screencast: introduce buffer_type

We want to support WL_SHM and DMABUFS based buffers. The buffer_type
member tracks the type of a xdpw_buffer and screencopy_frame_info of the
screencast_instance will be an array with an element for each buffer type
indexed by the value of the buffer_type enum. Only members of the
xdpw_screencopy_frame_info relevant to the buffer type should be used.

include/screencast_common.h

@@ -22,6 +22,11 @@ enum source_types {
   WINDOW = 2,
 };
 
+enum buffer_type {
+  WL_SHM = 0,
+  DMABUF = 1,
+};
+
 enum xdpw_chooser_types {
   XDPW_CHOOSER_DEFAULT,
   XDPW_CHOOSER_NONE,
@@ -68,6 +73,7 @@ struct xdpw_screencopy_frame_info {
 
 struct xdpw_buffer {
 	struct wl_list link;
+	enum buffer_type buffer_type;
 
 	uint32_t width;
 	uint32_t height;
@@ -127,11 +133,12 @@ struct xdpw_screencast_instance {
 	struct xdpw_wlr_output *target_output;
 	uint32_t max_framerate;
 	struct zwlr_screencopy_frame_v1 *wlr_frame;
-	struct xdpw_screencopy_frame_info screencopy_frame_info;
+	struct xdpw_screencopy_frame_info screencopy_frame_info[2];
 	bool with_cursor;
 	int err;
 	bool quit;
 	bool need_buffer;
+	enum buffer_type buffer_type;
 
 	// fps limit
 	struct fps_limit_state fps_limit;
@@ -152,7 +159,7 @@ struct xdpw_wlr_output {
 
 void randname(char *buf);
 struct xdpw_buffer *xdpw_buffer_create(struct xdpw_screencast_instance *cast,
-	struct xdpw_screencopy_frame_info *frame_info);
+	enum buffer_type buffer_type, struct xdpw_screencopy_frame_info *frame_info);
 void xdpw_buffer_destroy(struct xdpw_buffer *buffer);
 enum wl_shm_format xdpw_format_wl_shm_from_drm_fourcc(uint32_t format);
 uint32_t xdpw_format_drm_fourcc_from_wl_shm(enum wl_shm_format format);

src/screencast/pipewire_screencast.c

@@ -68,8 +68,8 @@ static struct spa_pod *build_format(struct spa_pod_builder *b, enum spa_video_fo
 static uint32_t build_formats(struct spa_pod_builder *b, struct xdpw_screencast_instance *cast,
 		const struct spa_pod *params[static 1]) {
 	uint32_t param_count = 1;
-	params[0] = build_format(b, xdpw_format_pw_from_drm_fourcc(cast->screencopy_frame_info.format),
+	params[0] = build_format(b, xdpw_format_pw_from_drm_fourcc(cast->screencopy_frame_info[WL_SHM].format),
-			cast->screencopy_frame_info.width, cast->screencopy_frame_info.height, cast->framerate);
+			cast->screencopy_frame_info[WL_SHM].width, cast->screencopy_frame_info[WL_SHM].height, cast->framerate);
 
 	return param_count;
 }
@@ -122,6 +122,8 @@ static void pwr_handle_stream_param_changed(void *data, uint32_t id,
 	struct spa_pod_builder b =
 		SPA_POD_BUILDER_INIT(params_buffer, sizeof(params_buffer));
 	const struct spa_pod *params[2];
+	uint32_t blocks;
+	uint32_t data_type;
 
 	if (!param || id != SPA_PARAM_Format) {
 		return;
@@ -130,9 +132,16 @@ static void pwr_handle_stream_param_changed(void *data, uint32_t id,
 	spa_format_video_raw_parse(param, &cast->pwr_format);
 	cast->framerate = (uint32_t)(cast->pwr_format.max_framerate.num / cast->pwr_format.max_framerate.denom);
 
+	if (spa_pod_find_prop(param, NULL, SPA_FORMAT_VIDEO_modifier) != NULL) {
+		abort();
+	} else {
+		cast->buffer_type = WL_SHM;
+		blocks = 1;
+		data_type = 1<<SPA_DATA_MemFd;
+	}
 
