yading@10: /*
yading@10:  * Copyright (c) 2007 Bobby Bingham
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 crop filter
yading@10:  */
yading@10: 
yading@10: /* #define DEBUG */
yading@10: 
yading@10: #include <stdio.h>
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/eval.h"
yading@10: #include "libavutil/avstring.h"
yading@10: #include "libavutil/internal.h"
yading@10: #include "libavutil/libm.h"
yading@10: #include "libavutil/imgutils.h"
yading@10: #include "libavutil/mathematics.h"
yading@10: #include "libavutil/opt.h"
yading@10: 
yading@10: static const char *const var_names[] = {
yading@10:     "in_w", "iw",   ///< width  of the input video
yading@10:     "in_h", "ih",   ///< height of the input video
yading@10:     "out_w", "ow",  ///< width  of the cropped video
yading@10:     "out_h", "oh",  ///< height of the cropped video
yading@10:     "a",
yading@10:     "sar",
yading@10:     "dar",
yading@10:     "hsub",
yading@10:     "vsub",
yading@10:     "x",
yading@10:     "y",
yading@10:     "n",            ///< number of frame
yading@10:     "pos",          ///< position in the file
yading@10:     "t",            ///< timestamp expressed in seconds
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_A,
yading@10:     VAR_SAR,
yading@10:     VAR_DAR,
yading@10:     VAR_HSUB,
yading@10:     VAR_VSUB,
yading@10:     VAR_X,
yading@10:     VAR_Y,
yading@10:     VAR_N,
yading@10:     VAR_POS,
yading@10:     VAR_T,
yading@10:     VAR_VARS_NB
yading@10: };
yading@10: 
yading@10: typedef struct {
yading@10:     const AVClass *class;
yading@10:     int  x;             ///< x offset of the non-cropped area with respect to the input area
yading@10:     int  y;             ///< y offset of the non-cropped area with respect to the input area
yading@10:     int  w;             ///< width of the cropped area
yading@10:     int  h;             ///< height of the cropped area
yading@10: 
yading@10:     AVRational out_sar; ///< output sample aspect ratio
yading@10:     int keep_aspect;    ///< keep display aspect ratio when cropping
yading@10: 
yading@10:     int max_step[4];    ///< max pixel step for each plane, expressed as a number of bytes
yading@10:     int hsub, vsub;     ///< chroma subsampling
yading@10:     char *x_expr, *y_expr, *w_expr, *h_expr;
yading@10:     AVExpr *x_pexpr, *y_pexpr;  /* parsed expressions for x and y */
yading@10:     double var_values[VAR_VARS_NB];
yading@10: } CropContext;
yading@10: 
yading@10: static int query_formats(AVFilterContext *ctx)
yading@10: {
yading@10:     static const enum AVPixelFormat pix_fmts[] = {
yading@10:         AV_PIX_FMT_RGB48BE,      AV_PIX_FMT_RGB48LE,
yading@10:         AV_PIX_FMT_BGR48BE,      AV_PIX_FMT_BGR48LE,
yading@10:         AV_PIX_FMT_ARGB,         AV_PIX_FMT_RGBA,
yading@10:         AV_PIX_FMT_ABGR,         AV_PIX_FMT_BGRA,
yading@10:         AV_PIX_FMT_RGB24,        AV_PIX_FMT_BGR24,
yading@10:         AV_PIX_FMT_RGB565BE,     AV_PIX_FMT_RGB565LE,
yading@10:         AV_PIX_FMT_RGB555BE,     AV_PIX_FMT_RGB555LE,
yading@10:         AV_PIX_FMT_BGR565BE,     AV_PIX_FMT_BGR565LE,
yading@10:         AV_PIX_FMT_BGR555BE,     AV_PIX_FMT_BGR555LE,
yading@10:         AV_PIX_FMT_GRAY16BE,     AV_PIX_FMT_GRAY16LE,
yading@10:         AV_PIX_FMT_YUV420P16LE,  AV_PIX_FMT_YUV420P16BE,
yading@10:         AV_PIX_FMT_YUV422P16LE,  AV_PIX_FMT_YUV422P16BE,
yading@10:         AV_PIX_FMT_YUV444P16LE,  AV_PIX_FMT_YUV444P16BE,
yading@10:         AV_PIX_FMT_YUV444P,      AV_PIX_FMT_YUV422P,
yading@10:         AV_PIX_FMT_YUV420P,      AV_PIX_FMT_YUV411P,
