Sound: Revert all the recent changes to sound

This happened to be a bigger rabbit hole to hell than it originally seemed,
and there are higher priority design tasks to be handled (at this point high
priority design task is more important than high priority bug fix).

After talking to Brecht the decision was made to revert to the known isolated
issue, which will allow everyone in the studio work same as prior to last
Friday.

The remaining bits will be worked on after all the design tasks are out of
the way.

This commit reverts:

4cdb4b9532c Fix T64161: Crashing using undo and multiple windows
064273a4ae7 Sound: Port more cases to be a part of dependency graph
2e582f8ab53 Sound: Fix access wrong dependency graph
5fc49d9c915 Sound: add stubs to build without audaspace
c68c81a870b Sound: Make sure spin lock is initialized for new sound datablocks
c02534469ac Sound: Delay creating sound scene handle for until is needed
9f681bea68f Fix T64144: Crash when displaying audio waveforms in VSE
2f79286453e Cleanup: unused vars
bed8ad6f95a Fix crash in background rendering after recent sound changes
773691310f9 Fix T64143: Crash when scrubbing in the graph editor
888852055c1 Sound: Fix for being unable to jump to a frame during playback with A/V sync
6ab7b384645 Sound: More fixes for access of original scene
35db1195455 Sound: Fix access original scene during playback
211c4fd2e9a Depsgraph: Make comment about evaluation more obvious
c5fe16e121e Sound: Make sound handles only be in evaluated datablocks
b4e1e0946bf Depsgraph: Preserve sound and audio pointers through copy-on-write
4eedf784b04 Depsgraph: Store original sequencer strip pointer
6990ef151c1 Sound: Move evaluation to dependency graph
d02da8de23b Sound: Delay opening handlers for until really needed
3369b828916 Depsgraph: Add scene audio component
e8f10d64757 Depsgraph: Tag sequencer for update on changes
6e4b7a6e4d9 Depsgraph: Initial work to cover sequencer
17447ac5a6b Depsgraph: Make sound ID part of the graph

13 files changed, 13 insertions, 376 deletions

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
index 64ca5902136..37712296bdf 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
@@ -58,7 +58,6 @@ extern "C" {
 #include "DNA_lightprobe_types.h"
 #include "DNA_rigidbody_types.h"
 #include "DNA_scene_types.h"
-#include "DNA_sequence_types.h"
 #include "DNA_sound_types.h"
 #include "DNA_speaker_types.h"
 #include "DNA_texture_types.h"
@@ -90,8 +89,6 @@ extern "C" {
 #include "BKE_particle.h"
 #include "BKE_pointcache.h"
 #include "BKE_rigidbody.h"
-#include "BKE_scene.h"
-#include "BKE_sequencer.h"
 #include "BKE_shader_fx.h"
 #include "BKE_sound.h"
 #include "BKE_tracking.h"
@@ -1563,42 +1560,12 @@ void DepsgraphNodeBuilder::build_sound(bSound *sound)
   if (built_map_.checkIsBuiltAndTag(sound)) {
     return;
   }
-  add_id_node(&sound->id);
-  bSound *sound_cow = get_cow_datablock(sound);
-  add_operation_node(&sound->id,
-                     NodeType::AUDIO,
-                     OperationCode::SOUND_EVAL,
-                     function_bind(BKE_sound_evaluate, _1, bmain_, sound_cow));
+  /* Placeholder so we can add relations and tag ID node for update. */
+  add_operation_node(&sound->id, NodeType::AUDIO, OperationCode::SOUND_EVAL);
   build_animdata(&sound->id);
   build_parameters(&sound->id);
 }
 
