Merge pull request #992 from emersion/screencontent

Implement wlr_export_dmabuf_unstable_v1 protocol

.build.yml

@@ -1,15 +1,16 @@
 image: archlinux
 packages:
-  - meson
+  - clang
-  - wayland
+  - ffmpeg
-  - wayland-protocols
+  - libcap
-  - mesa
   - libinput
   - libxkbcommon
-  - xcb-util-image
+  - mesa
-  - libcap
+  - meson
   - pixman
-  - clang
+  - wayland
+  - wayland-protocols
+  - xcb-util-image
 sources:
   - https://github.com/swaywm/wlroots
 tasks:

backend/drm/drm.c

@@ -254,6 +254,25 @@ static uint32_t drm_connector_get_gamma_size(struct wlr_output *output) {
 	return 0;
 }
 
+static bool drm_connector_export_dmabuf(struct wlr_output *output,
+		struct wlr_dmabuf_attributes *attribs) {
+	struct wlr_drm_connector *conn = (struct wlr_drm_connector *)output;
+	struct wlr_drm_backend *drm = (struct wlr_drm_backend *)output->backend;
+
+	if (!drm->session->active) {
+		return false;
+	}
+
+	struct wlr_drm_crtc *crtc = conn->crtc;
+	if (!crtc) {
+		return false;
+	}
+	struct wlr_drm_plane *plane = crtc->primary;
+	struct wlr_drm_surface *surf = &plane->surf;
+
+	return export_drm_bo(surf->back, attribs);
+}
+
 static void drm_connector_start_renderer(struct wlr_drm_connector *conn) {
 	if (conn->state != WLR_DRM_CONN_CONNECTED) {
 		return;
@@ -742,6 +761,7 @@ static const struct wlr_output_impl output_impl = {
 	.swap_buffers = drm_connector_swap_buffers,
 	.set_gamma = drm_connector_set_gamma,
 	.get_gamma_size = drm_connector_get_gamma_size,
+	.export_dmabuf = drm_connector_export_dmabuf,
 };
 
 bool wlr_output_is_drm(struct wlr_output *output) {

backend/drm/renderer.c

@@ -160,6 +160,34 @@ void post_drm_surface(struct wlr_drm_surface *surf) {
 	}
 }
 
+bool export_drm_bo(struct gbm_bo *bo, struct wlr_dmabuf_attributes *attribs) {
+	memset(attribs, 0, sizeof(struct wlr_dmabuf_attributes));
+
+	attribs->n_planes = gbm_bo_get_plane_count(bo);
+	if (attribs->n_planes > WLR_DMABUF_MAX_PLANES) {
+		return false;
+	}
+
+	attribs->width = gbm_bo_get_width(bo);
+	attribs->height = gbm_bo_get_height(bo);
+	attribs->format = gbm_bo_get_format(bo);
+	attribs->modifier = gbm_bo_get_modifier(bo);
+
+	for (int i = 0; i < attribs->n_planes; ++i) {
+		attribs->offset[i] = gbm_bo_get_offset(bo, i);
+		attribs->stride[i] = gbm_bo_get_stride_for_plane(bo, i);
+		attribs->fd[i] = gbm_bo_get_fd(bo);
+		if (attribs->fd[i] < 0) {
+			for (int j = 0; j < i; ++j) {
+				close(attribs->fd[j]);
+			}
+			return false;
+		}
+	}
+
+	return true;
+}
+
 struct tex {
 	struct wlr_egl *egl;
 	EGLImageKHR img;
@@ -186,16 +214,11 @@ static struct wlr_texture *get_tex_for_bo(struct wlr_drm_renderer *renderer,
 		return NULL;
 	}
 
-	struct wlr_dmabuf_attributes attribs = {
+	struct wlr_dmabuf_attributes attribs;
-		.n_planes = 1,
+	if (!export_drm_bo(bo, &attribs)) {
-		.width = gbm_bo_get_width(bo),
+		free(tex);
-		.height = gbm_bo_get_height(bo),
+		return NULL;
-		.format = gbm_bo_get_format(bo),
+	}
-		.modifier = DRM_FORMAT_MOD_LINEAR,
-	};
-	attribs.offset[0] = 0;
-	attribs.stride[0] = gbm_bo_get_stride_for_plane(bo, 0);
-	attribs.fd[0] = gbm_bo_get_fd(bo);
 
 	tex->tex = wlr_texture_from_dmabuf(renderer->wlr_rend, &attribs);
 	if (tex->tex == NULL) {

