timer: remove unnecessary timer thread

This removes the timer thread entirely in favor of a coordinated
delay loop directly within rmdGetFrame.

When there's an audio stream to synchronize with, avd is
maintained by the pcm buffer updates, and the fps-derived
frametimes synchronize with the audio that way.

When there's no audio stream (--no-sound), avd is now maintained
synthetically via clock_gettime(CLOCK_MONOTONIC) coordinating
with the clock instead.

There's been some reworking of frame sampling/reusing and cloning
logic, which may need some refinement.  But for now the tests
seem to show promise.

The old timer approach just increased the non-determinism by
adding more scheduler latency and influence unnecessarily.

1 files changed, 363 insertions, 243 deletions

diff --git a/src/rmd_get_frame.c b/src/rmd_get_frame.c
index 1a5f4d0..cd49258 100644
--- a/src/rmd_get_frame.c
+++ b/src/rmd_get_frame.c
@@ -120,7 +120,7 @@ static void mark_buffer_area(	unsigned char *data,
 	}
 }
 
-//besides taking the first screenshot, this functions primary purpose is to 
+//besides taking the first screenshot, this functions primary purpose is to
 //initialize the structures and memory.
 static int rmdFirstFrame(ProgData *pdata, Image *image)
 {
@@ -262,9 +262,140 @@ static void rmdBlocksFromList(	RectArea   **root,
 	}
 }
 
+
+static struct timespec us_to_timespec(unsigned us)
+{
+	return (struct timespec){
+		.tv_sec = us / 1000000,
+		.tv_nsec = (us % 1000000) * 1000,
+	};
+}
+
+
+/* subtract t2 from t1, return difference in microseconds */
+static unsigned timespec_delta_in_us(struct timespec *t1, struct timespec *t2)
+{
+	unsigned	us = (t1->tv_sec - t2->tv_sec) * 1000000;
+
+	us += t1->tv_nsec / 1000;
+	us -= t2->tv_nsec / 1000;
+
+	return us;
+}
+
+
+/* Synchronize the next frame with either just time, or if there's
+ * an audio stream, with the audio stream.
+ *
+ * Returns wether a new frame should be acquired, or if the current
+ * yuv contents should be reused as-is (when too far behind).
+ */
+static boolean sync_next_frame(ProgData *pdata)
+{
+	int	avd, delay_us;
+
+	assert(pdata);
+
+	if (pdata->args.nosound) {
+		struct timespec	now;
+
+		/* when there's no audio timeline to synchronize with,
+		 * drive avd entirely from CLOCK_MONOTONIC
+		 */
+		clock_gettime(CLOCK_MONOTONIC, &now);
+
+		if (pdata->last_frame_ts.tv_sec) {
+			pthread_mutex_lock(&pdata->avd_mutex);
+			pdata->avd -= timespec_delta_in_us(&now, &pdata->last_frame_ts);
+			avd = pdata->avd;
+			pthread_mutex_unlock(&pdata->avd_mutex);
+		}
+
+		pdata->last_frame_ts = now;
+	}
+
+	pthread_mutex_lock(&pdata->avd_mutex);
+	avd = pdata->avd;
+	pthread_mutex_unlock(&pdata->avd_mutex);
+
+	delay_us = (int)pdata->frametime_us + avd;
+	if (delay_us > 1000 /* only bother sleeping when > 1ms */) {
+		struct timespec	delay;
+
+		delay = us_to_timespec(delay_us);
+		nanosleep(&delay, NULL);
+
+		/* update avd post-sleep */
+		pthread_mutex_lock(&pdata->avd_mutex);
+		avd = pdata->avd;
+		pthread_mutex_unlock(&pdata->avd_mutex);
+	}
+
+
+	/* refresh the frame unless we're way too far behind */
+	return (avd > 2 * -(int)MAX(pdata->frametime_us, pdata->periodtime_us));
+}
+
+
+/* Advances *frameno according to avd, returns wether frameno was advanced. */
+static boolean advance_frameno(ProgData *pdata, unsigned *frameno)
+{
+	int	increment, avd;
+
+	assert(pdata);
+
+	pthread_mutex_lock(&pdata->avd_mutex);
+	avd = pdata->avd;
+
+	if (avd > (int)MAX(pdata->frametime_us, pdata->periodtime_us)) {
+		/* if we're far ahead, don't produce a frame */
+		increment = 0;
+	} else if (avd > 0) {
+		/* if we're just a little ahead, produce a frame */
+		increment = 1;
+	} else if (avd <= 2 * -(int)MAX(pdata->frametime_us, pdata->periodtime_us)) {
+		/* if we're far behind, clone as many frames as fit to ~avd=0 */
+		increment = -avd / (int)pdata->frametime_us;
+	} else {
+		/* if we're just a little behind produce a frame */
+		increment = 1;
+	}
+
+	pdata->avd += increment * (int)pdata->frametime_us;
+	pthread_mutex_unlock(&pdata->avd_mutex);
+
+	(*frameno) += increment;
+#if 0
+	printf("avd=%i increment=%u periodtime_us=%u frametime_us=%u\n", avd, increment, pdata->periodtime_us, pdata->frametime_us);
+#endif
+	return (increment > 0);
+}
+
+
+static boolean paused(ProgData *pdata)
+{
+	pthread_mutex_lock(&pdata->pause_mutex);
+	if (pdata->pause_state_changed) {
+		pdata->pause_state_changed = FALSE;
+
+		if (!pdata->paused) {
+			pdata->paused = TRUE;
+			fprintf(stderr, "STATE:PAUSED\n");
+		} else {
+			pdata->paused = FALSE;
+			fprintf(stderr, "STATE:RECORDING\n");
+			pthread_cond_broadcast(&pdata->pause_cond);
+		}
+	}
+	pthread_mutex_unlock(&pdata->pause_mutex);
+
+	return pdata->paused;
+}
+
+
 /* This thread just samples the recorded window in response to rmdTimer's
  * triggers, updating the yuv buffer hopefully at the desired frame rate.
- * Following every update, the time_frameno is propogated to capture_frameno
+ * Following every update, the frameno is propogated to capture_frameno
  * and image_buffer_ready is signaled for the cache/encode side to consume the
  * yuv buffer.
  */
@@ -280,6 +411,7 @@ void *rmdGetFrame(ProgData *pdata)
 	Image image = {}, image_back = {};	//the image that holds
 						//the current full screenshot
 	int init_img1 = 0, init_img2 = 0, img_sel, d_buff;
+	unsigned frameno = 0;
 