-void DepsgraphNodeBuilder::build_sequencer(Scene *scene)
-{
-  if (scene->ed == NULL) {
-    return;
-  }
-  Scene *scene_cow = get_cow_datablock(scene_);
-  add_operation_node(&scene->id,
-                     NodeType::SEQUENCER,
-                     OperationCode::SEQUENCES_EVAL,
-                     function_bind(BKE_scene_eval_sequencer_sequences, _1, scene_cow));
-  /* Make sure data for sequences is in the graph. */
-  Sequence *seq;
-  SEQ_BEGIN (scene->ed, seq) {
-    if (seq->sound != NULL) {
-      build_sound(seq->sound);
-    }
-    /* TODO(sergey): Movie clip, scene, camera, mask. */
-  }
-  SEQ_END;
-}
-
-void DepsgraphNodeBuilder::build_scene_audio(Scene *scene)
-{
-  add_operation_node(&scene->id, NodeType::AUDIO, OperationCode::SOUND_EVAL);
-}
-
 /* **** ID traversal callbacks functions **** */
 
 void DepsgraphNodeBuilder::modifier_walk(void *user_data,
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
index 9074efefe50..68fb9ab6cc2 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
@@ -208,8 +208,6 @@ class DepsgraphNodeBuilder : public DepsgraphBuilder {
   void build_lightprobe(LightProbe *probe);
   void build_speaker(Speaker *speaker);
   void build_sound(bSound *sound);
-  void build_sequencer(Scene *scene);
-  void build_scene_audio(Scene *scene);
 
   /* Per-ID information about what was already in the dependency graph.
    * Allows to re-use certain values, to speed up following evaluation. */
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes_view_layer.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes_view_layer.cc
index 1b9524e5832..60b711d76d3 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes_view_layer.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes_view_layer.cc
@@ -152,11 +152,6 @@ void DepsgraphNodeBuilder::build_view_layer(Scene *scene,
       build_collection(NULL, fls->group);
     }
   }
-  /* Sequencer. */
-  if (linked_state == DEG_ID_LINKED_DIRECTLY) {
-    build_scene_audio(scene);
-    build_sequencer(scene);
-  }
   /* Collections. */
   add_operation_node(
       &scene->id,
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index 4c4bc01a3dd..9fc5dc64a60 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -58,7 +58,6 @@ extern "C" {
 #include "DNA_object_types.h"
 #include "DNA_rigidbody_types.h"
 #include "DNA_scene_types.h"
-#include "DNA_sequence_types.h"
 #include "DNA_sound_types.h"
 #include "DNA_speaker_types.h"
 #include "DNA_texture_types.h"
@@ -85,7 +84,6 @@ extern "C" {
 #include "BKE_particle.h"
 #include "BKE_pointcache.h"
 #include "BKE_rigidbody.h"
-#include "BKE_sequencer.h"
 #include "BKE_shader_fx.h"
 #include "BKE_shrinkwrap.h"
 #include "BKE_sound.h"
@@ -2316,35 +2314,6 @@ void DepsgraphRelationBuilder::build_sound(bSound *sound)
   build_parameters(&sound->id);
 }
 
-void DepsgraphRelationBuilder::build_sequencer(Scene *scene)
-{
-  if (scene->ed == NULL) {
-    return;
-  }
-  /* Make sure dependencies from sequences data goes to the sequencer evaluation. */
-  ComponentKey sequencer_key(&scene->id, NodeType::SEQUENCER);
-  Sequence *seq;
-  bool has_audio_strips = false;
-  SEQ_BEGIN (scene->ed, seq) {
-    if (seq->sound != NULL) {
-      build_sound(seq->sound);
-      ComponentKey sound_key(&seq->sound->id, NodeType::AUDIO);
-      add_relation(sound_key, sequencer_key, "Sound -> Sequencer");
-      has_audio_strips = true;
-    }
-    /* TODO(sergey): Movie clip, scene, camera, mask. */
-  }
-  SEQ_END;
-  if (has_audio_strips) {
-    ComponentKey scene_audio_key(&scene->id, NodeType::AUDIO);
-    add_relation(sequencer_key, scene_audio_key, "Sequencer -> Audio");
-  }
-}
-
-void DepsgraphRelationBuilder::build_scene_audio(Scene * /*scene*/)
-{
-}
-
 void DepsgraphRelationBuilder::build_copy_on_write_relations()
 {
   for (IDNode *id_node : graph_->id_nodes) {
@@ -2408,10 +2377,6 @@ void DepsgraphRelationBuilder::build_copy_on_write_relations(IDNode *id_node)
         (id_type == ID_CF && comp_node->type == NodeType::CACHE)) {
       rel_flag &= ~RELATION_FLAG_NO_FLUSH;
     }
-    /* TODO(sergey): Needs better solution for this. */
-    if (id_type == ID_SO) {
-      rel_flag &= ~RELATION_FLAG_NO_FLUSH;
-    }
     /* Notes on exceptions:
      * - Parameters component is where drivers are living. Changing any
      *   of the (custom) properties in the original datablock (even the
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.h b/source/blender/depsgraph/intern/builder/deg_builder_relations.h
index 30fbe5bcf6b..e84bd857090 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.h
@@ -41,7 +41,6 @@
 #include "intern/builder/deg_builder_rna.h"
 #include "intern/depsgraph.h"
 #include "intern/node/deg_node.h"
-#include "intern/node/deg_node_id.h"
 #include "intern/node/deg_node_component.h"
 #include "intern/node/deg_node_operation.h"
 
