/*
  * 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/imgutils.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/opt.h"
 #include "avfilter.h"

 #include "filters.h"

 #include "formats.h"

 #include "framesync.h"

 #include "internal.h"
 #include "video.h"
 
 typedef struct PreMultiplyContext {
     const AVClass *class;
     int width[4], height[4];

     int linesize[4];

     int nb_planes;
     int planes;

     int inverse;

     int inplace;

     int half, depth, offset, max;

     FFFrameSync fs;
 
     void (*premultiply[4])(const uint8_t *msrc, const uint8_t *asrc,
                            uint8_t *dst,
                            ptrdiff_t mlinesize, ptrdiff_t alinesize,
                            ptrdiff_t dlinesize,
                            int w, int h,
                            int half, int shift, int offset);
 } PreMultiplyContext;
 
 #define OFFSET(x) offsetof(PreMultiplyContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 

 static const AVOption options[] = {

     { "planes", "set planes", OFFSET(planes), AV_OPT_TYPE_INT, {.i64=0xF}, 0, 0xF, FLAGS },

     { "inplace","enable inplace mode", OFFSET(inplace), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },

     { NULL }
 };
 

 #define premultiply_options options

 AVFILTER_DEFINE_CLASS(premultiply);
 
 static int query_formats(AVFilterContext *ctx)
 {

     PreMultiplyContext *s = ctx->priv;
 
     static const enum AVPixelFormat no_alpha_pix_fmts[] = {

         AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
         AV_PIX_FMT_YUV444P9, AV_PIX_FMT_YUV444P10,
         AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV444P14,
         AV_PIX_FMT_YUV444P16,
         AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
         AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,

         AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY16,

         AV_PIX_FMT_NONE
     };
 

     static const enum AVPixelFormat alpha_pix_fmts[] = {
         AV_PIX_FMT_YUVA444P,
         AV_PIX_FMT_YUVA444P9, AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P16,
         AV_PIX_FMT_GBRAP,
         AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
         AV_PIX_FMT_NONE
     };
 
     return ff_set_common_formats(ctx, ff_make_format_list(s->inplace ? alpha_pix_fmts : no_alpha_pix_fmts));

 }
 
 static void premultiply8(const uint8_t *msrc, const uint8_t *asrc,
                          uint8_t *dst,
                          ptrdiff_t mlinesize, ptrdiff_t alinesize,
                          ptrdiff_t dlinesize,
                          int w, int h,
                          int half, int shift, int offset)
 {
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             dst[x] = ((msrc[x] * (((asrc[x] >> 1) & 1) + asrc[x])) + 128) >> 8;
         }
 
         dst  += dlinesize;
         msrc += mlinesize;
         asrc += alinesize;
     }
 }
 
 static void premultiply8yuv(const uint8_t *msrc, const uint8_t *asrc,
                             uint8_t *dst,
                             ptrdiff_t mlinesize, ptrdiff_t alinesize,
                             ptrdiff_t dlinesize,
                             int w, int h,
                             int half, int shift, int offset)
 {
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {

             dst[x] = ((((msrc[x] - 128) * (((asrc[x] >> 1) & 1) + asrc[x]))) >> 8) + 128;

         }
 
         dst  += dlinesize;
         msrc += mlinesize;
         asrc += alinesize;
     }
 }
 
 static void premultiply8offset(const uint8_t *msrc, const uint8_t *asrc,
                                uint8_t *dst,
                                ptrdiff_t mlinesize, ptrdiff_t alinesize,
                                ptrdiff_t dlinesize,
                                int w, int h,
                                int half, int shift, int offset)
 {
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             dst[x] = ((((msrc[x] - offset) * (((asrc[x] >> 1) & 1) + asrc[x])) + 128) >> 8) + offset;
         }
 
         dst  += dlinesize;
         msrc += mlinesize;
         asrc += alinesize;
     }
 }
 
