yading@10: /*
yading@10:  * Copyright (c) 2008 vmrsss
yading@10:  * Copyright (c) 2009 Stefano Sabatini
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * video padding filter
yading@10:  */
yading@10: 
yading@10: #include "avfilter.h"
yading@10: #include "formats.h"
yading@10: #include "internal.h"
yading@10: #include "video.h"
yading@10: #include "libavutil/avstring.h"
yading@10: #include "libavutil/common.h"
yading@10: #include "libavutil/eval.h"
yading@10: #include "libavutil/pixdesc.h"
yading@10: #include "libavutil/colorspace.h"
yading@10: #include "libavutil/avassert.h"
yading@10: #include "libavutil/imgutils.h"
yading@10: #include "libavutil/opt.h"
yading@10: #include "libavutil/parseutils.h"
yading@10: #include "libavutil/mathematics.h"
yading@10: #include "libavutil/opt.h"
yading@10: 
yading@10: #include "drawutils.h"
yading@10: 
yading@10: static const char *const var_names[] = {
yading@10:     "in_w",   "iw",
yading@10:     "in_h",   "ih",
yading@10:     "out_w",  "ow",
yading@10:     "out_h",  "oh",
yading@10:     "x",
yading@10:     "y",
yading@10:     "a",
yading@10:     "sar",
yading@10:     "dar",
yading@10:     "hsub",
yading@10:     "vsub",
yading@10:     NULL
yading@10: };
yading@10: 
yading@10: enum var_name {
yading@10:     VAR_IN_W,   VAR_IW,
yading@10:     VAR_IN_H,   VAR_IH,
yading@10:     VAR_OUT_W,  VAR_OW,
yading@10:     VAR_OUT_H,  VAR_OH,
yading@10:     VAR_X,
yading@10:     VAR_Y,
yading@10:     VAR_A,
yading@10:     VAR_SAR,
yading@10:     VAR_DAR,
yading@10:     VAR_HSUB,
yading@10:     VAR_VSUB,
yading@10:     VARS_NB
yading@10: };
yading@10: 
yading@10: static int query_formats(AVFilterContext *ctx)
yading@10: {
yading@10:     ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: typedef struct {
yading@10:     const AVClass *class;
yading@10:     int w, h;               ///< output dimensions, a value of 0 will result in the input size
yading@10:     int x, y;               ///< offsets of the input area with respect to the padded area
yading@10:     int in_w, in_h;         ///< width and height for the padded input video, which has to be aligned to the chroma values in order to avoid chroma issues
yading@10: 
yading@10:     char *w_expr;           ///< width  expression string
yading@10:     char *h_expr;           ///< height expression string
yading@10:     char *x_expr;           ///< width  expression string
yading@10:     char *y_expr;           ///< height expression string
yading@10:     char *color_str;
yading@10:     uint8_t rgba_color[4];  ///< color for the padding area
yading@10:     FFDrawContext draw;
yading@10:     FFDrawColor color;
yading@10: } PadContext;
yading@10: 
yading@10: static av_cold int init(AVFilterContext *ctx)
yading@10: {
yading@10:     PadContext *pad = ctx->priv;
yading@10: 
yading@10:     if (av_parse_color(pad->rgba_color, pad->color_str, -1, ctx) < 0)
yading@10:         return AVERROR(EINVAL);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int config_input(AVFilterLink *inlink)
yading@10: {
yading@10:     AVFilterContext *ctx = inlink->dst;
yading@10:     PadContext *pad = ctx->priv;
yading@10:     int ret;
yading@10:     double var_values[VARS_NB], res;
yading@10:     char *expr;
yading@10: 
yading@10:     ff_draw_init(&pad->draw, inlink->format, 0);
yading@10:     ff_draw_color(&pad->draw, &pad->color, pad->rgba_color);
yading@10: 
yading@10:     var_values[VAR_IN_W]  = var_values[VAR_IW] = inlink->w;
yading@10:     var_values[VAR_IN_H]  = var_values[VAR_IH] = inlink->h;
yading@10:     var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
yading@10:     var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
yading@10:     var_values[VAR_A]     = (double) inlink->w / inlink->h;
yading@10:     var_values[VAR_SAR]   = inlink->sample_aspect_ratio.num ?
