#include "avfilter.h"
#include "libavutil/eval.h"
#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/imgutils.h"
#include "libavutil/mathematics.h"
#include "internal.h"
+#include "drawutils.h"
-static const char *var_names[] = {
+static const char * const var_names[] = {
"main_w", "W", ///< width of the main video
"main_h", "H", ///< height of the main video
"overlay_w", "w", ///< width of the overlay video
#define MAIN 0
#define OVERLAY 1
+#define R 0
+#define G 1
+#define B 2
+#define A 3
+
+#define Y 0
+#define U 1
+#define V 2
+
typedef struct {
+ const AVClass *class;
int x, y; ///< position of overlayed picture
+ int allow_packed_rgb;
+ uint8_t main_is_packed_rgb;
+ uint8_t main_rgba_map[4];
+ uint8_t main_has_alpha;
+ uint8_t overlay_is_packed_rgb;
+ uint8_t overlay_rgba_map[4];
+ uint8_t overlay_has_alpha;
+
AVFilterBufferRef *overpicref;
- int max_plane_step[4]; ///< steps per pixel for each plane
+ int main_pix_step[4]; ///< steps per pixel for each plane of the main output
+ int overlay_pix_step[4]; ///< steps per pixel for each plane of the overlay
int hsub, vsub; ///< chroma subsampling values
- char x_expr[256], y_expr[256];
+ char *x_expr, *y_expr;
} OverlayContext;
+#define OFFSET(x) offsetof(OverlayContext, x)
+
+static const AVOption overlay_options[] = {
+ { "x", "set the x expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX },
+ { "y", "set the y expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX },
+ {"rgb", "force packed RGB in input and output", OFFSET(allow_packed_rgb), AV_OPT_TYPE_INT, {.dbl=0}, 0, 1 },
+ {NULL},
+};
+
+static const char *overlay_get_name(void *ctx)
+{
+ return "overlay";
+}
+
+static const AVClass overlay_class = {
+ "OverlayContext",
+ overlay_get_name,
+ overlay_options
+};
+
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
OverlayContext *over = ctx->priv;
+ char *args1 = av_strdup(args);
+ char *expr, *bufptr = NULL;
+ int ret = 0;
- av_strlcpy(over->x_expr, "0", sizeof(over->x_expr));
- av_strlcpy(over->y_expr, "0", sizeof(over->y_expr));
+ over->class = &overlay_class;
+ av_opt_set_defaults(over);
+
+ if (expr = av_strtok(args1, ":", &bufptr)) {
+ if (!(over->x_expr = av_strdup(expr))) {
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+ }
+ if (expr = av_strtok(NULL, ":", &bufptr)) {
+ if (!(over->y_expr = av_strdup(expr))) {
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+ }
- if (args)
- sscanf(args, "%255[^:]:%255[^:]", over->x_expr, over->y_expr);
+ if (bufptr && (ret = av_set_options_string(over, bufptr, "=", ":")) < 0)
+ goto end;
- return 0;
+end:
+ av_free(args1);
+ return ret;
}
static av_cold void uninit(AVFilterContext *ctx)
{
OverlayContext *over = ctx->priv;
+ av_freep(&over->x_expr);
+ av_freep(&over->y_expr);
+
if (over->overpicref)
avfilter_unref_buffer(over->overpicref);
}
static int query_formats(AVFilterContext *ctx)
{
- const enum PixelFormat inout_pix_fmts[] = { PIX_FMT_YUV420P, PIX_FMT_NONE };
- const enum PixelFormat blend_pix_fmts[] = { PIX_FMT_YUVA420P, PIX_FMT_NONE };
- AVFilterFormats *inout_formats = avfilter_make_format_list(inout_pix_fmts);
- AVFilterFormats *blend_formats = avfilter_make_format_list(blend_pix_fmts);