examples/dmabuf-capture.c

@@ -0,0 +1,743 @@
+#define _XOPEN_SOURCE 700
+#define _POSIX_C_SOURCE 199309L
+#include <libavformat/avformat.h>
+#include <libavutil/display.h>
+#include <libavutil/hwcontext_drm.h>
+#include <libavutil/pixdesc.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <libdrm/drm_fourcc.h>
+#include "wlr-export-dmabuf-unstable-v1-client-protocol.h"
+
+struct wayland_output {
+	struct wl_list link;
+	uint32_t id;
+	struct wl_output *output;
+	char *make;
+	char *model;
+	int width;
+	int height;
+	AVRational framerate;
+};
+
+struct capture_context {
+	AVClass *class; /* For pretty logging */
+	struct wl_display *display;
+	struct wl_registry *registry;
+	struct zwlr_export_dmabuf_manager_v1 *export_manager;
+
+	struct wl_list output_list;
+
+	/* Target */
+	struct wl_output *target_output;
+
+	/* Main frame callback */
+	struct zwlr_export_dmabuf_frame_v1 *frame_callback;
+
+	/* If something happens during capture */
+	int err;
+	int quit;
+
+	/* FFmpeg specific parts */
+	AVFrame *current_frame;
+	AVBufferRef *drm_device_ref;
+	AVBufferRef *drm_frames_ref;
+
+	AVBufferRef *mapped_device_ref;
+	AVBufferRef *mapped_frames_ref;
+
+	AVFormatContext *avf;
+	AVCodecContext *avctx;
+
+	int64_t start_pts;
+
+	/* Config */
+	enum AVPixelFormat software_format;
+	enum AVHWDeviceType hw_device_type;
+	AVDictionary *encoder_opts;
+	int is_software_encoder;
+	char *hardware_device;
+	char *out_filename;
+	char *encoder_name;
+	float out_bitrate;
+};
+
+static void output_handle_geometry(void *data, struct wl_output *wl_output,
+		int32_t x, int32_t y, int32_t phys_width, int32_t phys_height,
+		int32_t subpixel, const char *make, const char *model,
+		int32_t transform) {
+	struct wayland_output *output = data;
+	output->make = av_strdup(make);
+	output->model = av_strdup(model);
+}
+
+static void output_handle_mode(void *data, struct wl_output *wl_output,
+		uint32_t flags, int32_t width, int32_t height, int32_t refresh) {
+	if (flags & WL_OUTPUT_MODE_CURRENT) {
+		struct wayland_output *output = data;
+		output->width = width;
+		output->height = height;
+		output->framerate = (AVRational){ refresh, 1000 };
+	}
+}
+
+static void output_handle_done(void* data, struct wl_output *wl_output) {
+	/* Nothing to do */
+}
+
+static void output_handle_scale(void* data, struct wl_output *wl_output,
+		int32_t factor) {
+	/* Nothing to do */
+}
+
+static const struct wl_output_listener output_listener = {
+	.geometry = output_handle_geometry,
+	.mode = output_handle_mode,
+	.done = output_handle_done,
+	.scale = output_handle_scale,
+};
+
+static void registry_handle_add(void *data, struct wl_registry *reg,
+		uint32_t id, const char *interface, uint32_t ver) {
+	struct capture_context *ctx = data;
+
+	if (!strcmp(interface, wl_output_interface.name)) {
+		struct wayland_output *output = av_mallocz(sizeof(*output));
+
+		output->id = id;
+		output->output = wl_registry_bind(reg, id, &wl_output_interface, 1);
+
+		wl_output_add_listener(output->output, &output_listener, output);
+		wl_list_insert(&ctx->output_list, &output->link);
+	}
+
+	if (!strcmp(interface, zwlr_export_dmabuf_manager_v1_interface.name)) {
+		ctx->export_manager = wl_registry_bind(reg, id,
+				&zwlr_export_dmabuf_manager_v1_interface, 1);
+	}
+}
+
+static void remove_output(struct wayland_output *out) {
+	wl_list_remove(&out->link);
+	av_free(out->make);
+	av_free(out->model);
+	av_free(out);
+}
+
+static struct wayland_output *find_output(struct capture_context *ctx,
+		struct wl_output *out, uint32_t id) {
+	struct wayland_output *output, *tmp;
+	wl_list_for_each_safe(output, tmp, &ctx->output_list, link) {
+		if ((output->output == out) || (output->id == id)) {
+			return output;
+		}
+	}
+	return NULL;
+}
+
+static void registry_handle_remove(void *data, struct wl_registry *reg,
+		uint32_t id) {
+	remove_output(find_output((struct capture_context *)data, NULL, id));
+}
+
+static const struct wl_registry_listener registry_listener = {
+	.global = registry_handle_add,
+	.global_remove = registry_handle_remove,
+};
+
+static void frame_free(void *opaque, uint8_t *data) {
+	AVDRMFrameDescriptor *desc = (AVDRMFrameDescriptor *)data;
+
+	for (int i = 0; i < desc->nb_objects; ++i) {
+		close(desc->objects[i].fd);
+	}
+
+	zwlr_export_dmabuf_frame_v1_destroy(opaque);
+
+	av_free(data);
+}
+
+static void frame_start(void *data, struct zwlr_export_dmabuf_frame_v1 *frame,
+		uint32_t width, uint32_t height, uint32_t offset_x, uint32_t offset_y,
+		uint32_t buffer_flags, uint32_t flags, uint32_t format,
+		uint32_t mod_high, uint32_t mod_low, uint32_t num_objects) {
+	struct capture_context *ctx = data;
+	int err = 0;
+
+	/* Allocate DRM specific struct */
+	AVDRMFrameDescriptor *desc = av_mallocz(sizeof(*desc));
+	if (!desc) {
+		err = AVERROR(ENOMEM);
+		goto fail;
+	}
+
+	desc->nb_objects = num_objects;
+	desc->objects[0].format_modifier = ((uint64_t)mod_high << 32) | mod_low;
+
+	desc->nb_layers = 1;
+	desc->layers[0].format = format;
+
+	/* Allocate a frame */
+	AVFrame *f = av_frame_alloc();
+	if (!f) {
+		err = AVERROR(ENOMEM);
+		goto fail;
+	}
+
+	/* Set base frame properties */
+	ctx->current_frame = f;
+	f->width = width;
+	f->height = height;
+	f->format = AV_PIX_FMT_DRM_PRIME;
+
+	/* Set the frame data to the DRM specific struct */
+	f->buf[0] = av_buffer_create((uint8_t*)desc, sizeof(*desc),
+			&frame_free, frame, 0);
+	if (!f->buf[0]) {
+		err = AVERROR(ENOMEM);
+		goto fail;
+	}
+
+	f->data[0] = (uint8_t*)desc;
+
+	return;
+
+fail:
+	ctx->err = err;
+	frame_free(frame, (uint8_t *)desc);
+}
+
+static void frame_object(void *data, struct zwlr_export_dmabuf_frame_v1 *frame,
+		uint32_t index, int32_t fd, uint32_t size, uint32_t offset,
+		uint32_t stride, uint32_t plane_index) {
+	struct capture_context *ctx = data;
+	AVFrame *f = ctx->current_frame;
+	AVDRMFrameDescriptor *desc = (AVDRMFrameDescriptor *)f->data[0];
+
+	desc->objects[index].fd = fd;
+	desc->objects[index].size = size;
+
+	desc->layers[0].planes[plane_index].object_index = index;
+	desc->layers[0].planes[plane_index].offset = offset;
+	desc->layers[0].planes[plane_index].pitch = stride;
+}
+
+static enum AVPixelFormat drm_fmt_to_pixfmt(uint32_t fmt) {
+	switch (fmt) {
+	case DRM_FORMAT_NV12: return AV_PIX_FMT_NV12;
+	case DRM_FORMAT_ARGB8888: return AV_PIX_FMT_BGRA;
+	case DRM_FORMAT_XRGB8888: return AV_PIX_FMT_BGR0;
+	case DRM_FORMAT_ABGR8888: return AV_PIX_FMT_RGBA;
+	case DRM_FORMAT_XBGR8888: return AV_PIX_FMT_RGB0;
+	case DRM_FORMAT_RGBA8888: return AV_PIX_FMT_ABGR;
+	case DRM_FORMAT_RGBX8888: return AV_PIX_FMT_0BGR;
+	case DRM_FORMAT_BGRA8888: return AV_PIX_FMT_ARGB;
+	case DRM_FORMAT_BGRX8888: return AV_PIX_FMT_0RGB;
+	default: return AV_PIX_FMT_NONE;
+	};
+}
+
+static int attach_drm_frames_ref(struct capture_context *ctx, AVFrame *f,
+		enum AVPixelFormat sw_format) {
+	int err = 0;
+	AVHWFramesContext *hwfc;
+
+	if (ctx->drm_frames_ref) {
+		hwfc = (AVHWFramesContext*)ctx->drm_frames_ref->data;
+		if (hwfc->width == f->width && hwfc->height == f->height &&
+				hwfc->sw_format == sw_format) {
+			goto attach;
+		}
+		av_buffer_unref(&ctx->drm_frames_ref);
+	}
+
+	ctx->drm_frames_ref = av_hwframe_ctx_alloc(ctx->drm_device_ref);
+	if (!ctx->drm_frames_ref) {
+		err = AVERROR(ENOMEM);
+		goto fail;
+	}
+
+	hwfc = (AVHWFramesContext*)ctx->drm_frames_ref->data;
+
+	hwfc->format = f->format;
+	hwfc->sw_format = sw_format;
+	hwfc->width = f->width;
+	hwfc->height = f->height;
+
+	err = av_hwframe_ctx_init(ctx->drm_frames_ref);
+	if (err) {
+		av_log(ctx, AV_LOG_ERROR, "AVHWFramesContext init failed: %s!\n",
+				av_err2str(err));
+		goto fail;
+	}
+
+attach:
+	/* Set frame hardware context referencce */
+	f->hw_frames_ctx = av_buffer_ref(ctx->drm_frames_ref);
+	if (!f->hw_frames_ctx) {
+		err = AVERROR(ENOMEM);
+		goto fail;
+	}
+
+	return 0;
+
+fail:
+	av_buffer_unref(&ctx->drm_frames_ref);
+	return err;
+}
+
+static void register_cb(struct capture_context *ctx);
+
+static void frame_ready(void *data, struct zwlr_export_dmabuf_frame_v1 *frame,
+		uint32_t tv_sec_hi, uint32_t tv_sec_lo, uint32_t tv_nsec) {
+	struct capture_context *ctx = data;
+	AVFrame *f = ctx->current_frame;
+	AVDRMFrameDescriptor *desc = (AVDRMFrameDescriptor *)f->data[0];
+	enum AVPixelFormat pix_fmt = drm_fmt_to_pixfmt(desc->layers[0].format);
+	int err = 0;
+
+	/* Attach the hardware frame context to the frame */
+	err = attach_drm_frames_ref(ctx, f, pix_fmt);
+	if (err) {
+		goto end;
+	}
+
+	/* TODO: support multiplane stuff */
+	desc->layers[0].nb_planes = av_pix_fmt_count_planes(pix_fmt);
+
+	AVFrame *mapped_frame = av_frame_alloc();
+	if (!mapped_frame) {
+		err = AVERROR(ENOMEM);
+		goto end;
+	}
+
+	AVHWFramesContext *mapped_hwfc;
+	mapped_hwfc = (AVHWFramesContext *)ctx->mapped_frames_ref->data;
+	mapped_frame->format = mapped_hwfc->format;
+
+	/* Set frame hardware context referencce */
+	mapped_frame->hw_frames_ctx = av_buffer_ref(ctx->mapped_frames_ref);
+	if (!mapped_frame->hw_frames_ctx) {
+		err = AVERROR(ENOMEM);
+		goto end;
+	}
+
+	err = av_hwframe_map(mapped_frame, f, 0);
+	if (err) {
+		av_log(ctx, AV_LOG_ERROR, "Error mapping: %s!\n", av_err2str(err));
+		goto end;
+	}
+
+	AVFrame *enc_input = mapped_frame;
+
+	if (ctx->is_software_encoder) {
+		AVFrame *soft_frame = av_frame_alloc();
+		av_hwframe_transfer_data(soft_frame, mapped_frame, 0);
+		av_frame_free(&mapped_frame);
+		enc_input = soft_frame;
+	}
+
+	/* Nanoseconds */
+	enc_input->pts = (((uint64_t)tv_sec_hi) << 32) | tv_sec_lo;
+	enc_input->pts *= 1000000000;
+	enc_input->pts += tv_nsec;
+
+	if (!ctx->start_pts) {
+		ctx->start_pts = enc_input->pts;
+	}
+
+	enc_input->pts -= ctx->start_pts;
+
+	enc_input->pts = av_rescale_q(enc_input->pts, (AVRational){ 1, 1000000000 },
+			ctx->avctx->time_base);
+
+	do {
+		err = avcodec_send_frame(ctx->avctx, enc_input);
+
+		av_frame_free(&enc_input);
+
+		if (err) {
+			av_log(ctx, AV_LOG_ERROR, "Error encoding: %s!\n", av_err2str(err));
