libavfilter/vf_fade.c

   1 /*
   2  * Copyright (c) 2010 Brandon Mintern
   3  * Copyright (c) 2007 Bobby Bingham
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * Libav is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * video fade filter
  25  * based heavily on vf_negate.c by Bobby Bingham
  26  */
  27
  28 #include "libavutil/common.h"
  29 #include "libavutil/opt.h"
  30 #include "libavutil/pixdesc.h"
  31 #include "avfilter.h"
  32 #include "formats.h"
  33 #include "internal.h"
  34 #include "video.h"
  35
  36 #define FADE_IN  0
  37 #define FADE_OUT 1
  38
  39 typedef struct FadeContext {
  40     const AVClass *class;
  41     int type;
  42     int factor, fade_per_frame;
  43     int start_frame, nb_frames;
  44     unsigned int frame_index, stop_frame;
  45     int hsub, vsub, bpp;
  46 } FadeContext;
  47
  48 static av_cold int init(AVFilterContext *ctx)
  49 {
  50     FadeContext *s = ctx->priv;
  51
  52     s->fade_per_frame = (1 << 16) / s->nb_frames;
  53     if (s->type == FADE_IN) {
  54         s->factor = 0;
  55     } else if (s->type == FADE_OUT) {
  56         s->fade_per_frame = -s->fade_per_frame;
  57         s->factor = (1 << 16);
  58     }
  59     s->stop_frame = s->start_frame + s->nb_frames;
  60
  61     av_log(ctx, AV_LOG_VERBOSE,
  62            "type:%s start_frame:%d nb_frames:%d\n",
  63            s->type == FADE_IN ? "in" : "out", s->start_frame,
  64            s->nb_frames);
  65     return 0;
  66 }
  67
  68 static int query_formats(AVFilterContext *ctx)
  69 {
  70     static const enum AVPixelFormat pix_fmts[] = {
  71         AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV420P,
  72         AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV410P,
  73         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
  74         AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ440P,
  75         AV_PIX_FMT_RGB24,    AV_PIX_FMT_BGR24,
  76         AV_PIX_FMT_NONE
  77     };
  78
  79     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
  80     return 0;
  81 }
  82
  83 static int config_props(AVFilterLink *inlink)
  84 {
  85     FadeContext *s = inlink->dst->priv;
  86     const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(inlink->format);
  87
  88     s->hsub = pixdesc->log2_chroma_w;
  89     s->vsub = pixdesc->log2_chroma_h;
  90
  91     s->bpp = av_get_bits_per_pixel(pixdesc) >> 3;
  92     return 0;
  93 }
  94
  95 static int filter_slice_luma(AVFilterContext *ctx, void *arg, int jobnr,
  96                              int nb_jobs)
  97 {
  98     FadeContext *s = ctx->priv;
  99     AVFrame *frame = arg;
 100     int slice_h     = frame->height / nb_jobs;
 101     int slice_start = jobnr * slice_h;
 102     int slice_end   = (jobnr == nb_jobs - 1) ? frame->height : (jobnr + 1) * slice_h;
 103     int i, j;
 104
 105     for (i = slice_start; i < slice_end; i++) {
 106         uint8_t *p = frame->data[0] + i * frame->linesize[0];
 107         for (j = 0; j < frame->width * s->bpp; j++) {
 108             /* s->factor is using 16 lower-order bits for decimal
 109              * places. 32768 = 1 << 15, it is an integer representation
 110              * of 0.5 and is for rounding. */
 111             *p = (*p * s->factor + 32768) >> 16;
 112             p++;
 113         }
 114     }
 115
 116     return 0;
 117 }
 118
 119 static int filter_slice_chroma(AVFilterContext *ctx, void *arg, int jobnr,
 120                                int nb_jobs)
 121 {
 122     FadeContext *s = ctx->priv;
 123     AVFrame *frame = arg;
 124     int slice_h     = FFALIGN(frame->height / nb_jobs, 1 << s->vsub);
 125     int slice_start = jobnr * slice_h;
 126     int slice_end   = (jobnr == nb_jobs - 1) ? frame->height :
 127                                                FFMIN((jobnr + 1) * slice_h, frame->height);
