lavfi: add dual input helpers.

4 files changed, 227 insertions, 135 deletions

diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index f53afb2bab..9682cba216 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -157,7 +157,7 @@ OBJS-$(CONFIG_NOISE_FILTER)                  += vf_noise.o
 OBJS-$(CONFIG_NULL_FILTER)                   += vf_null.o
 OBJS-$(CONFIG_OCV_FILTER)                    += vf_libopencv.o
 OBJS-$(CONFIG_OPENCL)                        += deshake_opencl.o unsharp_opencl.o
-OBJS-$(CONFIG_OVERLAY_FILTER)                += vf_overlay.o
+OBJS-$(CONFIG_OVERLAY_FILTER)                += vf_overlay.o dualinput.o
 OBJS-$(CONFIG_OWDENOISE_FILTER)              += vf_owdenoise.o
 OBJS-$(CONFIG_PAD_FILTER)                    += vf_pad.o
 OBJS-$(CONFIG_PERMS_FILTER)                  += f_perms.o
diff --git a/libavfilter/dualinput.c b/libavfilter/dualinput.c
new file mode 100644
index 0000000000..10e365267b
--- /dev/null
+++ b/libavfilter/dualinput.c
@@ -0,0 +1,159 @@
+/*
+ * 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
+ */
+
+#define MAIN  0
+#define SECOND 1
+
+#include "dualinput.h"
+#include "libavutil/timestamp.h"
+
+static int try_filter_frame(FFDualInputContext *s,
+                            AVFilterContext *ctx, AVFrame *mainpic)
+{
+    int ret;
+
+    /* Discard obsolete second frames: if there is a next second frame with pts
+     * before the main frame, we can drop the current second. */
+    while (1) {
+        AVFrame *next_overpic = ff_bufqueue_peek(&s->queue[SECOND], 0);
+        if (!next_overpic && s->second_eof && !s->repeatlast) {
+            av_frame_free(&s->second_frame);
+            break;
+        }
+        if (!next_overpic || av_compare_ts(next_overpic->pts, ctx->inputs[SECOND]->time_base,
+                                           mainpic->pts,      ctx->inputs[MAIN]->time_base) > 0)
+            break;
+        ff_bufqueue_get(&s->queue[SECOND]);
+        av_frame_free(&s->second_frame);
+        s->second_frame = next_overpic;
+    }
+
+    /* If there is no next frame and no EOF and the second frame is before
+     * the main frame, we can not know yet if it will be superseded. */
+    if (!s->queue[SECOND].available && !s->second_eof &&
+        (!s->second_frame || av_compare_ts(s->second_frame->pts, ctx->inputs[SECOND]->time_base,
+                                           mainpic->pts,         ctx->inputs[MAIN]->time_base) < 0))
+        return AVERROR(EAGAIN);
+
+    /* At this point, we know that the current second frame extends to the
+     * time of the main frame. */
+    av_dlog(ctx, "main_pts:%s main_pts_time:%s",
+            av_ts2str(mainpic->pts), av_ts2timestr(mainpic->pts, &ctx->inputs[MAIN]->time_base));
+    if (s->second_frame)
+        av_dlog(ctx, " second_pts:%s second_pts_time:%s",
+                av_ts2str(s->second_frame->pts), av_ts2timestr(s->second_frame->pts, &ctx->inputs[SECOND]->time_base));
+    av_dlog(ctx, "\n");
+
+    if (s->second_frame && !ctx->is_disabled)
+        mainpic = s->process(ctx, mainpic, s->second_frame);
+    ret = ff_filter_frame(ctx->outputs[0], mainpic);
+    av_assert1(ret != AVERROR(EAGAIN));
+    s->frame_requested = 0;
+    return ret;
+}
+
+static int try_filter_next_frame(FFDualInputContext *s, AVFilterContext *ctx)
+{
+    AVFrame *next_mainpic = ff_bufqueue_peek(&s->queue[MAIN], 0);
+    int ret;
+
+    if (!next_mainpic)
+        return AVERROR(EAGAIN);
+    if ((ret = try_filter_frame(s, ctx, next_mainpic)) == AVERROR(EAGAIN))
+        return ret;
+    ff_bufqueue_get(&s->queue[MAIN]);
+    return ret;
+}
+