+			goto end;
+		}
+
+		while (1) {
+			AVPacket pkt;
+			av_init_packet(&pkt);
+
+			int ret = avcodec_receive_packet(ctx->avctx, &pkt);
+			if (ret == AVERROR(EAGAIN)) {
+				break;
+			} else if (ret == AVERROR_EOF) {
+				av_log(ctx, AV_LOG_INFO, "Encoder flushed!\n");
+				ctx->quit = 2;
+				goto end;
+			} else if (ret) {
+				av_log(ctx, AV_LOG_ERROR, "Error encoding: %s!\n",
+						av_err2str(ret));
+				err = ret;
+				goto end;
+			}
+
+			pkt.stream_index = 0;
+			err = av_interleaved_write_frame(ctx->avf, &pkt);
+
+			av_packet_unref(&pkt);
+
+			if (err) {
+				av_log(ctx, AV_LOG_ERROR, "Writing packet fail: %s!\n",
+						av_err2str(err));
+				goto end;
+			}
+		};
+	} while (ctx->quit);
+
+	av_log(NULL, AV_LOG_INFO, "Encoded frame %i!\n", ctx->avctx->frame_number);
+
+	register_cb(ctx);
+
+end:
+	ctx->err = err;
+	av_frame_free(&ctx->current_frame);
+}
+
+static void frame_cancel(void *data, struct zwlr_export_dmabuf_frame_v1 *frame,
+		uint32_t reason) {
+	struct capture_context *ctx = data;
+	av_log(ctx, AV_LOG_WARNING, "Frame cancelled!\n");
+	av_frame_free(&ctx->current_frame);
+	if (reason == ZWLR_EXPORT_DMABUF_FRAME_V1_CANCEL_REASON_PERMANENT) {
+		av_log(ctx, AV_LOG_ERROR, "Permanent failure, exiting\n");
+		ctx->err = 1;
+	} else {
+		register_cb(ctx);
+	}
+}
+
+static const struct zwlr_export_dmabuf_frame_v1_listener frame_listener = {
+	.frame = frame_start,
+	.object = frame_object,
+	.ready = frame_ready,
+	.cancel = frame_cancel,
+};
+
+static void register_cb(struct capture_context *ctx) {
+	ctx->frame_callback = zwlr_export_dmabuf_manager_v1_capture_output(
+			ctx->export_manager, 0, ctx->target_output);
+
+	zwlr_export_dmabuf_frame_v1_add_listener(ctx->frame_callback,
+			&frame_listener, ctx);
+}
+
+static int init_lavu_hwcontext(struct capture_context *ctx) {
+	/* DRM hwcontext */
+	ctx->drm_device_ref = av_hwdevice_ctx_alloc(AV_HWDEVICE_TYPE_DRM);
+	if (!ctx->drm_device_ref)
+		return AVERROR(ENOMEM);
+
+	AVHWDeviceContext *ref_data = (AVHWDeviceContext*)ctx->drm_device_ref->data;
+	AVDRMDeviceContext *hwctx = ref_data->hwctx;
+
+	/* We don't need a device (we don't even know it and can't open it) */
+	hwctx->fd = -1;
+
+	av_hwdevice_ctx_init(ctx->drm_device_ref);
+
+	/* Mapped hwcontext */
+	int err = av_hwdevice_ctx_create(&ctx->mapped_device_ref,
+			ctx->hw_device_type, ctx->hardware_device, NULL, 0);
+	if (err < 0) {
+		av_log(ctx, AV_LOG_ERROR, "Failed to create a hardware device: %s\n",
+				av_err2str(err));
+		return err;
+	}
+
+	return 0;
+}
+
+static int set_hwframe_ctx(struct capture_context *ctx,
+		AVBufferRef *hw_device_ctx) {
+	AVHWFramesContext *frames_ctx = NULL;
+	int err = 0;
+
+	if (!(ctx->mapped_frames_ref = av_hwframe_ctx_alloc(hw_device_ctx))) {
+		return AVERROR(ENOMEM);
+	}
+
+	AVHWFramesConstraints *cst =
+			av_hwdevice_get_hwframe_constraints(ctx->mapped_device_ref, NULL);
+	if (!cst) {
+		av_log(ctx, AV_LOG_ERROR, "Failed to get hw device constraints!\n");
+		av_buffer_unref(&ctx->mapped_frames_ref);
+		return AVERROR(ENOMEM);
+	}
+
+	frames_ctx = (AVHWFramesContext *)(ctx->mapped_frames_ref->data);
+	frames_ctx->format = cst->valid_hw_formats[0];
+	frames_ctx->sw_format = ctx->avctx->pix_fmt;
+	frames_ctx->width = ctx->avctx->width;
+	frames_ctx->height = ctx->avctx->height;
+
+	av_hwframe_constraints_free(&cst);
+
+	if ((err = av_hwframe_ctx_init(ctx->mapped_frames_ref))) {
+		av_log(ctx, AV_LOG_ERROR, "Failed to initialize hw frame context: %s!\n",
+				av_err2str(err));
+		av_buffer_unref(&ctx->mapped_frames_ref);
+		return err;
+	}
+
+	if (!ctx->is_software_encoder) {
+		ctx->avctx->pix_fmt = frames_ctx->format;
+		ctx->avctx->hw_frames_ctx = av_buffer_ref(ctx->mapped_frames_ref);
+		if (!ctx->avctx->hw_frames_ctx) {
+			av_buffer_unref(&ctx->mapped_frames_ref);
+			err = AVERROR(ENOMEM);
+		}
+	}
+
+	return err;
+}
+
+static int init_encoding(struct capture_context *ctx) {
+	int err;
+
+	/* lavf init */
+	err = avformat_alloc_output_context2(&ctx->avf, NULL,
+			NULL, ctx->out_filename);
+	if (err) {
+		av_log(ctx, AV_LOG_ERROR, "Unable to init lavf context!\n");
+		return err;
+	}
+
+	AVStream *st = avformat_new_stream(ctx->avf, NULL);
+	if (!st) {
+		av_log(ctx, AV_LOG_ERROR, "Unable to alloc stream!\n");
+		return 1;
+	}
+
+	/* Find encoder */
+	AVCodec *out_codec = avcodec_find_encoder_by_name(ctx->encoder_name);
+	if (!out_codec) {
+		av_log(ctx, AV_LOG_ERROR, "Codec not found (not compiled in lavc?)!\n");
+		return AVERROR(EINVAL);
+	}
+	ctx->avf->oformat->video_codec = out_codec->id;
+	ctx->is_software_encoder = !(out_codec->capabilities & AV_CODEC_CAP_HARDWARE);
+
+	ctx->avctx = avcodec_alloc_context3(out_codec);
+	if (!ctx->avctx)
+		return 1;
+
+	ctx->avctx->opaque = ctx;
+	ctx->avctx->bit_rate = (int)ctx->out_bitrate*1000000.0f;
+	ctx->avctx->pix_fmt = ctx->software_format;
+	ctx->avctx->time_base = (AVRational){ 1, 1000 };
+	ctx->avctx->compression_level = 7;
+	ctx->avctx->width = find_output(ctx, ctx->target_output, 0)->width;
+	ctx->avctx->height = find_output(ctx, ctx->target_output, 0)->height;
+
+	if (ctx->avf->oformat->flags & AVFMT_GLOBALHEADER) {
+		ctx->avctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
+	}
+
+	st->id = 0;
+	st->time_base = ctx->avctx->time_base;
+	st->avg_frame_rate = find_output(ctx, ctx->target_output, 0)->framerate;
+
+	/* Init hw frames context */
+	err = set_hwframe_ctx(ctx, ctx->mapped_device_ref);
+	if (err) {
+		return err;
+	}
+
+	err = avcodec_open2(ctx->avctx, out_codec, &ctx->encoder_opts);
+	if (err) {
+		av_log(ctx, AV_LOG_ERROR, "Cannot open encoder: %s!\n",
+				av_err2str(err));
+		return err;
+	}
+
+	if (avcodec_parameters_from_context(st->codecpar, ctx->avctx) < 0) {
+		av_log(ctx, AV_LOG_ERROR, "Couldn't copy codec params: %s!\n",
+				av_err2str(err));
+		return err;
+	}
+
+	/* Debug print */
+	av_dump_format(ctx->avf, 0, ctx->out_filename, 1);
+
+	/* Open for writing */
+	err = avio_open(&ctx->avf->pb, ctx->out_filename, AVIO_FLAG_WRITE);
+	if (err) {
+		av_log(ctx, AV_LOG_ERROR, "Couldn't open %s: %s!\n", ctx->out_filename,
+				av_err2str(err));
+		return err;
+	}
+
+	err = avformat_write_header(ctx->avf, NULL);
+	if (err) {
+		av_log(ctx, AV_LOG_ERROR, "Couldn't write header: %s!\n", av_err2str(err));
+		return err;
+	}
+
+	return err;
+}
+
+struct capture_context *q_ctx = NULL;
+
+void on_quit_signal(int signo) {
+	printf("\r");
+	q_ctx->quit = 1;
+}
+
+static int main_loop(struct capture_context *ctx) {
+	int err;
+
+	q_ctx = ctx;
+
+	if (signal(SIGINT, on_quit_signal) == SIG_ERR) {
+		av_log(ctx, AV_LOG_ERROR, "Unable to install signal handler!\n");
+		return AVERROR(EINVAL);
+	}
+
+	err = init_lavu_hwcontext(ctx);
+	if (err) {
+		return err;
+	}
+
+	err = init_encoding(ctx);
+	if (err) {
+		return err;
+	}
+
+	/* Start the frame callback */
+	register_cb(ctx);
+
+	while (wl_display_dispatch(ctx->display) != -1 && !ctx->err &&
+			ctx->quit < 2) {
+		// This space intentionally left blank
+	}
+
+	err = av_write_trailer(ctx->avf);
+	if (err) {
+		av_log(ctx, AV_LOG_ERROR, "Error writing trailer: %s!\n",
+				av_err2str(err));
+		return err;
+	}
+
+	av_log(ctx, AV_LOG_INFO, "Wrote trailer!\n");
+
+	return ctx->err;
+}
+
+static int init(struct capture_context *ctx) {
+	ctx->display = wl_display_connect(NULL);
+	if (!ctx->display) {
+		av_log(ctx, AV_LOG_ERROR, "Failed to connect to display!\n");
+		return AVERROR(EINVAL);
+	}
+
+	wl_list_init(&ctx->output_list);
+
+	ctx->registry = wl_display_get_registry(ctx->display);
+	wl_registry_add_listener(ctx->registry, &registry_listener, ctx);
+
+	wl_display_roundtrip(ctx->display);
+	wl_display_dispatch(ctx->display);
+
+	if (!ctx->export_manager) {
+		av_log(ctx, AV_LOG_ERROR, "Compositor doesn't support %s!\n",
+				zwlr_export_dmabuf_manager_v1_interface.name);
+		return -1;
+	}
+
+	return 0;
+}
+
+static void uninit(struct capture_context *ctx);
+
+int main(int argc, char *argv[]) {
+	int err;
+	struct capture_context ctx = { 0 };
+	ctx.class = &((AVClass) {
+		.class_name = "dmabuf-capture",
+		.item_name  = av_default_item_name,
+		.version    = LIBAVUTIL_VERSION_INT,
+	});
+
+	err = init(&ctx);
+	if (err) {
+		goto end;
+	}
+
+	struct wayland_output *o, *tmp_o;
+	wl_list_for_each_reverse_safe(o, tmp_o, &ctx.output_list, link) {
+		printf("Capturable output: %s Model: %s: ID: %i\n",
+				o->make, o->model, o->id);
+	}
+
+	if (argc != 8) {
+		printf("Invalid number of arguments! Usage and example:\n"
+				"./dmabuf-capture <source id> <hardware device type> <device> "
+				"<encoder name> <pixel format> <bitrate in Mbps> <file path>\n"
+				"./dmabuf-capture 0 vaapi /dev/dri/renderD129 libx264 nv12 12 "
+				"dmabuf_recording_01.mkv\n");
+		return 1;
+	}
+
+	const int o_id = strtol(argv[1], NULL, 10);
+	o = find_output(&ctx, NULL, o_id);
+	if (!o) {
+		printf("Unable to find output with ID %i!\n", o_id);
+		return 1;
+	}
+
+	ctx.target_output = o->output;
+	ctx.hw_device_type = av_hwdevice_find_type_by_name(argv[2]);
+	ctx.hardware_device = argv[3];
+
+	ctx.encoder_name = argv[4];
+	ctx.software_format = av_get_pix_fmt(argv[5]);
+	ctx.out_bitrate = strtof(argv[6], NULL);
+	ctx.out_filename = argv[7];
+
+	av_dict_set(&ctx.encoder_opts, "preset", "veryfast", 0);
+
+	err = main_loop(&ctx);
+	if (err) {
+		goto end;
+	}
+
+end:
+	uninit(&ctx);
+	return err;
+}
+
+static void uninit(struct capture_context *ctx) {
+	struct wayland_output *output, *tmp_o;
+	wl_list_for_each_safe(output, tmp_o, &ctx->output_list, link) {
+		remove_output(output);
+	}
+
+	if (ctx->export_manager) {
+		zwlr_export_dmabuf_manager_v1_destroy(ctx->export_manager);
+	}
+
+	av_buffer_unref(&ctx->drm_frames_ref);
+	av_buffer_unref(&ctx->drm_device_ref);
+	av_buffer_unref(&ctx->mapped_frames_ref);
+	av_buffer_unref(&ctx->mapped_device_ref);
+
+	av_dict_free(&ctx->encoder_opts);
+
+	avcodec_close(ctx->avctx);
+	if (ctx->avf) {
+		avio_closep(&ctx->avf->pb);
+	}
+	avformat_free_context(ctx->avf);
+}

