wl_screenshooter: Wayland screen grabber

NEWS

@@ -4,6 +4,7 @@ Changes between 2.2.x and 3.0.0-git:
 Access:
  * Support HDS (Http Dynamic Streaming) from Adobe (f4m, f4v, etc.)
  * New SMB access module using libdsm
+ * Screen capture plugin for Wayland display
  * Support decompression and extraction through libarchive (tar, zip, rar...)
  * Improvements of cookie handling (share cookies between playlist items,
    domain / path matching, Secure cookies)

modules/MODULES_LIST

@@ -419,6 +419,7 @@ $Id$
  * windrive: Windows logical disc drives
  * wingdi: WIN 32 / WIN CE GDI video output
  * winstore: Windows Store App audio output
+ * wl_screenshooter: Wayland screen capture input
  * wl_shell_surface: Wayland shell surface window provider
  * wl_shm: Wayland shared memory video output
  * wma_fixed: wma decoder using integer decoder from Rockbox

modules/access/Makefile.am

@@ -198,6 +198,22 @@ if HAVE_XCB
 access_LTLIBRARIES += libxcb_screen_plugin.la
 endif
 
+libwl_screenshooter_plugin_la_DEPENDENCIES = \
+	access/screen/screenshooter-client-protocol.h
+libwl_screenshooter_plugin_la_SOURCES = \
+	access/screen/wayland.c
+nodist_libwl_screenshooter_plugin_la_SOURCES = \
+	access/screen/screenshooter-protocol.c
+libwl_screenshooter_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) -Iaccess/screen
+libwl_screenshooter_plugin_la_CFLAGS = $(WAYLAND_CLIENT_CFLAGS)
+libwl_screenshooter_plugin_la_LIBADD = $(WAYLAND_CLIENT_LIBS) \
+	$(LIBPTHREAD) $(LIBM)
+EXTRA_DIST += access/screen/screenshooter.xml
+CLEANFILES += $(nodist_libwl_screenshooter_plugin_la_SOURCES)
+if HAVE_WAYLAND
+access_LTLIBRARIES += libwl_screenshooter_plugin.la
+endif
+
 libscreen_plugin_la_SOURCES = access/screen/screen.c access/screen/screen.h
 libscreen_plugin_la_LDFLAGS = $(AM_LDFLAGS)
 if HAVE_WIN32

