[FFmpeg-devel] [WIP] [PATCH 2/2] lavfi/vf_framematch: add filter to output matching synchronized frames

[Nicolas George]

Signed-off-by: Nicolas George <george at nsup.org>
---
 libavfilter/Makefile        |  1 +
 libavfilter/allfilters.c    |  1 +
 libavfilter/vf_framematch.c | 82 +++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+)
 create mode 100644 libavfilter/vf_framematch.c


Unfinished yet, but should be rather straightforward. I think I can
squeeze some work on this the day after tomorrow.


diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 9b7813575a..290a473b63 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -313,6 +313,7 @@ OBJS-$(CONFIG_FIND_RECT_FILTER)              += vf_find_rect.o lavfutils.o
 OBJS-$(CONFIG_FLOODFILL_FILTER)              += vf_floodfill.o
 OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o
 OBJS-$(CONFIG_FPS_FILTER)                    += vf_fps.o
+OBJS-$(CONFIG_FRAMEMATCH_FILTER)             += vf_framematch.o
 OBJS-$(CONFIG_FRAMEPACK_FILTER)              += vf_framepack.o
 OBJS-$(CONFIG_FRAMERATE_FILTER)              += vf_framerate.o
 OBJS-$(CONFIG_FRAMESTEP_FILTER)              += vf_framestep.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 9a7fadc58d..aa42b353c1 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -289,6 +289,7 @@ extern const AVFilter ff_vf_flip_vulkan;
 extern const AVFilter ff_vf_floodfill;
 extern const AVFilter ff_vf_format;
 extern const AVFilter ff_vf_fps;
+extern const AVFilter ff_vf_framematch;
 extern const AVFilter ff_vf_framepack;
 extern const AVFilter ff_vf_framerate;
 extern const AVFilter ff_vf_framestep;
diff --git a/libavfilter/vf_framematch.c b/libavfilter/vf_framematch.c
new file mode 100644
index 0000000000..703b5ad93b
--- /dev/null
+++ b/libavfilter/vf_framematch.c
@@ -0,0 +1,82 @@
+
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+
+#include "avfilter.h"
+#include "framesync.h"
+#include "internal.h"
+
+typedef struct MatchContext {
+    const AVClass *class;
+    int nb;
+    FFFrameSync fs;
+} MatchContext;
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    int i, ret;
+    MatchContext *s = ctx->priv;
+
+    for (i = 0; i < s->nb; i++) {
+        AVFilterPad pad = { 0 };
+        pad.type = AVMEDIA_TYPE_VIDEO;
+        pad.name = av_asprintf("input%d", i);
+        if (!pad.name)
+            return AVERROR(ENOMEM);
+        if ((ret = ff_append_inpad_free_name(ctx, &pad)) < 0)
+            return ret;
+        pad.name = av_asprintf("output%d", i);
+        if (!pad.name)
+            return AVERROR(ENOMEM);
+        if ((ret = ff_append_outpad_free_name(ctx, &pad)) < 0)
+            return ret;
+    }
+    return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    MatchContext *s = ctx->priv;
+    int i, ret;
+
+    for (i = 0; i < s->nb; i++) {
+        AVFilterFormats *f = ff_all_formats(AVMEDIA_TYPE_AUDIO);
+        if ((ret = ff_formats_ref(f, &ctx->inputs [i]-> incfg.formats)) < 0 ||
+            (ret = ff_formats_ref(f, &ctx->outputs[i]->outcfg.formats)) < 0)
+            return ret;
+    }
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    MatchContext *s = ctx->priv;
+    //ff_framesync_uninit(&s->fs);
+}
+
+static int activate(AVFilterContext *ctx)
+{
+    MatchContext *s = ctx->priv;
+    return ff_framesync_activate(&s->fs);
+}
+
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+#define OFFSET(x) offsetof(MatchContext, x)
+static const AVOption framematch_options[] = {
+    { "s", "set number of streams", OFFSET(nb), AV_OPT_TYPE_INT, {.i64=2}, 2, INT_MAX, .flags = FLAGS },
+    { NULL },
+};
+
+AVFILTER_DEFINE_CLASS(framematch);
+
+const AVFilter ff_vf_framematch = {
+    .name          = "framematch",
+    .description   = NULL_IF_CONFIG_SMALL("Match frames from multiple inputs"),
+    .priv_size     = sizeof(MatchContext),
+    .priv_class    = &framematch_class,
+    FILTER_QUERY_FUNC(query_formats),
+    .init          = init,
+    .uninit        = uninit,
+    .activate      = activate,
+    .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_DYNAMIC_OUTPUTS,
+};
-- 
2.39.2