examples/meson.build

@@ -1,6 +1,10 @@
 threads = dependency('threads')
 wayland_cursor = dependency('wayland-cursor')
 
+libavutil = dependency('libavutil', required: false)
+libavcodec = dependency('libavcodec', required: false)
+libavformat = dependency('libavformat', required: false)
+
 executable('simple', 'simple.c', dependencies: wlroots)
 executable('pointer', 'pointer.c', dependencies: wlroots)
 executable('touch', 'touch.c', 'cat.c', dependencies: wlroots)
@@ -38,3 +42,11 @@ executable(
 	'input-inhibitor.c',
 	dependencies: [wayland_cursor, wayland_client, wlr_protos, wlroots]
 )
+
+if libavutil.found() and libavcodec.found() and libavformat.found()
+	executable(
+		'dmabuf-capture',
+		'dmabuf-capture.c',
+		dependencies: [wayland_client, wlr_protos, libavutil, libavcodec, libavformat, wlroots]
+	)
+endif

include/backend/drm/renderer.h

@@ -52,5 +52,6 @@ struct gbm_bo *get_drm_surface_front(struct wlr_drm_surface *surf);
 void post_drm_surface(struct wlr_drm_surface *surf);
 struct gbm_bo *copy_drm_surface_mgpu(struct wlr_drm_surface *dest,
 	struct gbm_bo *src);
+bool export_drm_bo(struct gbm_bo *bo, struct wlr_dmabuf_attributes *attribs);
 
