x;
     uint8_t *prev2 = parity ? prev : cur ;
     uint8_t *next2 = parity ? cur  : next;

     FILTER

 }
 

 static void filter_line_c_16bit(uint16_t *dst,
                                 uint16_t *prev, uint16_t *cur, uint16_t *next,

                                 int w, int prefs, int mrefs, int parity, int mode)

 {
     int x;
     uint16_t *prev2 = parity ? prev : cur ;
     uint16_t *next2 = parity ? cur  : next;

     mrefs /= 2;
     prefs /= 2;

     FILTER

 }
 

 static void filter(AVFilterContext *ctx, AVFilterBufferRef *dstpic,
                    int parity, int tff)
 {
     YADIFContext *yadif = ctx->priv;
     int y, i;
 

     for (i = 0; i < yadif->csp->nb_components; i++) {
         int w = dstpic->video->w;
         int h = dstpic->video->h;

         int refs = yadif->cur->linesize[i];

         int df = (yadif->csp->comp[i].depth_minus1+1) / 8;

         if (i) {
         /* Why is this not part of the per-plane description thing? */
             w >>= yadif->csp->log2_chroma_w;
             h >>= yadif->csp->log2_chroma_h;
         }
 

         for (y = 0; y < h; y++) {
             if ((y ^ parity) & 1) {
                 uint8_t *prev = &yadif->prev->data[i][y*refs];
                 uint8_t *cur  = &yadif->cur ->data[i][y*refs];
                 uint8_t *next = &yadif->next->data[i][y*refs];
                 uint8_t *dst  = &dstpic->data[i][y*dstpic->linesize[i]];

                 int     mode  = y==1 || y+2==h ? 2 : yadif->mode;
                 yadif->filter_line(dst, prev, cur, next, w, y+1<h ? refs : -refs, y ? -refs : refs, parity ^ tff, mode);

             } else {
                 memcpy(&dstpic->data[i][y*dstpic->linesize[i]],

                        &yadif->cur->data[i][y*refs], w*df);

             }
         }
     }
 #if HAVE_MMX
     __asm__ volatile("emms \n\t" : : : "memory");
 #endif
 }
 
 static AVFilterBufferRef *get_video_buffer(AVFilterLink *link, int perms, int w, int h)
 {
     AVFilterBufferRef *picref;
     int width = FFALIGN(w, 32);

     int height= FFALIGN(h+2, 32);

     int i;
 
     picref = avfilter_default_get_video_buffer(link, perms, width, height);
 
     picref->video->w = w;
     picref->video->h = h;
 
     for (i = 0; i < 3; i++)

         picref->data[i] += picref->linesize[i];

 
     return picref;
 }
 

 static void return_frame(AVFilterContext *ctx, int is_second)
 {

     YADIFContext *yadif = ctx->priv;
     AVFilterLink *link= ctx->outputs[0];

     int tff;
 
     if (yadif->parity == -1) {
         tff = yadif->cur->video->interlaced ?
             yadif->cur->video->top_field_first : 1;
     } else {
         tff = yadif->parity^1;
     }

     if (is_second)

         yadif->out = avfilter_get_video_buffer(link, AV_PERM_WRITE | AV_PERM_PRESERVE |

                                                AV_PERM_REUSE, link->w, link->h);

     if (!yadif->csp)
         yadif->csp = &av_pix_fmt_descriptors[link->format];

     if (yadif->csp->comp[0].depth_minus1 == 15)
         yadif->filter_line = filter_line_c_16bit;

     filter(ctx, yadif->out, tff ^ !is_second, tff);
 

     if (is_second) {
         if (yadif->next->pts != AV_NOPTS_VALUE &&
             yadif->cur->pts != AV_NOPTS_VALUE) {
             yadif->out->pts =
                 (yadif->next->pts&yadif->cur->pts) +
                 ((yadif->next->pts^yadif->cur->pts)>>1);
         } else {
             yadif->out->pts = AV_NOPTS_VALUE;
         }

         avfilter_start_frame(ctx->outputs[0], yadif->out);

     }

     avfilter_draw_slice(ctx->outputs[0], 0, link->h, 1);
     avfilter_end_frame(ctx->outputs[0]);
 

     yadif->frame_pending = (yadif->mode&1) && !is_second;

