lavfi: connect libavresample options to af_resample via AVFilterGraph

doc/APIchanges

@@ -13,6 +13,10 @@ libavutil:     2012-10-22
 
 API changes, most recent first:
 
+2013-xx-xx - xxxxxxx - lavfi 3.4.0 - avfiltergraph.h
+  Add resample_lavr_opts to AVFilterGraph for setting libavresample options
+  for auto-inserted resample filters.
+
 2013-xx-xx - xxxxxxx - lavu 52.7.0 - dict.h
   Add av_dict_parse_string() to set multiple key/value pairs at once from a
   string.

libavfilter/af_resample.c

@@ -25,6 +25,7 @@
 #include "libavutil/avassert.h"
 #include "libavutil/avstring.h"
 #include "libavutil/common.h"
+#include "libavutil/dict.h"
 #include "libavutil/mathematics.h"
 #include "libavutil/opt.h"
 
@@ -37,6 +38,7 @@
 
 typedef struct ResampleContext {
     AVAudioResampleContext *avr;
+    AVDictionary *options;
 
     int64_t next_pts;
 
@@ -44,6 +46,29 @@ typedef struct ResampleContext {
     int got_output;
 } ResampleContext;
 
+static av_cold int init(AVFilterContext *ctx, const char *args)
+{
+    ResampleContext *s = ctx->priv;
+
+    if (args) {
+        int ret = av_dict_parse_string(&s->options, args, "=", ":", 0);
+        if (ret < 0) {
+            av_log(ctx, AV_LOG_ERROR, "error setting option string: %s\n", args);
+            return ret;
+        }
+
+        /* do not allow the user to override basic format options */
+        av_dict_set(&s->options,  "in_channel_layout", NULL, 0);
+        av_dict_set(&s->options, "out_channel_layout", NULL, 0);
+        av_dict_set(&s->options,  "in_sample_fmt",     NULL, 0);
+        av_dict_set(&s->options, "out_sample_fmt",     NULL, 0);
+        av_dict_set(&s->options,  "in_sample_rate",    NULL, 0);
+        av_dict_set(&s->options, "out_sample_rate",    NULL, 0);
+    }
+
+    return 0;
+}
+
 static av_cold void uninit(AVFilterContext *ctx)
 {
     ResampleContext *s = ctx->priv;
@@ -52,6 +77,7 @@ static av_cold void uninit(AVFilterContext *ctx)
         avresample_close(s->avr);
         avresample_free(&s->avr);
     }
+    av_dict_free(&s->options);
 }
 
 static int query_formats(AVFilterContext *ctx)
@@ -103,6 +129,14 @@ static int config_output(AVFilterLink *outlink)
     if (!(s->avr = avresample_alloc_context()))
         return AVERROR(ENOMEM);
 
+    if (s->options) {
+        AVDictionaryEntry *e = NULL;
+        while ((e = av_dict_get(s->options, "", e, AV_DICT_IGNORE_SUFFIX)))
+            av_log(ctx, AV_LOG_VERBOSE, "lavr option: %s=%s\n", e->key, e->value);
+
+        av_opt_set_dict(s->avr, &s->options);
+    }
+
     av_opt_set_int(s->avr,  "in_channel_layout", inlink ->channel_layout, 0);
     av_opt_set_int(s->avr, "out_channel_layout", outlink->channel_layout, 0);
     av_opt_set_int(s->avr,  "in_sample_fmt",     inlink ->format,         0);
@@ -264,6 +298,7 @@ AVFilter avfilter_af_resample = {
     .description   = NULL_IF_CONFIG_SMALL("Audio resampling and conversion."),
     .priv_size     = sizeof(ResampleContext),
 
+    .init           = init,
     .uninit         = uninit,
     .query_formats  = query_formats,
 

libavfilter/avfiltergraph.c

@@ -54,6 +54,7 @@ void avfilter_graph_free(AVFilterGraph **graph)
     for (; (*graph)->filter_count > 0; (*graph)->filter_count--)
         avfilter_free((*graph)->filters[(*graph)->filter_count - 1]);
     av_freep(&(*graph)->scale_sws_opts);
+    av_freep(&(*graph)->resample_lavr_opts);
     av_freep(&(*graph)->filters);
     av_freep(graph);
 }
@@ -235,8 +236,13 @@ static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 
                     snprintf(inst_name, sizeof(inst_name), "auto-inserted resampler %d",
                              resampler_count++);
+                    scale_args[0] = '\0';
+                    if (graph->resample_lavr_opts)
+                        snprintf(scale_args, sizeof(scale_args), "%s",
+                                 graph->resample_lavr_opts);
                     if ((ret = avfilter_graph_create_filter(&convert, filter,
-                                                            inst_name, NULL, NULL, graph)) < 0)
+                                                            inst_name, scale_args,
+                                                            NULL, graph)) < 0)
                         return ret;
                     break;
                 default:

libavfilter/avfiltergraph.h

@@ -31,6 +31,7 @@ typedef struct AVFilterGraph {
     AVFilterContext **filters;
 
     char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
+    char *resample_lavr_opts;   ///< libavresample options to use for the auto-inserted resample filters
 } AVFilterGraph;
 
 /**

libavfilter/version.h

@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  3
+#define LIBAVFILTER_VERSION_MINOR  4
 #define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \