fftools/ffmpeg: initialize no-filter streams earlier

There is no reason to postpone it until transcode_init() anymore, it can
be done right at the end of of_open().

fftools/ffmpeg.c

@@ -1853,23 +1853,6 @@ static int process_input_packet(InputStream *ist, const AVPacket *pkt, int no_eo
     return !eof_reached;
 }
 
-static int init_output_stream_nofilter(OutputStream *ost)
-{
-    int ret = 0;
-
-    if (ost->enc_ctx) {
-        ret = enc_open(ost, NULL);
-        if (ret < 0)
-            return ret;
-    } else {
-        ret = of_stream_init(output_files[ost->file_index], ost);
-        if (ret < 0)
-            return ret;
-    }
-
-    return ret;
-}
-
 static int transcode_init(void)
 {
     int ret = 0;
@@ -1882,22 +1865,6 @@ static int transcode_init(void)
                 ifile->streams[j]->start = av_gettime_relative();
     }
 
-    /*
-     * initialize stream copy and subtitle/data streams.
-     * Encoded AVFrame based streams will get initialized when the first AVFrame
-     * is received in do_video_out
-     */
-    for (OutputStream *ost = ost_iter(NULL); ost; ost = ost_iter(ost)) {
-        if (ost->enc_ctx &&
-            (ost->st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO ||
-             ost->st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO))
-            continue;
-
-        ret = init_output_stream_nofilter(ost);
-        if (ret < 0)
-            goto dump_format;
-    }
-
     /* discard unused programs */
     for (int i = 0; i < nb_input_files; i++) {
         InputFile *ifile = input_files[i];
@@ -1914,7 +1881,6 @@ static int transcode_init(void)
         }
     }
 
- dump_format:
     /* dump the stream mapping */
     av_log(NULL, AV_LOG_INFO, "Stream mapping:\n");
     for (InputStream *ist = ist_iter(NULL); ist; ist = ist_iter(ist)) {

fftools/ffmpeg_mux_init.c

@@ -2317,6 +2317,23 @@ static void validate_enc_avopt(Muxer *mux, const AVDictionary *codec_avopt)
     av_dict_free(&unused_opts);
 }
 
+static int init_output_stream_nofilter(OutputStream *ost)
+{
+    int ret = 0;
+
+    if (ost->enc_ctx) {
+        ret = enc_open(ost, NULL);
+        if (ret < 0)
+            return ret;
+    } else {
+        ret = of_stream_init(output_files[ost->file_index], ost);
+        if (ret < 0)
+            return ret;
+    }
+
+    return ret;
+}
+
 static const char *output_file_item_name(void *obj)
 {
     const Muxer *mux = obj;
@@ -2512,6 +2529,21 @@ int of_open(const OptionsContext *o, const char *filename)
 
     of->url        = filename;
 
+    /* initialize stream copy and subtitle/data streams.
+     * Encoded AVFrame based streams will get initialized when the first AVFrame
+     * is received in do_video_out
+     */
+    for (int i = 0; i < of->nb_streams; i++) {
+        OutputStream *ost = of->streams[i];
+
+        if (ost->filter)
+            continue;
+
+        err = init_output_stream_nofilter(ost);
+        if (err < 0)
+            report_and_exit(err);
+    }
+
     /* write the header for files with no streams */
     if (of->format->flags & AVFMT_NOSTREAMS && oc->nb_streams == 0) {
         int ret = mux_check_init(mux);