 #endif

include/rootston/desktop.h

@@ -45,6 +45,7 @@ struct roots_desktop {
 	struct wlr_xdg_shell *xdg_shell;
 	struct wlr_gamma_control_manager *gamma_control_manager;
 	struct wlr_screenshooter *screenshooter;
+	struct wlr_export_dmabuf_manager_v1 *export_dmabuf_manager_v1;
 	struct wlr_server_decoration_manager *server_decoration_manager;
 	struct wlr_primary_selection_device_manager *primary_selection_device_manager;
 	struct wlr_idle *idle;

include/wlr/interfaces/wlr_output.h

@@ -23,6 +23,8 @@ struct wlr_output_impl {
 	void (*set_gamma)(struct wlr_output *output,
 		uint32_t size, uint16_t *r, uint16_t *g, uint16_t *b);
 	uint32_t (*get_gamma_size)(struct wlr_output *output);
+	bool (*export_dmabuf)(struct wlr_output *output,
+		struct wlr_dmabuf_attributes *attribs);
 };
 
 void wlr_output_init(struct wlr_output *output, struct wlr_backend *backend,

include/wlr/render/dmabuf.h

@@ -1,6 +1,8 @@
 #ifndef WLR_RENDER_DMABUF_H
 #define WLR_RENDER_DMABUF_H
 
+#include <stdint.h>
+
 // So we don't have to pull in linux specific drm headers
 #ifndef DRM_FORMAT_MOD_INVALID
 #define DRM_FORMAT_MOD_INVALID ((1ULL<<56) - 1)
@@ -26,4 +28,9 @@ struct wlr_dmabuf_attributes {
 	int fd[WLR_DMABUF_MAX_PLANES];
 };
 
+/**
+ * Closes all file descriptors in the DMA-BUF attributes.
+ */
+void wlr_dmabuf_attributes_finish(struct wlr_dmabuf_attributes *attribs);
+
 #endif

include/wlr/render/egl.h

@@ -18,9 +18,10 @@ struct wlr_egl {
 	struct {
 		bool bind_wayland_display_wl;
 		bool buffer_age_ext;
-		bool image_dmabuf_import_modifiers_ext;
-		bool image_dmabuf_import_ext;
 		bool image_base_khr;
+		bool image_dma_buf_export_mesa;
+		bool image_dmabuf_import_ext;
+		bool image_dmabuf_import_modifiers_ext;
 		bool swap_buffers_with_damage_ext;
 		bool swap_buffers_with_damage_khr;
 	} exts;
@@ -80,6 +81,10 @@ int wlr_egl_get_dmabuf_formats(struct wlr_egl *egl, int **formats);
 int wlr_egl_get_dmabuf_modifiers(struct wlr_egl *egl, int format,
 	uint64_t **modifiers);
 
+bool wlr_egl_export_image_to_dmabuf(struct wlr_egl *egl, EGLImageKHR image,
+	int32_t width, int32_t height, uint32_t flags,
+	struct wlr_dmabuf_attributes *attribs);
+
 /**
  * Destroys an EGL image created with the given wlr_egl.
  */

include/wlr/render/interface.h

@@ -60,6 +60,8 @@ struct wlr_texture_impl {
 		enum wl_shm_format wl_fmt, uint32_t stride, uint32_t width,
 		uint32_t height, uint32_t src_x, uint32_t src_y, uint32_t dst_x,
 		uint32_t dst_y, const void *data);
+	bool (*to_dmabuf)(struct wlr_texture *texture,
+		struct wlr_dmabuf_attributes *attribs);
 	void (*destroy)(struct wlr_texture *texture);
 };
 

include/wlr/render/wlr_texture.h

@@ -48,6 +48,9 @@ bool wlr_texture_write_pixels(struct wlr_texture *texture,
 	uint32_t src_x, uint32_t src_y, uint32_t dst_x, uint32_t dst_y,
 	const void *data);
 
+bool wlr_texture_to_dmabuf(struct wlr_texture *texture,
+	struct wlr_dmabuf_attributes *attribs);
+
 /**
  * Destroys this wlr_texture.
  */

include/wlr/types/wlr_export_dmabuf_v1.h

@@ -0,0 +1,37 @@
+#ifndef WLR_TYPES_WLR_EXPORT_DMABUF_V1_H
+#define WLR_TYPES_WLR_EXPORT_DMABUF_V1_H
+
+#include <wayland-server.h>
+#include <wlr/render/dmabuf.h>
+
+struct wlr_export_dmabuf_manager_v1;
+
+struct wlr_export_dmabuf_frame_v1 {
+	struct wl_resource *resource;
+	struct wlr_export_dmabuf_manager_v1 *manager;
+	struct wl_list link;
+
+	struct wlr_dmabuf_attributes attribs;
+	struct wlr_output *output;
+
+	struct wl_listener output_swap_buffers;
+};
+
+struct wlr_export_dmabuf_manager_v1 {
+	struct wl_global *global;
+	struct wl_list resources;
+	struct wl_list frames;
+
+	struct wl_listener display_destroy;
+
+	struct {
+		struct wl_signal destroy;
+	} events;
+};
+
+struct wlr_export_dmabuf_manager_v1 *wlr_export_dmabuf_manager_v1_create(
+	struct wl_display *display);
+void wlr_export_dmabuf_manager_v1_destroy(
+	struct wlr_export_dmabuf_manager_v1 *manager);
+
+#endif

include/wlr/types/wlr_output.h

@@ -6,6 +6,7 @@
 #include <time.h>
 #include <wayland-server.h>
 #include <wayland-util.h>
+#include <wlr/types/wlr_linux_dmabuf.h>
 
 struct wlr_output_mode {
 	uint32_t flags; // enum wl_output_mode
@@ -81,7 +82,7 @@ struct wlr_output {
 	struct {
 		struct wl_signal frame;
 		struct wl_signal needs_swap;
-		struct wl_signal swap_buffers;
+		struct wl_signal swap_buffers; // wlr_output_event_swap_buffers
 		struct wl_signal enable;
 		struct wl_signal mode;
 		struct wl_signal scale;
@@ -107,6 +108,12 @@ struct wlr_output {
 	void *data;
 };
 
+struct wlr_output_event_swap_buffers {
+	struct wlr_output *output;
+	struct timespec *when;
+	pixman_region32_t *damage;
+};
+
 struct wlr_surface;
 
 void wlr_output_enable(struct wlr_output *output, bool enable);
@@ -162,6 +169,8 @@ void wlr_output_schedule_frame(struct wlr_output *output);
 void wlr_output_set_gamma(struct wlr_output *output,
 	uint32_t size, uint16_t *r, uint16_t *g, uint16_t *b);
 uint32_t wlr_output_get_gamma_size(struct wlr_output *output);
+bool wlr_output_export_dmabuf(struct wlr_output *output,
+	struct wlr_dmabuf_attributes *attribs);
 void wlr_output_set_fullscreen_surface(struct wlr_output *output,
 	struct wlr_surface *surface);
 struct wlr_output *wlr_output_from_resource(struct wl_resource *resource);

protocol/meson.build

@@ -39,8 +39,9 @@ protocols = [
 	'screenshooter.xml',
 	'server-decoration.xml',
 	'virtual-keyboard-unstable-v1.xml',
-	'wlr-layer-shell-unstable-v1.xml',
+	'wlr-export-dmabuf-unstable-v1.xml',
 	'wlr-input-inhibitor-unstable-v1.xml',
+	'wlr-layer-shell-unstable-v1.xml',
 ]
 
 client_protocols = [
@@ -49,6 +50,7 @@ client_protocols = [
 	[wl_protocol_dir, 'unstable/idle-inhibit/idle-inhibit-unstable-v1.xml'],
 	'idle.xml',
 	'screenshooter.xml',
+	'wlr-export-dmabuf-unstable-v1.xml',
 	'wlr-layer-shell-unstable-v1.xml',
 	'wlr-input-inhibitor-unstable-v1.xml',
 ]

