fftools/ffmpeg_dec: move sub2video submission to ffmpeg_filter

This code is a sub2video analogue of ifilter_send_frame(), so it
properly belongs to the filtering code.

Note that using sub2video with more than one target for a given input
subtitle stream is currently broken and this commit does not change
that. It will be addressed in following commits.

fftools/ffmpeg.c

@@ -755,7 +755,7 @@ static void print_report(int is_last_report, int64_t timer_start, int64_t cur_ti
     first_report = 0;
 }
 
-static int copy_av_subtitle(AVSubtitle *dst, const AVSubtitle *src)
+int copy_av_subtitle(AVSubtitle *dst, const AVSubtitle *src)
 {
     int ret = AVERROR_BUG;
     AVSubtitle tmp = {

fftools/ffmpeg.h

@@ -744,9 +744,11 @@ int init_complex_filtergraph(FilterGraph *fg);
 
 void sub2video_update(InputStream *ist, int64_t heartbeat_pts,
                       const AVSubtitle *sub);
+int copy_av_subtitle(AVSubtitle *dst, const AVSubtitle *src);
 
 int ifilter_send_frame(InputFilter *ifilter, AVFrame *frame, int keep_reference);
 int ifilter_send_eof(InputFilter *ifilter, int64_t pts, AVRational tb);
+int ifilter_sub2video(InputFilter *ifilter, const AVSubtitle *sub);
 
 /**
  * Set up fallback filtering parameters from a decoder context. They will only

fftools/ffmpeg_dec.c

@@ -336,7 +336,6 @@ static void sub2video_flush(InputStream *ist)
 int process_subtitle(InputStream *ist, AVSubtitle *subtitle, int *got_output)
 {
     int ret = 0;
-    int free_sub = 1;
 
     if (ist->fix_sub_duration) {
         int end = 1;
@@ -361,18 +360,13 @@ int process_subtitle(InputStream *ist, AVSubtitle *subtitle, int *got_output)
     if (!*got_output)
         return ret;
 
-    if (ist->sub2video.frame) {
-        sub2video_update(ist, INT64_MIN, subtitle);
-    } else if (ist->nb_filters) {
-        if (!ist->sub2video.sub_queue)
-            ist->sub2video.sub_queue = av_fifo_alloc2(8, sizeof(AVSubtitle), AV_FIFO_FLAG_AUTO_GROW);
-        if (!ist->sub2video.sub_queue)
-            report_and_exit(AVERROR(ENOMEM));
-
-        ret = av_fifo_write(ist->sub2video.sub_queue, subtitle, 1);
-        if (ret < 0)
-            exit_program(1);
-        free_sub = 0;
+    for (int i = 0; i < ist->nb_filters; i++) {
+        ret = ifilter_sub2video(ist->filters[i], subtitle);
+        if (ret < 0) {
+            av_log(ist, AV_LOG_ERROR, "Error sending a subtitle for filtering: %s\n",
+                   av_err2str(ret));
+            goto out;
+        }
     }
 
     if (!subtitle->num_rects)
@@ -387,8 +381,7 @@ int process_subtitle(InputStream *ist, AVSubtitle *subtitle, int *got_output)
     }
 
 out:
-    if (free_sub)
-        avsubtitle_free(subtitle);
+    avsubtitle_free(subtitle);
     return ret;
 }
 

fftools/ffmpeg_filter.c

@@ -1638,6 +1638,36 @@ int reap_filters(int flush)
     return 0;
 }
 
+int ifilter_sub2video(InputFilter *ifilter, const AVSubtitle *subtitle)
+{
+    InputFilterPriv *ifp = ifp_from_ifilter(ifilter);
+    InputStream     *ist = ifp->ist;
+    int ret;
+
+    if (ist->sub2video.frame) {
+        sub2video_update(ist, INT64_MIN, subtitle);
+    } else {
+        AVSubtitle sub;
+
+        if (!ist->sub2video.sub_queue)
+            ist->sub2video.sub_queue = av_fifo_alloc2(8, sizeof(AVSubtitle), AV_FIFO_FLAG_AUTO_GROW);
+        if (!ist->sub2video.sub_queue)
+            return AVERROR(ENOMEM);
+
+        ret = copy_av_subtitle(&sub, subtitle);
+        if (ret < 0)
+            return ret;
+
+        ret = av_fifo_write(ist->sub2video.sub_queue, &sub, 1);
+        if (ret < 0) {
+            avsubtitle_free(&sub);
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
 int ifilter_send_eof(InputFilter *ifilter, int64_t pts, AVRational tb)
 {
     InputFilterPriv *ifp = ifp_from_ifilter(ifilter);