 static void premultiply16(const uint8_t *mmsrc, const uint8_t *aasrc,
                           uint8_t *ddst,
                           ptrdiff_t mlinesize, ptrdiff_t alinesize,
                           ptrdiff_t dlinesize,
                           int w, int h,
                           int half, int shift, int offset)
 {
     const uint16_t *msrc = (const uint16_t *)mmsrc;
     const uint16_t *asrc = (const uint16_t *)aasrc;
     uint16_t *dst = (uint16_t *)ddst;
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             dst[x] = ((msrc[x] * (((asrc[x] >> 1) & 1) + asrc[x])) + half) >> shift;
         }
 
         dst  += dlinesize / 2;
         msrc += mlinesize / 2;
         asrc += alinesize / 2;
     }
 }
 
 static void premultiply16yuv(const uint8_t *mmsrc, const uint8_t *aasrc,
                              uint8_t *ddst,
                              ptrdiff_t mlinesize, ptrdiff_t alinesize,
                              ptrdiff_t dlinesize,
                              int w, int h,
                              int half, int shift, int offset)
 {
     const uint16_t *msrc = (const uint16_t *)mmsrc;
     const uint16_t *asrc = (const uint16_t *)aasrc;
     uint16_t *dst = (uint16_t *)ddst;
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {

             dst[x] = ((((msrc[x] - half) * (((asrc[x] >> 1) & 1) + asrc[x]))) >> shift) + half;

         }
 
         dst  += dlinesize / 2;
         msrc += mlinesize / 2;
         asrc += alinesize / 2;
     }
 }
 
 static void premultiply16offset(const uint8_t *mmsrc, const uint8_t *aasrc,
                                 uint8_t *ddst,
                                 ptrdiff_t mlinesize, ptrdiff_t alinesize,
                                 ptrdiff_t dlinesize,
                                 int w, int h,
                                 int half, int shift, int offset)
 {
     const uint16_t *msrc = (const uint16_t *)mmsrc;
     const uint16_t *asrc = (const uint16_t *)aasrc;
     uint16_t *dst = (uint16_t *)ddst;
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             dst[x] = ((((msrc[x] - offset) * (((asrc[x] >> 1) & 1) + asrc[x])) + half) >> shift) + offset;
         }
 
         dst  += dlinesize / 2;
         msrc += mlinesize / 2;
         asrc += alinesize / 2;
     }
 }
 

 static void unpremultiply8(const uint8_t *msrc, const uint8_t *asrc,
                            uint8_t *dst,
                            ptrdiff_t mlinesize, ptrdiff_t alinesize,
                            ptrdiff_t dlinesize,
                            int w, int h,
                            int half, int max, int offset)
 {
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             if (asrc[x] > 0 && asrc[x] < 255)
                 dst[x] = FFMIN(msrc[x] * 255 / asrc[x], 255);
             else
                 dst[x] = msrc[x];
         }
 
         dst  += dlinesize;
         msrc += mlinesize;
         asrc += alinesize;
     }
 }
 
 static void unpremultiply8yuv(const uint8_t *msrc, const uint8_t *asrc,
                               uint8_t *dst,
                               ptrdiff_t mlinesize, ptrdiff_t alinesize,
                               ptrdiff_t dlinesize,
                               int w, int h,
                               int half, int max, int offset)
 {
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             if (asrc[x] > 0 && asrc[x] < 255)
                 dst[x] = FFMIN((msrc[x] - 128) * 255 / asrc[x] + 128, 255);
             else
                 dst[x] = msrc[x];
         }
 
         dst  += dlinesize;
         msrc += mlinesize;
         asrc += alinesize;
     }
 }
 
 static void unpremultiply8offset(const uint8_t *msrc, const uint8_t *asrc,
                                  uint8_t *dst,
                                  ptrdiff_t mlinesize, ptrdiff_t alinesize,
                                  ptrdiff_t dlinesize,
                                  int w, int h,
                                  int half, int max, int offset)
 {
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             if (asrc[x] > 0 && asrc[x] < 255)