modules/access/screen/wayland.c

+/**
+ * @file wayland.c
+ * @brief Wayland screenshooter extension module for VLC media player
+ */
+/*****************************************************************************
+ * Copyright © 2014 Rémi Denis-Courmont
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <wayland-client.h>
+#include "screenshooter-client-protocol.h"
+
+#include <vlc_common.h>
+#include <vlc_demux.h>
+#include <vlc_plugin.h>
+
+struct demux_sys_t
+{
+    struct wl_display *display;
+    struct wl_output *output;
+    struct wl_shm *shm;
+    struct screenshooter *screenshooter;
+    es_out_id_t *es;
+
+    long pagemask;
+    float rate;
+    int32_t x; /*< Requested horizontal offset */
+    int32_t y; /*< Requested vertical offset */
+    int32_t w; /*< Requested width */
+    int32_t h; /*< Requested height */
+    int32_t width; /*< Actual width */
+    int32_t height; /*< Actual height */
+
+    bool done;
+    mtime_t start;
+
+    vlc_thread_t thread;
+};
+
+static bool DisplayError(vlc_object_t *obj, struct wl_display *display)
+{
+    int val = wl_display_get_error(display);
+    if (val == 0)
+        return false;
+
+    if (val == EPROTO)
+    {
+        const struct wl_interface *iface;
+        uint32_t id;
+
+        val = wl_display_get_protocol_error(display, &iface, &id);
+        msg_Err(obj, "display protocol error %d on %s object %"PRIu32,
+                val, iface->name, id);
+    }
+    else
+        msg_Err(obj, "display fatal error: %s", vlc_strerror_c(val));
+
+    return true;
+}
+#define DisplayError(o,d) DisplayError(VLC_OBJECT(o), (d))
+
+static void output_geometry_cb(void *data, struct wl_output *output, int32_t x,
+                               int32_t y, int32_t width, int32_t height,
+                               int32_t subpixel, const char *vendor,
+                               const char *model, int32_t transform)
+{
+    demux_t *demux = data;
+
+    msg_Dbg(demux, "output geometry: %s %s %"PRId32"x%"PRId32"mm "
+            "@ %"PRId32"x%"PRId32" subpixel: %"PRId32" transform: %"PRId32,
+            vendor, model, width, height, x, y, subpixel, transform);
+    (void) output;
+}
+
+static void output_mode_cb(void *data, struct wl_output *output,
+                           uint32_t flags, int32_t width, int32_t height,
+                           int32_t refresh)
+{
+    demux_t *demux = data;
+    demux_sys_t *sys = demux->p_sys;
+
+    msg_Dbg(demux, "output mode: 0x%08"PRIX32" %"PRId32"x%"PRId32
+            " %"PRId32"mHz%s", flags, width, height, refresh,
+            (flags & WL_OUTPUT_MODE_CURRENT) ? " (current)" : "");
+
+    if (!(flags & WL_OUTPUT_MODE_CURRENT))
+        return;
+    if (width <= sys->x || height <= sys->y)
+        return;
+
+    if (sys->es != NULL)
+        es_out_Del(demux->out, sys->es);
+
+    es_format_t fmt;
+
+    es_format_Init(&fmt, VIDEO_ES, VLC_CODEC_RGB32);
+    fmt.video.i_chroma = VLC_CODEC_RGB32;
+    fmt.video.i_bits_per_pixel = 32;
+    fmt.video.i_sar_num = fmt.video.i_sar_den = 1;
+    fmt.video.i_frame_rate = lroundf(1000.f * sys->rate);
+    fmt.video.i_frame_rate_base = 1000;
+    fmt.video.i_width = width;
+
+    if (sys->w != 0 && width > sys->w + sys->x)
+        fmt.video.i_visible_width = sys->w;
+    else
+        fmt.video.i_visible_width = width - sys->x;
+
+    if (sys->h != 0 && height > sys->h + sys->y)
+        fmt.video.i_visible_height = sys->h;
+    else
+        fmt.video.i_visible_height = height - sys->y;
+
+    fmt.video.i_height = fmt.video.i_visible_height;
+
+    sys->es = es_out_Add(demux->out, &fmt);
+    sys->width = width;
+    sys->height = height;
+    (void) output;
+}
+
+static void output_done_cb(void *data, struct wl_output *output)
+{
+    demux_t *demux = data;
+
+    (void) demux; (void) output;
+}
+
+static void output_scale_cb(void *data, struct wl_output *output,
+                            int32_t factor)
+{
+    demux_t *demux = data;
+
+    (void) demux; (void) output; (void) factor;
+}
+
+const struct wl_output_listener output_cbs =
+{
+    output_geometry_cb,
+    output_mode_cb,
+    output_done_cb,
+    output_scale_cb,
+};
+
+static void screenshooter_done_cb(void *data,
+                                  struct screenshooter *screenshooter)
+{
+    bool *done = data;
+
+    *done = true;
+    (void) screenshooter;
+}
+
+const struct screenshooter_listener screenshooter_cbs =
+{
+    screenshooter_done_cb,
+};
+
+static block_t *Shoot(demux_t *demux)
+{
+    demux_sys_t *sys = demux->p_sys;
+
+    char bufpath[] = "/tmp/"PACKAGE_NAME"XXXXXX";
+    int fd = mkostemp(bufpath, O_CLOEXEC);
+    if (fd == -1)
+    {
+        msg_Err(demux, "buffer creation error: %s", vlc_strerror_c(errno));
+        return NULL;
+    }
+