yading@10:         (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
yading@10:     var_values[VAR_DAR]   = var_values[VAR_A] * var_values[VAR_SAR];
yading@10:     var_values[VAR_HSUB]  = 1 << pad->draw.hsub_max;
yading@10:     var_values[VAR_VSUB]  = 1 << pad->draw.vsub_max;
yading@10: 
yading@10:     /* evaluate width and height */
yading@10:     av_expr_parse_and_eval(&res, (expr = pad->w_expr),
yading@10:                            var_names, var_values,
yading@10:                            NULL, NULL, NULL, NULL, NULL, 0, ctx);
yading@10:     pad->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
yading@10:     if ((ret = av_expr_parse_and_eval(&res, (expr = pad->h_expr),
yading@10:                                       var_names, var_values,
yading@10:                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
yading@10:         goto eval_fail;
yading@10:     pad->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
yading@10:     /* evaluate the width again, as it may depend on the evaluated output height */
yading@10:     if ((ret = av_expr_parse_and_eval(&res, (expr = pad->w_expr),
yading@10:                                       var_names, var_values,
yading@10:                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
yading@10:         goto eval_fail;
yading@10:     pad->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
yading@10: 
yading@10:     /* evaluate x and y */
yading@10:     av_expr_parse_and_eval(&res, (expr = pad->x_expr),
yading@10:                            var_names, var_values,
yading@10:                            NULL, NULL, NULL, NULL, NULL, 0, ctx);
yading@10:     pad->x = var_values[VAR_X] = res;
yading@10:     if ((ret = av_expr_parse_and_eval(&res, (expr = pad->y_expr),
yading@10:                                       var_names, var_values,
yading@10:                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
yading@10:         goto eval_fail;
yading@10:     pad->y = var_values[VAR_Y] = res;
yading@10:     /* evaluate x again, as it may depend on the evaluated y value */
yading@10:     if ((ret = av_expr_parse_and_eval(&res, (expr = pad->x_expr),
yading@10:                                       var_names, var_values,
yading@10:                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
yading@10:         goto eval_fail;
yading@10:     pad->x = var_values[VAR_X] = res;
yading@10: 
yading@10:     /* sanity check params */
yading@10:     if (pad->w < 0 || pad->h < 0 || pad->x < 0 || pad->y < 0) {
yading@10:         av_log(ctx, AV_LOG_ERROR, "Negative values are not acceptable.\n");
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     if (!pad->w)
yading@10:         pad->w = inlink->w;
yading@10:     if (!pad->h)
yading@10:         pad->h = inlink->h;
yading@10: 
yading@10:     pad->w    = ff_draw_round_to_sub(&pad->draw, 0, -1, pad->w);
yading@10:     pad->h    = ff_draw_round_to_sub(&pad->draw, 1, -1, pad->h);
yading@10:     pad->x    = ff_draw_round_to_sub(&pad->draw, 0, -1, pad->x);
yading@10:     pad->y    = ff_draw_round_to_sub(&pad->draw, 1, -1, pad->y);
yading@10:     pad->in_w = ff_draw_round_to_sub(&pad->draw, 0, -1, inlink->w);
yading@10:     pad->in_h = ff_draw_round_to_sub(&pad->draw, 1, -1, inlink->h);
yading@10: 
yading@10:     av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d -> w:%d h:%d x:%d y:%d color:0x%02X%02X%02X%02X\n",
yading@10:            inlink->w, inlink->h, pad->w, pad->h, pad->x, pad->y,
yading@10:            pad->rgba_color[0], pad->rgba_color[1], pad->rgba_color[2], pad->rgba_color[3]);
yading@10: 
yading@10:     if (pad->x <  0 || pad->y <  0                      ||
yading@10:         pad->w <= 0 || pad->h <= 0                      ||
yading@10:         (unsigned)pad->x + (unsigned)inlink->w > pad->w ||
yading@10:         (unsigned)pad->y + (unsigned)inlink->h > pad->h) {
yading@10:         av_log(ctx, AV_LOG_ERROR,
yading@10:                "Input area %d:%d:%d:%d not within the padded area 0:0:%d:%d or zero-sized\n",
yading@10:                pad->x, pad->y, pad->x + inlink->w, pad->y + inlink->h, pad->w, pad->h);
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: 
yading@10: eval_fail:
yading@10:     av_log(NULL, AV_LOG_ERROR,
yading@10:            "Error when evaluating the expression '%s'\n", expr);
yading@10:     return ret;
yading@10: 
yading@10: }
yading@10: 
yading@10: static int config_output(AVFilterLink *outlink)
yading@10: {
yading@10:     PadContext *pad = outlink->src->priv;
yading@10: 
yading@10:     outlink->w = pad->w;
yading@10:     outlink->h = pad->h;