@@ -196,9 +195,7 @@ class DepsgraphRelationBuilder : public DepsgraphBuilder {
 
   void build_id(ID *id);
   void build_layer_collections(ListBase *lb);
-  void build_view_layer(Scene *scene,
-                        ViewLayer *view_layer,
-                        eDepsNode_LinkedState_Type linked_state);
+  void build_view_layer(Scene *scene, ViewLayer *view_layer);
   void build_collection(LayerCollection *from_layer_collection,
                         Object *object,
                         Collection *collection);
@@ -269,8 +266,6 @@ class DepsgraphRelationBuilder : public DepsgraphBuilder {
   void build_lightprobe(LightProbe *probe);
   void build_speaker(Speaker *speaker);
   void build_sound(bSound *sound);
-  void build_sequencer(Scene *scene);
-  void build_scene_audio(Scene *scene);
 
   void build_nested_datablock(ID *owner, ID *id);
   void build_nested_nodetree(ID *owner, bNodeTree *ntree);
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations_view_layer.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations_view_layer.cc
index cadb4ab3611..a325544e046 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations_view_layer.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations_view_layer.cc
@@ -75,9 +75,7 @@ void DepsgraphRelationBuilder::build_layer_collections(ListBase *lb)
   }
 }
 
-void DepsgraphRelationBuilder::build_view_layer(Scene *scene,
-                                                ViewLayer *view_layer,
-                                                eDepsNode_LinkedState_Type linked_state)
+void DepsgraphRelationBuilder::build_view_layer(Scene *scene, ViewLayer *view_layer)
 {
   /* Setup currently building context. */
   scene_ = scene;
@@ -130,15 +128,10 @@ void DepsgraphRelationBuilder::build_view_layer(Scene *scene,
       build_collection(NULL, NULL, fls->group);
     }
   }
-  /* Sequencer. */
-  if (linked_state == DEG_ID_LINKED_DIRECTLY) {
-    build_scene_audio(scene);
-    build_sequencer(scene);
-  }
   /* Build all set scenes. */
   if (scene->set != NULL) {
     ViewLayer *set_view_layer = BKE_view_layer_default_render(scene->set);
-    build_view_layer(scene->set, set_view_layer, DEG_ID_LINKED_VIA_SET);
+    build_view_layer(scene->set, set_view_layer);
   }
 }
 