+ OverlayContext *over = ctx->priv;
- avfilter_formats_ref(inout_formats, &ctx->inputs [MAIN ]->out_formats);
- avfilter_formats_ref(blend_formats, &ctx->inputs [OVERLAY]->out_formats);
- avfilter_formats_ref(inout_formats, &ctx->outputs[MAIN ]->in_formats );
+ /* overlay formats contains alpha, for avoiding conversion with alpha information loss */
+ const enum PixelFormat main_pix_fmts_yuv[] = { PIX_FMT_YUV420P, PIX_FMT_NONE };
+ const enum PixelFormat overlay_pix_fmts_yuv[] = { PIX_FMT_YUVA420P, PIX_FMT_NONE };
+ const enum PixelFormat main_pix_fmts_rgb[] = {
+ PIX_FMT_ARGB, PIX_FMT_RGBA,
+ PIX_FMT_ABGR, PIX_FMT_BGRA,
+ PIX_FMT_RGB24, PIX_FMT_BGR24,
+ PIX_FMT_NONE
+ };
+ const enum PixelFormat overlay_pix_fmts_rgb[] = {
+ PIX_FMT_ARGB, PIX_FMT_RGBA,
+ PIX_FMT_ABGR, PIX_FMT_BGRA,
+ PIX_FMT_NONE
+ };
+
+ AVFilterFormats *main_formats;
+ AVFilterFormats *overlay_formats;
+
+ if (over->allow_packed_rgb) {
+ main_formats = avfilter_make_format_list(main_pix_fmts_rgb);
+ overlay_formats = avfilter_make_format_list(overlay_pix_fmts_rgb);
+ } else {
+ main_formats = avfilter_make_format_list(main_pix_fmts_yuv);
+ overlay_formats = avfilter_make_format_list(overlay_pix_fmts_yuv);
+ }
+
+ avfilter_formats_ref(main_formats, &ctx->inputs [MAIN ]->out_formats);
+ avfilter_formats_ref(overlay_formats, &ctx->inputs [OVERLAY]->out_formats);
+ avfilter_formats_ref(main_formats, &ctx->outputs[MAIN ]->in_formats );
return 0;
}
+static const enum PixelFormat alpha_pix_fmts[] = {
+ PIX_FMT_YUVA420P, PIX_FMT_ARGB, PIX_FMT_ABGR, PIX_FMT_RGBA,
+ PIX_FMT_BGRA, PIX_FMT_NONE
+};
+
static int config_input_main(AVFilterLink *inlink)
{
OverlayContext *over = inlink->dst->priv;
const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
- av_image_fill_max_pixsteps(over->max_plane_step, NULL, pix_desc);
+ av_image_fill_max_pixsteps(over->main_pix_step, NULL, pix_desc);
+
over->hsub = pix_desc->log2_chroma_w;
over->vsub = pix_desc->log2_chroma_h;
+ over->main_is_packed_rgb =
+ ff_fill_rgba_map(over->main_rgba_map, inlink->format) >= 0;
+ over->main_has_alpha = ff_fmt_is_in(inlink->format, alpha_pix_fmts);
return 0;
}
char *expr;
double var_values[VAR_VARS_NB], res;
int ret;
+ const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
+
+ av_image_fill_max_pixsteps(over->overlay_pix_step, NULL, pix_desc);
/* Finish the configuration by evaluating the expressions
now when both inputs are configured. */
goto fail;
over->x = res;
+ over->overlay_is_packed_rgb =
+ ff_fill_rgba_map(over->overlay_rgba_map, inlink->format) >= 0;
+ over->overlay_has_alpha = ff_fmt_is_in(inlink->format, alpha_pix_fmts);
+
av_log(ctx, AV_LOG_INFO,
"main w:%d h:%d fmt:%s overlay x:%d y:%d w:%d h:%d fmt:%s\n",
ctx->inputs[MAIN]->w, ctx->inputs[MAIN]->h,
ctx->outputs[0]->time_base);
}
+// divide by 255 and round to nearest
+// apply a fast variant: (X+127)/255 = ((X+127)*257+257)>>16 = ((X+128)*257)>>16
+#define FAST_DIV255(x) ((((x) + 128) * 257) >> 16)
+
static void blend_slice(AVFilterContext *ctx,
AVFilterBufferRef *dst, AVFilterBufferRef *src,
int x, int y, int w, int h,
start_y = FFMAX(y, slice_y);
height = end_y - start_y;
- if (dst->format == PIX_FMT_BGR24 || dst->format == PIX_FMT_RGB24) {