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static AVFrame *get_video_buffer(AVFilterLink *inlink, int w, int h)
yading@10: {
yading@10:     PadContext *pad = inlink->dst->priv;
yading@10: 
yading@10:     AVFrame *frame = ff_get_video_buffer(inlink->dst->outputs[0],
yading@10:                                          w + (pad->w - pad->in_w),
yading@10:                                          h + (pad->h - pad->in_h));
yading@10:     int plane;
yading@10: 
yading@10:     if (!frame)
yading@10:         return NULL;
yading@10: 
yading@10:     frame->width  = w;
yading@10:     frame->height = h;
yading@10: 
yading@10:     for (plane = 0; plane < 4 && frame->data[plane]; plane++) {
yading@10:         int hsub = pad->draw.hsub[plane];
yading@10:         int vsub = pad->draw.vsub[plane];
yading@10:         frame->data[plane] += (pad->x >> hsub) * pad->draw.pixelstep[plane] +
yading@10:                               (pad->y >> vsub) * frame->linesize[plane];
yading@10:     }
yading@10: 
yading@10:     return frame;
yading@10: }
yading@10: 
yading@10: /* check whether each plane in this buffer can be padded without copying */
yading@10: static int buffer_needs_copy(PadContext *s, AVFrame *frame, AVBufferRef *buf)
yading@10: {
yading@10:     int planes[4] = { -1, -1, -1, -1}, *p = planes;
yading@10:     int i, j;
yading@10: 
yading@10:     /* get all planes in this buffer */
yading@10:     for (i = 0; i < FF_ARRAY_ELEMS(planes) && frame->data[i]; i++) {
yading@10:         if (av_frame_get_plane_buffer(frame, i) == buf)
yading@10:             *p++ = i;
yading@10:     }
yading@10: 
yading@10:     /* for each plane in this buffer, check that it can be padded without
yading@10:      * going over buffer bounds or other planes */
yading@10:     for (i = 0; i < FF_ARRAY_ELEMS(planes) && planes[i] >= 0; i++) {
yading@10:         int hsub = s->draw.hsub[planes[i]];
yading@10:         int vsub = s->draw.vsub[planes[i]];
yading@10: 
yading@10:         uint8_t *start = frame->data[planes[i]];
yading@10:         uint8_t *end   = start + (frame->height >> vsub) *
yading@10:                                  frame->linesize[planes[i]];
yading@10: 
yading@10:         /* amount of free space needed before the start and after the end
yading@10:          * of the plane */
yading@10:         ptrdiff_t req_start = (s->x >> hsub) * s->draw.pixelstep[planes[i]] +
yading@10:                               (s->y >> vsub) * frame->linesize[planes[i]];
yading@10:         ptrdiff_t req_end   = ((s->w - s->x - frame->width) >> hsub) *
yading@10:                               s->draw.pixelstep[planes[i]] +
yading@10:                               (s->y >> vsub) * frame->linesize[planes[i]];
yading@10: 
yading@10:         if (frame->linesize[planes[i]] < (s->w >> hsub) * s->draw.pixelstep[planes[i]])
yading@10:             return 1;
yading@10:         if (start - buf->data < req_start ||
yading@10:             (buf->data + buf->size) - end < req_end)
yading@10:             return 1;
yading@10: 
yading@10: #define SIGN(x) ((x) > 0 ? 1 : -1)
yading@10:         for (j = 0; j < FF_ARRAY_ELEMS(planes) && planes[j] >= 0; j++) {
yading@10:             int vsub1 = s->draw.vsub[planes[j]];
yading@10:             uint8_t *start1 = frame->data[planes[j]];
yading@10:             uint8_t *end1   = start1 + (frame->height >> vsub1) *
yading@10:                                        frame->linesize[planes[j]];
yading@10:             if (i == j)
yading@10:                 continue;
yading@10: 
yading@10:             if (SIGN(start - end1) != SIGN(start - end1 - req_start) ||
yading@10:                 SIGN(end - start1) != SIGN(end - start1 + req_end))
yading@10:                 return 1;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int frame_needs_copy(PadContext *s, AVFrame *frame)
yading@10: {
yading@10:     int i;
yading@10: 
yading@10:     if (!av_frame_is_writable(frame))
yading@10:         return 1;
yading@10: 
yading@10:     for (i = 0; i < 4 && frame->buf[i]; i++)
yading@10:         if (buffer_needs_copy(s, frame, frame->buf[i]))
yading@10:             return 1;
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *in)
yading@10: {
yading@10:     PadContext *pad = inlink->dst->priv;
yading@10:     AVFrame *out;
yading@10:     int needs_copy = frame_needs_copy(pad, in);
yading@10: 
yading@10:     if (needs_copy) {
yading@10:         av_log(inlink->dst, AV_LOG_DEBUG, "Direct padding impossible allocating new frame\n");
yading@10:         out = ff_get_video_buffer(inlink->dst->outputs[0],
yading@10:                                   FFMAX(inlink->w, pad->w),