+static int flush_frames(FFDualInputContext *s, AVFilterContext *ctx)
+{
+    int ret;
+
+    while (!(ret = try_filter_next_frame(s, ctx)));
+    return ret == AVERROR(EAGAIN) ? 0 : ret;
+}
+
+int ff_dualinput_filter_frame_main(FFDualInputContext *s,
+                                   AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    int ret;
+
+    if ((ret = flush_frames(s, ctx)) < 0)
+        return ret;
+    if ((ret = try_filter_frame(s, ctx, in)) < 0) {
+        if (ret != AVERROR(EAGAIN))
+            return ret;
+        ff_bufqueue_add(ctx, &s->queue[MAIN], in);
+    }
+
+    if (!s->second_frame)
+        return 0;
+    flush_frames(s, ctx);
+
+    return 0;
+}
+
+int ff_dualinput_filter_frame_second(FFDualInputContext *s,
+                                     AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    int ret;
+
+    if ((ret = flush_frames(s, ctx)) < 0)
+        return ret;
+    ff_bufqueue_add(ctx, &s->queue[SECOND], in);
+    ret = try_filter_next_frame(s, ctx);
+    return ret == AVERROR(EAGAIN) ? 0 : ret;
+}
+
+int ff_dualinput_request_frame(FFDualInputContext *s, AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    int input, ret;
+
+    if (!try_filter_next_frame(s, ctx))
+        return 0;
+    s->frame_requested = 1;
+    while (s->frame_requested) {
+        /* TODO if we had a frame duration, we could guess more accurately */
+        input = !s->second_eof && (s->queue[MAIN].available ||
+                                   s->queue[SECOND].available < 2) ?
+                SECOND : MAIN;
+        ret = ff_request_frame(ctx->inputs[input]);
+        /* EOF on main is reported immediately */
+        if (ret == AVERROR_EOF && input == SECOND) {
+            s->second_eof = 1;
+            if (s->shortest)
+                return ret;
+            if ((ret = try_filter_next_frame(s, ctx)) != AVERROR(EAGAIN))
+                return ret;
+            ret = 0; /* continue requesting frames on main */
+        }
+        if (ret < 0)
+            return ret;
+    }
+    return 0;
+}
+
+void ff_dualinput_uninit(FFDualInputContext *s)
+{
+    av_frame_free(&s->second_frame);
+    ff_bufqueue_discard_all(&s->queue[MAIN]);
+    ff_bufqueue_discard_all(&s->queue[SECOND]);
+}
diff --git a/libavfilter/dualinput.h b/libavfilter/dualinput.h
new file mode 100644
index 0000000000..98d05442c7
--- /dev/null
+++ b/libavfilter/dualinput.h
@@ -0,0 +1,46 @@
+/*
+ * 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
+ * Double input streams helper for filters
+ */
+
+#ifndef AVFILTER_DUALINPUT_H
+#define AVFILTER_DUALINPUT_H
+
+#include <stdint.h>
+#include "bufferqueue.h"
+#include "internal.h"
+
+typedef struct {
+    uint8_t frame_requested;
+    uint8_t second_eof;
+    AVFrame *second_frame;
+    struct FFBufQueue queue[2];
+    AVFrame *(*process)(AVFilterContext *ctx, AVFrame *main, const AVFrame *second);
+    int shortest;               ///< terminate stream when the second input terminates
+    int repeatlast;             ///< repeat last second frame
+} FFDualInputContext;
+
+int ff_dualinput_filter_frame_main(FFDualInputContext *s, AVFilterLink *inlink, AVFrame *in);
+int ff_dualinput_filter_frame_second(FFDualInputContext *s, AVFilterLink *inlink, AVFrame *in);
+int ff_dualinput_request_frame(FFDualInputContext *s, AVFilterLink *outlink);
+void ff_dualinput_uninit(FFDualInputContext *s);
+
+#endif /* AVFILTER_DUALINPUT_H */
diff --git a/libavfilter/vf_overlay.c b/libavfilter/vf_overlay.c
index 478d6504fd..e6d949f2b3 100644
--- a/libavfilter/vf_overlay.c
+++ b/libavfilter/vf_overlay.c
@@ -25,8 +25,6 @@
  * overlay one video on top of another
  */
 
