* turn til_fb_fragment_t.stream into a discrete parameter

This was mostly done out of convenience at the expense of turning
the fragment struct into more of a junk drawer.

But properly cleaning up owned stream pipes on context destroy
makes the inappropriateness of being part of til_fb_fragment_t
glaringly apparent.

Now the stream is just a separate thing passed to context create,
with a reference kept in the context for use throughout.  Cleanup
of the owned pipes on the stream supplied to context create is
automagic when the context gets destroyed.

Note that despite there being a stream in the module context, the
stream to use is still supplied to all the rendering family
functions (prepare/render/finish) and it's the passed-in stream
which should be used by these functions.  This is done to support
the possibility of switching out the stream frame-to-frame, which
may be interesting.  Imagine doing things like a latent stream
and a future stream and switching between them on the fly for
instance.  If there's a sequencing composite module, it could
flip between multiple sets of tracks or jump around multiple
streams with the visuals immediately flipping accordingly.

This should fix the --print-pipes crashing issues caused by lack
of cleanup when contexts were removed (like rtv does so often).

33 files changed, 173 insertions, 158 deletions

diff --git a/src/main.c b/src/main.c
index 5b2024d..37fef55 100644
--- a/src/main.c
+++ b/src/main.c
@@ -331,10 +331,9 @@ static void * rototiller_thread(void *_rt)
 		unsigned		ticks;
 
 		fragment = til_fb_page_get(rt->fb);
-		fragment->stream = rt->stream;
 		gettimeofday(&now, NULL);
 		ticks = get_ticks(&rt->start_tv, &now, rt->ticks_offset);
-		til_module_render(rt->module_context, ticks, &fragment);
+		til_module_render(rt->module_context, rt->stream, ticks, &fragment);
 		til_fb_fragment_submit(fragment);
 
 		if (rt->args.print_pipes) /* render threads are idle at this point */
@@ -389,8 +388,9 @@ int main(int argc, const char *argv[])
 		"unable to setup fps counter");
 
 	gettimeofday(&rototiller.start_tv, NULL);
-	exit_if((r = til_module_create_context(
-						rototiller.module, setup.seed,
+	exit_if((r = til_module_create_context(	rototiller.module,
+						rototiller.stream,
+						setup.seed,
 						get_ticks(&rototiller.start_tv,
 							&rototiller.start_tv,
 							rototiller.ticks_offset),
diff --git a/src/modules/blinds/blinds.c b/src/modules/blinds/blinds.c
index 890b569..b0aebdb 100644
--- a/src/modules/blinds/blinds.c
+++ b/src/modules/blinds/blinds.c
@@ -37,14 +37,14 @@ static blinds_setup_t blinds_default_setup = {
 };
 
 
-static til_module_context_t * blinds_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * blinds_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	blinds_context_t	*ctxt;
 
 	if (!setup)
 		setup = &blinds_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(blinds_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(blinds_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -83,7 +83,7 @@ static inline void draw_blind_vertical(til_fb_fragment_t *fragment, unsigned col
 
 
 /* draw blinds over the fragment */
-static void blinds_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void blinds_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	blinds_context_t	*ctxt = (blinds_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/checkers/checkers.c b/src/modules/checkers/checkers.c
index b7a4f11..c4a419f 100644
--- a/src/modules/checkers/checkers.c
+++ b/src/modules/checkers/checkers.c
@@ -79,7 +79,7 @@ static checkers_setup_t checkers_default_setup = {
 };
 
 
-static til_module_context_t * checkers_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * checkers_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	size_t			size = sizeof(checkers_context_t);
 	checkers_context_t	*ctxt;
@@ -90,7 +90,7 @@ static til_module_context_t * checkers_create_context(unsigned seed, unsigned ti
 	if (((checkers_setup_t *)setup)->fill_module)
 		size += sizeof(til_module_context_t *) * n_cpus;
 
-	ctxt = til_module_context_new(size, ticks, seed, n_cpus, path);
+	ctxt = til_module_context_new(stream, size, ticks, seed, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -104,7 +104,7 @@ static til_module_context_t * checkers_create_context(unsigned seed, unsigned ti
 
 		/* since checkers is already threaded, create an n_cpus=1 context per-cpu */
 		for (unsigned i = 0; i < n_cpus; i++) /* TODO: errors */
-			(void) til_module_create_context(module, seed, ticks, 1, path /* FIXME TODO path-per-context breaks down on these per-cpu-context abuses */, module_setup, &ctxt->fill_module_contexts[i]);
+			(void) til_module_create_context(module, stream, seed, ticks, 1, path /* FIXME TODO path-per-context breaks down on these per-cpu-context abuses */, module_setup, &ctxt->fill_module_contexts[i]);
 
 		/* XXX: it would be interesting to support various patterns/layouts by varying the seed, but this will require
 		 * more complex context allocation strategies while also maintaining the per-cpu allocation.
@@ -227,7 +227,7 @@ static int checkers_fragmenter(til_module_context_t *context, const til_fb_fragm
 }
 
 
-static void checkers_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void checkers_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	checkers_context_t	*ctxt = (checkers_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -255,7 +255,7 @@ static inline unsigned hash(unsigned x)
 }
 
 
-static void checkers_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void checkers_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	checkers_context_t	*ctxt = (checkers_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -323,7 +323,7 @@ static void checkers_render_fragment(til_module_context_t *context, unsigned tic
 			til_fb_fragment_fill(fragment, flags, color);
 		else {
 			/* TODO: we need a way to send down color and flags, and use the module render as a brush of sorts */
-			til_module_render(ctxt->fill_module_contexts[cpu], ticks, fragment_ptr);
+			til_module_render(ctxt->fill_module_contexts[cpu], stream, ticks, fragment_ptr);
 		}
 	}
 }
diff --git a/src/modules/compose/compose.c b/src/modules/compose/compose.c
index a73f2b7..92f6fd2 100644
--- a/src/modules/compose/compose.c
+++ b/src/modules/compose/compose.c
@@ -47,9 +47,9 @@ typedef struct compose_setup_t {
 	char			*layers[];
 } compose_setup_t;
 
-static til_module_context_t * compose_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup);
+static til_module_context_t * compose_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup);
 static void compose_destroy_context(til_module_context_t *context);
-static void compose_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
+static void compose_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
 static int compose_setup(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup);
 
 static compose_setup_t compose_default_setup = {
@@ -67,7 +67,7 @@ til_module_t	compose_module = {
 };
 
 
-static til_module_context_t * compose_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * compose_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	compose_context_t	*ctxt;
 	size_t			n;
@@ -77,7 +77,7 @@ static til_module_context_t * compose_create_context(unsigned seed, unsigned tic
 
 	for (n = 0; ((compose_setup_t *)setup)->layers[n]; n++);
 
