ffmpeg: Make video filter graph reinit user selectable

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

ffmpeg.c

@@ -1610,12 +1610,13 @@ static int decode_video(InputStream *ist, AVPacket *pkt, int *got_output)
         ist->resample_height  = decoded_frame->height;
         ist->resample_pix_fmt = decoded_frame->format;
 
-        for (i = 0; i < nb_filtergraphs; i++)
-            if (ist_in_filtergraph(filtergraphs[i], ist) &&
+        for (i = 0; i < nb_filtergraphs; i++) {
+            if (ist_in_filtergraph(filtergraphs[i], ist) && ist->reinit_filters &&
                 configure_filtergraph(filtergraphs[i]) < 0) {
                 av_log(NULL, AV_LOG_FATAL, "Error reinitializing filters!\n");
                 exit(1);
             }
+        }
     }
 
     frame_sample_aspect= av_opt_ptr(avcodec_get_frame_class(), decoded_frame, "sample_aspect_ratio");

ffmpeg.h

@@ -161,6 +161,8 @@ typedef struct OptionsContext {
     int        nb_copy_prior_start;
     SpecifierOpt *filters;
     int        nb_filters;
+    SpecifierOpt *reinit_filters;
+    int        nb_reinit_filters;
     SpecifierOpt *fix_sub_duration;
     int        nb_fix_sub_duration;
     SpecifierOpt *pass;
@@ -253,6 +255,8 @@ typedef struct InputStream {
      * currently video and audio only */
     InputFilter **filters;
     int        nb_filters;
+
+    int reinit_filters;
 } InputStream;
 
 typedef struct InputFile {

ffmpeg_opt.c

@@ -579,6 +579,9 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
 
         ist->dec = choose_decoder(o, ic, st);
 
+        ist->reinit_filters = -1;
+        MATCH_PER_STREAM_OPT(reinit_filters, i, ist->reinit_filters, ic, st);
+
         switch (dec->codec_type) {
         case AVMEDIA_TYPE_VIDEO:
             if(!ist->dec)
@@ -2341,6 +2344,8 @@ const OptionDef options[] = {
         "set profile", "profile" },
     { "filter",         HAS_ARG | OPT_STRING | OPT_SPEC,             { .off = OFFSET(filters) },
         "set stream filterchain", "filter_list" },
+    { "reinit_filter",  HAS_ARG | OPT_INT | OPT_SPEC,                { .off = OFFSET(reinit_filters) },
+        "reinit filtergraph on input parameter changes", "" },
     { "filter_complex", HAS_ARG | OPT_EXPERT,                        { .func_arg = opt_filter_complex },
         "create a complex filtergraph", "graph_description" },
     { "stats",          OPT_BOOL,                                    { &print_stats },