yading@10:         AV_PIX_FMT_YUV410P,      AV_PIX_FMT_YUV440P,
yading@10:         AV_PIX_FMT_YUVJ444P,     AV_PIX_FMT_YUVJ422P,
yading@10:         AV_PIX_FMT_YUVJ420P,     AV_PIX_FMT_YUVJ440P,
yading@10:         AV_PIX_FMT_YUVA420P,
yading@10:         AV_PIX_FMT_RGB8,         AV_PIX_FMT_BGR8,
yading@10:         AV_PIX_FMT_RGB4_BYTE,    AV_PIX_FMT_BGR4_BYTE,
yading@10:         AV_PIX_FMT_PAL8,         AV_PIX_FMT_GRAY8,
yading@10:         AV_PIX_FMT_NONE
yading@10:     };
yading@10: 
yading@10:     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold void uninit(AVFilterContext *ctx)
yading@10: {
yading@10:     CropContext *crop = ctx->priv;
yading@10: 
yading@10:     av_expr_free(crop->x_pexpr); crop->x_pexpr = NULL;
yading@10:     av_expr_free(crop->y_pexpr); crop->y_pexpr = NULL;
yading@10: }
yading@10: 
yading@10: static inline int normalize_double(int *n, double d)
yading@10: {
yading@10:     int ret = 0;
yading@10: 
yading@10:     if (isnan(d)) {
yading@10:         ret = AVERROR(EINVAL);
yading@10:     } else if (d > INT_MAX || d < INT_MIN) {
yading@10:         *n = d > INT_MAX ? INT_MAX : INT_MIN;
yading@10:         ret = AVERROR(EINVAL);
yading@10:     } else
yading@10:         *n = round(d);
yading@10: 
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static int config_input(AVFilterLink *link)
yading@10: {
yading@10:     AVFilterContext *ctx = link->dst;
yading@10:     CropContext *crop = ctx->priv;
yading@10:     const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format);
yading@10:     int ret;
yading@10:     const char *expr;
yading@10:     double res;
yading@10: 
yading@10:     crop->var_values[VAR_IN_W]  = crop->var_values[VAR_IW] = ctx->inputs[0]->w;
yading@10:     crop->var_values[VAR_IN_H]  = crop->var_values[VAR_IH] = ctx->inputs[0]->h;
yading@10:     crop->var_values[VAR_A]     = (float) link->w / link->h;
yading@10:     crop->var_values[VAR_SAR]   = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1;
yading@10:     crop->var_values[VAR_DAR]   = crop->var_values[VAR_A] * crop->var_values[VAR_SAR];
yading@10:     crop->var_values[VAR_HSUB]  = 1<<pix_desc->log2_chroma_w;
yading@10:     crop->var_values[VAR_VSUB]  = 1<<pix_desc->log2_chroma_h;
yading@10:     crop->var_values[VAR_X]     = NAN;
yading@10:     crop->var_values[VAR_Y]     = NAN;
yading@10:     crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = NAN;
yading@10:     crop->var_values[VAR_OUT_H] = crop->var_values[VAR_OH] = NAN;
yading@10:     crop->var_values[VAR_N]     = 0;
yading@10:     crop->var_values[VAR_T]     = NAN;
yading@10:     crop->var_values[VAR_POS]   = NAN;
yading@10: 
yading@10:     av_image_fill_max_pixsteps(crop->max_step, NULL, pix_desc);
yading@10:     crop->hsub = pix_desc->log2_chroma_w;
yading@10:     crop->vsub = pix_desc->log2_chroma_h;
yading@10: 
yading@10:     if ((ret = av_expr_parse_and_eval(&res, (expr = crop->w_expr),
yading@10:                                       var_names, crop->var_values,
yading@10:                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
yading@10:     crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = res;
yading@10:     if ((ret = av_expr_parse_and_eval(&res, (expr = crop->h_expr),
yading@10:                                       var_names, crop->var_values,
yading@10:                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
yading@10:     crop->var_values[VAR_OUT_H] = crop->var_values[VAR_OH] = res;
yading@10:     /* evaluate again ow as it may depend on oh */
yading@10:     if ((ret = av_expr_parse_and_eval(&res, (expr = crop->w_expr),