-	ctxt = til_module_context_new(sizeof(compose_context_t) + n * sizeof(compose_layer_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(compose_context_t) + n * sizeof(compose_layer_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -89,7 +89,7 @@ static til_module_context_t * compose_create_context(unsigned seed, unsigned tic
 		(void) til_module_randomize_setup(layer_module, rand_r(&seed), &layer_setup, NULL);
 
 		ctxt->layers[i].module = layer_module;
-		(void) til_module_create_context(layer_module, rand_r(&seed), ticks, 0, path, layer_setup, &ctxt->layers[i].module_ctxt);
+		(void) til_module_create_context(layer_module, stream, rand_r(&seed), ticks, 0, path, layer_setup, &ctxt->layers[i].module_ctxt);
 		til_setup_free(layer_setup);
 
 		ctxt->n_layers++;
@@ -101,7 +101,7 @@ static til_module_context_t * compose_create_context(unsigned seed, unsigned tic
 		ctxt->texture.module = til_lookup_module(((compose_setup_t *)setup)->texture);
 		(void) til_module_randomize_setup(ctxt->texture.module, rand_r(&seed), &texture_setup, NULL);
 
-		(void) til_module_create_context(ctxt->texture.module, rand_r(&seed), ticks, 0, path, texture_setup, &ctxt->texture.module_ctxt);
+		(void) til_module_create_context(ctxt->texture.module, stream, rand_r(&seed), ticks, 0, path, texture_setup, &ctxt->texture.module_ctxt);
 		til_setup_free(texture_setup);
 	}
 
@@ -125,7 +125,7 @@ static void compose_destroy_context(til_module_context_t *context)
 }
 
 
-static void compose_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void compose_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	compose_context_t	*ctxt = (compose_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr, *texture = &ctxt->texture_fb;
@@ -149,17 +149,17 @@ static void compose_render_fragment(til_module_context_t *context, unsigned tick
 
 		ctxt->texture_fb.cleared = 0;
 		/* XXX: if when snapshotting becomes a thing, ctxt->texture_fb is snapshottable, this will likely break as-is */
-		til_module_render(ctxt->texture.module_ctxt, ticks, &texture);
-		til_module_render(ctxt->layers[0].module_ctxt, ticks, &fragment);
+		til_module_render(ctxt->texture.module_ctxt, stream, ticks, &texture);
+		til_module_render(ctxt->layers[0].module_ctxt, stream, ticks, &fragment);
 
 		for (size_t i = 1; i < ctxt->n_layers; i++) {
 			fragment->texture = texture; /* keep forcing our texture, in case something below us installed their own. */
-			til_module_render(ctxt->layers[i].module_ctxt, ticks, &fragment);
+			til_module_render(ctxt->layers[i].module_ctxt, stream, ticks, &fragment);
 		}
 	} else {
 		for (size_t i = 0; i < ctxt->n_layers; i++) {
 			fragment->texture = NULL; /* keep forcing no texture, in case something below us installed their own. TODO: more formally define texture semantics as it pertains to module nesting */
-			til_module_render(ctxt->layers[i].module_ctxt, ticks, &fragment);
+			til_module_render(ctxt->layers[i].module_ctxt, stream, ticks, &fragment);
 		}
 	}
 
diff --git a/src/modules/drizzle/drizzle.c b/src/modules/drizzle/drizzle.c
index e5b79eb..307e0d3 100644
--- a/src/modules/drizzle/drizzle.c
+++ b/src/modules/drizzle/drizzle.c
@@ -85,14 +85,14 @@ static inline uint32_t color_to_uint32(v3f_t color) {
 }
 
 
-static til_module_context_t * drizzle_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * drizzle_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	drizzle_context_t	*ctxt;
 
 	if (!setup)
 		setup = &drizzle_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(drizzle_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(drizzle_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -117,7 +117,7 @@ static void drizzle_destroy_context(til_module_context_t *context)
 }
 
 
-static void drizzle_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void drizzle_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	drizzle_context_t	*ctxt = (drizzle_context_t *)context;
 
@@ -249,7 +249,7 @@ static void puddle_sample_normal(const puddle_t *puddle, const v2f_t *coordinate
 }
 
 
-static void drizzle_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void drizzle_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	drizzle_context_t	*ctxt = (drizzle_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -329,7 +329,7 @@ static void drizzle_render_fragment(til_module_context_t *context, unsigned tick
 }
 
 
-static void drizzle_finish_frame(til_module_context_t *context, unsigned int ticks, til_fb_fragment_t **fragment_ptr)
+static void drizzle_finish_frame(til_module_context_t *context, til_stream_t *stream, unsigned int ticks, til_fb_fragment_t **fragment_ptr)
 {
 	drizzle_context_t	*ctxt = (drizzle_context_t *)context;
 
diff --git a/src/modules/flui2d/flui2d.c b/src/modules/flui2d/flui2d.c
index 4b75520..9ae3e94 100644
--- a/src/modules/flui2d/flui2d.c
+++ b/src/modules/flui2d/flui2d.c
@@ -245,7 +245,7 @@ static void gamma_init(float gamma)
 }
 
 
-static til_module_context_t * flui2d_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * flui2d_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	static int		initialized;
 	flui2d_context_t	*ctxt;
@@ -253,7 +253,7 @@ static til_module_context_t * flui2d_create_context(unsigned seed, unsigned tick
 	if (!setup)
 		setup = &flui2d_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(flui2d_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(flui2d_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -273,7 +273,7 @@ static til_module_context_t * flui2d_create_context(unsigned seed, unsigned tick
 
 
 /* Prepare a frame for concurrent drawing of fragment using multiple fragments */
-static void flui2d_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void flui2d_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	flui2d_context_t	*ctxt = (flui2d_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -334,7 +334,7 @@ static void flui2d_prepare_frame(til_module_context_t *context, unsigned ticks,
 
 
 /* Draw a the flui2d densities */
-static void flui2d_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void flui2d_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	flui2d_context_t	*ctxt = (flui2d_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/julia/julia.c b/src/modules/julia/julia.c
index 0dcefe5..65a15b6 100644
--- a/src/modules/julia/julia.c
+++ b/src/modules/julia/julia.c
@@ -67,11 +67,11 @@ static uint32_t	colors[] = {
 		};
 
 
-static til_module_context_t * julia_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * julia_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	julia_context_t	*ctxt;
 
-	ctxt = til_module_context_new(sizeof(julia_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(julia_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -106,7 +106,7 @@ static inline unsigned julia_iter(float real, float imag, float creal, float cim
 
 
 /* Prepare a frame for concurrent drawing of fragment using multiple fragments */
-static void julia_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void julia_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	julia_context_t	*ctxt = (julia_context_t *)context;
 
@@ -133,7 +133,7 @@ static void julia_prepare_frame(til_module_context_t *context, unsigned ticks, t
 
