diff --git a/src/xpra/codecs/enc_x264/encoder.pyx b/src/xpra/codecs/enc_x264/encoder.pyx
index bc213eb629..e2fa38210c 100644
--- a/src/xpra/codecs/enc_x264/encoder.pyx
+++ b/src/xpra/codecs/enc_x264/encoder.pyx
@@ -680,6 +680,15 @@ cdef class Encoder:
         if self.first_frame_timestamp==0:
             self.first_frame_timestamp = image.get_timestamp()
 
+        source = options.get("source", "unknown")
+        b_frames = options.get("b-frames", 0)
+        if source!=self.source or self.b_frames!=b_frames:
+            #some options have changed:
+            log("compress_image: reconfig b-frames=%s, source=%s (from %s, %s)", b_frames, source, self.b_frames, self.source)
+            self.source = source
+            self.b_frames = b_frames
+            self.reconfig_tune()
+
         pixels = image.get_pixels()
         istrides = image.get_rowstride()
         assert pixels, "failed to get pixels from %s" % image
@@ -799,33 +808,33 @@ cdef class Encoder:
         self.tune = self.get_tune()
         x264_param_default_preset(&param, get_preset_names()[new_preset], self.tune)
         #ensure quality remains what it was:
-        set_f_rf(&param, get_x264_quality(self.quality, self.profile))
-        self.tune_param(&param)
-        #apply it:
-        x264_param_apply_profile(&param, self.profile)
-        if x264_encoder_reconfig(self.context, &param)!=0:
-            raise Exception("x264_encoder_reconfig failed for speed=%s" % pct)
+        self.do_reconfig_tune(&param)
         self.preset = new_preset
 
     def set_encoding_quality(self, int pct):
         assert pct>=0 and pct<=100, "invalid percentage: %s" % pct
-        assert self.context!=NULL, "context is closed!"
         if self.quality==pct:
             return
         if abs(self.quality - pct)<=4 and pct!=100 and self.quality!=100:
             #not enough of a change to bother (but always change to/from 100)
             return
-        cdef x264_param_t param                  #@DuplicatedSignature
-        #only f_rf_constant is changing
-        #retrieve current parameters:
+        #adjust quality:
+        self.quality = pct
+        self.reconfig_tune()
+
+    def reconfig_tune(self):
+        cdef x264_param_t param
         x264_encoder_parameters(self.context, &param)
+        self.do_reconfig_tune(&param)
+
+    cdef do_reconfig_tune(self, x264_param_t *param):
+        assert self.context!=NULL, "context is closed!"
         #adjust quality:
-        set_f_rf(&param, get_x264_quality(self.quality, self.profile))
-        self.tune_param(&param)
+        set_f_rf(param, get_x264_quality(self.quality, self.profile))
+        self.tune_param(param)
         #apply it:
-        if x264_encoder_reconfig(self.context, &param)!=0:
-            raise Exception("x264_encoder_reconfig failed for quality=%s" % pct)
-        self.quality = pct
+        if x264_encoder_reconfig(self.context, param)!=0:
+            raise Exception("x264_encoder_reconfig failed")
 
 
 def selftest(full=False):
diff --git a/src/xpra/server/window/window_video_source.py b/src/xpra/server/window/window_video_source.py
index 5ea657c63d..d7b9744ee3 100644
--- a/src/xpra/server/window/window_video_source.py
+++ b/src/xpra/server/window/window_video_source.py
@@ -1322,12 +1322,7 @@ def setup_pipeline_option(self, width, height, src_format,
         dst_formats = self.full_csc_modes.get(encoder_spec.encoding)
         ve = encoder_spec.make_instance()
         options = self.encoding_options.copy()
-        #tweaks for "real" video:
-        if self.matches_video_subregion(width, height) and self.subregion_is_video():
-            options["source"] = "video"
-            if encoder_spec.encoding in self.supports_video_b_frames:
-                #could take av-sync into account here to choose the number of b-frames:
-                options["b-frames"] = 1
+        options.update(self.get_video_encoder_options(encoder_spec.encoding, width, height))
         ve.init_context(enc_width, enc_height, enc_in_format, dst_formats, encoder_spec.encoding, quality, speed, encoder_scaling, options)
         #record new actual limits:
         self.actual_scaling = scaling
@@ -1345,6 +1340,16 @@ def setup_pipeline_option(self, width, height, src_format,
         scalinglog("setup_pipeline: scaling=%s, encoder_scaling=%s", scaling, encoder_scaling)
         return  True
 
+    def get_video_encoder_options(self, encoding, width, height):
+        #tweaks for "real" video:
+        if self.matches_video_subregion(width, height) and self.subregion_is_video():
+            return {
+                       "source"     : "video",
+                       #could take av-sync into account here to choose the number of b-frames:
+                       "b-frames"   : int(encoding in self.supports_video_b_frames),
+                       }
+        return {}
+
 
     def encode_scrolling(self, image, distances, old_csums, csums, options):
         tstart = time.time()
@@ -1539,6 +1544,7 @@ def video_fallback():
         start = time.time()
         quality = max(0, min(100, self._current_quality))
         speed = max(0, min(100, self._current_speed))
+        options.update(self.get_video_encoder_options(ve.get_encoding(), width, height))
         ret = ve.compress_image(csc_image, quality, speed, options)
         if ret is None:
             videolog.error("video_encode: ouch, %s compression failed", encoding)