 }
 
 static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
 {
     AVFilterContext *ctx = link->dst;
     YADIFContext *yadif = ctx->priv;
 

     if (yadif->frame_pending)

         return_frame(ctx, 1);
 
     if (yadif->prev)
         avfilter_unref_buffer(yadif->prev);
     yadif->prev = yadif->cur;
     yadif->cur  = yadif->next;
     yadif->next = picref;
 

     if (!yadif->cur)

         return;
 

     if (!yadif->prev)
         yadif->prev = avfilter_ref_buffer(yadif->cur, AV_PERM_READ);
 

     yadif->out = avfilter_get_video_buffer(ctx->outputs[0], AV_PERM_WRITE | AV_PERM_PRESERVE |
                                        AV_PERM_REUSE, link->w, link->h);
 

     avfilter_copy_buffer_ref_props(yadif->out, yadif->cur);
     yadif->out->video->interlaced = 0;

     avfilter_start_frame(ctx->outputs[0], yadif->out);
 }
 
 static void end_frame(AVFilterLink *link)
 {
     AVFilterContext *ctx = link->dst;
     YADIFContext *yadif = ctx->priv;
 

     if (!yadif->out)

         return;
 
     return_frame(ctx, 0);
 }
 
 static int request_frame(AVFilterLink *link)
 {
     AVFilterContext *ctx = link->src;
     YADIFContext *yadif = ctx->priv;
 

     if (yadif->frame_pending) {

         return_frame(ctx, 1);
         return 0;
     }
 

     do {

         int ret;
 
         if ((ret = avfilter_request_frame(link->src->inputs[0])))
             return ret;

     } while (!yadif->cur);

 
     return 0;
 }
 
 static int poll_frame(AVFilterLink *link)
 {
     YADIFContext *yadif = link->src->priv;
     int ret, val;
 

     if (yadif->frame_pending)

         return 1;
 

     val = avfilter_poll_frame(link->src->inputs[0]);

     if (val==1 && !yadif->next) { //FIXME change API to not requre this red tape

         if ((ret = avfilter_request_frame(link->src->inputs[0])) < 0)
             return ret;
         val = avfilter_poll_frame(link->src->inputs[0]);
     }

     assert(yadif->next || !val);

 
     return val * ((yadif->mode&1)+1);
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     YADIFContext *yadif = ctx->priv;
 
     if (yadif->prev) avfilter_unref_buffer(yadif->prev);
     if (yadif->cur ) avfilter_unref_buffer(yadif->cur );
     if (yadif->next) avfilter_unref_buffer(yadif->next);
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum PixelFormat pix_fmts[] = {
         PIX_FMT_YUV420P,

         PIX_FMT_YUV422P,
         PIX_FMT_YUV444P,
         PIX_FMT_YUV410P,
         PIX_FMT_YUV411P,

         PIX_FMT_GRAY8,

         PIX_FMT_YUVJ420P,
         PIX_FMT_YUVJ422P,
         PIX_FMT_YUVJ444P,

         AV_NE( PIX_FMT_GRAY16BE, PIX_FMT_GRAY16LE ),

         PIX_FMT_YUV440P,
         PIX_FMT_YUVJ440P,

         AV_NE( PIX_FMT_YUV420P16BE, PIX_FMT_YUV420P16LE ),
         AV_NE( PIX_FMT_YUV422P16BE, PIX_FMT_YUV422P16LE ),
         AV_NE( PIX_FMT_YUV444P16BE, PIX_FMT_YUV444P16LE ),

         PIX_FMT_NONE
     };
 

     avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));

 
     return 0;
 }
 
 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     YADIFContext *yadif = ctx->priv;
     av_unused int cpu_flags = av_get_cpu_flags();
 
     yadif->mode = 0;
     yadif->parity = -1;

     yadif->csp = NULL;

 
     if (args) sscanf(args, "%d:%d", &yadif->mode, &yadif->parity);
 
     yadif->filter_line = filter_line_c;

     if (HAVE_SSSE3 && cpu_flags & AV_CPU_FLAG_SSSE3)
         yadif->filter_line = ff_yadif_filter_line_ssse3;
     else if (HAVE_SSE && cpu_flags & AV_CPU_FLAG_SSE2)
         yadif->filter_line = ff_yadif_filter_line_sse2;
     else if (HAVE_MMX && cpu_flags & AV_CPU_FLAG_MMX)

         yadif->filter_line = ff_yadif_filter_line_mmx;
 
     av_log(ctx, AV_LOG_INFO, "mode:%d parity:%d\n", yadif->mode, yadif->parity);
 
     return 0;
 }
 
 static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
 
 AVFilter avfilter_vf_yadif = {
     .name          = "yadif",
     .description   = NULL_IF_CONFIG_SMALL("Deinterlace the input image"),
 
     .priv_size     = sizeof(YADIFContext),
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
 
     .inputs    = (AVFilterPad[]) {{ .name             = "default",
                                     .type             = AVMEDIA_TYPE_VIDEO,
                                     .start_frame      = start_frame,
                                     .get_video_buffer = get_video_buffer,
                                     .draw_slice       = null_draw_slice,
                                     .end_frame        = end_frame, },
                                   { .name = NULL}},
 
     .outputs   = (AVFilterPad[]) {{ .name             = "default",
                                     .type             = AVMEDIA_TYPE_VIDEO,
                                     .poll_frame       = poll_frame,
                                     .request_frame    = request_frame, },
                                   { .name = NULL}},
 };