 
 /* Draw a morphing Julia set */
-static void julia_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void julia_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	julia_context_t		*ctxt = (julia_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/meta2d/meta2d.c b/src/modules/meta2d/meta2d.c
index 978f32f..6d9d307 100644
--- a/src/modules/meta2d/meta2d.c
+++ b/src/modules/meta2d/meta2d.c
@@ -67,11 +67,11 @@ static inline uint32_t color_to_uint32(v3f_t color) {
 }
 
 
-static til_module_context_t * meta2d_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * meta2d_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	meta2d_context_t	*ctxt;
 
-	ctxt = til_module_context_new(sizeof(meta2d_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(meta2d_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -101,7 +101,7 @@ static void meta2d_destroy_context(til_module_context_t *context)
 }
 
 
-static void meta2d_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void meta2d_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	meta2d_context_t	*ctxt = (meta2d_context_t *)context;
 
@@ -178,7 +178,7 @@ static void meta2d_prepare_frame(til_module_context_t *context, unsigned ticks,
 }
 
 
-static void meta2d_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void meta2d_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	meta2d_context_t	*ctxt = (meta2d_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/moire/moire.c b/src/modules/moire/moire.c
index 9bf782c..b010cdd 100644
--- a/src/modules/moire/moire.c
+++ b/src/modules/moire/moire.c
@@ -47,14 +47,14 @@ static moire_setup_t moire_default_setup = {
 };
 
 
-static til_module_context_t * moire_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * moire_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	moire_context_t	*ctxt;
 
 	if (!setup)
 		setup = &moire_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(moire_context_t) + ((moire_setup_t *)setup)->n_centers * sizeof(moire_center_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(moire_context_t) + ((moire_setup_t *)setup)->n_centers * sizeof(moire_center_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -71,7 +71,7 @@ static til_module_context_t * moire_create_context(unsigned seed, unsigned ticks
 }
 
 
-static void moire_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void moire_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	moire_context_t	*ctxt = (moire_context_t *)context;
 
@@ -84,7 +84,7 @@ static void moire_prepare_frame(til_module_context_t *context, unsigned ticks, t
 }
 
 
-static void moire_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void moire_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	moire_context_t		*ctxt = (moire_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/montage/montage.c b/src/modules/montage/montage.c
index 6697bc5..3ab944f 100644
--- a/src/modules/montage/montage.c
+++ b/src/modules/montage/montage.c
@@ -16,10 +16,10 @@ typedef struct montage_context_t {
 	size_t			n_modules;
 } montage_context_t;
 
-static til_module_context_t * montage_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup);
+static til_module_context_t * montage_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup);
 static void montage_destroy_context(til_module_context_t *context);
-static void montage_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan);
-static void montage_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
+static void montage_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan);
+static void montage_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
 
 
 til_module_t	montage_module = {
@@ -32,13 +32,13 @@ til_module_t	montage_module = {
 };
 
 
-static til_module_context_t * montage_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * montage_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	const til_module_t	**modules, *rtv_module, *compose_module;
 	size_t			n_modules;
 	montage_context_t	*ctxt;
 
-	ctxt = til_module_context_new(sizeof(montage_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(montage_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -92,7 +92,7 @@ static til_module_context_t * montage_create_context(unsigned seed, unsigned tic
 		(void) til_module_randomize_setup(module, rand_r(&seed), &setup, NULL);
 
 		/* FIXME errors */
-		(void) til_module_create_context(module, rand_r(&seed), ticks, 1, path, setup, &ctxt->contexts[i]);
+		(void) til_module_create_context(module, stream, rand_r(&seed), ticks, 1, path, setup, &ctxt->contexts[i]);
 
 		til_setup_free(setup);
 	}
@@ -210,13 +210,13 @@ static int montage_fragmenter(til_module_context_t *context, const til_fb_fragme
 }
 
 
-static void montage_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void montage_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	*res_frame_plan = (til_frame_plan_t){ .fragmenter = montage_fragmenter };
 }
 
 
-static void montage_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void montage_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	montage_context_t	*ctxt = (montage_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -227,5 +227,5 @@ static void montage_render_fragment(til_module_context_t *context, unsigned tick
 		return;
 	}
 
-	til_module_render(ctxt->contexts[fragment->number], ticks, fragment_ptr);
+	til_module_render(ctxt->contexts[fragment->number], stream, ticks, fragment_ptr);
 }
diff --git a/src/modules/pixbounce/pixbounce.c b/src/modules/pixbounce/pixbounce.c
index f10bd5b..8a26be2 100644
--- a/src/modules/pixbounce/pixbounce.c
+++ b/src/modules/pixbounce/pixbounce.c
@@ -240,11 +240,11 @@ static uint32_t pick_color(unsigned *seedp)
 	return makergb(rand_r(seedp)%256, rand_r(seedp)%256, rand_r(seedp)%256, 1);
 }
 
-static til_module_context_t * pixbounce_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * pixbounce_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	pixbounce_context_t *ctxt;
 
-	ctxt = til_module_context_new(sizeof(pixbounce_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(pixbounce_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -260,7 +260,7 @@ static til_module_context_t * pixbounce_create_context(unsigned seed, unsigned t
 	return &ctxt->til_module_context;
 }
 
-static void pixbounce_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void pixbounce_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	pixbounce_context_t	*ctxt = (pixbounce_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/plasma/plasma.c b/src/modules/plasma/plasma.c
index f49b396..c42efd2 100644
--- a/src/modules/plasma/plasma.c
+++ b/src/modules/plasma/plasma.c
@@ -53,7 +53,7 @@ static void init_plasma(int32_t *costab, int32_t *sintab)
 }
 
 
-static til_module_context_t * plasma_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * plasma_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	static int		initialized;
 	plasma_context_t	*ctxt;
@@ -64,7 +64,7 @@ static til_module_context_t * plasma_create_context(unsigned seed, unsigned tick
 		init_plasma(costab, sintab);
 	}
 
-	ctxt = til_module_context_new(sizeof(plasma_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(plasma_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -75,7 +75,7 @@ static til_module_context_t * plasma_create_context(unsigned seed, unsigned tick
 
 
 /* Prepare a frame for concurrent drawing of fragment using multiple fragments */
-static void plasma_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void plasma_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	plasma_context_t	*ctxt = (plasma_context_t *)context;
 
@@ -85,7 +85,7 @@ static void plasma_prepare_frame(til_module_context_t *context, unsigned ticks,
 
 
 /* Draw a plasma effect */
-static void plasma_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void plasma_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	plasma_context_t	*ctxt = (plasma_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/plato/plato.c b/src/modules/plato/plato.c
index 1dc56a3..4334eda 100644
--- a/src/modules/plato/plato.c
+++ b/src/modules/plato/plato.c
@@ -630,11 +630,11 @@ static void draw_polyhedron(const polyhedron_t *polyhedron, m4f_t *transform, ti
 }
 
 
-static til_module_context_t * plato_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * plato_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	plato_context_t	*ctxt;
 