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_rna.cc b/source/blender/depsgraph/intern/builder/deg_builder_rna.cc
index ca60e4370cd..ea5f86a31a8 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_rna.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_rna.cc
@@ -309,8 +309,10 @@ RNANodeIdentifier RNANodeQuery::construct_node_identifier(const PointerRNA *ptr,
     return node_identifier;
   }
   else if (RNA_struct_is_a(ptr->type, &RNA_Sequence)) {
+    const Sequence *seq = static_cast<Sequence *>(ptr->data);
     /* Sequencer strip */
     node_identifier.type = NodeType::SEQUENCER;
+    node_identifier.component_name = seq->name;
     return node_identifier;
   }
   else if (RNA_struct_is_a(ptr->type, &RNA_NodeSocket)) {
diff --git a/source/blender/depsgraph/intern/depsgraph_build.cc b/source/blender/depsgraph/intern/depsgraph_build.cc
index a4082c24dec..dd2979160cd 100644
--- a/source/blender/depsgraph/intern/depsgraph_build.cc
+++ b/source/blender/depsgraph/intern/depsgraph_build.cc
@@ -249,7 +249,7 @@ void DEG_graph_build_from_view_layer(Depsgraph *graph,
    * order. */
   DEG::DepsgraphRelationBuilder relation_builder(bmain, deg_graph, &builder_cache);
   relation_builder.begin_build();
-  relation_builder.build_view_layer(scene, view_layer, DEG::DEG_ID_LINKED_DIRECTLY);
+  relation_builder.build_view_layer(scene, view_layer);
   relation_builder.build_copy_on_write_relations();
   /* Detect and solve cycles. */
   DEG::deg_graph_detect_cycles(deg_graph);
diff --git a/source/blender/depsgraph/intern/depsgraph_query.cc b/source/blender/depsgraph/intern/depsgraph_query.cc
index 75eabc6930f..a653366a588 100644
--- a/source/blender/depsgraph/intern/depsgraph_query.cc
+++ b/source/blender/depsgraph/intern/depsgraph_query.cc
@@ -152,19 +152,6 @@ Scene *DEG_get_evaluated_scene(const Depsgraph *graph)
   return scene_cow;
 }
 
-Scene *DEG_get_evaluated_scene_if_exists(const Depsgraph *graph)
-{
-  if (graph == NULL) {
-    return NULL;
-  }
-  const DEG::Depsgraph *deg_graph = reinterpret_cast<const DEG::Depsgraph *>(graph);
-  Scene *scene_cow = deg_graph->scene_cow;
-  if (scene_cow == NULL || !DEG::deg_copy_on_write_is_expanded(&scene_cow->id)) {
-    return NULL;
-  }
-  return scene_cow;
-}
-
 ViewLayer *DEG_get_evaluated_view_layer(const Depsgraph *graph)
 {
   const DEG::Depsgraph *deg_graph = reinterpret_cast<const DEG::Depsgraph *>(graph);
diff --git a/source/blender/depsgraph/intern/depsgraph_tag.cc b/source/blender/depsgraph/intern/depsgraph_tag.cc
index f932011ccab..f682dadee8e 100644
--- a/source/blender/depsgraph/intern/depsgraph_tag.cc
+++ b/source/blender/depsgraph/intern/depsgraph_tag.cc
@@ -215,16 +215,6 @@ void depsgraph_tag_to_component_opcode(const ID *id,
       /* There is no such node in depsgraph, this tag is to be handled
        * separately. */
       break;
-    case ID_RECALC_SEQUENCER_STRIPS:
-      *component_type = NodeType::SEQUENCER;
-      break;
-    case ID_RECALC_AUDIO_SEEK:
-    case ID_RECALC_AUDIO_FPS:
-    case ID_RECALC_AUDIO_VOLUME:
-    case ID_RECALC_AUDIO_MUTE:
-    case ID_RECALC_AUDIO_LISTENER:
-      *component_type = NodeType::AUDIO;
-      break;
     case ID_RECALC_ALL:
     case ID_RECALC_PSYS_ALL:
       BLI_assert(!"Should not happen");
@@ -625,18 +615,6 @@ const char *DEG_update_tag_as_string(IDRecalcFlag flag)
       return "POINT_CACHE";
     case ID_RECALC_EDITORS:
       return "EDITORS";
-    case ID_RECALC_SEQUENCER_STRIPS:
-      return "SEQUENCER_STRIPS";
-    case ID_RECALC_AUDIO_SEEK:
-      return "AUDIO_SEEK";
-    case ID_RECALC_AUDIO_FPS:
-      return "AUDIO_FPS";
-    case ID_RECALC_AUDIO_VOLUME:
-      return "AUDIO_VOLUME";
-    case ID_RECALC_AUDIO_MUTE:
-      return "AUDIO_MUTE";
-    case ID_RECALC_AUDIO_LISTENER:
-      return "AUDIO_LISTENER";
     case ID_RECALC_ALL:
       return "ALL";
   }
diff --git a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
index bb4300e5330..2a76d5cd362 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
@@ -59,8 +59,6 @@ extern "C" {
 #include "DNA_mesh_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_scene_types.h"
-#include "DNA_sequence_types.h"
-#include "DNA_sound_types.h"
 #include "DNA_object_types.h"
 #include "DNA_particle_types.h"
 