yading@10:                                   FFMAX(inlink->h, pad->h));
yading@10:         if (!out) {
yading@10:             av_frame_free(&in);
yading@10:             return AVERROR(ENOMEM);
yading@10:         }
yading@10: 
yading@10:         av_frame_copy_props(out, in);
yading@10:     } else {
yading@10:         int i;
yading@10: 
yading@10:         out = in;
yading@10:         for (i = 0; i < 4 && out->data[i]; i++) {
yading@10:             int hsub = pad->draw.hsub[i];
yading@10:             int vsub = pad->draw.vsub[i];
yading@10:             out->data[i] -= (pad->x >> hsub) * pad->draw.pixelstep[i] +
yading@10:                             (pad->y >> vsub) * out->linesize[i];
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     /* top bar */
yading@10:     if (pad->y) {
yading@10:         ff_fill_rectangle(&pad->draw, &pad->color,
yading@10:                           out->data, out->linesize,
yading@10:                           0, 0, pad->w, pad->y);
yading@10:     }
yading@10: 
yading@10:     /* bottom bar */
yading@10:     if (pad->h > pad->y + pad->in_h) {
yading@10:         ff_fill_rectangle(&pad->draw, &pad->color,
yading@10:                           out->data, out->linesize,
yading@10:                           0, pad->y + pad->in_h, pad->w, pad->h - pad->y - pad->in_h);
yading@10:     }
yading@10: 
yading@10:     /* left border */
yading@10:     ff_fill_rectangle(&pad->draw, &pad->color, out->data, out->linesize,
yading@10:                       0, pad->y, pad->x, in->height);
yading@10: 
yading@10:     if (needs_copy) {
yading@10:         ff_copy_rectangle2(&pad->draw,
yading@10:                           out->data, out->linesize, in->data, in->linesize,
yading@10:                           pad->x, pad->y, 0, 0, in->width, in->height);
yading@10:     }
yading@10: 
yading@10:     /* right border */
yading@10:     ff_fill_rectangle(&pad->draw, &pad->color, out->data, out->linesize,
yading@10:                       pad->x + pad->in_w, pad->y, pad->w - pad->x - pad->in_w,
yading@10:                       in->height);
yading@10: 
yading@10:     out->width  = pad->w;
yading@10:     out->height = pad->h;
yading@10: 
yading@10:     if (in != out)
yading@10:         av_frame_free(&in);
yading@10:     return ff_filter_frame(inlink->dst->outputs[0], out);
yading@10: }
yading@10: 
yading@10: #define OFFSET(x) offsetof(PadContext, x)
yading@10: #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
yading@10: 
yading@10: static const AVOption pad_options[] = {
yading@10:     { "width",  "set the pad area width expression",       OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "w",      "set the pad area width expression",       OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "height", "set the pad area height expression",      OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "h",      "set the pad area height expression",      OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "x",      "set the x offset expression for the input image position", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "y",      "set the y offset expression for the input image position", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "color",  "set the color of the padded area border", OFFSET(color_str), AV_OPT_TYPE_STRING, {.str = "black"}, .flags = FLAGS },
yading@10:     { NULL },
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(pad);
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_pad_inputs[] = {
yading@10:     {
yading@10:         .name             = "default",
yading@10:         .type             = AVMEDIA_TYPE_VIDEO,
yading@10:         .config_props     = config_input,
yading@10:         .get_video_buffer = get_video_buffer,
yading@10:         .filter_frame     = filter_frame,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_pad_outputs[] = {
yading@10:     {
yading@10:         .name         = "default",
yading@10:         .type         = AVMEDIA_TYPE_VIDEO,
yading@10:         .config_props = config_output,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFilter avfilter_vf_pad = {
yading@10:     .name          = "pad",
yading@10:     .description   = NULL_IF_CONFIG_SMALL("Pad input image to width:height[:x:y[:color]] (default x and y: 0, default color: black)."),
yading@10: 
yading@10:     .priv_size     = sizeof(PadContext),
yading@10:     .priv_class    = &pad_class,
yading@10:     .init          = init,
yading@10:     .query_formats = query_formats,
yading@10: 
yading@10:     .inputs    = avfilter_vf_pad_inputs,
yading@10: 
yading@10:     .outputs   = avfilter_vf_pad_outputs,
yading@10: };