-/* #define DEBUG */
-
 #include "avfilter.h"
 #include "formats.h"
 #include "libavutil/common.h"
@@ -37,9 +35,8 @@
 #include "libavutil/imgutils.h"
 #include "libavutil/mathematics.h"
 #include "libavutil/opt.h"
-#include "libavutil/timestamp.h"
 #include "internal.h"
-#include "bufferqueue.h"
+#include "dualinput.h"
 #include "drawutils.h"
 #include "video.h"
 
@@ -90,8 +87,6 @@ typedef struct {
     int x, y;                   ///< position of overlayed picture
 
     int allow_packed_rgb;
-    uint8_t frame_requested;
-    uint8_t overlay_eof;
     uint8_t main_is_packed_rgb;
     uint8_t main_rgba_map[4];
     uint8_t main_has_alpha;
@@ -101,21 +96,20 @@ typedef struct {
     enum OverlayFormat { OVERLAY_FORMAT_YUV420, OVERLAY_FORMAT_YUV444, OVERLAY_FORMAT_RGB, OVERLAY_FORMAT_NB} format;
     enum EvalMode { EVAL_MODE_INIT, EVAL_MODE_FRAME, EVAL_MODE_NB } eval_mode;
 
-    AVFrame *overpicref;
-    struct FFBufQueue queue_main;
-    struct FFBufQueue queue_over;
+    FFDualInputContext dinput;
 
     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
-    int shortest;               ///< terminate stream when the shortest input terminates
-    int repeatlast;             ///< repeat last overlay frame
 
     double var_values[VAR_VARS_NB];
     char *x_expr, *y_expr;
     AVExpr *x_pexpr, *y_pexpr;
 } OverlayContext;
 
+// TODO: remove forward declaration
+static AVFrame *do_blend(AVFilterContext *ctx, AVFrame *mainpic, const AVFrame *second);
+
 static av_cold int init(AVFilterContext *ctx)
 {
     OverlayContext *s = ctx->priv;
@@ -125,6 +119,7 @@ static av_cold int init(AVFilterContext *ctx)
                "The rgb option is deprecated and is overriding the format option, use format instead\n");
         s->format = OVERLAY_FORMAT_RGB;
     }
+    s->dinput.process = do_blend;
     return 0;
 }
 
@@ -132,9 +127,7 @@ static av_cold void uninit(AVFilterContext *ctx)
 {
     OverlayContext *s = ctx->priv;
 
-    av_frame_free(&s->overpicref);
-    ff_bufqueue_discard_all(&s->queue_main);
-    ff_bufqueue_discard_all(&s->queue_over);
+    ff_dualinput_uninit(&s->dinput);
     av_expr_free(s->x_pexpr); s->x_pexpr = NULL;
     av_expr_free(s->y_pexpr); s->y_pexpr = NULL;
 }
@@ -355,7 +348,7 @@ static int config_output(AVFilterLink *outlink)
  * Blend image in src to destination buffer dst at position (x, y).
  */
 static void blend_image(AVFilterContext *ctx,
-                        AVFrame *dst, AVFrame *src,
+                        AVFrame *dst, const AVFrame *src,
                         int x, int y)
 {
     OverlayContext *s = ctx->priv;
@@ -542,46 +535,13 @@ static void blend_image(AVFilterContext *ctx,
     }
 }
 
