video_export: increment number frame index first

Actually the value+1 (so 1 for first frame) is can be incremented
directly, this also removes the need to increment it in failed paths.
Here the behavior has been inconsistent, because if queue was full,
the index was incremented but on incompatible description it wasn't.
Now it is always incremented.

src/video_export.c

@@ -3,7 +3,7 @@
  * @author Martin Pulec     <[email protected]>
  */
 /*
- * Copyright (c) 2012-2016 CESNET, z. s. p. o.
+ * Copyright (c) 2012-2024 CESNET, z. s. p. o.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -214,6 +214,7 @@ void video_export(struct video_export *s, struct video_frame *frame)
         }
 
         assert(frame != NULL);
+        s->total += 1;
 
         if(s->saved_desc.width == 0) {
                 s->saved_desc = video_desc_from_frame(frame);
@@ -235,10 +236,14 @@ void video_export(struct video_export *s, struct video_frame *frame)
                 entry->next = NULL;
 
                 if(frame->tile_count == 1) {
-                        snprintf(entry->filename, 512, "%s/%08d.%s", s->path, s->total + 1, get_codec_file_extension(frame->color_spec));
+                        snprintf(entry->filename, 512, "%s/%08d.%s", s->path,
+                                 s->total,
+                                 get_codec_file_extension(frame->color_spec));
                 } else {
                         // add also tile index
-                        snprintf(entry->filename, 512, "%s/%08d_%d.%s", s->path, s->total + 1, i, get_codec_file_extension(frame->color_spec));
+                        snprintf(entry->filename, 512, "%s/%08d_%d.%s", s->path,
+                                 s->total, i,
+                                 get_codec_file_extension(frame->color_spec));
                 }
                 memcpy(entry->data, frame->tiles[i].data, entry->data_len);
 
@@ -248,7 +253,7 @@ void video_export(struct video_export *s, struct video_frame *frame)
                         if(s->queue_len >= MAX_QUEUE_SIZE) {
                                 fprintf(stderr, "[Video export] Maximal queue size (%d) exceeded, not saving frame %d.\n",
                                                 MAX_QUEUE_SIZE,
-                                                s->total++); // we increment total size to keep the index
+                                                s->total); // we increment total size to keep the index
                                 pthread_mutex_unlock(&s->lock);
                                 free(entry->data);
                                 free(entry);
@@ -267,7 +272,5 @@ void video_export(struct video_export *s, struct video_frame *frame)
 
                 platform_sem_post(&s->semaphore);
         }
-
-        s->total += 1;
 }