 128     int i, j, plane;
 129
 130     for (plane = 1; plane < 3; plane++) {
 131         for (i = slice_start; i < slice_end; i++) {
 132             uint8_t *p = frame->data[plane] + (i >> s->vsub) * frame->linesize[plane];
 133             for (j = 0; j < frame->width >> s->hsub; j++) {
 134                 /* 8421367 = ((128 << 1) + 1) << 15. It is an integer
 135                  * representation of 128.5. The .5 is for rounding
 136                  * purposes. */
 137                 *p = ((*p - 128) * s->factor + 8421367) >> 16;
 138                 p++;
 139             }
 140         }
 141     }
 142
 143     return 0;
 144 }
 145
 146 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
 147 {
 148     AVFilterContext *ctx = inlink->dst;
 149     FadeContext *s       = ctx->priv;
 150
 151     if (s->factor < UINT16_MAX) {
 152         /* luma or rgb plane */
 153         ctx->internal->execute(ctx, filter_slice_luma, frame, NULL,
 154                                FFMIN(frame->height, ctx->graph->nb_threads));
 155
 156         if (frame->data[1] && frame->data[2]) {
 157             /* chroma planes */
 158             ctx->internal->execute(ctx, filter_slice_chroma, frame, NULL,
 159                                    FFMIN(frame->height, ctx->graph->nb_threads));
 160         }
 161     }
 162
 163     if (s->frame_index >= s->start_frame &&
 164         s->frame_index <= s->stop_frame)
 165         s->factor += s->fade_per_frame;
 166     s->factor = av_clip_uint16(s->factor);
 167     s->frame_index++;
 168
 169     return ff_filter_frame(inlink->dst->outputs[0], frame);
 170 }
 171
 172 #define OFFSET(x) offsetof(FadeContext, x)
 173 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
 174 static const AVOption options[] = {
 175     { "type", "'in' or 'out' for fade-in/fade-out", OFFSET(type), AV_OPT_TYPE_INT, { .i64 = FADE_IN }, FADE_IN, FADE_OUT, FLAGS, "type" },
 176         { "in",  "fade-in",  0, AV_OPT_TYPE_CONST, { .i64 = FADE_IN },  .unit = "type" },
 177         { "out", "fade-out", 0, AV_OPT_TYPE_CONST, { .i64 = FADE_OUT }, .unit = "type" },
 178     { "start_frame", "Number of the first frame to which to apply the effect.",
 179                                                     OFFSET(start_frame), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
 180     { "nb_frames",   "Number of frames to which the effect should be applied.",
 181                                                     OFFSET(nb_frames),   AV_OPT_TYPE_INT, { .i64 = 1 }, 0, INT_MAX, FLAGS },
 182     { NULL },
 183 };
 184
 185 static const AVClass fade_class = {
 186     .class_name = "fade",
 187     .item_name  = av_default_item_name,
 188     .option     = options,
 189     .version    = LIBAVUTIL_VERSION_INT,
 190 };
 191
 192 static const AVFilterPad avfilter_vf_fade_inputs[] = {
 193     {
 194         .name             = "default",
 195         .type             = AVMEDIA_TYPE_VIDEO,
 196         .config_props     = config_props,
 197         .get_video_buffer = ff_null_get_video_buffer,
 198         .filter_frame     = filter_frame,
 199         .needs_writable   = 1,
 200     },
 201     { NULL }
 202 };
 203
 204 static const AVFilterPad avfilter_vf_fade_outputs[] = {
 205     {
 206         .name = "default",
 207         .type = AVMEDIA_TYPE_VIDEO,
 208     },
 209     { NULL }
 210 };
 211
 212 AVFilter ff_vf_fade = {
 213     .name          = "fade",
 214     .description   = NULL_IF_CONFIG_SMALL("Fade in/out input video"),
 215     .init          = init,
 216     .priv_size     = sizeof(FadeContext),
 217     .priv_class    = &fade_class,
 218     .query_formats = query_formats,
 219
 220     .inputs    = avfilter_vf_fade_inputs,
 221     .outputs   = avfilter_vf_fade_outputs,
 222     .flags     = AVFILTER_FLAG_SLICE_THREADS,
 223 };