                 dst[x] = FFMIN(FFMAX(msrc[x] - offset, 0) * 255 / asrc[x] + offset, 255);

             else
                 dst[x] = msrc[x];
         }
 
         dst  += dlinesize;
         msrc += mlinesize;
         asrc += alinesize;
     }
 }
 
 static void unpremultiply16(const uint8_t *mmsrc, const uint8_t *aasrc,
                             uint8_t *ddst,
                             ptrdiff_t mlinesize, ptrdiff_t alinesize,
                             ptrdiff_t dlinesize,
                             int w, int h,
                             int half, int max, int offset)
 {
     const uint16_t *msrc = (const uint16_t *)mmsrc;
     const uint16_t *asrc = (const uint16_t *)aasrc;
     uint16_t *dst = (uint16_t *)ddst;
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             if (asrc[x] > 0 && asrc[x] < max)
                 dst[x] = FFMIN(msrc[x] * (unsigned)max / asrc[x], max);
             else
                 dst[x] = msrc[x];
         }
 
         dst  += dlinesize / 2;
         msrc += mlinesize / 2;
         asrc += alinesize / 2;
     }
 }
 
 static void unpremultiply16yuv(const uint8_t *mmsrc, const uint8_t *aasrc,
                                uint8_t *ddst,
                                ptrdiff_t mlinesize, ptrdiff_t alinesize,
                                ptrdiff_t dlinesize,
                                int w, int h,
                                int half, int max, int offset)
 {
     const uint16_t *msrc = (const uint16_t *)mmsrc;
     const uint16_t *asrc = (const uint16_t *)aasrc;
     uint16_t *dst = (uint16_t *)ddst;
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             if (asrc[x] > 0 && asrc[x] < max)
                 dst[x] = FFMAX(FFMIN((msrc[x] - half) * max / asrc[x], half - 1), -half) + half;
             else
                 dst[x] = msrc[x];
         }
 
         dst  += dlinesize / 2;
         msrc += mlinesize / 2;
         asrc += alinesize / 2;
     }
 }
 
 static void unpremultiply16offset(const uint8_t *mmsrc, const uint8_t *aasrc,
                                   uint8_t *ddst,
                                   ptrdiff_t mlinesize, ptrdiff_t alinesize,
                                   ptrdiff_t dlinesize,
                                   int w, int h,
                                   int half, int max, int offset)
 {
     const uint16_t *msrc = (const uint16_t *)mmsrc;
     const uint16_t *asrc = (const uint16_t *)aasrc;
     uint16_t *dst = (uint16_t *)ddst;
     int x, y;
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             if (asrc[x] > 0 && asrc[x] < max)

                 dst[x] = FFMAX(FFMIN(FFMAX(msrc[x] - offset, 0) * (unsigned)max / asrc[x] + offset, max), 0);

             else
                 dst[x] = msrc[x];
         }
 
         dst  += dlinesize / 2;
         msrc += mlinesize / 2;
         asrc += alinesize / 2;
     }
 }
 

 static int filter_frame(AVFilterContext *ctx,
                         AVFrame **out, AVFrame *base, AVFrame *alpha)

 {

     PreMultiplyContext *s = ctx->priv;

     AVFilterLink *outlink = ctx->outputs[0];
 
     if (ctx->is_disabled) {

         *out = av_frame_clone(base);
         if (!*out)

             return AVERROR(ENOMEM);
     } else {
         int p, full, limited;
 