-	ctxt = til_module_context_new(sizeof(plato_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(plato_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -647,14 +647,14 @@ static til_module_context_t * plato_create_context(unsigned seed, unsigned ticks
 }
 
 
-static void plato_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void plato_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	plato_context_t		*ctxt = (plato_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
 
 	/* since we don't automate the rates ourselves, we don't care about the tap return values */
-	(void) til_stream_tap_context(fragment->stream, context, &ctxt->taps.orbit_rate);
-	(void) til_stream_tap_context(fragment->stream, context, &ctxt->taps.spin_rate);
+	(void) til_stream_tap_context(stream, context, &ctxt->taps.orbit_rate);
+	(void) til_stream_tap_context(stream, context, &ctxt->taps.spin_rate);
 
 	ctxt->r += (float)(ticks - context->ticks) * (*ctxt->orbit_rate * .001f);
 	ctxt->rr += (float)(ticks - context->ticks) * (*ctxt->spin_rate * .001f);
diff --git a/src/modules/ray/ray.c b/src/modules/ray/ray.c
index e3887b6..0017da3 100644
--- a/src/modules/ray/ray.c
+++ b/src/modules/ray/ray.c
@@ -132,11 +132,11 @@ typedef struct ray_context_t {
 } ray_context_t;
 
 
-static til_module_context_t * ray_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * ray_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	ray_context_t	*ctxt;
 
-	ctxt = til_module_context_new(sizeof(ray_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(ray_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -145,7 +145,7 @@ static til_module_context_t * ray_create_context(unsigned seed, unsigned ticks,
 
 
 /* prepare a frame for concurrent rendering */
-static void ray_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void ray_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	ray_context_t		*ctxt = (ray_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -178,7 +178,7 @@ static void ray_prepare_frame(til_module_context_t *context, unsigned ticks, til
 
 
 /* ray trace a simple scene into the fragment */
-static void ray_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void ray_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	ray_context_t		*ctxt = (ray_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -187,7 +187,7 @@ static void ray_render_fragment(til_module_context_t *context, unsigned ticks, u
 }
 
 
-static void ray_finish_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr)
+static void ray_finish_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr)
 {
 	ray_context_t	*ctxt = (ray_context_t *)context;
 
diff --git a/src/modules/roto/roto.c b/src/modules/roto/roto.c
index c5106ab..1b20e2e 100644
--- a/src/modules/roto/roto.c
+++ b/src/modules/roto/roto.c
@@ -62,7 +62,7 @@ static void init_roto(uint8_t texture[256][256], int32_t *costab, int32_t *sinta
 }
 
 
-static til_module_context_t * roto_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * roto_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	static int	initialized;
 	roto_context_t	*ctxt;
@@ -73,7 +73,7 @@ static til_module_context_t * roto_create_context(unsigned seed, unsigned ticks,
 		init_roto(texture, costab, sintab);
 	}
 
-	ctxt = til_module_context_new(sizeof(roto_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(roto_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -182,7 +182,7 @@ static uint32_t bilerp_color(uint8_t texture[256][256], color_t *palette, int tx
 
 
 /* prepare a frame for concurrent rendering */
-static void roto_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void roto_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	roto_context_t	*ctxt = (roto_context_t *)context;
 
@@ -208,7 +208,7 @@ static void roto_prepare_frame(til_module_context_t *context, unsigned ticks, ti
 
 
 /* Draw a rotating checkered 256x256 texture into fragment. */
-static void roto_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void roto_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	roto_context_t		*ctxt = (roto_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/rtv/rtv.c b/src/modules/rtv/rtv.c
index a8cac2a..b7f500a 100644
--- a/src/modules/rtv/rtv.c
+++ b/src/modules/rtv/rtv.c
@@ -61,10 +61,10 @@ typedef struct rtv_setup_t {
 } rtv_setup_t;
 
 static void setup_next_channel(rtv_context_t *ctxt, unsigned ticks);
-static til_module_context_t * rtv_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup);
+static til_module_context_t * rtv_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup);
 static void rtv_destroy_context(til_module_context_t *context);
-static void rtv_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
-static void rtv_finish_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr);
+static void rtv_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
+static void rtv_finish_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr);
 static int rtv_setup(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup);
 
 static rtv_setup_t rtv_default_setup = {
@@ -188,7 +188,7 @@ static void setup_next_channel(rtv_context_t *ctxt, unsigned ticks)
 	}
 
 	if (!ctxt->channel->module_ctxt)
-		(void) til_module_create_context(ctxt->channel->module, rand_r(&ctxt->til_module_context.seed), ticks, 0, ctxt->til_module_context.path, ctxt->channel->module_setup, &ctxt->channel->module_ctxt);
+		(void) til_module_create_context(ctxt->channel->module, ctxt->til_module_context.stream, rand_r(&ctxt->til_module_context.seed), ticks, 0, ctxt->til_module_context.path, ctxt->channel->module_setup, &ctxt->channel->module_ctxt);
 
 	ctxt->channel->last_on_time = now;
 }
@@ -215,7 +215,7 @@ static int rtv_should_skip_module(const rtv_setup_t *setup, const til_module_t *
 }
 
 
-static til_module_context_t * rtv_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * rtv_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	rtv_context_t		*ctxt;
 	const til_module_t	**modules;
@@ -232,7 +232,7 @@ static til_module_context_t * rtv_create_context(unsigned seed, unsigned ticks,
 			n_channels++;
 	}
 
-	ctxt = til_module_context_new(sizeof(rtv_context_t) + n_channels * sizeof(rtv_channel_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(rtv_context_t) + n_channels * sizeof(rtv_channel_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -244,7 +244,7 @@ static til_module_context_t * rtv_create_context(unsigned seed, unsigned ticks,
 	ctxt->snow_channel.module = &rtv_none_module;
 	if (((rtv_setup_t *)setup)->snow_module) {
 		ctxt->snow_channel.module = til_lookup_module(((rtv_setup_t *)setup)->snow_module);
-		(void) til_module_create_context(ctxt->snow_channel.module, rand_r(&seed), ticks, 0, path, NULL, &ctxt->snow_channel.module_ctxt);
+		(void) til_module_create_context(ctxt->snow_channel.module, stream, rand_r(&seed), ticks, 0, path, NULL, &ctxt->snow_channel.module_ctxt);
 	}
 
 	for (size_t i = 0; i < n_modules; i++) {
@@ -268,7 +268,7 @@ static void rtv_destroy_context(til_module_context_t *context)
 }
 
 
-static void rtv_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void rtv_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	rtv_context_t	*ctxt = (rtv_context_t *)context;
 	time_t		now = time(NULL);
@@ -279,11 +279,11 @@ static void rtv_render_fragment(til_module_context_t *context, unsigned ticks, u
 	if (now >= ctxt->next_hide_caption)
 		ctxt->caption = NULL;
 