 	rmdThreadsSetName("rmdGetFrame");
 
@@ -335,284 +467,272 @@ void *rmdGetFrame(ProgData *pdata)
 	mouse_pos_abs.height = mouse_pos_temp.height = pdata->dummy_p_size;
 	
 	//This is the the place where we call XSelectInput
-	//and arrange so that we listen for damage on all 
+	//and arrange so that we listen for damage on all
 	//windows
 	rmdInitEventsPolling(pdata);
 
 	while (pdata->running) {
-		unsigned	time_frameno;
-
-		pthread_mutex_lock(&pdata->time_mutex);
-		while (pdata->capture_frameno >= pdata->time_frameno) {
-			pthread_cond_wait(&pdata->time_cond, &pdata->time_mutex);
-
-			if (pdata->capture_frameno >= pdata->time_frameno) {
-				/* *Likely* paused, but could be a spurious wakeup.
-				 * either way, it's harmless to service the event loop
-				 * before waiting again.  This is how the timer keeps
-				 * the event loop serviced by signaling us without
-				 * advancing time_frameno.
-				 */
-				pthread_mutex_unlock(&pdata->time_mutex);
-				rmdEventLoop(pdata);
-				pthread_mutex_lock(&pdata->time_mutex);
-			}
+
+		if (paused(pdata)) {
+			/* just pump events while paused, so shortcuts can work for unpausing */
+			nanosleep(&(struct timespec) { .tv_nsec = 100000000 }, NULL);
+			rmdEventLoop(pdata);
+			continue;
 		}
 
