summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--doc/libavfilter.texi31
-rw-r--r--libavfilter/Makefile1
-rw-r--r--libavfilter/allfilters.c1
-rw-r--r--libavfilter/vf_crop.c233
4 files changed, 266 insertions, 0 deletions
diff --git a/doc/libavfilter.texi b/doc/libavfilter.texi
index f8189f1c38..7253abfa0f 100644
--- a/doc/libavfilter.texi
+++ b/doc/libavfilter.texi
@@ -84,4 +84,35 @@ Below is a description of the currently available video filters.
Pass the source unchanged to the output.
+@section crop
+
+Crop the input video to x:y:width:height.
+
+@example
+./ffmpeg -i in.avi -vfilters "crop=0:0:0:240" out.avi
+@end example
+
+``x'' and ``y'' specify the position of the top-left corner of the
+output (non-cropped) area.
+
+The default value of ``x'' and ``y'' is 0.
+
+The ``w'' and ``h'' parameters specify the width and height of the
+output (non-cropped) area.
+
+A value of 0 is interpreted as the maximum possible size contained in
+the area delimited by the top-left corner at position x:y.
+
+For example the parameters:
+
+@example
+"crop=100:100:0:0"
+@end example
+
+will delimit the rectangle with the top-left corner placed at position
+100:100 and the right-bottom corner corresponding to the right-bottom
+corner of the input image.
+
+The default value of ``w'' and ``h'' is 0.
+
@bye
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index e79eb47da4..c5bf2bbb9c 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -11,6 +11,7 @@ OBJS = allfilters.o \
defaults.o \
formats.o \
+OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
OBJS-$(CONFIG_NULL_FILTER) += vf_null.o
include $(SUBDIR)../subdir.mak
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index f8188852bb..1104f610a8 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -34,5 +34,6 @@ void avfilter_register_all(void)
return;
initialized = 1;
+ REGISTER_FILTER (CROP,crop,vf);
REGISTER_FILTER (NULL,null,vf);
}
diff --git a/libavfilter/vf_crop.c b/libavfilter/vf_crop.c
new file mode 100644
index 0000000000..6b1592836e
--- /dev/null
+++ b/libavfilter/vf_crop.c
@@ -0,0 +1,233 @@
+/*
+ * copyright (c) 2007 Bobby Bingham
+ *
+ * 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
+ */
+
+/**
+ * @file libavfilter/vf_crop.c
+ * video crop filter
+ */
+
+#include "avfilter.h"
+
+typedef struct {
+ int x; ///< x offset of the non-cropped area with respect to the input area
+ int y; ///< y offset of the non-cropped area with respect to the input area
+ int w; ///< width of the cropped area
+ int h; ///< height of the cropped area
+
+ int bpp; ///< bits per pixel
+ int hsub, vsub; ///< chroma subsampling
+} CropContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+ enum PixelFormat pix_fmts[] = {
+ PIX_FMT_RGB48BE, PIX_FMT_RGB48LE,
+ PIX_FMT_ARGB, PIX_FMT_RGBA,
+ PIX_FMT_ABGR, PIX_FMT_BGRA,
+ PIX_FMT_RGB24, PIX_FMT_BGR24,
+ PIX_FMT_RGB565BE, PIX_FMT_RGB565LE,
+ PIX_FMT_RGB555BE, PIX_FMT_RGB555LE,
+ PIX_FMT_BGR565BE, PIX_FMT_BGR565LE,
+ PIX_FMT_BGR555BE, PIX_FMT_BGR555LE,
+ PIX_FMT_GRAY16BE, PIX_FMT_GRAY16LE,
+ PIX_FMT_YUV420P16LE, PIX_FMT_YUV420P16BE,
+ PIX_FMT_YUV422P16LE, PIX_FMT_YUV422P16BE,
+ PIX_FMT_YUV444P16LE, PIX_FMT_YUV444P16BE,
+ PIX_FMT_YUV444P, PIX_FMT_YUV422P,
+ PIX_FMT_YUV420P, PIX_FMT_YUV411P,
+ PIX_FMT_YUV410P, PIX_FMT_YUV440P,
+ PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P,
+ PIX_FMT_YUVJ420P, PIX_FMT_YUVJ440P,
+ PIX_FMT_YUVA420P,
+ PIX_FMT_NV12, PIX_FMT_NV21,
+ PIX_FMT_YUYV422, PIX_FMT_UYVY422,
+ PIX_FMT_UYYVYY411,
+ PIX_FMT_RGB8, PIX_FMT_BGR8,
+ PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE,
+ PIX_FMT_PAL8, PIX_FMT_GRAY8,
+ PIX_FMT_NONE
+ };
+
+ avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
+
+ return 0;
+}
+
+static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+ CropContext *crop = ctx->priv;