-	til_module_render(ctxt->channel->module_ctxt, ticks, fragment_ptr);
+	til_module_render(ctxt->channel->module_ctxt, stream, ticks, fragment_ptr);
 }
 
 
-static void rtv_finish_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr)
+static void rtv_finish_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr)
 {
 	rtv_context_t		*ctxt = (rtv_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/shapes/shapes.c b/src/modules/shapes/shapes.c
index 65a13fa..1be9f03 100644
--- a/src/modules/shapes/shapes.c
+++ b/src/modules/shapes/shapes.c
@@ -98,14 +98,14 @@ static shapes_setup_t shapes_default_setup = {
 };
 
 
-static til_module_context_t * shapes_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * shapes_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	shapes_context_t	*ctxt;
 
 	if (!setup)
 		setup = &shapes_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(shapes_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(shapes_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -115,7 +115,7 @@ static til_module_context_t * shapes_create_context(unsigned seed, unsigned tick
 }
 
 
-static void shapes_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void shapes_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	shapes_context_t	*ctxt = (shapes_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/snow/snow.c b/src/modules/snow/snow.c
index 9a86689..bcf1cc4 100644
--- a/src/modules/snow/snow.c
+++ b/src/modules/snow/snow.c
@@ -22,11 +22,11 @@ typedef struct snow_context_t {
 } snow_context_t;
 
 
-static til_module_context_t * snow_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * snow_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	snow_context_t	*ctxt;
 
-	ctxt = til_module_context_new(sizeof(snow_context_t) + n_cpus * sizeof(snow_seed_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(snow_context_t) + n_cpus * sizeof(snow_seed_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -37,13 +37,13 @@ static til_module_context_t * snow_create_context(unsigned seed, unsigned ticks,
 }
 
 
-static void snow_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void snow_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	*res_frame_plan = (til_frame_plan_t){ .fragmenter = til_fragmenter_slice_per_cpu };
 }
 
 
-static void snow_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void snow_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	snow_context_t		*ctxt = (snow_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/sparkler/sparkler.c b/src/modules/sparkler/sparkler.c
index 1a2c8bb..afe4f0f 100644
--- a/src/modules/sparkler/sparkler.c
+++ b/src/modules/sparkler/sparkler.c
@@ -35,14 +35,14 @@ extern particle_ops_t	simple_ops;
 
 static sparkler_setup_t sparkler_default_setup;
 
-static til_module_context_t * sparkler_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * sparkler_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	sparkler_context_t	*ctxt;
 
 	if (!setup)
 		setup = &sparkler_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(sparkler_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(sparkler_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -75,7 +75,7 @@ static void sparkler_destroy_context(til_module_context_t *context)
 }
 
 
-static void sparkler_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void sparkler_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	sparkler_context_t	*ctxt = (sparkler_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -92,7 +92,7 @@ static void sparkler_prepare_frame(til_module_context_t *context, unsigned ticks
 
 
 /* Render a 3D particle system */
-static void sparkler_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void sparkler_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	sparkler_context_t	*ctxt = (sparkler_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/spiro/spiro.c b/src/modules/spiro/spiro.c
index 236dd4a..ab11aab 100644
--- a/src/modules/spiro/spiro.c
+++ b/src/modules/spiro/spiro.c
@@ -31,12 +31,12 @@ typedef struct spiro_context_t {
 } spiro_context_t;
 
 
-static til_module_context_t * spiro_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * spiro_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	spiro_context_t *ctxt;
 	float		z;
 
-	ctxt = til_module_context_new(sizeof(spiro_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(spiro_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -53,7 +53,7 @@ static til_module_context_t * spiro_create_context(unsigned seed, unsigned ticks
 	return &ctxt->til_module_context;
 }
 
-static void spiro_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void spiro_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	spiro_context_t		*ctxt = (spiro_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/stars/stars.c b/src/modules/stars/stars.c
index 82619d7..26f2913 100644
--- a/src/modules/stars/stars.c
+++ b/src/modules/stars/stars.c
@@ -70,7 +70,7 @@ float get_random_unit_coord(unsigned *seed) {
 }
 
 
-static til_module_context_t * stars_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * stars_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	stars_context_t *ctxt;
 	float		z;
@@ -79,7 +79,7 @@ static til_module_context_t * stars_create_context(unsigned seed, unsigned ticks
 	if (!setup)
 		setup = &stars_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(stars_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(stars_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -131,7 +131,7 @@ static void stars_destroy_context(til_module_context_t *context)
 }
 
 
-static void stars_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void stars_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	stars_context_t		*ctxt = (stars_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -223,10 +223,10 @@ static void stars_render_fragment(til_module_context_t *context, unsigned ticks,
 		ctxt->points = tmp_ptr;
 	}
 
-	if (!til_stream_tap_context(fragment->stream, context, &ctxt->taps.rot_angle))
+	if (!til_stream_tap_context(stream, context, &ctxt->taps.rot_angle))
 		*ctxt->rot_angle+=*ctxt->rot_rate;
 
-	if (!til_stream_tap_context(fragment->stream, context, &ctxt->taps.rot_rate)) {
+	if (!til_stream_tap_context(stream, context, &ctxt->taps.rot_rate)) {
 		// handle rotation parameters
 		if(*ctxt->rot_angle>M_PI_4)
 			*ctxt->rot_rate=*ctxt->rot_rate-ctxt->rot_adj;
@@ -235,16 +235,16 @@ static void stars_render_fragment(til_module_context_t *context, unsigned ticks,
 	}
 
 	/* there's no automation of offset_angle */
-	(void) til_stream_tap_context(fragment->stream, context, &ctxt->taps.offset_angle);
+	(void) til_stream_tap_context(stream, context, &ctxt->taps.offset_angle);
 
 	// handle offset parameters
-	if (!til_stream_tap_context(fragment->stream, context, &ctxt->taps.offset_x)) {
+	if (!til_stream_tap_context(stream, context, &ctxt->taps.offset_x)) {
 		float tmp_x = (*ctxt->offset_x*cosf(*ctxt->offset_angle))-
 				(*ctxt->offset_y*sinf(*ctxt->offset_angle));
 		*ctxt->offset_x = tmp_x;
 	}
 
-	if (!til_stream_tap_context(fragment->stream, context, &ctxt->taps.offset_y)) {
+	if (!til_stream_tap_context(stream, context, &ctxt->taps.offset_y)) {
 		float tmp_y = (*ctxt->offset_x*sinf(*ctxt->offset_angle))+
 				(*ctxt->offset_y*cosf(*ctxt->offset_angle));
 		*ctxt->offset_y = tmp_y;
diff --git a/src/modules/strobe/strobe.c b/src/modules/strobe/strobe.c
index bc0c365..5410ffb 100644
--- a/src/modules/strobe/strobe.c
+++ b/src/modules/strobe/strobe.c
@@ -40,14 +40,14 @@ static strobe_setup_t strobe_default_setup = {
 };
 