protocol/wlr-export-dmabuf-unstable-v1.xml

@@ -0,0 +1,203 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="wlr_export_dmabuf_unstable_v1">
+  <copyright>
+    Copyright © 2018 Rostislav Pehlivanov
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice (including the next
+    paragraph) shall be included in all copies or substantial portions of the
+    Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+  </copyright>
+
+  <description summary="a protocol for low overhead screen content capturing">
+    An interface to capture surfaces in an efficient way by exporting DMA-BUFs.
+
+    Warning! The protocol described in this file is experimental and
+    backward incompatible changes may be made. Backward compatible changes
+    may be added together with the corresponding interface version bump.
+    Backward incompatible changes are done by bumping the version number in
+    the protocol and interface names and resetting the interface version.
+    Once the protocol is to be declared stable, the 'z' prefix and the
+    version number in the protocol and interface names are removed and the
+    interface version number is reset.
+  </description>
+
+  <interface name="zwlr_export_dmabuf_manager_v1" version="1">
+    <description summary="manager to inform clients and begin capturing">
+      This object is a manager with which to start capturing from sources.
+    </description>
+
+    <request name="capture_output">
+      <description summary="capture a frame from an output">
+        Capture the next frame of a an entire output.
+      </description>
+      <arg name="frame" type="new_id" interface="zwlr_export_dmabuf_frame_v1"/>
+      <arg name="overlay_cursor" type="int"
+           summary="include custom client hardware cursor on top of the frame"/>
+      <arg name="output" type="object" interface="wl_output"/>
+    </request>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the manager">
+        All objects created by the manager will still remain valid, until their
+        appropriate destroy request has been called.
+      </description>
+    </request>
+  </interface>
+
+  <interface name="zwlr_export_dmabuf_frame_v1" version="1">
+    <description summary="a DMA-BUF frame">
+      This object represents a single DMA-BUF frame.
+
+      If the capture is successful, the compositor will first send a "frame"
+      event, followed by one or several "object". When the frame is available
+      for readout, the "ready" event is sent.
+
+      If the capture failed, the "cancel" event is sent. This can happen anytime
+      before the "ready" event.
+
+      Once either a "ready" or a "cancel" event is received, the client should
+      destroy the frame. Once an "object" event is received, the client is
+      responsible for closing the associated file descriptor.
+
+      All frames are read-only and may not be written into or altered.
+    </description>
+
+    <enum name="flags">
+      <description summary="frame flags">
+        Special flags that should be respected by the client.
+      </description>
+      <entry name="transient" value="0x1"
+             summary="clients should copy frame before processing"/>
+    </enum>
+
+    <event name="frame">
+      <description summary="a frame description">
+        Main event supplying the client with information about the frame. If the
+        capture didn't fail, this event is always emitted first before any other
+        events.
+
+        This event is followed by a number of "object" as specified by the
+        "num_objects" argument.
+      </description>
+      <arg name="width" type="uint"
+           summary="frame width in pixels"/>
+      <arg name="height" type="uint"
+           summary="frame height in pixels"/>
+      <arg name="offset_x" type="uint"
+           summary="crop offset for the x axis"/>
+      <arg name="offset_y" type="uint"
+           summary="crop offset for the y axis"/>
+      <arg name="buffer_flags" type="uint"
+           summary="flags which indicate properties (invert, interlacing),
+                    has the same values as zwp_linux_buffer_params_v1:flags"/>
+      <arg name="flags" type="uint" enum="flags"
+           summary="indicates special frame features"/>
+      <arg name="format" type="uint"
+           summary="format of the frame (DRM_FORMAT_*)"/>
+      <arg name="mod_high" type="uint"
+           summary="drm format modifier, high"/>
+      <arg name="mod_low" type="uint"
+           summary="drm format modifier, low"/>
+      <arg name="num_objects" type="uint"
+           summary="indicates how many objects (FDs) the frame has (max 4)"/>
+    </event>
+
+    <event name="object">
+      <description summary="an object description">
+        Event which serves to supply the client with the file descriptors
+        containing the data for each object.
+
+        After receiving this event, the client must always close the file
+        descriptor as soon as they're done with it and even if the frame fails.
+      </description>
+      <arg name="index" type="uint"
+           summary="index of the current object"/>
+      <arg name="fd" type="fd"
+           summary="fd of the current object"/>
+      <arg name="size" type="uint"
+           summary="size in bytes for the current object"/>
+      <arg name="offset" type="uint"
+           summary="starting point for the data in the object's fd"/>
+      <arg name="stride" type="uint"
+           summary="line size in bytes"/>
+      <arg name="plane_index" type="uint"
+           summary="index of the the plane the data in the object applies to"/>
+    </event>
+
+    <event name="ready">
+      <description summary="indicates frame is available for reading">
+        This event is sent as soon as the frame is presented, indicating it is
+        available for reading. This event includes the time at which
+        presentation happened at.
+
+        The timestamp is expressed as tv_sec_hi, tv_sec_lo, tv_nsec triples,
+        each component being an unsigned 32-bit value. Whole seconds are in
+        tv_sec which is a 64-bit value combined from tv_sec_hi and tv_sec_lo,
+        and the additional fractional part in tv_nsec as nanoseconds. Hence,
+        for valid timestamps tv_nsec must be in [0, 999999999]. The seconds part
+        may have an arbitrary offset at start.
+
+        After receiving this event, the client should destroy this object.
+      </description>
+      <arg name="tv_sec_hi" type="uint"
+           summary="high 32 bits of the seconds part of the timestamp"/>
+      <arg name="tv_sec_lo" type="uint"
+           summary="low 32 bits of the seconds part of the timestamp"/>
+      <arg name="tv_nsec" type="uint"
+           summary="nanoseconds part of the timestamp"/>
+    </event>
+
+    <enum name="cancel_reason">
+      <description summary="cancel reason">
+        Indicates reason for cancelling the frame.
+      </description>
+      <entry name="temporary" value="0"
+             summary="temporary error, source will produce more frames"/>
+      <entry name="permanent" value="1"
+             summary="fatal error, source will not produce frames"/>
+      <entry name="resizing" value="2"
+             summary="temporary error, source will produce more frames"/>
+    </enum>
+
+    <event name="cancel">
+      <description summary="indicates the frame is no longer valid">
+        If the capture failed or if the frame is no longer valid after the
+        "frame" event has been emitted, this event will be used to inform the
+        client to scrap the frame.
+
+        If the failure is temporary, the client may capture again the same
+        source. If the failure is permanent, any further attempts to capture the
+        same source will fail again.
+
+        After receiving this event, the client should destroy this object.
+      </description>
+      <arg name="reason" type="uint" enum="cancel_reason"
+           summary="indicates a reason for cancelling this frame capture"/>
+    </event>
+
+    <request name="destroy" type="destructor">
+      <description summary="delete this object, used or not">
+        Unreferences the frame. This request must be called as soon as its no
+        longer used.
+
+        It can be called at any time by the client. The client will still have
+        to close any FDs it has been given.
+      </description>
+    </request>
+  </interface>
+</protocol>

render/dmabuf.c

@@ -0,0 +1,10 @@
+#include <unistd.h>
+#include <wlr/render/dmabuf.h>
+
+void wlr_dmabuf_attributes_finish( struct wlr_dmabuf_attributes *attribs) {
+	for (int i = 0; i < attribs->n_planes; ++i) {
+		close(attribs->fd[i]);
+		attribs->fd[i] = -1;
+	}
+	attribs->n_planes = 0;
+}

render/egl.c

@@ -164,6 +164,11 @@ bool wlr_egl_init(struct wlr_egl *egl, EGLenum platform, void *remote_display,
 	egl->exts.image_dmabuf_import_modifiers_ext =
 		check_egl_ext(egl->exts_str, "EGL_EXT_image_dma_buf_import_modifiers")
 		&& eglQueryDmaBufFormatsEXT && eglQueryDmaBufModifiersEXT;
+
+	egl->exts.image_dma_buf_export_mesa =
+		check_egl_ext(egl->exts_str, "EGL_MESA_image_dma_buf_export") &&
+		eglExportDMABUFImageQueryMESA && eglExportDMABUFImageMESA;
+
 	print_dmabuf_formats(egl);
 
 	egl->exts.bind_wayland_display_wl =
@@ -511,6 +516,37 @@ int wlr_egl_get_dmabuf_modifiers(struct wlr_egl *egl,
 	return num;
 }
 
