Sequencer: Option to skip strip proxy generation if they already exists

This is a per-strip option next to the build proxy size which tells blender
whether to skip building proxy size if the file for it already exists or not.
The option is called "Overwrite" for simplicity.

This option is enabled by default to avoid changes in the file behavior.

TODO: Would be nice to do something like that for movie clips as well.

2 files changed, 33 insertions, 4 deletions

diff --git a/source/blender/imbuf/IMB_imbuf.h b/source/blender/imbuf/IMB_imbuf.h
index ce6a7eb1c47..b0250a142ff 100644
--- a/source/blender/imbuf/IMB_imbuf.h
+++ b/source/blender/imbuf/IMB_imbuf.h
@@ -236,11 +236,14 @@ void IMB_anim_set_index_dir(struct anim *anim, const char *dir);
 int IMB_anim_index_get_frame_index(struct anim *anim, IMB_Timecode_Type tc,
                                    int position);
 
+IMB_Proxy_Size IMB_anim_proxy_get_existing(struct anim *anim);
+
 struct IndexBuildContext;
 
 /* prepare context for proxies/imecodes builder */
 struct IndexBuildContext *IMB_anim_index_rebuild_context(struct anim *anim, IMB_Timecode_Type tcs_in_use,
-                                                         IMB_Proxy_Size proxy_sizes_in_use, int quality);
+                                                         IMB_Proxy_Size proxy_sizes_in_use, int quality,
+                                                         const bool overwite);
 
 /* will rebuild all used indices and proxies at once */
 void IMB_anim_index_rebuild(struct IndexBuildContext *context,
diff --git a/source/blender/imbuf/intern/indexer.c b/source/blender/imbuf/intern/indexer.c
index e067cd64022..856f870fb38 100644
--- a/source/blender/imbuf/intern/indexer.c
+++ b/source/blender/imbuf/intern/indexer.c
@@ -1148,19 +1148,30 @@ static void index_rebuild_fallback(FallbackIndexBuilderContext *context,
  * ---------------------------------------------------------------------- */
 
 IndexBuildContext *IMB_anim_index_rebuild_context(struct anim *anim, IMB_Timecode_Type tcs_in_use,
-                                                  IMB_Proxy_Size proxy_sizes_in_use, int quality)
+                                                  IMB_Proxy_Size proxy_sizes_in_use, int quality,
+                                                  const bool overwrite)
 {
 	IndexBuildContext *context = NULL;
+	IMB_Proxy_Size proxy_sizes_to_build = proxy_sizes_in_use;
+
+	if (!overwrite) {
+		IMB_Proxy_Size built_proxies = IMB_anim_proxy_get_existing(anim);
+		proxy_sizes_to_build &= ~built_proxies;
+	}
+
+	if (proxy_sizes_to_build == 0) {
+		return NULL;
+	}
 
 	switch (anim->curtype) {
 #ifdef WITH_FFMPEG
 		case ANIM_FFMPEG:
-			context = index_ffmpeg_create_context(anim, tcs_in_use, proxy_sizes_in_use, quality);
+			context = index_ffmpeg_create_context(anim, tcs_in_use, proxy_sizes_to_build, quality);
 			break;
 #endif
 #ifdef WITH_AVI
 		default:
-			context = index_fallback_create_context(anim, tcs_in_use, proxy_sizes_in_use, quality);
+			context = index_fallback_create_context(anim, tcs_in_use, proxy_sizes_to_build, quality);
 			break;
 #endif
 	}
@@ -1304,3 +1315,18 @@ int IMB_anim_index_get_frame_index(struct anim *anim, IMB_Timecode_Type tc,
 	return IMB_indexer_get_frame_index(idx, position);
 }
 
+IMB_Proxy_Size IMB_anim_proxy_get_existing(struct anim *anim)
+{
+	const int num_proxy_sizes = IMB_PROXY_MAX_SLOT;
+	IMB_Proxy_Size existing = 0;
+	int i;
+	for (i = 0; i < num_proxy_sizes; ++i) {
+		IMB_Proxy_Size proxy_size = proxy_sizes[i];
+		char filename[FILE_MAX];
+		get_proxy_filename(anim, proxy_size, filename, false);
+		if (BLI_exists(filename)) {
+			existing |= proxy_size;
+		}
+	}
+	return existing;
+}