@@ -86,8 +84,6 @@ extern "C" {
 #include "BKE_library_query.h"
 #include "BKE_modifier.h"
 #include "BKE_object.h"
-#include "BKE_sequencer.h"
-#include "BKE_sound.h"
 }
 
 #include "intern/depsgraph.h"
@@ -428,25 +424,6 @@ void scene_setup_view_layers_after_remap(const Depsgraph *depsgraph,
    * Still not an excuse to have those. */
 }
 
-void update_sequence_orig_pointers(const ListBase *sequences_orig, ListBase *sequences_cow)
-{
-  Sequence *sequence_orig = reinterpret_cast<Sequence *>(sequences_orig->first);
-  Sequence *sequence_cow = reinterpret_cast<Sequence *>(sequences_cow->first);
-  while (sequence_orig != NULL) {
-    update_sequence_orig_pointers(&sequence_orig->seqbase, &sequence_cow->seqbase);
-    sequence_cow->orig_sequence = sequence_orig;
-    sequence_cow = sequence_cow->next;
-    sequence_orig = sequence_orig->next;
-  }
-}
-
-void update_scene_orig_pointers(const Scene *scene_orig, Scene *scene_cow)
-{
-  if (scene_orig->ed != NULL) {
-    update_sequence_orig_pointers(&scene_orig->ed->seqbase, &scene_cow->ed->seqbase);
-  }
-}
-
 /* Check whether given ID is expanded or still a shallow copy. */
 BLI_INLINE bool check_datablock_expanded(const ID *id_cow)
 {
@@ -731,7 +708,6 @@ void update_id_after_copy(const Depsgraph *depsgraph,
       scene_cow->toolsettings = scene_orig->toolsettings;
       scene_cow->eevee.light_cache = scene_orig->eevee.light_cache;
       scene_setup_view_layers_after_remap(depsgraph, id_node, reinterpret_cast<Scene *>(id_cow));
-      update_scene_orig_pointers(scene_orig, scene_cow);
       break;
     }
     default:
@@ -862,205 +838,6 @@ ID *deg_expand_copy_on_write_datablock(const Depsgraph *depsgraph,
 