         *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!*out)

             return AVERROR(ENOMEM);

         av_frame_copy_props(*out, base);

 
         full = base->color_range == AVCOL_RANGE_JPEG;
         limited = base->color_range == AVCOL_RANGE_MPEG;
 

         if (s->inverse) {
             switch (outlink->format) {
             case AV_PIX_FMT_YUV444P:

             case AV_PIX_FMT_YUVA444P:

                 s->premultiply[0] = full ? unpremultiply8 : unpremultiply8offset;
                 s->premultiply[1] = s->premultiply[2] = unpremultiply8yuv;
                 break;
             case AV_PIX_FMT_YUVJ444P:
                 s->premultiply[0] = unpremultiply8;
                 s->premultiply[1] = s->premultiply[2] = unpremultiply8yuv;
                 break;
             case AV_PIX_FMT_GBRP:

             case AV_PIX_FMT_GBRAP:

                 s->premultiply[0] = s->premultiply[1] = s->premultiply[2] = limited ? unpremultiply8offset : unpremultiply8;
                 break;
             case AV_PIX_FMT_YUV444P9:

             case AV_PIX_FMT_YUVA444P9:

             case AV_PIX_FMT_YUV444P10:

             case AV_PIX_FMT_YUVA444P10:

             case AV_PIX_FMT_YUV444P12:
             case AV_PIX_FMT_YUV444P14:
             case AV_PIX_FMT_YUV444P16:

             case AV_PIX_FMT_YUVA444P16:

                 s->premultiply[0] = full ? unpremultiply16 : unpremultiply16offset;
                 s->premultiply[1] = s->premultiply[2] = unpremultiply16yuv;
                 break;
             case AV_PIX_FMT_GBRP9:
             case AV_PIX_FMT_GBRP10:

             case AV_PIX_FMT_GBRAP10:

             case AV_PIX_FMT_GBRP12:

             case AV_PIX_FMT_GBRAP12:

             case AV_PIX_FMT_GBRP14:
             case AV_PIX_FMT_GBRP16:

             case AV_PIX_FMT_GBRAP16:

                 s->premultiply[0] = s->premultiply[1] = s->premultiply[2] = limited ? unpremultiply16offset : unpremultiply16;
                 break;
             case AV_PIX_FMT_GRAY8:
                 s->premultiply[0] = limited ? unpremultiply8offset : unpremultiply8;
                 break;

             case AV_PIX_FMT_GRAY9:

             case AV_PIX_FMT_GRAY10:
             case AV_PIX_FMT_GRAY12:
             case AV_PIX_FMT_GRAY16:
                 s->premultiply[0] = limited ? unpremultiply16offset : unpremultiply16;
                 break;
             }
         } else {
             switch (outlink->format) {
             case AV_PIX_FMT_YUV444P:

             case AV_PIX_FMT_YUVA444P:

                 s->premultiply[0] = full ? premultiply8 : premultiply8offset;
                 s->premultiply[1] = s->premultiply[2] = premultiply8yuv;
                 break;
             case AV_PIX_FMT_YUVJ444P:
                 s->premultiply[0] = premultiply8;
                 s->premultiply[1] = s->premultiply[2] = premultiply8yuv;
                 break;
             case AV_PIX_FMT_GBRP:

             case AV_PIX_FMT_GBRAP:

                 s->premultiply[0] = s->premultiply[1] = s->premultiply[2] = limited ? premultiply8offset : premultiply8;
                 break;
             case AV_PIX_FMT_YUV444P9:

             case AV_PIX_FMT_YUVA444P9:

             case AV_PIX_FMT_YUV444P10:

             case AV_PIX_FMT_YUVA444P10:

             case AV_PIX_FMT_YUV444P12:
             case AV_PIX_FMT_YUV444P14:
             case AV_PIX_FMT_YUV444P16:

             case AV_PIX_FMT_YUVA444P16:

                 s->premultiply[0] = full ? premultiply16 : premultiply16offset;
                 s->premultiply[1] = s->premultiply[2] = premultiply16yuv;
                 break;
             case AV_PIX_FMT_GBRP9:
             case AV_PIX_FMT_GBRP10:

             case AV_PIX_FMT_GBRAP10:

             case AV_PIX_FMT_GBRP12:

             case AV_PIX_FMT_GBRAP12:

             case AV_PIX_FMT_GBRP14:
             case AV_PIX_FMT_GBRP16:

             case AV_PIX_FMT_GBRAP16:

                 s->premultiply[0] = s->premultiply[1] = s->premultiply[2] = limited ? premultiply16offset : premultiply16;
                 break;
             case AV_PIX_FMT_GRAY8:
                 s->premultiply[0] = limited ? premultiply8offset : premultiply8;
                 break;

             case AV_PIX_FMT_GRAY9:

             case AV_PIX_FMT_GRAY10:
             case AV_PIX_FMT_GRAY12:
             case AV_PIX_FMT_GRAY16:
                 s->premultiply[0] = limited ? premultiply16offset : premultiply16;
                 break;
             }

         }
 
         for (p = 0; p < s->nb_planes; p++) {

             if (!((1 << p) & s->planes) || p == 3) {
                 av_image_copy_plane((*out)->data[p], (*out)->linesize[p], base->data[p], base->linesize[p],

                                     s->linesize[p], s->height[p]);
                 continue;
             }
 

             s->premultiply[p](base->data[p], s->inplace ? alpha->data[3] : alpha->data[0],
                               (*out)->data[p],
                               base->linesize[p], s->inplace ? alpha->linesize[3] : alpha->linesize[0],
                               (*out)->linesize[p],

                               s->width[p], s->height[p],

                               s->half, s->inverse ? s->max : s->depth, s->offset);

         }
     }

 
     return 0;
 }
 
 static int process_frame(FFFrameSync *fs)
 {
     AVFilterContext *ctx = fs->parent;
     PreMultiplyContext *s = fs->opaque;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *out = NULL, *base, *alpha;
     int ret;
 

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

         return ret;
 
     if ((ret = filter_frame(ctx, &out, base, alpha)) < 0)
         return ret;
 

     out->pts = av_rescale_q(base->pts, s->fs.time_base, outlink->time_base);
 
     return ff_filter_frame(outlink, out);
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     PreMultiplyContext *s = ctx->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

     int vsub, hsub, ret;

 
     s->nb_planes = av_pix_fmt_count_planes(inlink->format);
 

     if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
         return ret;
 

     hsub = desc->log2_chroma_w;
     vsub = desc->log2_chroma_h;
     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->depth = desc->comp[0].depth;

     s->max = (1 << s->depth) - 1;

     s->half = (1 << s->depth) / 2;
     s->offset = 16 << (s->depth - 8);
 
     return 0;
 }
 
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     PreMultiplyContext *s = ctx->priv;
     AVFilterLink *base = ctx->inputs[0];

     AVFilterLink *alpha;

     FFFrameSyncIn *in;
     int ret;
 

     if (!s->inplace) {
         alpha = ctx->inputs[1];
 
         if (base->format != alpha->format) {
             av_log(ctx, AV_LOG_ERROR, "inputs must be of same pixel format\n");
             return AVERROR(EINVAL);
         }
         if (base->w                       != alpha->w ||
             base->h                       != alpha->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 (%dx%d) ",
                    ctx->input_pads[0].name, base->w, base->h,
                    ctx->input_pads[1].name, alpha->w, alpha->h);
             return AVERROR(EINVAL);
         }

     }
 
     outlink->w = base->w;
     outlink->h = base->h;
     outlink->time_base = base->time_base;
     outlink->sample_aspect_ratio = base->sample_aspect_ratio;
     outlink->frame_rate = base->frame_rate;
 

     if (s->inplace)
         return 0;
 

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

         return ret;
 
     in = s->fs.in;
     in[0].time_base = base->time_base;
     in[1].time_base = alpha->time_base;
     in[0].sync   = 1;
     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;
 

     return ff_framesync_configure(&s->fs);

 }
 

 static int activate(AVFilterContext *ctx)