-	params[0] = build_buffer(&b, 1, cast->screencopy_frame_info.size,
+	params[0] = build_buffer(&b, blocks, cast->screencopy_frame_info[cast->buffer_type].size,
-			cast->screencopy_frame_info.stride, 1<<SPA_DATA_MemFd);
+			cast->screencopy_frame_info[cast->buffer_type].stride, data_type);
 
 	params[1] = spa_pod_builder_add_object(&b,
 		SPA_TYPE_OBJECT_ParamMeta, SPA_PARAM_Meta,
@@ -152,6 +161,7 @@ static void pwr_handle_stream_add_buffer(void *data, struct pw_buffer *buffer) {
 
 	// Select buffer type from negotiation result
 	if ((d[0].type & (1u << SPA_DATA_MemFd)) > 0) {
+		assert(cast->buffer_type == WL_SHM);
 		d[0].type = SPA_DATA_MemFd;
 	} else {
 		logprint(ERROR, "pipewire: unsupported buffer type");
@@ -161,7 +171,7 @@ static void pwr_handle_stream_add_buffer(void *data, struct pw_buffer *buffer) {
 
 	logprint(TRACE, "pipewire: selected buffertype %u", d[0].type);
 
-	struct xdpw_buffer *xdpw_buffer = xdpw_buffer_create(cast, &cast->screencopy_frame_info);
+	struct xdpw_buffer *xdpw_buffer = xdpw_buffer_create(cast, cast->buffer_type, &cast->screencopy_frame_info[cast->buffer_type]);
 	if (xdpw_buffer == NULL) {
 		logprint(ERROR, "pipewire: failed to create xdpw buffer");
 		cast->err = 1;

src/screencast/screencast.c

@@ -455,7 +455,7 @@ static int method_screencast_start(sd_bus_message *msg, void *data,
 		"streams", "a(ua{sv})", 1,
 		cast->node_id, 2,
 		"position", "(ii)", 0, 0,
-		"size", "(ii)", cast->screencopy_frame_info.width, cast->screencopy_frame_info.height);
+		"size", "(ii)", cast->screencopy_frame_info[WL_SHM].width, cast->screencopy_frame_info[WL_SHM].height);
 
 	if (ret < 0) {
 		return ret;

src/screencast/screencast_common.c

@@ -57,35 +57,43 @@ static struct wl_buffer *import_wl_shm_buffer(struct xdpw_screencast_instance *c
 }
 
 struct xdpw_buffer *xdpw_buffer_create(struct xdpw_screencast_instance *cast,
-		struct xdpw_screencopy_frame_info *frame_info) {
+		enum buffer_type buffer_type, struct xdpw_screencopy_frame_info *frame_info) {
 	struct xdpw_buffer *buffer = calloc(1, sizeof(struct xdpw_buffer));
 	buffer->width = frame_info->width;
 	buffer->height = frame_info->height;
 	buffer->format = frame_info->format;
-	buffer->size = frame_info->size;
+	buffer->buffer_type = buffer_type;
-	buffer->stride = frame_info->stride;
-	buffer->offset = 0;
-	buffer->fd = anonymous_shm_open();
-	if (buffer->fd == -1) {
-		logprint(ERROR, "xdpw: unable to create anonymous filedescriptor");
-		free(buffer);
-		return NULL;
-	}
 
-	if (ftruncate(buffer->fd, buffer->size) < 0) {
+	switch (buffer_type) {
-		logprint(ERROR, "xdpw: unable to truncate filedescriptor");
+	case WL_SHM:
-		close(buffer->fd);
+		buffer->size = frame_info->size;
-		free(buffer);
+		buffer->stride = frame_info->stride;
-		return NULL;
+		buffer->offset = 0;
-	}
+		buffer->fd = anonymous_shm_open();
+		if (buffer->fd == -1) {
+			logprint(ERROR, "xdpw: unable to create anonymous filedescriptor");
+			free(buffer);
+			return NULL;
+		}
 