-		time_frameno = pdata->time_frameno;
-		pthread_mutex_unlock(&pdata->time_mutex);
+		if (sync_next_frame(pdata)) {
+			//read all events and construct list with damage
+			//events (if not full_shots)
+			rmdEventLoop(pdata);
 
-		//read all events and construct list with damage 
-		//events (if not full_shots)
-		rmdEventLoop(pdata);
+			/* TODO: refactor this inherited spaghetti into functions */
 
-		//switch back and front buffers (full_shots only)
-		if (d_buff)
-			img_sel = img_sel ? 0 : 1;
+			//switch back and front buffers (full_shots only)
+			if (d_buff)
+				img_sel = img_sel ? 0 : 1;
 
-		rmdBRWinCpy(&temp_brwin, &pdata->brwin);
+			rmdBRWinCpy(&temp_brwin, &pdata->brwin);
 
 
-		if (	pdata->args.xfixes_cursor ||
-			pdata->args.have_dummy_cursor ||
-			pdata->args.follow_mouse) {
+			if (	pdata->args.xfixes_cursor ||
+				pdata->args.have_dummy_cursor ||
+				pdata->args.follow_mouse) {
 
 
-			// Pointer sequence:
-			// * Mark previous position as dirty with rmdRectInsert()
-			// * Update to new position
-			// * Mark new position as dirty with rmdRectInsert()
-			if (	!pdata->args.full_shots &&
-				mouse_pos_temp.x >= 0 &&
-				mouse_pos_temp.y >= 0 &&
-				mouse_pos_temp.width > 0 &&
-				mouse_pos_temp.height > 0) {
-				rmdRectInsert(&pdata->rect_root, &mouse_pos_temp);
-			}
-
-			if (pdata->args.xfixes_cursor) {
-				xcim = XFixesGetCursorImage(pdata->dpy);
-				mouse_pos_abs.x = xcim->x - xcim->xhot;
-				mouse_pos_abs.y = xcim->y - xcim->yhot;
-				mouse_pos_abs.width = xcim->width;
-				mouse_pos_abs.height = xcim->height;
-			} else {
-				XQueryPointer(	pdata->dpy,
-						pdata->specs.root,
-						&root_ret, &child_ret,
-						(int *)&mouse_pos_abs.x,
-						(int *)&mouse_pos_abs.y,
-						(int *)&mouse_pos_rel.x,
-						(int *)&mouse_pos_rel.y,
-						&msk_ret);
-			}
-			
-			clip_dummy_pointer_area(&mouse_pos_abs, &temp_brwin.rrect, &mouse_pos_temp);
-			if (	mouse_pos_temp.x >= 0 &&
-				mouse_pos_temp.y >= 0 &&
-				mouse_pos_temp.width > 0 &&
-				mouse_pos_temp.height > 0) {
-
-				//there are 3 capture scenarios:
-				// * Xdamage
-				// * full-shots with double buffering 
-				// * full-shots on a single buffer
-				//The last one cannot be reached through
-				//this code (see above how the d_buf variable is set), but 
-				//even if it could, it would not be of interest regarding the 
-				//marking of the cursor area. Single buffer means full repaint 
-				//on every frame so there is no need for marking at all.
-
-				if (!pdata->args.full_shots) { 
+				// Pointer sequence:
+				// * Mark previous position as dirty with rmdRectInsert()
+				// * Update to new position
+				// * Mark new position as dirty with rmdRectInsert()
+				if (	!pdata->args.full_shots &&
+					mouse_pos_temp.x >= 0 &&
+					mouse_pos_temp.y >= 0 &&
+					mouse_pos_temp.width > 0 &&
+					mouse_pos_temp.height > 0) {
 					rmdRectInsert(&pdata->rect_root, &mouse_pos_temp);
-				} else if (d_buff) {
-					unsigned char *back_buff= img_sel ?
-								((unsigned char*)image.ximage->data) :
-								((unsigned char*)image_back.ximage->data);
-
-					mark_buffer_area(
-						back_buff,
-						mouse_pos_temp.x - temp_brwin.rrect.x,
-						mouse_pos_temp.y - temp_brwin.rrect.y,
-						mouse_pos_temp.width, mouse_pos_temp.height, temp_brwin.rrect.width,
-						pdata->specs.depth
-					);
 				}
-			}
-		}
 