+
+ if (args)
+ sscanf(args, "%d:%d:%d:%d", &crop->x, &crop->y, &crop->w, &crop->h);
+
+ return 0;
+}
+
+static int config_input(AVFilterLink *link)
+{
+ AVFilterContext *ctx = link->dst;
+ CropContext *crop = ctx->priv;
+
+ switch (link->format) {
+ case PIX_FMT_RGB48BE:
+ case PIX_FMT_RGB48LE:
+ crop->bpp = 48;
+ break;
+ case PIX_FMT_ARGB:
+ case PIX_FMT_RGBA:
+ case PIX_FMT_ABGR:
+ case PIX_FMT_BGRA:
+ crop->bpp = 32;
+ break;
+ case PIX_FMT_RGB24:
+ case PIX_FMT_BGR24:
+ crop->bpp = 24;
+ break;
+ case PIX_FMT_RGB565BE:
+ case PIX_FMT_RGB565LE:
+ case PIX_FMT_RGB555BE:
+ case PIX_FMT_RGB555LE:
+ case PIX_FMT_BGR565BE:
+ case PIX_FMT_BGR565LE:
+ case PIX_FMT_BGR555BE:
+ case PIX_FMT_BGR555LE:
+ case PIX_FMT_GRAY16BE:
+ case PIX_FMT_GRAY16LE:
+ case PIX_FMT_YUV420P16LE:
+ case PIX_FMT_YUV420P16BE:
+ case PIX_FMT_YUV422P16LE:
+ case PIX_FMT_YUV422P16BE:
+ case PIX_FMT_YUV444P16LE:
+ case PIX_FMT_YUV444P16BE:
+ crop->bpp = 16;
+ break;
+ default:
+ crop->bpp = 8;
+ }
+
+ avcodec_get_chroma_sub_sample(link->format, &crop->hsub, &crop->vsub);
+
+ if (crop->w == 0)
+ crop->w = link->w - crop->x;
+ if (crop->h == 0)
+ crop->h = link->h - crop->y;
+
+ crop->x &= ~((1 << crop->hsub) - 1);
+ crop->y &= ~((1 << crop->vsub) - 1);
+
+ av_log(link->dst, AV_LOG_INFO, "x:%d y:%d w:%d h:%d\n",
+ crop->x, crop->y, crop->w, crop->h);
+
+ if (crop->x < 0 || crop->y < 0 ||
+ crop->w <= 0 || crop->h <= 0 ||
+ (unsigned)crop->x + (unsigned)crop->w > link->w ||
+ (unsigned)crop->y + (unsigned)crop->h > link->h) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Output area %d:%d:%d:%d not within the input area 0:0:%d:%d or zero-sized\n",
+ crop->x, crop->y, crop->w, crop->h, link->w, link->h);
+ return -1;
+ }
+
+ return 0;
+}
+
+static int config_output(AVFilterLink *link)
+{
+ CropContext *crop = link->src->priv;
+
+ link->w = crop->w;
+ link->h = crop->h;
+
+ return 0;
+}
+
+static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
+ int w, int h)
+{
+ return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
+}
+
+static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
+{
+ CropContext *crop = link->dst->priv;
+ AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
+ int i;
+
+ ref2->w = crop->w;
+ ref2->h = crop->h;
+
+ ref2->data[0] += crop->y * ref2->linesize[0];
+ ref2->data[0] += (crop->x * crop->bpp) >> 3;
+
+ if (link->format != PIX_FMT_PAL8) {
+ for (i = 1; i < 3; i ++) {
+ if (ref2->data[i]) {
+ ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];
+ ref2->data[i] += crop->x >> crop->hsub;
+ }
+ }
+ }
+
+ /* alpha plane */
+ if (ref2->data[3]) {
+ ref2->data[3] += crop->y * ref2->linesize[3];
+ ref2->data[3] += (crop->x * crop->bpp) >> 3;
+ }
+
+ avfilter_start_frame(link->dst->outputs[0], ref2);
+}
+
+static void draw_slice(AVFilterLink *link, int y, int h)
+{
+ AVFilterContext *ctx = link->dst;
+ CropContext *crop = ctx->priv;
+
+ if (y >= crop->y + crop->h || y + h <= crop->y)
+ return;
+
+ if (y < crop->y) {
+ h -= crop->y - y;
+ y = crop->y;
+ }
+ if (y + h > crop->y + crop->h)
+ h = crop->y + crop->h - y;
+
+ avfilter_draw_slice(ctx->outputs[0], y - crop->y, h);
+}
+
+AVFilter avfilter_vf_crop = {
+ .name = "crop",
+ .priv_size = sizeof(CropContext),
+
+ .query_formats = query_formats,
+ .init = init,
+
+ .inputs = (AVFilterPad[]) {{ .name = "default",
+ .type = CODEC_TYPE_VIDEO,
+ .start_frame = start_frame,
+ .draw_slice = draw_slice,
+ .get_video_buffer = get_video_buffer,
+ .config_props = config_input, },
+ { .name = NULL}},
+ .outputs = (AVFilterPad[]) {{ .name = "default",
+ .type = CODEC_TYPE_VIDEO,
+ .config_props = config_output, },
+ { .name = NULL}},
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 14:51:10 +0000