-	buffer->buffer = import_wl_shm_buffer(cast, buffer->fd, xdpw_format_wl_shm_from_drm_fourcc(frame_info->format),
+		if (ftruncate(buffer->fd, buffer->size) < 0) {
-			frame_info->width, frame_info->height, frame_info->stride);
+			logprint(ERROR, "xdpw: unable to truncate filedescriptor");
-	if (buffer->buffer == NULL) {
+			close(buffer->fd);
-		logprint(ERROR, "xdpw: unable to create wl_buffer");
+			free(buffer);
-		close(buffer->fd);
+			return NULL;
-		free(buffer);
+		}
-		return NULL;
+
+		buffer->buffer = import_wl_shm_buffer(cast, buffer->fd, xdpw_format_wl_shm_from_drm_fourcc(frame_info->format),
+				frame_info->width, frame_info->height, frame_info->stride);
+		if (buffer->buffer == NULL) {
+			logprint(ERROR, "xdpw: unable to create wl_buffer");
+			close(buffer->fd);
+			free(buffer);
+			return NULL;
+		}
+		break;
+	case DMABUF:
+		abort();
 	}
 
 	return buffer;

src/screencast/wlr_screencast.c

@@ -87,11 +87,11 @@ static void wlr_frame_buffer(void *data, struct zwlr_screencopy_frame_v1 *frame,
 	logprint(TRACE, "wlroots: buffer event handler");
 	cast->wlr_frame = frame;
 
-	cast->screencopy_frame_info.width = width;
+	cast->screencopy_frame_info[WL_SHM].width = width;
-	cast->screencopy_frame_info.height = height;
+	cast->screencopy_frame_info[WL_SHM].height = height;
-	cast->screencopy_frame_info.stride = stride;
+	cast->screencopy_frame_info[WL_SHM].stride = stride;
-	cast->screencopy_frame_info.size = stride * height;
+	cast->screencopy_frame_info[WL_SHM].size = stride * height;
-	cast->screencopy_frame_info.format = xdpw_format_drm_fourcc_from_wl_shm(format);
+	cast->screencopy_frame_info[WL_SHM].format = xdpw_format_drm_fourcc_from_wl_shm(format);
 
 	if (zwlr_screencopy_manager_v1_get_version(cast->ctx->screencopy_manager) < 3) {
 		wlr_frame_buffer_done(cast, frame);
@@ -116,10 +116,10 @@ static void wlr_frame_buffer_done(void *data,
 	}
 
 	// Check if announced screencopy information is compatible with pipewire meta
-	if ((cast->pwr_format.format != xdpw_format_pw_from_drm_fourcc(cast->screencopy_frame_info.format) &&
+	if ((cast->pwr_format.format != xdpw_format_pw_from_drm_fourcc(cast->screencopy_frame_info[cast->buffer_type].format) &&
-			cast->pwr_format.format != xdpw_format_pw_strip_alpha(xdpw_format_pw_from_drm_fourcc(cast->screencopy_frame_info.format))) ||
+			cast->pwr_format.format != xdpw_format_pw_strip_alpha(xdpw_format_pw_from_drm_fourcc(cast->screencopy_frame_info[cast->buffer_type].format))) ||
-			cast->pwr_format.size.width != cast->screencopy_frame_info.width ||
+			cast->pwr_format.size.width != cast->screencopy_frame_info[cast->buffer_type].width ||
-			cast->pwr_format.size.height != cast->screencopy_frame_info.height) {
+			cast->pwr_format.size.height != cast->screencopy_frame_info[cast->buffer_type].height) {
 		logprint(DEBUG, "wlroots: pipewire and wlroots metadata are incompatible. Renegotiate stream");
 		cast->frame_state = XDPW_FRAME_STATE_RENEG;
 		xdpw_wlr_frame_finish(cast);
@@ -140,8 +140,11 @@ static void wlr_frame_buffer_done(void *data,
 	assert(cast->current_frame.xdpw_buffer);
 
 	// Check if dequeued buffer is compatible with announced buffer
-	if (cast->current_frame.xdpw_buffer->size != cast->screencopy_frame_info.size ||
+	if (( cast->buffer_type == WL_SHM &&
-			cast->current_frame.xdpw_buffer->stride != cast->screencopy_frame_info.stride) {
+				(cast->current_frame.xdpw_buffer->size != cast->screencopy_frame_info[cast->buffer_type].size ||
+				cast->current_frame.xdpw_buffer->stride != cast->screencopy_frame_info[cast->buffer_type].stride)) ||
+			cast->current_frame.xdpw_buffer->width != cast->screencopy_frame_info[cast->buffer_type].width ||
+			cast->current_frame.xdpw_buffer->height != cast->screencopy_frame_info[cast->buffer_type].height) {
 		logprint(DEBUG, "wlroots: pipewire buffer has wrong dimensions");
 		cast->frame_state = XDPW_FRAME_STATE_FAILED;
 		xdpw_wlr_frame_finish(cast);