-		if (pdata->args.follow_mouse) {
-			rmdMoveCaptureArea(	&pdata->brwin.rrect,
-						mouse_pos_abs.x + pdata->args.xfixes_cursor ? xcim->xhot : 0,
-						mouse_pos_abs.y + pdata->args.xfixes_cursor ? xcim->yhot : 0,
-						pdata->specs.width,
-						pdata->specs.height);
-
-			if (!pdata->args.noframe)
-				rmdMoveFrame(	pdata->dpy,
-						pdata->shaped_w,
-						temp_brwin.rrect.x,
-						temp_brwin.rrect.y);
-		}
+				if (pdata->args.xfixes_cursor) {
+					xcim = XFixesGetCursorImage(pdata->dpy);
+					mouse_pos_abs.x = xcim->x - xcim->xhot;
+					mouse_pos_abs.y = xcim->y - xcim->yhot;
+					mouse_pos_abs.width = xcim->width;
+					mouse_pos_abs.height = xcim->height;
+				} else {
+					XQueryPointer(	pdata->dpy,
+							pdata->specs.root,
+							&root_ret, &child_ret,
+							(int *)&mouse_pos_abs.x,
+							(int *)&mouse_pos_abs.y,
+							(int *)&mouse_pos_rel.x,
+							(int *)&mouse_pos_rel.y,
+							&msk_ret);
+				}
 
-		if (!pdata->args.full_shots) {
-			pthread_mutex_lock(&pdata->yuv_mutex);
-			rmdUpdateImage(	pdata->dpy,
-					&pdata->enc_data->yuv,
-					&pdata->specs,
-					&pdata->rect_root,
-					&temp_brwin,
-					pdata->enc_data,
-					&image,
-					pdata->args.noshared,
-					pdata->shm_opcode,
-					pdata->args.no_quick_subsample);
-
-			rmdBlocksFromList(	&pdata->rect_root,
-						temp_brwin.rrect.x,
-						temp_brwin.rrect.y,
-						blocks_w,
-						blocks_h);
-
-			pthread_mutex_unlock(&pdata->yuv_mutex);
-		} else {
-			unsigned char *front_buff = !img_sel ?	((unsigned char*)image.ximage->data):
-								((unsigned char*)image_back.ximage->data);
-			unsigned char *back_buff = !d_buff ? NULL : (img_sel ?
-								((unsigned char*)image.ximage->data):
-								((unsigned char*)image_back.ximage->data));
-
-			if (pdata->args.noshared) {
-				rmdGetZPixmap(	pdata->dpy,
-						pdata->specs.root,
-						image.ximage->data,
-						temp_brwin.rrect.x,
-						temp_brwin.rrect.y,
-						temp_brwin.rrect.width,
-						temp_brwin.rrect.height);
-			} else {
-				XShmGetImage(	pdata->dpy,
-						pdata->specs.root,
-						((!img_sel) ? image.ximage : image_back.ximage),
-						temp_brwin.rrect.x,
-						temp_brwin.rrect.y,
-						AllPlanes);
+				clip_dummy_pointer_area(&mouse_pos_abs, &temp_brwin.rrect, &mouse_pos_temp);
+				if (	mouse_pos_temp.x >= 0 &&
+					mouse_pos_temp.y >= 0 &&
+					mouse_pos_temp.width > 0 &&
+					mouse_pos_temp.height > 0) {
+
+					//there are 3 capture scenarios:
+					// * Xdamage
+					// * full-shots with double buffering
+					// * full-shots on a single buffer
+					//The last one cannot be reached through
+					//this code (see above how the d_buf variable is set), but
+					//even if it could, it would not be of interest regarding the
+					//marking of the cursor area. Single buffer means full repaint
+					//on every frame so there is no need for marking at all.
+
+					if (!pdata->args.full_shots) {
+						rmdRectInsert(&pdata->rect_root, &mouse_pos_temp);
+					} else if (d_buff) {
+						unsigned char *back_buff= img_sel ?
+									((unsigned char*)image.ximage->data) :
+									((unsigned char*)image_back.ximage->data);
+
+						mark_buffer_area(
+							back_buff,
+							mouse_pos_temp.x - temp_brwin.rrect.x,
+							mouse_pos_temp.y - temp_brwin.rrect.y,
+							mouse_pos_temp.width, mouse_pos_temp.height, temp_brwin.rrect.width,
+							pdata->specs.depth
+						);
+					}
+				}
 			}
 