+    /* NOTE: one extra line for overflow if screen-left > 0 */
+    uint32_t pitch = 4u * sys->width;
+    size_t size = (pitch * (sys->height + 1) + sys->pagemask) & ~sys->pagemask;
+    block_t *block = NULL;
+
+    if (ftruncate(fd, size) < 0)
+    {
+        msg_Err(demux, "buffer allocation error: %s", vlc_strerror_c(errno));
+        goto out;
+    }
+
+    struct wl_shm_pool *pool = wl_shm_create_pool(sys->shm, fd, size);
+    if (pool == NULL)
+        goto out;
+
+    struct wl_buffer *buffer;
+    buffer = wl_shm_pool_create_buffer(pool, 0, sys->width, sys->height,
+                                       pitch, WL_SHM_FORMAT_XRGB8888);
+    wl_shm_pool_destroy(pool);
+    if (buffer == NULL)
+        goto out;
+
+    sys->done = false;
+    screenshooter_shoot(sys->screenshooter, sys->output, buffer);
+
+    while (!sys->done)
+        wl_display_roundtrip(sys->display);
+
+    wl_buffer_destroy(buffer);
+    block = block_File(fd);
+
+    if (block != NULL)
+    {
+        size_t skip = (sys->y * sys->width + sys->x) * 4;
+
+        block->p_buffer += skip;
+        block->i_buffer -= skip;
+    }
+
+out:
+    close(fd);
+    return block;
+}
+
+static void cleanup_wl_display_read(void *data)
+{
+    struct wl_display *display = data;
+
+    wl_display_cancel_read(display);
+}
+
+static void *Thread(void *data)
+{
+    demux_t *demux = data;
+    demux_sys_t *sys = demux->p_sys;
+    struct wl_display *display = sys->display;
+    struct pollfd ufd[1];
+    unsigned interval = lroundf(CLOCK_FREQ / (sys->rate * 1000.f));
+
+    int canc = vlc_savecancel();
+    vlc_cleanup_push(cleanup_wl_display_read, display);
+
+    ufd[0].fd = wl_display_get_fd(display);
+    ufd[0].events = POLLIN;
+
+    for (;;)
+    {
+        if (DisplayError(demux, display))
+            break;
+
+        if (sys->es != NULL)
+        {
+            block_t *block = Shoot(demux);
+
+            block->i_pts = block->i_dts = mdate();
+            es_out_Control(demux->out, ES_OUT_SET_PCR, block->i_pts);
+            es_out_Send(demux->out, sys->es, block);
+        }
+
+        while (wl_display_prepare_read(display) != 0)
+            wl_display_dispatch_pending(display);
+        wl_display_flush(display);
+        vlc_restorecancel(canc);
+
+        while (poll(ufd, 1, interval) < 0);
+
+        canc = vlc_savecancel();
+        wl_display_read_events(display);
+        wl_display_dispatch_pending(display);
+    }
+    vlc_cleanup_pop();
+    vlc_restorecancel(canc);
+    return NULL;
+}
+
+static int Control(demux_t *demux, int query, va_list args)
+{
+    demux_sys_t *sys = demux->p_sys;
+
+    switch (query)
+    {
+        case DEMUX_GET_POSITION:
+            *va_arg(args, float *) = 0.f;
+            break;
+
+        case DEMUX_GET_LENGTH:
+            *va_arg(args, int64_t *) = 0;
+            break;
+
+        case DEMUX_GET_TIME:
+            *va_arg(args, int64_t *) = mdate() - sys->start;
+            break;
+
+        case DEMUX_GET_FPS:
+            *va_arg(args, float *) = sys->rate;
+            break;
+
+        case DEMUX_CAN_PAUSE:
+            *va_arg(args, bool *) = false; /* TODO */
+            break;
+        //case DEMUX_SET_PAUSE_STATE:
+        //    break;
+
+        case DEMUX_GET_PTS_DELAY:
+            *va_arg(args, int64_t *) = INT64_C(1000)
+                * var_InheritInteger(demux, "live-caching");
+            break;
+
+        case DEMUX_CAN_CONTROL_PACE:
+        case DEMUX_CAN_CONTROL_RATE:
+        case DEMUX_CAN_SEEK:
+            *va_arg(args, bool *) = false;
+            break;
+
+        default:
+            return VLC_EGENERIC;
+    }
+
+    return VLC_SUCCESS;
+}
+
+static void registry_global_cb(void *data, struct wl_registry *registry,
+                               uint32_t name, const char *iface, uint32_t vers)
+{
+    demux_t *demux = data;
+    demux_sys_t *sys = demux->p_sys;
+
+    msg_Dbg(demux, "global %3"PRIu32": %s version %"PRIu32, name, iface, vers);
+
+    if (!strcmp(iface, "wl_output"))
+        sys->output = wl_registry_bind(registry, name, &wl_output_interface,
+                                       1);
+    else
+    if (!strcmp(iface, "wl_shm"))
+        sys->shm = wl_registry_bind(registry, name, &wl_shm_interface, 1);
+    else
+    if (!strcmp(iface, "screenshooter"))
+        sys->screenshooter = wl_registry_bind(registry, name,
+                                              &screenshooter_interface, 1);
+}
+
+static void registry_global_remove_cb(void *data, struct wl_registry *registry,
+                                      uint32_t name)
+{
+    demux_t *demux = data;
+
+    msg_Dbg(demux, "global remove %3"PRIu32, name);
+    (void) registry;
+}
+
+static const struct wl_registry_listener registry_cbs =
+{
+    registry_global_cb,