+bool wlr_egl_export_image_to_dmabuf(struct wlr_egl *egl, EGLImageKHR image,
+		int32_t width, int32_t height, uint32_t flags,
+		struct wlr_dmabuf_attributes *attribs) {
+	memset(attribs, 0, sizeof(struct wlr_dmabuf_attributes));
+
+	if (!egl->exts.image_dma_buf_export_mesa) {
+		return false;
+	}
+
+	// Only one set of modifiers is returned for all planes
+	if (!eglExportDMABUFImageQueryMESA(egl->display, image,
+			(int *)&attribs->format, &attribs->n_planes, &attribs->modifier)) {
+		return false;
+	}
+	if (attribs->n_planes > WLR_DMABUF_MAX_PLANES) {
+		wlr_log(L_ERROR, "EGL returned %d planes, but only %d are supported",
+			attribs->n_planes, WLR_DMABUF_MAX_PLANES);
+		return false;
+	}
+
+	if (!eglExportDMABUFImageMESA(egl->display, image, attribs->fd,
+			(EGLint *)attribs->stride, (EGLint *)attribs->offset)) {
+		return false;
+	}
+
+	attribs->width = width;
+	attribs->height = height;
+	attribs->flags = flags;
+	return true;
+}
+
 bool wlr_egl_destroy_surface(struct wlr_egl *egl, EGLSurface surface) {
 	if (!surface) {
 		return true;

render/glapi.txt

@@ -10,6 +10,8 @@ eglCreatePlatformWindowSurfaceEXT
 -eglSwapBuffersWithDamageKHR
 -eglQueryDmaBufFormatsEXT
 -eglQueryDmaBufModifiersEXT
+-eglExportDMABUFImageQueryMESA
+-eglExportDMABUFImageMESA
 -eglDebugMessageControlKHR
 -glDebugMessageCallbackKHR
 -glDebugMessageControlKHR

render/gles2/texture.c

@@ -74,6 +74,34 @@ static bool gles2_texture_write_pixels(struct wlr_texture *wlr_texture,
 	return true;
 }
 
+static bool gles2_texture_to_dmabuf(struct wlr_texture *wlr_texture,
+		struct wlr_dmabuf_attributes *attribs) {
+	struct wlr_gles2_texture *texture = gles2_get_texture(wlr_texture);
+
+	if (!texture->image) {
+		assert(texture->type == WLR_GLES2_TEXTURE_GLTEX);
+
+		if (!eglCreateImageKHR) {
+			return false;
+		}
+
+		texture->image = eglCreateImageKHR(texture->egl->display,
+			texture->egl->context, EGL_GL_TEXTURE_2D_KHR,
+			(EGLClientBuffer)(uintptr_t)texture->gl_tex, NULL);
+		if (texture->image == EGL_NO_IMAGE_KHR) {
+			return false;
+		}
+	}
+
+	uint32_t flags = 0;
+	if (texture->inverted_y) {
+		flags |= WLR_DMABUF_ATTRIBUTES_FLAGS_Y_INVERT;
+	}
+
+	return wlr_egl_export_image_to_dmabuf(texture->egl, texture->image,
+		texture->width, texture->height, flags, attribs);
+}
+
 static void gles2_texture_destroy(struct wlr_texture *wlr_texture) {
 	if (wlr_texture == NULL) {
 		return;
@@ -102,6 +130,7 @@ static void gles2_texture_destroy(struct wlr_texture *wlr_texture) {
 static const struct wlr_texture_impl texture_impl = {
 	.get_size = gles2_texture_get_size,
 	.write_pixels = gles2_texture_write_pixels,
+	.to_dmabuf = gles2_texture_to_dmabuf,
 	.destroy = gles2_texture_destroy,
 };
 

render/meson.build

@@ -9,6 +9,7 @@ glapi = custom_target('glapi',
 lib_wlr_render = static_library(
 	'wlr_render',
 	files(
+		'dmabuf.c',
 		'egl.c',
 		'gles2/pixel_format.c',
 		'gles2/renderer.c',

render/wlr_texture.c

@@ -54,3 +54,11 @@ bool wlr_texture_write_pixels(struct wlr_texture *texture,
 	return texture->impl->write_pixels(texture, wl_fmt, stride, width, height,
 		src_x, src_y, dst_x, dst_y, data);
 }
+
+bool wlr_texture_to_dmabuf(struct wlr_texture *texture,
+		struct wlr_dmabuf_attributes *attribs) {
+	if (!texture->impl->to_dmabuf) {
+		return false;
+	}
+	return texture->impl->to_dmabuf(texture, attribs);
+}

rootston/desktop.c

@@ -7,9 +7,10 @@
 #include <wlr/types/wlr_box.h>
 #include <wlr/types/wlr_compositor.h>
 #include <wlr/types/wlr_cursor.h>
+#include <wlr/types/wlr_export_dmabuf_v1.h>
 #include <wlr/types/wlr_gamma_control.h>
-#include <wlr/types/wlr_idle.h>
 #include <wlr/types/wlr_idle_inhibit_v1.h>
+#include <wlr/types/wlr_idle.h>
 #include <wlr/types/wlr_input_inhibitor.h>
 #include <wlr/types/wlr_layer_shell.h>
 #include <wlr/types/wlr_linux_dmabuf.h>
@@ -18,9 +19,9 @@
 #include <wlr/types/wlr_server_decoration.h>
 #include <wlr/types/wlr_wl_shell.h>
 #include <wlr/types/wlr_xcursor_manager.h>
+#include <wlr/types/wlr_xdg_output.h>
 #include <wlr/types/wlr_xdg_shell_v6.h>
 #include <wlr/types/wlr_xdg_shell.h>
-#include <wlr/types/wlr_xdg_output.h>
 #include <wlr/util/log.h>
 #include "rootston/layers.h"
 #include "rootston/seat.h"
@@ -845,6 +846,8 @@ struct roots_desktop *desktop_create(struct roots_server *server,
 	desktop->gamma_control_manager = wlr_gamma_control_manager_create(
 		server->wl_display);
 	desktop->screenshooter = wlr_screenshooter_create(server->wl_display);
+	desktop->export_dmabuf_manager_v1 =
+		wlr_export_dmabuf_manager_v1_create(server->wl_display);
 	desktop->server_decoration_manager =
 		wlr_server_decoration_manager_create(server->wl_display);
 	wlr_server_decoration_manager_set_default_mode(

types/meson.build

@@ -23,6 +23,7 @@ lib_wlr_types = static_library(
 		'wlr_buffer.c',
 		'wlr_compositor.c',
 		'wlr_cursor.c',
+		'wlr_export_dmabuf_v1.c',
 		'wlr_gamma_control.c',
 		'wlr_idle_inhibit_v1.c',
 		'wlr_idle.c',