- uint8_t *dp = dst->data[0] + x * 3 + start_y * dst->linesize[0];
+ if (over->main_is_packed_rgb) {
+ uint8_t *dp = dst->data[0] + x * over->main_pix_step[0] +
+ start_y * dst->linesize[0];
uint8_t *sp = src->data[0];
- int b = dst->format == PIX_FMT_BGR24 ? 2 : 0;
- int r = dst->format == PIX_FMT_BGR24 ? 0 : 2;
+ uint8_t alpha; ///< the amount of overlay to blend on to main
+ const int dr = over->main_rgba_map[R];
+ const int dg = over->main_rgba_map[G];
+ const int db = over->main_rgba_map[B];
+ const int da = over->main_rgba_map[A];
+ const int dstep = over->main_pix_step[0];
+ const int sr = over->overlay_rgba_map[R];
+ const int sg = over->overlay_rgba_map[G];
+ const int sb = over->overlay_rgba_map[B];
+ const int sa = over->overlay_rgba_map[A];
+ const int sstep = over->overlay_pix_step[0];
+ const int main_has_alpha = over->main_has_alpha;
if (slice_y > y)
sp += (slice_y - y) * src->linesize[0];
for (i = 0; i < height; i++) {
uint8_t *d = dp, *s = sp;
for (j = 0; j < width; j++) {
- d[r] = (d[r] * (0xff - s[3]) + s[0] * s[3] + 128) >> 8;
- d[1] = (d[1] * (0xff - s[3]) + s[1] * s[3] + 128) >> 8;
- d[b] = (d[b] * (0xff - s[3]) + s[2] * s[3] + 128) >> 8;
- d += 3;
- s += 4;
+ alpha = s[sa];
+
+ // if the main channel has an alpha channel, alpha has to be calculated
+ // to create an un-premultiplied (straight) alpha value
+ if (main_has_alpha && alpha != 0 && alpha != 255) {
+ // apply the general equation:
+ // alpha = alpha_overlay / ( (alpha_main + alpha_overlay) - (alpha_main * alpha_overlay) )
+ alpha =
+ // the next line is a faster version of: 255 * 255 * alpha
+ ( (alpha << 16) - (alpha << 9) + alpha )
+ /
+ // the next line is a faster version of: 255 * (alpha + d[da])
+ ( ((alpha + d[da]) << 8 ) - (alpha + d[da])
+ - d[da] * alpha );
+ }
+
+ switch (alpha) {
+ case 0:
+ break;
+ case 255:
+ d[dr] = s[sr];
+ d[dg] = s[sg];
+ d[db] = s[sb];
+ break;
+ default:
+ // main_value = main_value * (1 - alpha) + overlay_value * alpha
+ // since alpha is in the range 0-255, the result must divided by 255
+ d[dr] = FAST_DIV255(d[dr] * (255 - alpha) + s[sr] * alpha);
+ d[dg] = FAST_DIV255(d[dg] * (255 - alpha) + s[sg] * alpha);
+ d[db] = FAST_DIV255(d[db] * (255 - alpha) + s[sb] * alpha);
+ }
+ if (main_has_alpha) {
+ switch (alpha) {
+ case 0:
+ break;
+ case 255:
+ d[da] = s[sa];
+ break;
+ default:
+ // apply alpha compositing: main_alpha += (1-main_alpha) * overlay_alpha
+ d[da] += FAST_DIV255((255 - d[da]) * s[sa]);
+ }
+ }
+ d += dstep;
+ s += sstep;
}
dp += dst->linesize[0];
sp += src->linesize[0];
alpha = (alpha_v + alpha_h) >> 1;
} else
alpha = a[0];
- *d = (*d * (0xff - alpha) + *s++ * alpha + 128) >> 8;
+ *d = FAST_DIV255(*d * (255 - alpha) + *s * alpha);
+ s++;
d++;
a += 1 << hsub;
}
.query_formats = query_formats,
- .inputs = (AVFilterPad[]) {{ .name = "main",
+ .inputs = (const AVFilterPad[]) {{ .name = "main",
.type = AVMEDIA_TYPE_VIDEO,
.start_frame = start_frame,
.get_video_buffer= get_video_buffer,
.min_perms = AV_PERM_READ,
.rej_perms = AV_PERM_REUSE2, },
{ .name = NULL}},
- .outputs = (AVFilterPad[]) {{ .name = "default",
+ .outputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output, },
{ .name = NULL}},
projects / ffmpeg / blobdiff