+    registry_global_remove_cb,
+};
+
+static int Open(vlc_object_t *obj)
+{
+    demux_t *demux = (demux_t *)obj;
+    demux_sys_t *sys = malloc(sizeof (*sys));
+    if (unlikely(sys == NULL))
+        return VLC_ENOMEM;
+
+    /* Connect to the display server */
+    char *dpy_name = var_InheritString(demux, "wl-display");
+    sys->display = wl_display_connect(dpy_name);
+    free(dpy_name);
+
+    if (sys->display == NULL)
+    {
+        free(sys);
+        return VLC_EGENERIC;
+    }
+
+    sys->output = NULL;
+    sys->shm = NULL;
+    sys->screenshooter = NULL;
+    sys->es = NULL;
+    sys->pagemask = sysconf(_SC_PAGE_SIZE) - 1;
+    sys->rate = var_InheritFloat(demux, "screen-fps");
+    sys->x = var_InheritInteger(demux, "screen-left");
+    sys->y = var_InheritInteger(demux, "screen-top");
+    sys->w = var_InheritInteger(demux, "screen-width");
+    sys->h = var_InheritInteger(demux, "screen-height");
+
+    if (1000.f * sys->rate <= 0x1.p-30)
+        goto error;
+
+    demux->p_sys = sys;
+
+    /* Find the interesting singleton(s) */
+    struct wl_registry *registry = wl_display_get_registry(sys->display);
+    if (registry == NULL)
+        goto error;
+
+    wl_registry_add_listener(registry, &registry_cbs, demux);
+    wl_display_roundtrip(sys->display);
+    wl_registry_destroy(registry);
+
+    if (sys->output == NULL || sys->shm == NULL || sys->screenshooter == NULL)
+    {
+        msg_Err(demux, "screenshooter extension not supported");
+        goto error;
+    }
+
+    wl_output_add_listener(sys->output, &output_cbs, demux);
+    screenshooter_add_listener(sys->screenshooter, &screenshooter_cbs,
+                               &sys->done);
+    wl_display_roundtrip(sys->display);
+
+    if (DisplayError(demux, sys->display))
+        goto error;
+
+    /* Initializes demux */
+    sys->start = mdate();
+
+    if (vlc_clone(&sys->thread, Thread, demux, VLC_THREAD_PRIORITY_INPUT))
+        goto error;
+
+    demux->pf_demux = NULL;
+    demux->pf_control = Control;
+    return VLC_SUCCESS;
+
+error:
+    if (sys->screenshooter != NULL)
+        screenshooter_destroy(sys->screenshooter);
+    if (sys->shm != NULL)
+        wl_shm_destroy(sys->shm);
+    if (sys->output != NULL)
+        wl_output_destroy(sys->output);
+    wl_display_disconnect(sys->display);
+    free(sys);
+    return VLC_EGENERIC;
+}
+
+static void Close(vlc_object_t *obj)
+{
+    demux_t *demux = (demux_t *)obj;
+    demux_sys_t *sys = demux->p_sys;
+
+    vlc_cancel(sys->thread);
+    vlc_join(sys->thread, NULL);
+
+    screenshooter_destroy(sys->screenshooter);
+    wl_shm_destroy(sys->shm);
+    wl_output_destroy(sys->output);
+    wl_display_disconnect(sys->display);
+    free(sys);
+}
+
+#define FPS_TEXT N_("Frame rate")
+#define FPS_LONGTEXT N_( \
+    "How many times the screen content should be refreshed per second.")
+
+#define LEFT_TEXT N_("Region left column")
+#define LEFT_LONGTEXT N_( \
+    "Abscissa of the capture region in pixels.")
+
+#define TOP_TEXT N_("Region top row")
+#define TOP_LONGTEXT N_( \
+    "Ordinate of the capture region in pixels.")
+
+#define WIDTH_TEXT N_("Capture region width")
+#define WIDTH_LONGTEXT N_( \
+    "Pixel width of the capture region, or 0 for full width")
+
+#define HEIGHT_TEXT N_("Capture region height")
+#define HEIGHT_LONGTEXT N_( \
+    "Pixel height of the capture region, or 0 for full height")
+
+vlc_module_begin ()
+    set_shortname (N_("Screen"))
+    set_description (N_("Screen capture (with Wayland)"))
+    set_category (CAT_INPUT)
+    set_subcategory (SUBCAT_INPUT_ACCESS)
+    set_capability ("access_demux", 0)
+    set_callbacks (Open, Close)
+
+    /* XXX: VLC core does not support multiple configuration items with the
+     * same name. So all default values and ranges must be the same as for XCB
+     * for the time being. */
+    add_float ("screen-fps", 2.0, FPS_TEXT, FPS_LONGTEXT, true)
+    add_integer ("screen-left", 0, LEFT_TEXT, LEFT_LONGTEXT, true)
+        change_integer_range (-32768, 32767)
+        change_safe ()
+    add_integer ("screen-top", 0, TOP_TEXT, TOP_LONGTEXT, true)
+        change_integer_range (-32768, 32767)
+        change_safe ()
+    add_integer ("screen-width", 0, WIDTH_TEXT, WIDTH_LONGTEXT, true)
+        change_integer_range (0, 65535)
+        change_safe ()
+    add_integer ("screen-height", 0, HEIGHT_TEXT, HEIGHT_LONGTEXT, true)
+        change_integer_range (0, 65535)
+        change_safe ()
+    add_shortcut ("screen")
+vlc_module_end ()

po/POTFILES.in

@@ -254,6 +254,7 @@ modules/access/rtsp/rtsp.h
 modules/access/screen/mac.c
 modules/access/screen/screen.c
 modules/access/screen/screen.h
+modules/access/screen/wayland.c
 modules/access/screen/win32.c
 modules/access/screen/xcb.c
 modules/access/sdp.c