 {

     PreMultiplyContext *s = ctx->priv;

 
     if (s->inplace) {
         AVFrame *frame = NULL;
         AVFrame *out = NULL;
         int ret, status;
         int64_t pts;
 
         if ((ret = ff_inlink_consume_frame(ctx->inputs[0], &frame)) > 0) {

             ret = filter_frame(ctx, &out, frame, frame);

             av_frame_free(&frame);

             if (ret < 0)
                 return ret;

             ret = ff_filter_frame(ctx->outputs[0], out);
         }
         if (ret < 0) {
             return ret;
         } else if (ff_inlink_acknowledge_status(ctx->inputs[0], &status, &pts)) {
             ff_outlink_set_status(ctx->outputs[0], status, pts);
             return 0;
         } else {
             if (ff_outlink_frame_wanted(ctx->outputs[0]))
                 ff_inlink_request_frame(ctx->inputs[0]);
             return 0;
         }
     } else {

         return ff_framesync_activate(&s->fs);

     }

 }
 

 static av_cold int init(AVFilterContext *ctx)
 {
     PreMultiplyContext *s = ctx->priv;

     AVFilterPad pad = { 0 };
     int ret;

 
     if (!strcmp(ctx->filter->name, "unpremultiply"))
         s->inverse = 1;
 

     pad.type         = AVMEDIA_TYPE_VIDEO;
     pad.name         = av_strdup("main");
     pad.config_props = config_input;
     if (!pad.name)
         return AVERROR(ENOMEM);
 
     if ((ret = ff_insert_inpad(ctx, 0, &pad)) < 0) {
         av_freep(&pad.name);
         return ret;
     }
 
     if (!s->inplace) {
         pad.type         = AVMEDIA_TYPE_VIDEO;
         pad.name         = av_strdup("alpha");
         pad.config_props = NULL;
         if (!pad.name)
             return AVERROR(ENOMEM);
 
         if ((ret = ff_insert_inpad(ctx, 1, &pad)) < 0) {
             av_freep(&pad.name);
             return ret;
         }
     }
 

     return 0;
 }
 

 static av_cold void uninit(AVFilterContext *ctx)
 {
     PreMultiplyContext *s = ctx->priv;
 

     if (!s->inplace)

         ff_framesync_uninit(&s->fs);

 }
 
 static const AVFilterPad premultiply_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = config_output,
     },
     { NULL }
 };
 

 #if CONFIG_PREMULTIPLY_FILTER
 

 AVFilter ff_vf_premultiply = {
     .name          = "premultiply",
     .description   = NULL_IF_CONFIG_SMALL("PreMultiply first stream with first plane of second stream."),
     .priv_size     = sizeof(PreMultiplyContext),

     .init          = init,

     .uninit        = uninit,
     .query_formats = query_formats,

     .activate      = activate,

     .inputs        = NULL,

     .outputs       = premultiply_outputs,
     .priv_class    = &premultiply_class,

     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
                      AVFILTER_FLAG_DYNAMIC_INPUTS,

 };

 
 #endif /* CONFIG_PREMULTIPLY_FILTER */
 
 #if CONFIG_UNPREMULTIPLY_FILTER
 
 #define unpremultiply_options options
 AVFILTER_DEFINE_CLASS(unpremultiply);
 
 AVFilter ff_vf_unpremultiply = {
     .name          = "unpremultiply",
     .description   = NULL_IF_CONFIG_SMALL("UnPreMultiply first stream with first plane of second stream."),
     .priv_size     = sizeof(PreMultiplyContext),
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
     .activate      = activate,

     .inputs        = NULL,

     .outputs       = premultiply_outputs,
     .priv_class    = &unpremultiply_class,

     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
                      AVFILTER_FLAG_DYNAMIC_INPUTS,

 };
 
 #endif /* CONFIG_UNPREMULTIPLY_FILTER */