-			pthread_mutex_lock(&pdata->yuv_mutex);
-			rmdBlocksReset(blocks_w, blocks_h);
-			rmdUpdateYuvBuffer(	&pdata->enc_data->yuv,
-						front_buff,
-						back_buff,
-						0,
-						0,
-						temp_brwin.rrect.width,
-						temp_brwin.rrect.height,
-						pdata->args.no_quick_subsample,
-						pdata->specs.depth);
-
-			pthread_mutex_unlock(&pdata->yuv_mutex);
-		}
-
-		if (pdata->args.xfixes_cursor || pdata->args.have_dummy_cursor) {
-			int mouse_xoffset, mouse_yoffset;
-
-			//avoid segfaults
-			clip_dummy_pointer_area(&mouse_pos_abs, &temp_brwin.rrect, &mouse_pos_temp);
-			mouse_xoffset = mouse_pos_temp.x - mouse_pos_abs.x;
-			mouse_yoffset = mouse_pos_temp.y - mouse_pos_abs.y;
-
-			if ((mouse_xoffset < 0) || (mouse_xoffset > mouse_pos_abs.width))
-				mouse_xoffset = 0;
+			if (pdata->args.follow_mouse) {
+				rmdMoveCaptureArea(	&pdata->brwin.rrect,
+							mouse_pos_abs.x + pdata->args.xfixes_cursor ? xcim->xhot : 0,
+							mouse_pos_abs.y + pdata->args.xfixes_cursor ? xcim->yhot : 0,
+							pdata->specs.width,
+							pdata->specs.height);
+
+				if (!pdata->args.noframe)
+					rmdMoveFrame(	pdata->dpy,
+							pdata->shaped_w,
+							temp_brwin.rrect.x,
+							temp_brwin.rrect.y);
+			}
 
-			if ((mouse_yoffset < 0) || (mouse_yoffset > mouse_pos_abs.height))
-				mouse_yoffset = 0;
+			if (!pdata->args.full_shots) {
+				pthread_mutex_lock(&pdata->yuv_mutex);
+				rmdUpdateImage(	pdata->dpy,
+						&pdata->enc_data->yuv,
+						&pdata->specs,
+						&pdata->rect_root,
+						&temp_brwin,
+						pdata->enc_data,
+						&image,
+						pdata->args.noshared,
+						pdata->shm_opcode,
+						pdata->args.no_quick_subsample);
+
+				rmdBlocksFromList(	&pdata->rect_root,
+							temp_brwin.rrect.x,
+							temp_brwin.rrect.y,
+							blocks_w,
+							blocks_h);
+
+				pthread_mutex_unlock(&pdata->yuv_mutex);
+			} else {
+				unsigned char *front_buff = !img_sel ?	((unsigned char*)image.ximage->data):
+									((unsigned char*)image_back.ximage->data);
+				unsigned char *back_buff = !d_buff ? NULL : (img_sel ?
+									((unsigned char*)image.ximage->data):
+									((unsigned char*)image_back.ximage->data));
+
+				if (pdata->args.noshared) {
+					rmdGetZPixmap(	pdata->dpy,
+							pdata->specs.root,
+							image.ximage->data,
+							temp_brwin.rrect.x,
+							temp_brwin.rrect.y,
+							temp_brwin.rrect.width,
+							temp_brwin.rrect.height);
+				} else {
+					XShmGetImage(	pdata->dpy,
+							pdata->specs.root,
+							((!img_sel) ? image.ximage : image_back.ximage),
+							temp_brwin.rrect.x,
+							temp_brwin.rrect.y,
+							AllPlanes);
+				}
 
