[FFmpeg-cvslog] avfilter/xstack: Add support for fixed size grid
Vignesh Venkatasubramanian
git at videolan.org
Mon Jul 4 20:49:07 EEST 2022
ffmpeg | branch: master | Vignesh Venkatasubramanian <vigneshv-at-google.com at ffmpeg.org> | Wed Jun 29 10:14:26 2022 -0700| [aa8905a1b13c6ac206d532afbad953dc71319247] | committer: Paul B Mahol
avfilter/xstack: Add support for fixed size grid
Add a short hand parameter for making a fixed size grid. The existing
xstack layout parameter syntax gets tedious if all one wants is a
matrix like grid of the input streams. Add a grid option to the xstack
filter that simplifies this use case by simply specifying the number of
rows and columns instead of specific x/y co-ordinate for each stream.
Also updating the filter documentation to explain the new option.
Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=aa8905a1b13c6ac206d532afbad953dc71319247
---
doc/filters.texi | 22 ++++++++++++--
libavfilter/vf_stack.c | 80 ++++++++++++++++++++++++++++++++++++++++++--------
2 files changed, 87 insertions(+), 15 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index e525e87b3c..5a889895c6 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -24381,8 +24381,26 @@ the output video frame will be filled. Similarly, videos can overlap each
other if their position doesn't leave enough space for the full frame of
adjoining videos.
-For 2 inputs, a default layout of @code{0_0|w0_0} is set. In all other cases,
-a layout must be set by the user.
+For 2 inputs, a default layout of @code{0_0|w0_0} (equivalent to
+ at code{grid=2x1}) is set. In all other cases, a layout or a grid must be set by
+the user. Either @code{grid} or @code{layout} can be specified at a time.
+Specifying both will result in an error.
+
+ at item grid
+Specify a fixed size grid of inputs.
+This option is used to create a fixed size grid of the input streams. Set the
+grid size in the form @code{COLUMNSxROWS}. There must be @code{ROWS * COLUMNS}
+input streams and they will be arranged as a grid with @code{ROWS} rows and
+ at code{COLUMNS} columns. When using this option, each input stream within a row
+must have the same height and all the rows must have the same width.
+
+If @code{grid} is set, then @code{inputs} option is ignored and is implicitly
+set to @code{ROWS * COLUMNS}.
+
+For 2 inputs, a default grid of @code{2x1} (equivalent to
+ at code{layout=0_0|w0_0}) is set. In all other cases, a layout or a grid must be
+set by the user. Either @code{grid} or @code{layout} can be specified at a time.
+Specifying both will result in an error.
@item shortest
If set to 1, force the output to terminate when the shortest input
diff --git a/libavfilter/vf_stack.c b/libavfilter/vf_stack.c
index aa32a1bf5e..331dc7b3e3 100644
--- a/libavfilter/vf_stack.c
+++ b/libavfilter/vf_stack.c
@@ -48,6 +48,8 @@ typedef struct StackContext {
int is_vertical;
int is_horizontal;
int nb_planes;
+ int nb_grid_columns;
+ int nb_grid_rows;
uint8_t fillcolor[4];
char *fillcolor_str;
int fillcolor_enable;
@@ -85,33 +87,42 @@ static av_cold int init(AVFilterContext *ctx)
if (!strcmp(ctx->filter->name, "hstack"))
s->is_horizontal = 1;
- s->frames = av_calloc(s->nb_inputs, sizeof(*s->frames));
- if (!s->frames)
- return AVERROR(ENOMEM);
-
- s->items = av_calloc(s->nb_inputs, sizeof(*s->items));
- if (!s->items)
- return AVERROR(ENOMEM);
-
if (!strcmp(ctx->filter->name, "xstack")) {