-static int try_filter_frame(AVFilterContext *ctx, AVFrame *mainpic)
+static AVFrame *do_blend(AVFilterContext *ctx, AVFrame *mainpic,
+                         const AVFrame *second)
 {
     OverlayContext *s = ctx->priv;
     AVFilterLink *inlink = ctx->inputs[0];
-    AVFrame *next_overpic;
-    int ret;
-
-    /* Discard obsolete overlay frames: if there is a next overlay frame with pts
-     * before the main frame, we can drop the current overlay. */
-    while (1) {
-        next_overpic = ff_bufqueue_peek(&s->queue_over, 0);
-        if (!next_overpic && s->overlay_eof && !s->repeatlast) {
-            av_frame_free(&s->overpicref);
-            break;
-        }
-        if (!next_overpic || av_compare_ts(next_overpic->pts, ctx->inputs[OVERLAY]->time_base,
-                                           mainpic->pts     , ctx->inputs[MAIN]->time_base) > 0)
-            break;
-        ff_bufqueue_get(&s->queue_over);
-        av_frame_free(&s->overpicref);
-        s->overpicref = next_overpic;
-    }
 
-    /* If there is no next frame and no EOF and the overlay frame is before
-     * the main frame, we can not know yet if it will be superseded. */
-    if (!s->queue_over.available && !s->overlay_eof &&
-        (!s->overpicref || av_compare_ts(s->overpicref->pts, ctx->inputs[OVERLAY]->time_base,
-                                            mainpic->pts         , ctx->inputs[MAIN]->time_base) < 0))
-        return AVERROR(EAGAIN);
-
-    /* At this point, we know that the current overlay frame extends to the
-     * time of the main frame. */
-    av_dlog(ctx, "main_pts:%s main_pts_time:%s",
-            av_ts2str(mainpic->pts), av_ts2timestr(mainpic->pts, &ctx->inputs[MAIN]->time_base));
-    if (s->overpicref)
-        av_dlog(ctx, " over_pts:%s over_pts_time:%s",
-                av_ts2str(s->overpicref->pts), av_ts2timestr(s->overpicref->pts, &ctx->inputs[OVERLAY]->time_base));
-    av_dlog(ctx, "\n");
-
-    if (s->overpicref) {
+        /* TODO: reindent */
         if (s->eval_mode == EVAL_MODE_FRAME) {
             int64_t pos = av_frame_get_pkt_pos(mainpic);
 
@@ -596,100 +556,27 @@ static int try_filter_frame(AVFilterContext *ctx, AVFrame *mainpic)
                    s->var_values[VAR_X], s->x,
                    s->var_values[VAR_Y], s->y);
         }
-        if (!ctx->is_disabled)
-            blend_image(ctx, mainpic, s->overpicref, s->x, s->y);
-
-    }
-    ret = ff_filter_frame(ctx->outputs[0], mainpic);
-    av_assert1(ret != AVERROR(EAGAIN));
-    s->frame_requested = 0;
-    return ret;
-}
-
-static int try_filter_next_frame(AVFilterContext *ctx)
-{
-    OverlayContext *s = ctx->priv;
-    AVFrame *next_mainpic = ff_bufqueue_peek(&s->queue_main, 0);
-    int ret;
-
-    if (!next_mainpic)
-        return AVERROR(EAGAIN);
-    if ((ret = try_filter_frame(ctx, next_mainpic)) == AVERROR(EAGAIN))
-        return ret;
-    ff_bufqueue_get(&s->queue_main);
-    return ret;
-}
-
-static int flush_frames(AVFilterContext *ctx)
-{
-    int ret;
 