yading@10:                                       var_names, crop->var_values,
yading@10:                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
yading@10:     crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = res;
yading@10:     if (normalize_double(&crop->w, crop->var_values[VAR_OUT_W]) < 0 ||
yading@10:         normalize_double(&crop->h, crop->var_values[VAR_OUT_H]) < 0) {
yading@10:         av_log(ctx, AV_LOG_ERROR,
yading@10:                "Too big value or invalid expression for out_w/ow or out_h/oh. "
yading@10:                "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
yading@10:                crop->w_expr, crop->h_expr);
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10:     crop->w &= ~((1 << crop->hsub) - 1);
yading@10:     crop->h &= ~((1 << crop->vsub) - 1);
yading@10: 
yading@10:     if ((ret = av_expr_parse(&crop->x_pexpr, crop->x_expr, var_names,
yading@10:                              NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
yading@10:         (ret = av_expr_parse(&crop->y_pexpr, crop->y_expr, var_names,
yading@10:                              NULL, NULL, NULL, NULL, 0, ctx)) < 0)
yading@10:         return AVERROR(EINVAL);
yading@10: 
yading@10:     if (crop->keep_aspect) {
yading@10:         AVRational dar = av_mul_q(link->sample_aspect_ratio,
yading@10:                                   (AVRational){ link->w, link->h });
yading@10:         av_reduce(&crop->out_sar.num, &crop->out_sar.den,
yading@10:                   dar.num * crop->h, dar.den * crop->w, INT_MAX);
yading@10:     } else
yading@10:         crop->out_sar = link->sample_aspect_ratio;
yading@10: 
yading@10:     av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n",
yading@10:            link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den,
yading@10:            crop->w, crop->h, crop->out_sar.num, crop->out_sar.den);
yading@10: 
yading@10:     if (crop->w <= 0 || crop->h <= 0 ||
yading@10:         crop->w > link->w || crop->h > link->h) {
yading@10:         av_log(ctx, AV_LOG_ERROR,
yading@10:                "Invalid too big or non positive size for width '%d' or height '%d'\n",
yading@10:                crop->w, crop->h);
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     /* set default, required in the case the first computed value for x/y is NAN */
yading@10:     crop->x = (link->w - crop->w) / 2;
yading@10:     crop->y = (link->h - crop->h) / 2;
yading@10:     crop->x &= ~((1 << crop->hsub) - 1);
yading@10:     crop->y &= ~((1 << crop->vsub) - 1);
yading@10:     return 0;
yading@10: 
yading@10: fail_expr:
yading@10:     av_log(NULL, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static int config_output(AVFilterLink *link)
yading@10: {
yading@10:     CropContext *crop = link->src->priv;
yading@10: 
yading@10:     link->w = crop->w;
yading@10:     link->h = crop->h;
yading@10:     link->sample_aspect_ratio = crop->out_sar;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *link, AVFrame *frame)
yading@10: {
yading@10:     AVFilterContext *ctx = link->dst;
yading@10:     CropContext *crop = ctx->priv;
yading@10:     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
yading@10:     int i;
yading@10: 
yading@10:     frame->width  = crop->w;
yading@10:     frame->height = crop->h;
yading@10: 
yading@10:     crop->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
yading@10:         NAN : frame->pts * av_q2d(link->time_base);
yading@10:     crop->var_values[VAR_POS] = av_frame_get_pkt_pos(frame) == -1 ?