-			//draw the cursor
-			if (	(mouse_pos_temp.x >= 0) &&
-				(mouse_pos_temp.y >= 0) &&
-				(mouse_pos_temp.width > 0) &&
-				(mouse_pos_temp.height > 0)) {
+				pthread_mutex_lock(&pdata->yuv_mutex);
+				rmdBlocksReset(blocks_w, blocks_h);
+				rmdUpdateYuvBuffer(	&pdata->enc_data->yuv,
+							front_buff,
+							back_buff,
+							0,
+							0,
+							temp_brwin.rrect.width,
+							temp_brwin.rrect.height,
+							pdata->args.no_quick_subsample,
+							pdata->specs.depth);
+
+				pthread_mutex_unlock(&pdata->yuv_mutex);
+			}
 
-					if (pdata->args.xfixes_cursor) {
-						rmdXFixesPointerToYuv(
-							&pdata->enc_data->yuv,
-							((unsigned char*)xcim->pixels),
-							mouse_pos_temp.x - temp_brwin.rrect.x,
-							mouse_pos_temp.y - temp_brwin.rrect.y,
-							mouse_pos_temp.width,
-							mouse_pos_temp.height,
-							mouse_xoffset,
-							mouse_yoffset,
-							xcim->width-mouse_pos_temp.width
-						);
-					} else {
-						rmdDummyPointerToYuv(
-							&pdata->enc_data->yuv,
-							pdata->dummy_pointer,
+			if (pdata->args.xfixes_cursor || pdata->args.have_dummy_cursor) {
+				int mouse_xoffset, mouse_yoffset;
+
+				//avoid segfaults
+				clip_dummy_pointer_area(&mouse_pos_abs, &temp_brwin.rrect, &mouse_pos_temp);
+				mouse_xoffset = mouse_pos_temp.x - mouse_pos_abs.x;
+				mouse_yoffset = mouse_pos_temp.y - mouse_pos_abs.y;
+
+				if ((mouse_xoffset < 0) || (mouse_xoffset > mouse_pos_abs.width))
+					mouse_xoffset = 0;
+
+				if ((mouse_yoffset < 0) || (mouse_yoffset > mouse_pos_abs.height))
+					mouse_yoffset = 0;
+
+				//draw the cursor
+				if (	(mouse_pos_temp.x >= 0) &&
+					(mouse_pos_temp.y >= 0) &&
+					(mouse_pos_temp.width > 0) &&
+					(mouse_pos_temp.height > 0)) {
+
+						if (pdata->args.xfixes_cursor) {
+							rmdXFixesPointerToYuv(
+								&pdata->enc_data->yuv,
+								((unsigned char*)xcim->pixels),
+								mouse_pos_temp.x - temp_brwin.rrect.x,
+								mouse_pos_temp.y - temp_brwin.rrect.y,
+								mouse_pos_temp.width,
+								mouse_pos_temp.height,
+								mouse_xoffset,
+								mouse_yoffset,
+								xcim->width-mouse_pos_temp.width
+							);
+						} else {
+							rmdDummyPointerToYuv(
+								&pdata->enc_data->yuv,
+								pdata->dummy_pointer,
+								mouse_pos_temp.x - temp_brwin.rrect.x,
+								mouse_pos_temp.y - temp_brwin.rrect.y,
+								mouse_pos_temp.width,
+								mouse_pos_temp.height,
+								mouse_xoffset,
+								mouse_yoffset,
+								pdata->npxl
+							);
+						}
+
+					if (d_buff) {
+						//make previous cursor position dirty
+						//on the currently front buffer (which
+						//will be the back buffer next time it's
+						//used)
+						unsigned char *front_buff = !img_sel ?
+									((unsigned char*)image.ximage->data) :
+									((unsigned char*)image_back.ximage->data);
+
+						mark_buffer_area(
+							front_buff,
 							mouse_pos_temp.x - temp_brwin.rrect.x,
 							mouse_pos_temp.y - temp_brwin.rrect.y,
 							mouse_pos_temp.width,
 							mouse_pos_temp.height,
-							mouse_xoffset,
-							mouse_yoffset,
-							pdata->npxl
+							temp_brwin.rrect.width,
+							pdata->specs.depth
 						);
 					}
 
