Fix content type (#4333)

CHANGELOG.md

@@ -72,6 +72,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Error in create project from backup for standard 3D annotation (<https://github.com/openvinotoolkit/cvat/pull/4160>)
 - Annotations search does not work correctly in some corner cases (when use complex properties with width, height) (<https://github.com/openvinotoolkit/cvat/pull/4198>)
 - Kibana requests are not proxied due to django-revproxy incompatibility with Django >3.2.x (<https://github.com/openvinotoolkit/cvat/issues/4085>)
+- Content type for getting frame with tasks/{id}/data/ endpoint (<https://github.com/openvinotoolkit/cvat/pull/4333>)
 
 ### Security
 - Updated ELK to 6.8.23 which uses log4j 2.17.1 (<https://github.com/openvinotoolkit/cvat/pull/4206>)

cvat/apps/engine/views.py

@@ -478,7 +478,7 @@ class DataChunkGetter:
                 raise ValidationError('The frame number should be in ' +
                     f'[{start}, {stop}] range')
 
-            buf, mime = frame_provider.get_frame(self.number, self.quality)
+            buf, (mime, _) = frame_provider.get_frame(self.number, self.quality)
             return HttpResponse(buf.getvalue(), content_type=mime)
 
         elif self.type == 'preview':