 namespace {
 
-/* Backup of sequencer strips runtime data. */
-
-/* Backup of a single strip. */
-class SequenceBackup {
- public:
-  SequenceBackup()
-  {
-    reset();
-  }
-
-  inline void reset()
-  {
-    scene_sound = NULL;
-  }
-
-  void init_from_sequence(Sequence *sequence)
-  {
-    scene_sound = sequence->scene_sound;
-
-    sequence->scene_sound = NULL;
-  }
-
-  void restore_to_sequence(Sequence *sequence)
-  {
-    sequence->scene_sound = scene_sound;
-    reset();
-  }
-
-  inline bool isEmpty() const
-  {
-    return (scene_sound == NULL);
-  }
-
-  void *scene_sound;
-};
-
-class SequencerBackup {
- public:
-  SequencerBackup();
-
-  void init_from_scene(Scene *scene);
-  void restore_to_scene(Scene *scene);
-
-  typedef map<Sequence *, SequenceBackup> SequencesBackupMap;
-  SequencesBackupMap sequences_backup;
-};
-
-SequencerBackup::SequencerBackup()
-{
-}
-
-void SequencerBackup::init_from_scene(Scene *scene)
-{
-  Sequence *sequence;
-  SEQ_BEGIN (scene->ed, sequence) {
-    SequenceBackup sequence_backup;
-    sequence_backup.init_from_sequence(sequence);
-    if (!sequence_backup.isEmpty()) {
-      sequences_backup.insert(make_pair(sequence->orig_sequence, sequence_backup));
-    }
-  }
-  SEQ_END;
-}
-
-void SequencerBackup::restore_to_scene(Scene *scene)
-{
-  Sequence *sequence;
-  SEQ_BEGIN (scene->ed, sequence) {
-    SequencesBackupMap::iterator it = sequences_backup.find(sequence->orig_sequence);
-    if (it == sequences_backup.end()) {
-      continue;
-    }
-    SequenceBackup &sequence_backup = it->second;
-    sequence_backup.restore_to_sequence(sequence);
-  }
-  SEQ_END;
-  /* Cleanup audio while the scene is still known. */
-  for (SequencesBackupMap::value_type &it : sequences_backup) {
-    SequenceBackup &sequence_backup = it.second;
-    if (sequence_backup.scene_sound != NULL) {
-      BKE_sound_remove_scene_sound(scene, sequence_backup.scene_sound);
-    }
-  }
-}
-
-/* Backup of scene runtime data. */
-
-class SceneBackup {
- public:
-  SceneBackup();
-
-  void reset();
-
-  void init_from_scene(Scene *scene);
-  void restore_to_scene(Scene *scene);
-
-  /* Sound/audio related pointers of the scene itself.
-   *
-   * NOTE: Scene can not disappear after relations update, because otherwise the entire dependency
-   * graph will be gone. This means we don't need to compare original scene pointer, or worry about
-   * freeing those if they cant' be restorted: we just copy them over to a new scene. */
-  void *sound_scene;
-  void *playback_handle;
-  void *sound_scrub_handle;
-  void *speaker_handles;
-
-  SequencerBackup sequencer_backup;
-};
-
-SceneBackup::SceneBackup()
-{
-  reset();
-}
-
-void SceneBackup::reset()
-{
-  sound_scene = NULL;
-  playback_handle = NULL;
-  sound_scrub_handle = NULL;
-  speaker_handles = NULL;
-}
-
-void SceneBackup::init_from_scene(Scene *scene)
-{
-  sound_scene = scene->sound_scene;
-  playback_handle = scene->playback_handle;
-  sound_scrub_handle = scene->sound_scrub_handle;
-  speaker_handles = scene->speaker_handles;
-
-  /* Clear pointers stored in the scene, so they are not freed when copied-on-written datablock
-   * is freed for re-allocation. */
-  scene->sound_scene = NULL;
-  scene->playback_handle = NULL;
-  scene->sound_scrub_handle = NULL;
-  scene->speaker_handles = NULL;
-
-  sequencer_backup.init_from_scene(scene);
-}
-
-void SceneBackup::restore_to_scene(Scene *scene)
-{
-  scene->sound_scene = sound_scene;
-  scene->playback_handle = playback_handle;
-  scene->sound_scrub_handle = sound_scrub_handle;
-  scene->speaker_handles = speaker_handles;
-
-  sequencer_backup.restore_to_scene(scene);
-
-  reset();
-}
-
-/* Backup of sound datablocks runtime data. */
-
-class SoundBackup {
- public:
-  SoundBackup();
-
-  void reset();
-
-  void init_from_sound(bSound *sound);
-  void restore_to_sound(bSound *sound);
-
-  void *cache;
-  void *waveform;
-  void *playback_handle;
-};
-
-SoundBackup::SoundBackup()
-{
-  reset();
-}
-
-void SoundBackup::reset()
-{
-  cache = NULL;
-  waveform = NULL;
-  playback_handle = NULL;
-}
-
-void SoundBackup::init_from_sound(bSound *sound)
-{
-  cache = sound->cache;
-  waveform = sound->waveform;
-  playback_handle = sound->playback_handle;
-
-  sound->cache = NULL;
-  sound->waveform = NULL;
-  sound->playback_handle = NULL;
-}
-
-void SoundBackup::restore_to_sound(bSound *sound)
-{
-  sound->cache = cache;
-  sound->waveform = waveform;
-  sound->playback_handle = playback_handle;
-
-  reset();
-}
-
 /* Identifier used to match modifiers to backup/restore their runtime data.
  * Identification is happening using original modifier data pointer and the
  * modifier type.
@@ -1101,8 +878,7 @@ typedef map<ModifierDataBackupID, void *> ModifierRuntimeDataBackup;
 /* Storage for backed up pose channel runtime data. */
 typedef map<bPoseChannel *, bPoseChannel_Runtime> PoseChannelRuntimeDataBackup;
 