 
-static til_module_context_t * strobe_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * strobe_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	strobe_context_t	*ctxt;
 
 	if (!setup)
 		setup = &strobe_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(strobe_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(strobe_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -58,7 +58,7 @@ static til_module_context_t * strobe_create_context(unsigned seed, unsigned tick
 }
 
 
-static void strobe_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void strobe_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	strobe_context_t	*ctxt = (strobe_context_t *)context;
 
@@ -73,7 +73,7 @@ static void strobe_prepare_frame(til_module_context_t *context, unsigned ticks,
 }
 
 
-static void strobe_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void strobe_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	strobe_context_t	*ctxt = (strobe_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -85,7 +85,7 @@ static void strobe_render_fragment(til_module_context_t *context, unsigned ticks
 }
 
 
-static void strobe_finish_frame(til_module_context_t *context, unsigned int ticks, til_fb_fragment_t **fragment_ptr)
+static void strobe_finish_frame(til_module_context_t *context, til_stream_t *stream, unsigned int ticks, til_fb_fragment_t **fragment_ptr)
 {
 	strobe_context_t	*ctxt = (strobe_context_t *)context;
 
diff --git a/src/modules/submit/submit.c b/src/modules/submit/submit.c
index f46a205..b3c7220 100644
--- a/src/modules/submit/submit.c
+++ b/src/modules/submit/submit.c
@@ -267,14 +267,14 @@ static void setup_grid(submit_context_t *ctxt)
 }
 
 
-static til_module_context_t * submit_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * submit_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	submit_context_t	*ctxt;
 
 	if (!setup)
 		setup = &submit_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(submit_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(submit_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -294,7 +294,7 @@ static void submit_destroy_context(til_module_context_t *context)
 }
 
 
-static void submit_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void submit_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	submit_context_t	*ctxt = (submit_context_t *)context;
 
@@ -317,7 +317,7 @@ static void submit_prepare_frame(til_module_context_t *context, unsigned ticks,
 }
 
 
-static void submit_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void submit_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	submit_context_t	*ctxt = (submit_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/swab/swab.c b/src/modules/swab/swab.c
index b7ccf9d..0465de7 100644
--- a/src/modules/swab/swab.c
+++ b/src/modules/swab/swab.c
@@ -66,11 +66,11 @@ static inline uint32_t color_to_uint32(color_t color) {
 }
 
 
-static til_module_context_t * swab_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * swab_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	swab_context_t	*ctxt;
 
-	ctxt = til_module_context_new(sizeof(swab_context_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(swab_context_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -93,7 +93,7 @@ static void swab_destroy_context(til_module_context_t *context)
 }
 
 
-static void swab_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void swab_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	swab_context_t	*ctxt = (swab_context_t *)context;
 
@@ -103,7 +103,7 @@ static void swab_prepare_frame(til_module_context_t *context, unsigned ticks, ti
 }
 
 
-static void swab_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void swab_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	swab_context_t		*ctxt = (swab_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/swarm/swarm.c b/src/modules/swarm/swarm.c
index 48b70aa..5a58210 100644
--- a/src/modules/swarm/swarm.c
+++ b/src/modules/swarm/swarm.c
@@ -181,14 +181,14 @@ static inline uint32_t color_to_uint32(v3f_t color) {
 }
 
 
-static til_module_context_t * swarm_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * swarm_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	swarm_context_t	*ctxt;
 
 	if (!setup)
 		setup = &swarm_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(swarm_context_t) + sizeof(*(ctxt->boids)) * SWARM_SIZE, seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(swarm_context_t) + sizeof(*(ctxt->boids)) * SWARM_SIZE, seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -401,7 +401,7 @@ static void swarm_draw_as_lines(swarm_context_t *ctxt, til_fb_fragment_t *fragme
 }
 
 
-static void swarm_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void swarm_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	swarm_context_t		*ctxt = (swarm_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/modules/voronoi/voronoi.c b/src/modules/voronoi/voronoi.c
index bf82ca3..647871b 100644
--- a/src/modules/voronoi/voronoi.c
+++ b/src/modules/voronoi/voronoi.c
@@ -80,14 +80,14 @@ static void voronoi_randomize(voronoi_context_t *ctxt)
 }
 
 
-static til_module_context_t * voronoi_create_context(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
+static til_module_context_t * voronoi_create_context(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup)
 {
 	voronoi_context_t	*ctxt;
 
 	if (!setup)
 		setup = &voronoi_default_setup.til_setup;
 
-	ctxt = til_module_context_new(sizeof(voronoi_context_t) + ((voronoi_setup_t *)setup)->n_cells * sizeof(voronoi_cell_t), seed, ticks, n_cpus, path);
+	ctxt = til_module_context_new(stream, sizeof(voronoi_context_t) + ((voronoi_setup_t *)setup)->n_cells * sizeof(voronoi_cell_t), seed, ticks, n_cpus, path);
 	if (!ctxt)
 		return NULL;
 
@@ -281,7 +281,7 @@ static void voronoi_sample_colors(voronoi_context_t *ctxt, til_fb_fragment_t *fr
 }
 
 
-static void voronoi_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void voronoi_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	voronoi_context_t	*ctxt = (voronoi_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
@@ -315,7 +315,7 @@ static void voronoi_prepare_frame(til_module_context_t *context, unsigned ticks,
 }
 
 
-static void voronoi_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void voronoi_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	voronoi_context_t	*ctxt = (voronoi_context_t *)context;
 	til_fb_fragment_t	*fragment = *fragment_ptr;
diff --git a/src/til.c b/src/til.c
index 9435e28..44d48eb 100644
--- a/src/til.c
+++ b/src/til.c
@@ -102,13 +102,13 @@ void til_shutdown(void)
 }
 
 
-static void _blank_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+static void _blank_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
 {
 	*res_frame_plan = (til_frame_plan_t){ .fragmenter = til_fragmenter_slice_per_cpu };
 }
 
 
-static void _blank_render_fragment(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+static void _blank_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
 {
 	til_fb_fragment_clear(*fragment_ptr);
 }
@@ -164,7 +164,7 @@ void til_get_modules(const til_module_t ***res_modules, size_t *res_n_modules)
 }
 
 
-static void module_render_fragment(til_module_context_t *context, til_threads_t *threads, unsigned ticks, til_fb_fragment_t **fragment_ptr)
+static void module_render_fragment(til_module_context_t *context, til_stream_t *stream, til_threads_t *threads, unsigned ticks, til_fb_fragment_t **fragment_ptr)
 {
 	const til_module_t	*module;
 
@@ -178,7 +178,7 @@ static void module_render_fragment(til_module_context_t *context, til_threads_t
 	if (module->prepare_frame) {
 		til_frame_plan_t	frame_plan = {};
 
-		module->prepare_frame(context, ticks, fragment_ptr, &frame_plan);
+		module->prepare_frame(context, stream, ticks, fragment_ptr, &frame_plan);
 