-				if (d_buff) {
-					//make previous cursor position dirty
-					//on the currently front buffer (which 
-					//will be the back buffer next time it's 
-					//used) 
-					unsigned char *front_buff = !img_sel ?
-								((unsigned char*)image.ximage->data) :
-								((unsigned char*)image_back.ximage->data);
-
-					mark_buffer_area(
-						front_buff,
-						mouse_pos_temp.x - temp_brwin.rrect.x,
-						mouse_pos_temp.y - temp_brwin.rrect.y,
-						mouse_pos_temp.width,
-						mouse_pos_temp.height,
-						temp_brwin.rrect.width,
-						pdata->specs.depth
-					);
 				}
 
+				if (pdata->args.xfixes_cursor) {
+					XFree(xcim);
+					xcim = NULL;
+				}
 			}
 
-			if (pdata->args.xfixes_cursor) {
-				XFree(xcim);
-				xcim = NULL;
-			}
+			if (!pdata->args.full_shots)
+				rmdClearList(&pdata->rect_root);
 		}
 
-		if (!pdata->args.full_shots)
-			rmdClearList(&pdata->rect_root);
-
-		/* Since frame acquisition may take a long and variable time, update
-		 * frameno again just in case we've missed some so they can be included
-		 * as this frame by the encoder.
-		 */
-		pthread_mutex_lock(&pdata->time_mutex);
-		time_frameno = pdata->time_frameno;
-		pthread_mutex_unlock(&pdata->time_mutex);
-
-		/* notify the encoder of the new frame */
-		pthread_mutex_lock(&pdata->img_buff_ready_mutex);
-		pdata->capture_frameno = time_frameno;
-		pthread_cond_signal(&pdata->image_buffer_ready);
-		pthread_mutex_unlock(&pdata->img_buff_ready_mutex);
-
-		/* XXX: note if the encoder thread doesn't manage to wake up and grab the yuv_mutex
-		 * before this thread does in response to another tick, then the frame just
-		 * submitted is lost and the encoder thread will wait again for another frame.
-		 * In practice if this never happens it's irrelevant, but if it proves to be an
-		 * issue there are options.
-		 */
+		if (advance_frameno(pdata, &frameno)) {
+			/* notify the encoder of additional frames */
+			pthread_mutex_lock(&pdata->img_buff_ready_mutex);
+			pdata->capture_frameno = frameno;
+			pthread_cond_signal(&pdata->image_buffer_ready);
+			pthread_mutex_unlock(&pdata->img_buff_ready_mutex);
+		}
 	}
 
+	/* Make sure the encoder/cacher doen't get lost in pthread_cond_wait indefinitely,
+	 * now that !pdata->running they will exit their wait loops.
+	 */
+	pthread_cond_signal(&pdata->image_buffer_ready);
+
+	/* Same for waiters on pause_cond in case we quit from being paused */
+	pthread_mutex_lock(&pdata->pause_mutex);
+	pdata->paused = FALSE;
+	pthread_cond_broadcast(&pdata->pause_cond);
+	pthread_mutex_unlock(&pdata->pause_mutex);
+
 	if (!pdata->args.noframe)
 		XDestroyWindow(pdata->dpy, pdata->shaped_w);