-class ObjectRuntimeBackup {
- public:
+struct ObjectRuntimeBackup {
   ObjectRuntimeBackup() : base_flag(0), base_local_view_bits(0)
   {
     /* TODO(sergey): Use something like BKE_object_runtime_reset(). */
@@ -1280,8 +1056,6 @@ class RuntimeBackup {
   /* Restore fields to the given ID. */
   void restore_to_id(ID *id);
 
-  SceneBackup scene_backup;
-  SoundBackup sound_backup;
   ObjectRuntimeBackup object_backup;
   DrawDataList drawdata_backup;
   DrawDataList *drawdata_ptr;
@@ -1297,12 +1071,6 @@ void RuntimeBackup::init_from_id(ID *id)
     case ID_OB:
       object_backup.init_from_object(reinterpret_cast<Object *>(id));
       break;
-    case ID_SCE:
-      scene_backup.init_from_scene(reinterpret_cast<Scene *>(id));
-      break;
-    case ID_SO:
-      sound_backup.init_from_sound(reinterpret_cast<bSound *>(id));
-      break;
     default:
       break;
   }
@@ -1322,12 +1090,6 @@ void RuntimeBackup::restore_to_id(ID *id)
     case ID_OB:
       object_backup.restore_to_object(reinterpret_cast<Object *>(id));
       break;
-    case ID_SCE:
-      scene_backup.restore_to_scene(reinterpret_cast<Scene *>(id));
-      break;
-    case ID_SO:
-      sound_backup.restore_to_sound(reinterpret_cast<bSound *>(id));
-      break;
     default:
       break;
   }
@@ -1516,7 +1278,9 @@ bool deg_copy_on_write_is_expanded(const ID *id_cow)
 bool deg_copy_on_write_is_needed(const ID *id_orig)
 {
   const ID_Type id_type = GS(id_orig->name);
-  return !ELEM(id_type, ID_IM);
+  /* TODO(sergey): Make Sound copyable. It is here only because the code for dependency graph is
+   * being work in progress. */
+  return !ELEM(id_type, ID_IM, ID_SO);
 }
 
 }  // namespace DEG
diff --git a/source/blender/depsgraph/intern/node/deg_node_operation.cc b/source/blender/depsgraph/intern/node/deg_node_operation.cc
index 09a761d282f..62a61675bcc 100644
--- a/source/blender/depsgraph/intern/node/deg_node_operation.cc
+++ b/source/blender/depsgraph/intern/node/deg_node_operation.cc
@@ -185,9 +185,6 @@ const char *operationCodeAsString(OperationCode opcode)
     /* Generic datablock. */
     case OperationCode::GENERIC_DATABLOCK_UPDATE:
       return "GENERIC_DATABLOCK_UPDATE";
-    /* Sequencer. */
-    case OperationCode::SEQUENCES_EVAL:
-      return "SEQUENCES_EVAL";
     /* instancing/duplication. */
     case OperationCode::DUPLI:
       return "DUPLI";
diff --git a/source/blender/depsgraph/intern/node/deg_node_operation.h b/source/blender/depsgraph/intern/node/deg_node_operation.h
index 8fc565cfa77..ab6242a6196 100644
--- a/source/blender/depsgraph/intern/node/deg_node_operation.h
+++ b/source/blender/depsgraph/intern/node/deg_node_operation.h
@@ -185,16 +185,12 @@ enum class OperationCode {
   /* Images. -------------------------------------------------------------- */
   IMAGE_ANIMATION,
 
-  /* Synchronization. ----------------------------------------------------- */
+  /* Synchronization clips. ----------------------------------------------- */
   SYNCHRONIZE_TO_ORIGINAL,
 
   /* Generic datablock ---------------------------------------------------- */
   GENERIC_DATABLOCK_UPDATE,
 
-  /* Sequencer. ----------------------------------------------------------- */
-
-  SEQUENCES_EVAL,
-
   /* Duplication/instancing system. --------------------------------------- */
   DUPLI,
 };