1 files changed, 83 insertions, 0 deletions
diff --git a/libavfilter/dualinput.c b/libavfilter/dualinput.c
new file mode 100644
index 0000000000..45f681078d
--- /dev/null
+++ b/libavfilter/dualinput.c
@@ -0,0 +1,83 @@
+/*
+ * 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
+ */
+
+#include "dualinput.h"
+#include "libavutil/timestamp.h"
+
+static int process_frame(FFFrameSync *fs)
+{
+    AVFilterContext *ctx = fs->parent;
+    FFDualInputContext *s = fs->opaque;
+    AVFrame *mainpic = NULL, *secondpic = NULL;
+    int ret = 0;
+
+    if ((ret = ff_framesync_get_frame(&s->fs, 0, &mainpic,   1)) < 0 ||
+        (ret = ff_framesync_get_frame(&s->fs, 1, &secondpic, 0)) < 0) {
+        av_frame_free(&mainpic);
+        return ret;
+    }
+    av_assert0(mainpic);
+    mainpic->pts = av_rescale_q(mainpic->pts, s->fs.time_base, ctx->outputs[0]->time_base);
+    if (secondpic && !ctx->is_disabled)
+        mainpic = s->process(ctx, mainpic, secondpic);
+    ret = ff_filter_frame(ctx->outputs[0], mainpic);
+    av_assert1(ret != AVERROR(EAGAIN));
+    return ret;
+}
+
+int ff_dualinput_init(AVFilterContext *ctx, FFDualInputContext *s)
+{
+    FFFrameSyncIn *in = s->fs.in;
+
+    ff_framesync_init(&s->fs, ctx, 2);
+    s->fs.opaque = s;
+    s->fs.on_event = process_frame;
+    in[0].time_base = ctx->inputs[0]->time_base;
+    in[1].time_base = ctx->inputs[1]->time_base;
+    in[0].sync   = 2;
+    in[0].before = EXT_STOP;
+    in[0].after  = EXT_INFINITY;
+    in[1].sync   = 1;
+    in[1].before = EXT_NULL;
+    in[1].after  = EXT_INFINITY;
+
+    if (s->shortest)
+        in[0].after = in[1].after = EXT_STOP;
+    if (!s->repeatlast) {
+        in[1].after = EXT_NULL;
+        in[1].sync  = 0;
+    }
+
+    return ff_framesync_configure(&s->fs);
+}
+
+int ff_dualinput_filter_frame(FFDualInputContext *s,
+                                   AVFilterLink *inlink, AVFrame *in)
+{
+    return ff_framesync_filter_frame(&s->fs, inlink, in);
+}
+
+int ff_dualinput_request_frame(FFDualInputContext *s, AVFilterLink *outlink)
+{
+    return ff_framesync_request_frame(&s->fs, outlink);
+}
+
+void ff_dualinput_uninit(FFDualInputContext *s)
+{
+    ff_framesync_uninit(&s->fs);
+}