 		/* XXX: any module which provides prepare_frame() must return a frame_plan.fragmenter,
 		 * and provide render_fragment()
@@ -187,7 +187,7 @@ static void module_render_fragment(til_module_context_t *context, til_threads_t
 		assert(module->render_fragment);
 
 		if (context->n_cpus > 1) {
-			til_threads_frame_submit(threads, fragment_ptr, &frame_plan, module->render_fragment, context, ticks);
+			til_threads_frame_submit(threads, fragment_ptr, &frame_plan, module->render_fragment, context, stream, ticks);
 			til_threads_wait_idle(threads);
 		} else {
 			unsigned		fragnum = 0;
@@ -197,13 +197,13 @@ static void module_render_fragment(til_module_context_t *context, til_threads_t
 				frag.texture = &texture; /* fragmenter needs the space */
 
 			while (frame_plan.fragmenter(context, *fragment_ptr, fragnum++, &frag))
-				module->render_fragment(context, ticks, 0, &frag_ptr);
+				module->render_fragment(context, stream, ticks, 0, &frag_ptr);
 		}
 	} else if (module->render_fragment)
-		module->render_fragment(context, ticks, 0, fragment_ptr);
+		module->render_fragment(context, stream, ticks, 0, fragment_ptr);
 
 	if (module->finish_frame)
-		module->finish_frame(context, ticks, fragment_ptr);
+		module->finish_frame(context, stream, ticks, fragment_ptr);
 
 	(*fragment_ptr)->cleared = 1;
 }
@@ -212,9 +212,9 @@ static void module_render_fragment(til_module_context_t *context, til_threads_t
 /* This is a public interface to the threaded module rendering intended for use by
  * modules that wish to get the output of other modules for their own use.
  */
-void til_module_render(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr)
+void til_module_render(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr)
 {
-	module_render_fragment(context, til_threads, ticks, fragment_ptr);
+	module_render_fragment(context, stream, til_threads, ticks, fragment_ptr);
 }
 
 
@@ -223,7 +223,7 @@ void til_module_render(til_module_context_t *context, unsigned ticks, til_fb_fra
  * the purpose of explicitly constraining rendering parallelization to less than n_threads,
  * if n_cpus is specified > n_threads it won't increase n_threads...
  */
-int til_module_create_context(const til_module_t *module, unsigned seed, unsigned ticks, unsigned n_cpus, const char *parent_path, til_setup_t *setup, til_module_context_t **res_context)
+int til_module_create_context(const til_module_t *module, til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, const char *parent_path, til_setup_t *setup, til_module_context_t **res_context)
 {
 	til_module_context_t	*context;
 	char			*path;
@@ -248,9 +248,9 @@ int til_module_create_context(const til_module_t *module, unsigned seed, unsigne
 		n_cpus = til_threads_num_threads(til_threads);
 
 	if (!module->create_context)
-		context = til_module_context_new(sizeof(til_module_context_t), seed, ticks, n_cpus, path);
+		context = til_module_context_new(stream, sizeof(til_module_context_t), seed, ticks, n_cpus, path);
 	else
-		context = module->create_context(seed, ticks, n_cpus, path, setup);
+		context = module->create_context(stream, seed, ticks, n_cpus, path, setup);
 
 	if (!context) {
 		free(path);
diff --git a/src/til.h b/src/til.h
index 852cb96..b863868 100644
--- a/src/til.h
+++ b/src/til.h
@@ -18,15 +18,16 @@ typedef struct til_frame_plan_t {
 typedef struct til_settings_t settings;
 typedef struct til_setting_desc_t til_setting_desc_t;
 typedef struct til_knob_t til_knob_t;
+typedef struct til_stream_t til_stream_t;
 
 #define TIL_MODULE_OVERLAYABLE	1u
 
 typedef struct til_module_t {
-	til_module_context_t *	(*create_context)(unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup);
-	void			(*destroy_context)(til_module_context_t *context);
-	void			(*prepare_frame)(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan);
-	void			(*render_fragment)(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
-	void			(*finish_frame)(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr);
+	til_module_context_t *	(*create_context)(til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, char *path, til_setup_t *setup);
+	void			(*destroy_context)(til_module_context_t *context);	/* destroy gets stream in context, but the render-related functions should always use the passed-in stream so it can potentially change */
+	void			(*prepare_frame)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan);
+	void			(*render_fragment)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
+	void			(*finish_frame)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr);
 	int			(*setup)(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup);
 	size_t			(*knobs)(til_module_context_t *context, til_knob_t **res_knobs);
 	char			*name;
@@ -40,9 +41,9 @@ void til_quiesce(void);
 void til_shutdown(void);
 const til_module_t * til_lookup_module(const char *name);
 void til_get_modules(const til_module_t ***res_modules, size_t *res_n_modules);
-void til_module_render(til_module_context_t *context, unsigned ticks, til_fb_fragment_t **fragment_ptr);
-int til_module_create_context(const til_module_t *module, unsigned seed, unsigned ticks, unsigned n_cpus, const char *parent_path, til_setup_t *setup, til_module_context_t **res_context);
-til_module_context_t * til_module_destroy_context(til_module_context_t *context);
+void til_module_render(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr);
+int til_module_create_context(const til_module_t *module, til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, const char *parent_path, til_setup_t *setup, til_module_context_t **res_context);
+til_module_context_t * til_module_destroy_context(til_module_context_t *context, til_stream_t *stream);
 int til_module_setup(til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup);
 int til_module_randomize_setup(const til_module_t *module, unsigned seed, til_setup_t **res_setup, char **res_arg);
 int til_fragmenter_slice_per_cpu(til_module_context_t *context, const til_fb_fragment_t *fragment, unsigned number, til_fb_fragment_t *res_fragment);
diff --git a/src/til_fb.h b/src/til_fb.h
index 48113d7..80ffeb4 100644
--- a/src/til_fb.h
+++ b/src/til_fb.h
@@ -9,7 +9,6 @@
 #include "til_setup.h"
 #include "til_util.h"
 
-typedef struct til_stream_t til_stream_t;
 typedef struct til_fb_fragment_t til_fb_fragment_t;
 typedef struct til_fb_fragment_ops_t til_fb_fragment_ops_t;
 
@@ -22,7 +21,6 @@ typedef struct til_fb_fragment_ops_t til_fb_fragment_ops_t;
 typedef struct til_fb_fragment_t {
 	const til_fb_fragment_ops_t	*ops;		/* optional opaque ops for physical fragments, NULL for strictly logical fragments */
 