+ int is_grid;
if (strcmp(s->fillcolor_str, "none") &&
av_parse_color(s->fillcolor, s->fillcolor_str, -1, ctx) >= 0) {
s->fillcolor_enable = 1;
} else {
s->fillcolor_enable = 0;
}
- if (!s->layout) {
+ is_grid = s->nb_grid_rows && s->nb_grid_columns;
+ if (s->layout && is_grid) {
+ av_log(ctx, AV_LOG_ERROR, "Both layout and grid were specified. Only one is allowed.\n");
+ return AVERROR(EINVAL);
+ }
+ if (!s->layout && !is_grid) {
if (s->nb_inputs == 2) {
- s->layout = av_strdup("0_0|w0_0");
- if (!s->layout)
- return AVERROR(ENOMEM);
+ s->nb_grid_rows = 1;
+ s->nb_grid_columns = 2;
+ is_grid = 1;
} else {
- av_log(ctx, AV_LOG_ERROR, "No layout specified.\n");
+ av_log(ctx, AV_LOG_ERROR, "No layout or grid specified.\n");
return AVERROR(EINVAL);
}
}
+
+ if (is_grid)
+ s->nb_inputs = s->nb_grid_rows * s->nb_grid_columns;
}
+ s->frames = av_calloc(s->nb_inputs, sizeof(*s->frames));
+ if (!s->frames)
+ return AVERROR(ENOMEM);
+
+ s->items = av_calloc(s->nb_inputs, sizeof(*s->items));
+ if (!s->items)
+ return AVERROR(ENOMEM);
+
for (i = 0; i < s->nb_inputs; i++) {
AVFilterPad pad = { 0 };
@@ -244,6 +255,48 @@ static int config_output(AVFilterLink *outlink)
width += ctx->inputs[i]->w;
}
}
+ } else if (s->nb_grid_rows && s->nb_grid_columns) {
+ int inw = 0, inh = 0;
+ int k = 0;
+ int row_height;
+ height = 0;
+ width = 0;
+ for (i = 0; i < s->nb_grid_rows; i++, inh += row_height) {
+ row_height = ctx->inputs[i * s->nb_grid_columns]->h;
+ inw = 0;
+ for (int j = 0; j < s->nb_grid_columns; j++, k++) {
+ AVFilterLink *inlink = ctx->inputs[k];
+ StackItem *item = &s->items[k];
+
+ if (ctx->inputs[k]->h != row_height) {
+ av_log(ctx, AV_LOG_ERROR, "Input %d height %d does not match current row's height %d.\n",
+ k, ctx->inputs[k]->h, row_height);
+ return AVERROR(EINVAL);
+ }
+
+ if ((ret = av_image_fill_linesizes(item->linesize, inlink->format, inlink->w)) < 0) {
+ return ret;
+ }
+
+ item->height[1] = item->height[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
+ item->height[0] = item->height[3] = inlink->h;
+
+ if ((ret = av_image_fill_linesizes(item->x, inlink->format, inw)) < 0) {
+ return ret;
+ }
+
+ item->y[1] = item->y[2] = AV_CEIL_RSHIFT(inh, s->desc->log2_chroma_h);
+ item->y[0] = item->y[3] = inh;
+ inw += ctx->inputs[k]->w;
+ }
+ height += row_height;
+ if (!i)
+ width = inw;
+ if (i && width != inw) {
+ av_log(ctx, AV_LOG_ERROR, "Row %d width %d does not match previous row width %d.\n", i, inw, width);
+ return AVERROR(EINVAL);
+ }
+ }
} else {
char *arg, *p = s->layout, *saveptr = NULL;
char *arg2, *p2, *saveptr2 = NULL;
@@ -436,6 +489,7 @@ const AVFilter ff_vf_vstack = {
static const AVOption xstack_options[] = {
{ "inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=2}, 2, INT_MAX, .flags = FLAGS },
{ "layout", "set custom layout", OFFSET(layout), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, .flags = FLAGS },
+ { "grid", "set fixed size grid layout", OFFSET(nb_grid_columns), AV_OPT_TYPE_IMAGE_SIZE, {.str=NULL}, 0, 0, .flags = FLAGS },
{ "shortest", "force termination when the shortest input terminates", OFFSET(shortest), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, .flags = FLAGS },
{ "fill", "set the color for unused pixels", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str = "none"}, .flags = FLAGS },
{ NULL },
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