types/wlr_export_dmabuf_v1.c

@@ -0,0 +1,197 @@
+#include <assert.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <wlr/interfaces/wlr_output.h>
+#include <wlr/types/wlr_export_dmabuf_v1.h>
+#include <wlr/types/wlr_linux_dmabuf.h>
+#include <wlr/types/wlr_output.h>
+#include "wlr-export-dmabuf-unstable-v1-protocol.h"
+#include <wlr/util/log.h>
+
+#define EXPORT_DMABUF_MANAGER_VERSION 1
+
+
+static const struct zwlr_export_dmabuf_frame_v1_interface frame_impl;
+
+static struct wlr_export_dmabuf_frame_v1 *frame_from_resource(
+		struct wl_resource *resource) {
+	assert(wl_resource_instance_of(resource,
+		&zwlr_export_dmabuf_frame_v1_interface, &frame_impl));
+	return wl_resource_get_user_data(resource);
+}
+
+static void frame_handle_destroy(struct wl_client *client,
+		struct wl_resource *resource) {
+	wl_resource_destroy(resource);
+}
+
+static const struct zwlr_export_dmabuf_frame_v1_interface frame_impl = {
+	.destroy = frame_handle_destroy,
+};
+
+static void frame_handle_resource_destroy(struct wl_resource *resource) {
+	struct wlr_export_dmabuf_frame_v1 *frame = frame_from_resource(resource);
+	wl_list_remove(&frame->link);
+	wl_list_remove(&frame->output_swap_buffers.link);
+	wlr_dmabuf_attributes_finish(&frame->attribs);
+	free(frame);
+}
+
+static void frame_output_handle_swap_buffers(struct wl_listener *listener,
+		void *data) {
+	struct wlr_export_dmabuf_frame_v1 *frame =
+		wl_container_of(listener, frame, output_swap_buffers);
+	struct wlr_output_event_swap_buffers *event = data;
+
+	wl_list_remove(&frame->output_swap_buffers.link);
+	wl_list_init(&frame->output_swap_buffers.link);
+
+	uint32_t tv_sec_hi = event->when->tv_sec >> 32;
+	uint32_t tv_sec_lo = event->when->tv_sec & 0xFFFFFFFF;
+	zwlr_export_dmabuf_frame_v1_send_ready(frame->resource,
+		tv_sec_hi, tv_sec_lo, event->when->tv_nsec);
+}
+
+
+static const struct zwlr_export_dmabuf_manager_v1_interface manager_impl;
+
+static struct wlr_export_dmabuf_manager_v1 *manager_from_resource(
+		struct wl_resource *resource) {
+	assert(wl_resource_instance_of(resource,
+		&zwlr_export_dmabuf_manager_v1_interface, &manager_impl));
+	return wl_resource_get_user_data(resource);
+}
+
+static void manager_handle_capture_output(struct wl_client *client,
+		struct wl_resource *manager_resource, uint32_t id,
+		int32_t overlay_cursor, struct wl_resource *output_resource) {
+	struct wlr_export_dmabuf_manager_v1 *manager =
+		manager_from_resource(manager_resource);
+	struct wlr_output *output = wlr_output_from_resource(output_resource);
+
+	struct wlr_export_dmabuf_frame_v1 *frame =
+		calloc(1, sizeof(struct wlr_export_dmabuf_frame_v1));
+	if (frame == NULL) {
+		wl_resource_post_no_memory(manager_resource);
+		return;
+	}
+	frame->manager = manager;
+	frame->output = output;
+	wl_list_init(&frame->output_swap_buffers.link);
+
+	uint32_t version = wl_resource_get_version(manager_resource);
+	frame->resource = wl_resource_create(client,
+		&zwlr_export_dmabuf_frame_v1_interface, version, id);
+	if (frame->resource == NULL) {
+		wl_client_post_no_memory(client);
+		return;
+	}
+	wl_resource_set_implementation(frame->resource, &frame_impl, frame,
+		frame_handle_resource_destroy);
+
+	wl_list_insert(&manager->frames, &frame->link);
+
+	if (!output->impl->export_dmabuf) {
+		zwlr_export_dmabuf_frame_v1_send_cancel(frame->resource,
+			ZWLR_EXPORT_DMABUF_FRAME_V1_CANCEL_REASON_PERMANENT);
+		return;
+	}
+
+	struct wlr_dmabuf_attributes *attribs = &frame->attribs;
+	if (!wlr_output_export_dmabuf(output, attribs)) {
+		zwlr_export_dmabuf_frame_v1_send_cancel(frame->resource,
+			ZWLR_EXPORT_DMABUF_FRAME_V1_CANCEL_REASON_TEMPORARY);
+		return;
+	}
+
+	uint32_t frame_flags = ZWLR_EXPORT_DMABUF_FRAME_V1_FLAGS_TRANSIENT;
+	uint32_t mod_high = attribs->modifier >> 32;
+	uint32_t mod_low = attribs->modifier & 0xFFFFFFFF;
+
+	zwlr_export_dmabuf_frame_v1_send_frame(frame->resource,
+		output->width, output->height, 0, 0, attribs->flags, frame_flags,
+		attribs->format, mod_high, mod_low, attribs->n_planes);
+
+	for (int i = 0; i < attribs->n_planes; ++i) {
+		off_t size = lseek(attribs->fd[i], 0, SEEK_END);
+
+		zwlr_export_dmabuf_frame_v1_send_object(frame->resource, i,
+			attribs->fd[i], size, attribs->offset[i], attribs->stride[i], i);
+	}
+
+	wl_list_remove(&frame->output_swap_buffers.link);
+	wl_signal_add(&output->events.swap_buffers, &frame->output_swap_buffers);
+	frame->output_swap_buffers.notify = frame_output_handle_swap_buffers;
+}
+
+static const struct zwlr_export_dmabuf_manager_v1_interface manager_impl = {
+	.capture_output = manager_handle_capture_output,
+};
+
+static void manager_handle_resource_destroy(struct wl_resource *resource) {
+	wl_list_remove(wl_resource_get_link(resource));
+}
+
+static void manager_bind(struct wl_client *client, void *data, uint32_t version,
+		uint32_t id) {
+	struct wlr_export_dmabuf_manager_v1 *manager = data;
+
+	struct wl_resource *resource = wl_resource_create(client,
+		&zwlr_export_dmabuf_manager_v1_interface, version, id);
+	if (resource == NULL) {
+		wl_client_post_no_memory(client);
+		return;
+	}
+	wl_resource_set_implementation(resource, &manager_impl, manager,
+		manager_handle_resource_destroy);
+
+	wl_list_insert(&manager->resources, wl_resource_get_link(resource));
+}
+
+static void handle_display_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_export_dmabuf_manager_v1 *manager =
+		wl_container_of(listener, manager, display_destroy);
+	wlr_export_dmabuf_manager_v1_destroy(manager);
+}
+
+struct wlr_export_dmabuf_manager_v1 *wlr_export_dmabuf_manager_v1_create(
+		struct wl_display *display) {
+	struct wlr_export_dmabuf_manager_v1 *manager =
+		calloc(1, sizeof(struct wlr_export_dmabuf_manager_v1));
+	if (manager == NULL) {
+		return NULL;
+	}
+	wl_list_init(&manager->resources);
+	wl_list_init(&manager->frames);
+
+	manager->global = wl_global_create(display,
+		&zwlr_export_dmabuf_manager_v1_interface, EXPORT_DMABUF_MANAGER_VERSION,
+		manager, manager_bind);
+	if (manager->global == NULL) {
+		free(manager);
+		return NULL;
+	}
+
+	manager->display_destroy.notify = handle_display_destroy;
+	wl_display_add_destroy_listener(display, &manager->display_destroy);
+
+	return manager;
+}
+
+void wlr_export_dmabuf_manager_v1_destroy(
+		struct wlr_export_dmabuf_manager_v1 *manager) {
+	if (manager == NULL) {
+		return;
+	}
+	wl_list_remove(&manager->display_destroy.link);
+	wl_global_destroy(manager->global);
+	struct wl_resource *resource, *resource_tmp;
+	wl_resource_for_each_safe(resource, resource_tmp, &manager->resources) {
+		wl_resource_destroy(resource);
+	}
+	struct wlr_export_dmabuf_frame_v1 *frame, *frame_tmp;
+	wl_list_for_each_safe(frame, frame_tmp, &manager->frames, link) {
+		wl_resource_destroy(frame->resource);
+	}
+	free(manager);
+}

types/wlr_linux_dmabuf.c

@@ -52,11 +52,7 @@ struct wlr_dmabuf_buffer *wlr_dmabuf_buffer_from_buffer_resource(
 }
 
 static void linux_dmabuf_buffer_destroy(struct wlr_dmabuf_buffer *buffer) {
-	for (int i = 0; i < buffer->attributes.n_planes; i++) {
+	wlr_dmabuf_attributes_finish(&buffer->attributes);
-		close(buffer->attributes.fd[i]);
-		buffer->attributes.fd[i] = -1;
-	}
-	buffer->attributes.n_planes = 0;
 	free(buffer);
 }
 

types/wlr_output.c

@@ -467,7 +467,12 @@ bool wlr_output_swap_buffers(struct wlr_output *output, struct timespec *when,
 		output->idle_frame = NULL;
 	}
 
-	wlr_signal_emit_safe(&output->events.swap_buffers, damage);
+	struct wlr_output_event_swap_buffers event = {
+		.output = output,
+		.when = when,
+		.damage = damage,
+	};
+	wlr_signal_emit_safe(&output->events.swap_buffers, &event);
 
 	int width, height;
 	wlr_output_transformed_resolution(output, &width, &height);
@@ -560,6 +565,14 @@ uint32_t wlr_output_get_gamma_size(struct wlr_output *output) {
 	return output->impl->get_gamma_size(output);
 }
 
+bool wlr_output_export_dmabuf(struct wlr_output *output,
+		struct wlr_dmabuf_attributes *attribs) {
+	if (!output->impl->export_dmabuf) {
+		return false;
+	}
+	return output->impl->export_dmabuf(output, attribs);
+}
+
 void wlr_output_update_needs_swap(struct wlr_output *output) {
 	output->needs_swap = true;
 	wlr_signal_emit_safe(&output->events.needs_swap, output);