-	til_stream_t			*stream;	/* optional stream of continuity this fragment participates in */
 	til_fb_fragment_t		*texture;	/* optional source texture when drawing to this fragment */
 	uint32_t			*buf;		/* pointer to the first pixel in the fragment */
 	unsigned			x, y;		/* absolute coordinates of the upper left corner of this fragment */
diff --git a/src/til_module_context.c b/src/til_module_context.c
index 9767d96..58de3d5 100644
--- a/src/til_module_context.c
+++ b/src/til_module_context.c
@@ -6,6 +6,7 @@
 #include "til.h"
 #include "til_jenkins.h"
 #include "til_module_context.h"
+#include "til_stream.h"
 
 
 /* Allocate and initialize a new til_module_context_t of size bytes.
@@ -27,7 +28,7 @@
  *
  * path must not be NULL, and the context takes ownership of the path; it's freed @ context_free().
  */
-void * til_module_context_new(size_t size, unsigned seed, unsigned ticks, unsigned n_cpus, char *path)
+void * til_module_context_new(til_stream_t *stream, size_t size, unsigned seed, unsigned ticks, unsigned n_cpus, char *path)
 {
 	til_module_context_t	*module_context;
 
@@ -39,6 +40,7 @@ void * til_module_context_new(size_t size, unsigned seed, unsigned ticks, unsign
 	if (!module_context)
 		return NULL;
 
+	module_context->stream = stream;
 	module_context->seed = seed;
 	module_context->ticks = ticks;
 	module_context->n_cpus = n_cpus;
@@ -56,12 +58,14 @@ void * til_module_context_new(size_t size, unsigned seed, unsigned ticks, unsign
  */
 void * til_module_context_free(til_module_context_t *module_context)
 {
-	char	*path;
+	char		*path;
+	til_stream_t	*stream;
 
 	if (!module_context)
 		return NULL;
 
 	path = module_context->path; /* free last just in case the module destructor makes use of it */
+	stream = module_context->stream;
 
 	if (module_context->module->destroy_context)
 		module_context->module->destroy_context(module_context);
@@ -70,5 +74,12 @@ void * til_module_context_free(til_module_context_t *module_context)
 
 	free(path);
 
+	/* cleanup any pipes this context might have had in the stream, if the
+	 * module's destroy_context() also does this it's harmlessly idempotent
+	 * besides wasting some cycles.  But by always doing it here, we're sure
+	 * to not leave dangling references.
+	 */
+	til_stream_untap_owner(stream, module_context);
+
 	return NULL;
 }
diff --git a/src/til_module_context.h b/src/til_module_context.h
index b2caf28..6f4339b 100644
--- a/src/til_module_context.h
+++ b/src/til_module_context.h
@@ -5,9 +5,11 @@
 
 typedef struct til_module_context_t til_module_context_t;
 typedef struct til_module_t til_module_t;
+typedef struct til_stream_t til_stream_t;
 
 struct til_module_context_t {
 	const til_module_t	*module;
+	til_stream_t		*stream; /* optional stream this context is part of */
 	unsigned		seed;
 	unsigned		ticks;
 	unsigned		n_cpus;
@@ -15,7 +17,7 @@ struct til_module_context_t {
 	uint32_t		path_hash;
 };
 
-void * til_module_context_new(size_t size, unsigned seed, unsigned ticks, unsigned n_cpus, char *path);
+void * til_module_context_new(til_stream_t *stream, size_t size, unsigned seed, unsigned ticks, unsigned n_cpus, char *path);
 void * til_module_context_free(til_module_context_t *module_context);
 
 #endif
diff --git a/src/til_threads.c b/src/til_threads.c
index 9e55a29..b9c781f 100644
--- a/src/til_threads.c
+++ b/src/til_threads.c
@@ -22,8 +22,9 @@ typedef struct til_threads_t {
 
 	pthread_mutex_t		frame_mutex;
 	pthread_cond_t		frame_cond;
-	void			(*render_fragment_func)(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
+	void			(*render_fragment_func)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
 	void			*context;
+	til_stream_t		*stream;
 	til_fb_fragment_t	**fragment_ptr;
 	til_frame_plan_t	frame_plan;
 	unsigned		ticks;
@@ -74,7 +75,7 @@ static void * thread_func(void *_thread)
 				if (!threads->frame_plan.fragmenter(threads->context, *(threads->fragment_ptr), frag_num, &frag))
 					break;
 
-				threads->render_fragment_func(threads->context, threads->ticks, thread->id, &frag_ptr);
+				threads->render_fragment_func(threads->context, threads->stream, threads->ticks, thread->id, &frag_ptr);
 				frag_num += threads->n_threads;
 			}
 		} else { /* render *any* available fragment */
@@ -91,7 +92,7 @@ static void * thread_func(void *_thread)
 				if (!threads->frame_plan.fragmenter(threads->context, *(threads->fragment_ptr), frag_num, &frag))
 					break;
 
-				threads->render_fragment_func(threads->context, threads->ticks, thread->id, &frag_ptr);
+				threads->render_fragment_func(threads->context, threads->stream, threads->ticks, thread->id, &frag_ptr);
 			}
 		}
 
@@ -120,7 +121,7 @@ void til_threads_wait_idle(til_threads_t *threads)
 
 
 /* submit a frame's fragments to the threads */
-void til_threads_frame_submit(til_threads_t *threads, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *frame_plan, void (*render_fragment_func)(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr), til_module_context_t *context, unsigned ticks)
+void til_threads_frame_submit(til_threads_t *threads, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *frame_plan, void (*render_fragment_func)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr), til_module_context_t *context, til_stream_t *stream, unsigned ticks)
 {
 	til_threads_wait_idle(threads);	/* XXX: likely non-blocking; already happens pre page flip */
 
@@ -130,6 +131,7 @@ void til_threads_frame_submit(til_threads_t *threads, til_fb_fragment_t **fragme
 	threads->frame_plan = *frame_plan;
 	threads->render_fragment_func = render_fragment_func;
 	threads->context = context;
+	threads->stream = stream;
 	threads->ticks = ticks;
 	threads->frame_num++;
 	threads->n_idle = threads->next_fragment = 0;
diff --git a/src/til_threads.h b/src/til_threads.h
index 4e6836d..664a0a5 100644
--- a/src/til_threads.h
+++ b/src/til_threads.h
@@ -3,11 +3,12 @@
 
 typedef struct til_fb_fragment_t til_fb_fragment_t;
 typedef struct til_threads_t til_threads_t;
+typedef struct til_stream_t til_stream_t;
 
 til_threads_t * til_threads_create();
 void til_threads_destroy(til_threads_t *threads);
 
-void til_threads_frame_submit(til_threads_t *threads, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *frame_plan, void (*render_fragment_func)(til_module_context_t *context, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr), til_module_context_t *context, unsigned ticks);
+void til_threads_frame_submit(til_threads_t *threads, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *frame_plan, void (*render_fragment_func)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr), til_module_context_t *context, til_stream_t *stream, unsigned ticks);
 void til_threads_wait_idle(til_threads_t *threads);
 unsigned til_threads_num_threads(til_threads_t *threads);