screencast: pipewire change to self allocation of shm buffers

include/screencast_common.h

@@ -122,6 +122,7 @@ struct xdpw_wlr_output {
 };
 
 void randname(char *buf);
+int anonymous_shm_open(void);
 enum spa_video_format xdpw_format_pw_from_wl_shm(enum wl_shm_format format);
 enum spa_video_format xdpw_format_pw_strip_alpha(enum spa_video_format format);
 

src/screencast/pipewire_screencast.c

@@ -5,6 +5,8 @@
 #include <spa/param/props.h>
 #include <spa/param/format-utils.h>
 #include <spa/param/video/format-utils.h>
+#include <sys/mman.h>
+#include <unistd.h>
 
 #include "wlr_screencast.h"
 #include "xdpw.h"
@@ -145,7 +147,7 @@ static void pwr_handle_stream_param_changed(void *data, uint32_t id,
 		SPA_PARAM_BUFFERS_size,    SPA_POD_Int(cast->simple_frame.size),
 		SPA_PARAM_BUFFERS_stride,  SPA_POD_Int(cast->simple_frame.stride),
 		SPA_PARAM_BUFFERS_align,   SPA_POD_Int(XDPW_PWR_ALIGN),
-		SPA_PARAM_BUFFERS_dataType,SPA_POD_CHOICE_FLAGS_Int(1<<SPA_DATA_MemPtr));
+		SPA_PARAM_BUFFERS_dataType,SPA_POD_CHOICE_FLAGS_Int(1<<SPA_DATA_MemFd));
 
 	params[1] = spa_pod_builder_add_object(&b,
 		SPA_TYPE_OBJECT_ParamMeta, SPA_PARAM_Meta,
@@ -164,28 +166,61 @@ static void pwr_handle_stream_add_buffer(void *data, struct pw_buffer *buffer) {
 	d = buffer->buffer->datas;
 
 	// Select buffer type from negotiation result
-	if ((d[0].type & (1u << SPA_DATA_MemPtr)) > 0) {
-		d[0].type = SPA_DATA_MemPtr;
+	if ((d[0].type & (1u << SPA_DATA_MemFd)) > 0) {
+		d[0].type = SPA_DATA_MemFd;
 	} else {
 		logprint(ERROR, "pipewire: unsupported buffer type");
 		cast->err = 1;
 		return;
 	}
 
+	logprint(TRACE, "pipewire: selected buffertype %u", d[0].type);
 	// Prepare buffer for choosen type
-	if (d[0].type == SPA_DATA_MemPtr) {
+	if (d[0].type == SPA_DATA_MemFd) {
 		d[0].maxsize = cast->simple_frame.size;
 		d[0].mapoffset = 0;
 		d[0].chunk->size = cast->simple_frame.size;
 		d[0].chunk->stride = cast->simple_frame.stride;
 		d[0].chunk->offset = 0;
 		d[0].flags = 0;
+		d[0].fd = anonymous_shm_open();
+
+		if (d[0].fd == -1) {
+			logprint(ERROR, "pipewire: unable to create anonymous filedescriptor");
+			cast->err = 1;
+			return;
+		}
+
+		if (ftruncate(d[0].fd, d[0].maxsize) < 0) {
+			logprint(ERROR, "pipewire: unable to truncate filedescriptor");
+			close(d[0].fd);
 			d[0].fd = -1;
+			cast->err = 1;
+			return;
+		}
+
+		// mmap buffer, so we can use the data_ptr in on_process
+		d[0].data = mmap(NULL, d[0].maxsize, PROT_READ | PROT_WRITE, MAP_SHARED, d[0].fd, d[0].mapoffset);
+		if (d[0].data == MAP_FAILED) {
+			logprint(ERROR, "pipewire: unable to mmap memory");
+			cast->err = 1;
+			return;
+		}
 	}
 }
 
 static void pwr_handle_stream_remove_buffer(void *data, struct pw_buffer *buffer) {
 	logprint(TRACE, "pipewire: remove buffer event handle");
+
+	struct spa_data *d = buffer->buffer->datas;
+	switch (d[0].type) {
+	case SPA_DATA_MemFd:
+		munmap(d[0].data, d[0].maxsize);
+		close(d[0].fd);
+		break;
+	default:
+		break;
+	}
 }
 
 static const struct pw_stream_events pwr_stream_events = {
@@ -250,7 +285,8 @@ void xdpw_pwr_stream_create(struct xdpw_screencast_instance *cast) {
 	pw_stream_connect(cast->stream,
 		PW_DIRECTION_OUTPUT,
 		PW_ID_ANY,
-		PW_STREAM_FLAG_DRIVER,
+		(PW_STREAM_FLAG_DRIVER |
+			PW_STREAM_FLAG_ALLOC_BUFFERS),
 		&param, 1);
 }
 

src/screencast/screencast_common.c

@@ -1,5 +1,10 @@
 #include "screencast_common.h"
 #include <assert.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 void randname(char *buf) {
 	struct timespec ts;
@@ -12,6 +17,25 @@ void randname(char *buf) {
 	}
 }
 
+int anonymous_shm_open(void) {
+	char name[] = "/xdpw-shm-XXXXXX";
+	int retries = 100;
+
+	do {
+		randname(name + strlen(name) - 6);
+
+		--retries;
+		// shm_open guarantees that O_CLOEXEC is set
+		int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+		if (fd >= 0) {
+			shm_unlink(name);
+			return fd;
+		}
+	} while (retries > 0 && errno == EEXIST);
+
+	return -1;
+}
+
 enum spa_video_format xdpw_format_pw_from_wl_shm(enum wl_shm_format format) {
 	switch (format) {
 	case WL_SHM_FORMAT_ARGB8888:

src/screencast/wlr_screencast.c

@@ -61,25 +61,6 @@ void xdpw_wlr_frame_free(struct xdpw_screencast_instance *cast) {
 	}
 }
 
-static int anonymous_shm_open(void) {
-	char name[] = "/xdpw-shm-XXXXXX";
-	int retries = 100;
-
-	do {
-		randname(name + strlen(name) - 6);
-
-		--retries;
-		// shm_open guarantees that O_CLOEXEC is set
-		int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
-		if (fd >= 0) {
-			shm_unlink(name);
-			return fd;
-		}
-	} while (retries > 0 && errno == EEXIST);
-
-	return -1;
-}
-
 static struct wl_buffer *create_shm_buffer(struct xdpw_screencast_instance *cast,
 		enum wl_shm_format fmt, int width, int height, int stride,
 		void **data_out) {