From fa8160bf8daf9c4713b7e8106d62512e28d640e6 Mon Sep 17 00:00:00 2001
From: columbarius <co1umbarius@protonmail.com>
Date: Fri, 28 May 2021 10:42:25 +0200
Subject: [PATCH] screencast: renegotiate if buffersize changes

---
 src/screencast/pipewire_screencast.c | 25 +++++++++++++++++++++++--
 src/screencast/wlr_screencast.c      |  3 +--
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/screencast/pipewire_screencast.c b/src/screencast/pipewire_screencast.c
index 9cf0989e..67e05c7b 100644
--- a/src/screencast/pipewire_screencast.c
+++ b/src/screencast/pipewire_screencast.c
@@ -50,6 +50,16 @@ static inline struct spa_pod *build_format(struct spa_pod_builder *b, uint32_t f
 	return spa_pod_builder_pop(b, &f[0]);
 }
 
+void pwr_destroy_shm_buffer(struct xdpw_screencast_instance *cast, struct pw_buffer *buffer) {
+	struct spa_data *d;
+
+	logprint(TRACE, "pipewire: destroy buffer %p", buffer);
+	d = buffer->buffer->datas;
+	wl_buffer_destroy(d[0].data);
+	d[0].data = NULL;
+	close(d[0].fd);
+}
+
 static void pwr_handle_stream_state_changed(void *data,
 		enum pw_stream_state old, enum pw_stream_state state, const char *error) {
 	struct xdpw_screencast_instance *cast = data;
@@ -101,6 +111,7 @@ static void pwr_handle_stream_param_changed(void *data, uint32_t id,
 		SPA_PARAM_META_size, SPA_POD_Int(sizeof(struct spa_meta_header)));
 
 	pw_stream_update_params(stream, params, 2);
+	cast->changed = false;
 }
 
 static void pwr_handle_stream_add_buffer(void *data, struct pw_buffer *buffer) {
@@ -149,15 +160,23 @@ static void pwr_handle_stream_add_buffer(void *data, struct pw_buffer *buffer) {
 }
 
 static void pwr_handle_stream_remove_buffer(void *data, struct pw_buffer *buffer) {
+	struct xdpw_screencast_instance *cast = data;
 	struct spa_data *d;
 
 	logprint(TRACE, "pipewire: remove buffer event handle");
 
+	logprint(TRACE, "pipewire: buffer %p", buffer);
 	d = buffer->buffer->datas;
+	if (buffer == cast->current_pw_buffer) {
+		logprint(TRACE, "pipewire: can't remove buffer. still in use");
+		// TODO: We shouldn't trigger that currently, because we export the buffer before update_params which should
+		// flush the buffers at all clients, but what happens, if a client renegotiates parameters?
+		abort();
+		return;
+	}
 	switch (d[0].type) {
 	case SPA_DATA_MemFd:
-		wl_buffer_destroy(d[0].data);
-		close(d[0].fd);
+		pwr_destroy_shm_buffer(cast, buffer);
 		break;
 	default:
 		break;
@@ -240,11 +259,13 @@ void pwr_update_stream_param(struct xdpw_screencast_instance *cast) {
 		SPA_POD_BUILDER_INIT(params_buffer, sizeof(params_buffer));
 	const struct spa_pod *params[1];
 
+
 	enum spa_video_format format = xdpw_format_pw_from_wl_shm(cast);
 
 	params[0] = build_format(&b, format,
 			cast->simple_frame.width, cast->simple_frame.height, cast->framerate);
 
+	logprint(TRACE, "pipewire: params updated");
 	pw_stream_update_params(stream, params, 1);
 }
 
diff --git a/src/screencast/wlr_screencast.c b/src/screencast/wlr_screencast.c
index 64b0db5e..e6567432 100644
--- a/src/screencast/wlr_screencast.c
+++ b/src/screencast/wlr_screencast.c
@@ -34,7 +34,7 @@ void xdpw_wlr_frame_free(struct xdpw_screencast_instance *cast) {
 		return ;
 	}
 
-	if (cast->pwr_stream_state) {
+	if (cast->pwr_stream_state && !cast->changed) {
 		xdpw_wlr_frame_start(cast);
 	}
 }
@@ -106,7 +106,6 @@ static void wlr_frame_buffer_done(void *data,
 		if (cast->pwr_stream_state) {
 			pwr_update_stream_param(cast);
 		}
-		cast->changed = false;
 		xdpw_wlr_frame_free(cast);
 		return;
 	}