yading@10:         NAN : av_frame_get_pkt_pos(frame);
yading@10:     crop->var_values[VAR_X] = av_expr_eval(crop->x_pexpr, crop->var_values, NULL);
yading@10:     crop->var_values[VAR_Y] = av_expr_eval(crop->y_pexpr, crop->var_values, NULL);
yading@10:     crop->var_values[VAR_X] = av_expr_eval(crop->x_pexpr, crop->var_values, NULL);
yading@10: 
yading@10:     normalize_double(&crop->x, crop->var_values[VAR_X]);
yading@10:     normalize_double(&crop->y, crop->var_values[VAR_Y]);
yading@10: 
yading@10:     if (crop->x < 0) crop->x = 0;
yading@10:     if (crop->y < 0) crop->y = 0;
yading@10:     if ((unsigned)crop->x + (unsigned)crop->w > link->w) crop->x = link->w - crop->w;
yading@10:     if ((unsigned)crop->y + (unsigned)crop->h > link->h) crop->y = link->h - crop->h;
yading@10:     crop->x &= ~((1 << crop->hsub) - 1);
yading@10:     crop->y &= ~((1 << crop->vsub) - 1);
yading@10: 
yading@10:     av_dlog(ctx, "n:%d t:%f pos:%f x:%d y:%d x+w:%d y+h:%d\n",
yading@10:             (int)crop->var_values[VAR_N], crop->var_values[VAR_T], crop->var_values[VAR_POS],
yading@10:             crop->x, crop->y, crop->x+crop->w, crop->y+crop->h);
yading@10: 
yading@10:     frame->data[0] += crop->y * frame->linesize[0];
yading@10:     frame->data[0] += crop->x * crop->max_step[0];
yading@10: 
yading@10:     if (!(desc->flags & PIX_FMT_PAL || desc->flags & PIX_FMT_PSEUDOPAL)) {
yading@10:         for (i = 1; i < 3; i ++) {
yading@10:             if (frame->data[i]) {
yading@10:                 frame->data[i] += (crop->y >> crop->vsub) * frame->linesize[i];
yading@10:                 frame->data[i] += (crop->x * crop->max_step[i]) >> crop->hsub;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     /* alpha plane */
yading@10:     if (frame->data[3]) {
yading@10:         frame->data[3] += crop->y * frame->linesize[3];
yading@10:         frame->data[3] += crop->x * crop->max_step[3];
yading@10:     }
yading@10: 
yading@10:     crop->var_values[VAR_N] += 1.0;
yading@10: 
yading@10:     return ff_filter_frame(link->dst->outputs[0], frame);
yading@10: }
yading@10: 
yading@10: #define OFFSET(x) offsetof(CropContext, x)
yading@10: #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
yading@10: 
yading@10: static const AVOption crop_options[] = {
yading@10:     { "out_w",       "set the width crop area expression",   OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "w",           "set the width crop area expression",   OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "out_h",       "set the height crop area expression",  OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "h",           "set the height crop area expression",  OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "x",           "set the x crop area expression",       OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "(in_w-out_w)/2"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "y",           "set the y crop area expression",       OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "(in_h-out_h)/2"}, CHAR_MIN, CHAR_MAX, FLAGS },
yading@10:     { "keep_aspect", "keep aspect ratio",                    OFFSET(keep_aspect), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
yading@10:     {NULL}
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(crop);
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_crop_inputs[] = {
yading@10:     {
yading@10:         .name             = "default",
yading@10:         .type             = AVMEDIA_TYPE_VIDEO,
yading@10:         .filter_frame     = filter_frame,
yading@10:         .get_video_buffer = ff_null_get_video_buffer,
yading@10:         .config_props     = config_input,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_crop_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_crop = {
yading@10:     .name      = "crop",
yading@10:     .description = NULL_IF_CONFIG_SMALL("Crop the input video to width:height:x:y."),
yading@10: 
yading@10:     .priv_size = sizeof(CropContext),
yading@10:     .priv_class = &crop_class,
yading@10: 
yading@10:     .query_formats = query_formats,
yading@10:     .uninit        = uninit,
yading@10: 
yading@10:     .inputs    = avfilter_vf_crop_inputs,
yading@10:     .outputs   = avfilter_vf_crop_outputs,
yading@10: };