lavfi: deprecate default config_props() callback and refactor avfilter_config_links()

Link properties have to be checked after config_props() is called to
make sure everything is sane, so the default config_props() for output
links was redundant.

Remove now empty defaults.c
Signed-off-by: Anton Khirnov <anton@khirnov.net>

libavfilter/Makefile

@@ -18,7 +18,6 @@ OBJS = allfilters.o                                                     \
        buffer.o                                                         \
        buffersink.o                                                     \
        buffersrc.o                                                      \
-       defaults.o                                                       \
        drawutils.o                                                      \
        formats.o                                                        \
        graphparser.o                                                    \

libavfilter/avfilter.c

@@ -155,18 +155,38 @@ int avfilter_config_links(AVFilterContext *filter)
             if ((ret = avfilter_config_links(link->src)) < 0)
                 return ret;
 
-            if (!(config_link = link->srcpad->config_props))
-                config_link  = avfilter_default_config_output_link;
-            if ((ret = config_link(link)) < 0)
+            if (!(config_link = link->srcpad->config_props)) {
+                if (link->src->input_count != 1) {
+                    av_log(link->src, AV_LOG_ERROR, "Source filters and filters "
+                                                    "with more than one input "
+                                                    "must set config_props() "
+                                                    "callbacks on all outputs\n");
+                    return AVERROR(EINVAL);
+                }
+            } else if ((ret = config_link(link)) < 0)
                 return ret;
 
             if (link->time_base.num == 0 && link->time_base.den == 0)
                 link->time_base = link->src && link->src->input_count ?
                     link->src->inputs[0]->time_base : AV_TIME_BASE_Q;
 
-            if (link->sample_aspect_ratio.num == 0 && link->sample_aspect_ratio.den == 0)
-                link->sample_aspect_ratio = link->src->input_count ?
-                    link->src->inputs[0]->sample_aspect_ratio : (AVRational){1,1};
+            if (link->type == AVMEDIA_TYPE_VIDEO) {
+                if (!link->sample_aspect_ratio.num && !link->sample_aspect_ratio.den)
+                    link->sample_aspect_ratio = link->src->input_count ?
+                        link->src->inputs[0]->sample_aspect_ratio : (AVRational){1,1};
+
+                if (link->src->input_count) {
+                    if (!link->w)
+                        link->w = link->src->inputs[0]->w;
+                    if (!link->h)
+                        link->h = link->src->inputs[0]->h;
+                } else if (!link->w || !link->h) {
+                    av_log(link->src, AV_LOG_ERROR,
+                           "Video source filters must set their output link's "
+                           "width and height\n");
+                    return AVERROR(EINVAL);
+                }
+            }
 
             if ((config_link = link->dstpad->config_props))
                 if ((ret = config_link(link)) < 0)
@@ -400,3 +420,10 @@ int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque
         ret = filter->filter->init(filter, args, opaque);
     return ret;
 }
+
+#if FF_API_DEFAULT_CONFIG_OUTPUT_LINK
+int avfilter_default_config_output_link(AVFilterLink *link)
+{
+    return 0;
+}
+#endif

libavfilter/avfilter.h

@@ -460,8 +460,11 @@ void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir
 /** default handler for end_frame() for video inputs */
 void avfilter_default_end_frame(AVFilterLink *link);
 
+#if FF_API_DEFAULT_CONFIG_OUTPUT_LINK
 /** default handler for config_props() for audio/video outputs */
+attribute_deprecated
 int avfilter_default_config_output_link(AVFilterLink *link);
+#endif
 
 /** default handler for get_video_buffer() for video inputs */
 AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link,

libavfilter/defaults.c

-/*
- * Filter layer - default implementations
- * Copyright (c) 2007 Bobby Bingham
- *
- * This file is part of Libav.
- *
- * Libav 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.
- *
- * Libav 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 Libav; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include "libavutil/audioconvert.h"
-#include "libavutil/imgutils.h"
-#include "libavutil/samplefmt.h"
-
-#include "avfilter.h"
-#include "internal.h"
-#include "formats.h"
-
-/**
- * default config_link() implementation for output video links to simplify
- * the implementation of one input one output video filters */
-int avfilter_default_config_output_link(AVFilterLink *link)
-{
-    if (link->src->input_count && link->src->inputs[0]) {
-        if (link->type == AVMEDIA_TYPE_VIDEO) {
-            link->w = link->src->inputs[0]->w;
-            link->h = link->src->inputs[0]->h;
-            link->time_base = link->src->inputs[0]->time_base;
-        }
-    } else {
-        /* XXX: any non-simple filter which would cause this branch to be taken
-         * really should implement its own config_props() for this link. */
-        return -1;
-    }
-
-    return 0;
-}

libavfilter/version.h

@@ -53,5 +53,8 @@
 #ifndef FF_API_VSRC_BUFFER_ADD_FRAME
 #define FF_API_VSRC_BUFFER_ADD_FRAME        (LIBAVFILTER_VERSION_MAJOR < 3)
 #endif
+#ifndef FF_API_DEFAULT_CONFIG_OUTPUT_LINK
+#define FF_API_DEFAULT_CONFIG_OUTPUT_LINK   (LIBAVFILTER_VERSION_MAJOR < 3)
+#endif
 
 #endif // AVFILTER_VERSION_H