fftools/ffmpeg_filter: always pass graph description to fg_create()

Currently NULL would be passed for simple filtergraphs, which would
make the filter code extract the graph description from the output
stream when needed. This is unnecessarily convoluted.

fftools/ffmpeg.h

@@ -590,7 +590,6 @@ typedef struct OutputStream {
     FILE *logfile;
 
     OutputFilter *filter;
-    char *avfilter;
 
     AVDictionary *encoder_opts;
     AVDictionary *sws_dict;
@@ -737,7 +736,8 @@ int parse_and_set_vsync(const char *arg, int *vsync_var, int file_idx, int st_id
 int configure_filtergraph(FilterGraph *fg);
 void check_filter_outputs(void);
 int filtergraph_is_simple(FilterGraph *fg);
-int init_simple_filtergraph(InputStream *ist, OutputStream *ost);
+int init_simple_filtergraph(InputStream *ist, OutputStream *ost,
+                            char *graph_desc);
 int init_complex_filtergraph(FilterGraph *fg);
 
 void sub2video_update(InputStream *ist, int64_t heartbeat_pts, AVSubtitle *sub);

fftools/ffmpeg_filter.c

@@ -352,7 +352,8 @@ FilterGraph *fg_create(char *graph_desc)
     return fg;
 }
 
-int init_simple_filtergraph(InputStream *ist, OutputStream *ost)
+int init_simple_filtergraph(InputStream *ist, OutputStream *ost,
+                            char *graph_desc)
 {
     FilterGraph *fg;
     FilterGraphPriv *fgp;
@@ -360,7 +361,7 @@ int init_simple_filtergraph(InputStream *ist, OutputStream *ost)
     InputFilter  *ifilter;
     int ret;
 
-    fg = fg_create(NULL);
+    fg = fg_create(graph_desc);
     if (!fg)
         report_and_exit(AVERROR(ENOMEM));
     fgp = fgp_from_fg(fg);
@@ -1263,8 +1264,7 @@ int configure_filtergraph(FilterGraph *fg)
     AVBufferRef *hw_device;
     AVFilterInOut *inputs, *outputs, *cur;
     int ret, i, simple = filtergraph_is_simple(fg);
-    const char *graph_desc = simple ? fg->outputs[0]->ost->avfilter :
-                                      fgp->graph_desc;
+    const char *graph_desc = fgp->graph_desc;
 
     cleanup_filtergraph(fg);
     if (!(fg->graph = avfilter_graph_alloc()))

fftools/ffmpeg_mux.c

@@ -853,7 +853,6 @@ static void ost_free(OutputStream **post)
     av_freep(&ost->kf.pts);
     av_expr_free(ost->kf.pexpr);
 
-    av_freep(&ost->avfilter);
     av_freep(&ost->logfile_prefix);
     av_freep(&ost->apad);
 

fftools/ffmpeg_mux_init.c

@@ -432,7 +432,7 @@ static MuxStream *mux_stream_alloc(Muxer *mux, enum AVMediaType type)
 }
 
 static int ost_get_filters(const OptionsContext *o, AVFormatContext *oc,
-                           OutputStream *ost)
+                           OutputStream *ost, char **dst)
 {
     const char *filters = NULL, *filters_script = NULL;
 
@@ -470,12 +470,12 @@ static int ost_get_filters(const OptionsContext *o, AVFormatContext *oc,
     }
 
     if (filters_script)
-        ost->avfilter = file_read(filters_script);
+        *dst = file_read(filters_script);
     else if (filters)
-        ost->avfilter = av_strdup(filters);
+        *dst = av_strdup(filters);
     else
-        ost->avfilter = av_strdup(ost->type == AVMEDIA_TYPE_VIDEO ? "null" : "anull");
-    return ost->avfilter ? 0 : AVERROR(ENOMEM);
+        *dst = av_strdup(ost->type == AVMEDIA_TYPE_VIDEO ? "null" : "anull");
+    return *dst ? 0 : AVERROR(ENOMEM);
 }
 
 static void parse_matrix_coeffs(void *logctx, uint16_t *dest, const char *str)
@@ -995,7 +995,7 @@ static OutputStream *ost_add(Muxer *mux, const OptionsContext *o,
     AVStream *st = avformat_new_stream(oc, NULL);
     int ret = 0;
     const char *bsfs = NULL, *time_base = NULL;
-    char *next, *codec_tag = NULL;
+    char *filters = NULL, *next, *codec_tag = NULL;
     double qscale = -1;
     int i;
 
@@ -1250,7 +1250,7 @@ static OutputStream *ost_add(Muxer *mux, const OptionsContext *o,
     }
 
     if (type == AVMEDIA_TYPE_VIDEO || type == AVMEDIA_TYPE_AUDIO) {
-        ret = ost_get_filters(o, oc, ost);
+        ret = ost_get_filters(o, oc, ost, &filters);
         if (ret < 0)
             exit_program(1);
     }
@@ -1262,7 +1262,7 @@ static OutputStream *ost_add(Muxer *mux, const OptionsContext *o,
             ofilter->ost      = ost;
             avfilter_inout_free(&ofilter->out_tmp);
         } else {
-            ret = init_simple_filtergraph(ost->ist, ost);
+            ret = init_simple_filtergraph(ost->ist, ost, filters);
             if (ret < 0) {
                 av_log(ost, AV_LOG_ERROR,
                        "Error initializing a simple filtergraph\n");