-    while (!(ret = try_filter_next_frame(ctx)));
-    return ret == AVERROR(EAGAIN) ? 0 : ret;
+    blend_image(ctx, mainpic, second, s->x, s->y);
+    return mainpic;
 }
 
 static int filter_frame_main(AVFilterLink *inlink, AVFrame *inpicref)
 {
-    AVFilterContext *ctx = inlink->dst;
-    OverlayContext *s = ctx->priv;
-    int ret;
-
-    if ((ret = flush_frames(ctx)) < 0)
-        return ret;
-    if ((ret = try_filter_frame(ctx, inpicref)) < 0) {
-        if (ret != AVERROR(EAGAIN))
-            return ret;
-        ff_bufqueue_add(ctx, &s->queue_main, inpicref);
-    }
-
-    if (!s->overpicref)
-        return 0;
-    flush_frames(ctx);
-
-    return 0;
+    OverlayContext *s = inlink->dst->priv;
+    return ff_dualinput_filter_frame_main(&s->dinput, inlink, inpicref);
 }
 
 static int filter_frame_over(AVFilterLink *inlink, AVFrame *inpicref)
 {
-    AVFilterContext *ctx = inlink->dst;
-    OverlayContext *s = ctx->priv;
-    int ret;
-
-    if ((ret = flush_frames(ctx)) < 0)
-        return ret;
-    ff_bufqueue_add(ctx, &s->queue_over, inpicref);
-    ret = try_filter_next_frame(ctx);
-    return ret == AVERROR(EAGAIN) ? 0 : ret;
+    OverlayContext *s = inlink->dst->priv;
+    return ff_dualinput_filter_frame_second(&s->dinput, inlink, inpicref);
 }
 
 static int request_frame(AVFilterLink *outlink)
 {
-    AVFilterContext *ctx = outlink->src;
-    OverlayContext *s = ctx->priv;
-    int input, ret;
-
-    if (!try_filter_next_frame(ctx))
-        return 0;
-    s->frame_requested = 1;
-    while (s->frame_requested) {
-        /* TODO if we had a frame duration, we could guess more accurately */
-        input = !s->overlay_eof && (s->queue_main.available ||
-                                       s->queue_over.available < 2) ?
-                OVERLAY : MAIN;
-        ret = ff_request_frame(ctx->inputs[input]);
-        /* EOF on main is reported immediately */
-        if (ret == AVERROR_EOF && input == OVERLAY) {
-            s->overlay_eof = 1;
-            if (s->shortest)
-                return ret;
-            if ((ret = try_filter_next_frame(ctx)) != AVERROR(EAGAIN))
-                return ret;
-            ret = 0; /* continue requesting frames on main */
-        }
-        if (ret < 0)
-            return ret;
-    }
-    return 0;
+    OverlayContext *s = outlink->src->priv;
+    return ff_dualinput_request_frame(&s->dinput, outlink);
 }
 
 #define OFFSET(x) offsetof(OverlayContext, x)
@@ -702,12 +589,12 @@ static const AVOption overlay_options[] = {
          { "init",  "eval expressions once during initialization", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_INIT},  .flags = FLAGS, .unit = "eval" },
          { "frame", "eval expressions per-frame",                  0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_FRAME}, .flags = FLAGS, .unit = "eval" },
     { "rgb", "force packed RGB in input and output (deprecated)", OFFSET(allow_packed_rgb), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
-    { "shortest", "force termination when the shortest input terminates", OFFSET(shortest), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
+    { "shortest", "force termination when the shortest input terminates", OFFSET(dinput.shortest), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
     { "format", "set output format", OFFSET(format), AV_OPT_TYPE_INT, {.i64=OVERLAY_FORMAT_YUV420}, 0, OVERLAY_FORMAT_NB-1, FLAGS, "format" },
         { "yuv420", "", 0, AV_OPT_TYPE_CONST, {.i64=OVERLAY_FORMAT_YUV420}, .flags = FLAGS, .unit = "format" },
         { "yuv444", "", 0, AV_OPT_TYPE_CONST, {.i64=OVERLAY_FORMAT_YUV444}, .flags = FLAGS, .unit = "format" },
         { "rgb",    "", 0, AV_OPT_TYPE_CONST, {.i64=OVERLAY_FORMAT_RGB},    .flags = FLAGS, .unit = "format" },
-    { "repeatlast", "repeat overlay of the last overlay frame", OFFSET(repeatlast), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS },
+    { "repeatlast", "repeat overlay of the last overlay frame", OFFSET(dinput.repeatlast), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS },
     { NULL }
 };