XCB screen & window capture

configure.ac

@@ -4089,6 +4089,7 @@ AS_IF([test "${enable_xcb}" != "no"], [
   PKG_CHECK_MODULES(XCB, [xcb])
   PKG_CHECK_MODULES(XCB_SHM, [xcb-shm])
   VLC_ADD_PLUGIN([xcb])
+  VLC_ADD_PLUGIN([xcb_screen])
 
   AS_IF([test "${enable_xvideo}" != "no"], [
     PKG_CHECK_MODULES(XCB_XV, [xcb-xv >= 1.1.90.1], [

modules/access/Modules.am

@@ -51,3 +51,11 @@ libvlc_LTLIBRARIES += \
 	libaccess_ftp_plugin.la \
 	libaccess_fake_plugin.la \
 	$(NULL)
+
+libxcb_screen_plugin_la_SOURCES = screen/xcb.c
+libxcb_screen_plugin_la_CFLAGS = $(AM_CFLAGS) \
+	$(XCB_CFLAGS)
+libxcb_screen_plugin_la_LIBADD = $(AM_LIBADD) \
+	$(XCB_LIBS)
+libxcb_screen_plugin_la_DEPENDENCIES =
+EXTRA_LTLIBRARIES += libxcb_screen_plugin.la

modules/access/screen/xcb.c

+/**
+ * @file xcb.c
+ * @brief X11 C Bindings screen capture demux module for VLC media player
+ */
+/*****************************************************************************
+ * Copyright © 2009 Rémi Denis-Courmont
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2.0
+ * of the License, or (at your option) any later version.
+ *
+ * This library 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ ****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <stdarg.h>
+#include <xcb/xcb.h>
+#include <vlc_common.h>
+#include <vlc_demux.h>
+#include <vlc_plugin.h>
+
+#define CACHING_TEXT N_("Caching value in ms")
+#define CACHING_LONGTEXT N_( \
+    "Caching value for screen capture. " \
+    "This value should be set in milliseconds.")
+
+#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 reion 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")
+
+static int  Open (vlc_object_t *);
+static void Close (vlc_object_t *);
+
+/*
+ * Module descriptor
+ */
+vlc_module_begin ()
+    set_shortname (N_("Screen"))
+    set_description (N_("Screen capture (with X11/XCB)"))
+    set_category (CAT_INPUT)
+    set_subcategory (SUBCAT_INPUT_ACCESS)
+    set_capability ("access_demux", 0)
+    set_callbacks (Open, Close)
+
+    add_integer ("screen-caching", DEFAULT_PTS_DELAY * 1000 / CLOCK_FREQ,
+                 NULL, CACHING_TEXT, CACHING_LONGTEXT, true)
+    add_float ("screen-fps", 2.0, NULL, FPS_TEXT, FPS_LONGTEXT, true)
+    add_integer ("screen-left", 0, NULL, LEFT_TEXT, LEFT_LONGTEXT, true)
+        change_integer_range (-32768, 32767)
+        change_safe ()
+    add_integer ("screen-top", 0, NULL, LEFT_TEXT, LEFT_LONGTEXT, true)
+        change_integer_range (-32768, 32767)
+        change_safe ()
+    add_integer ("screen-width", 0, NULL, LEFT_TEXT, LEFT_LONGTEXT, true)
+        change_integer_range (0, 65535)
+        change_safe ()
+    add_integer ("screen-height", 0, NULL, LEFT_TEXT, LEFT_LONGTEXT, true)
+        change_integer_range (0, 65535)
+        change_safe ()
+
+    add_shortcut ("screen")
+    add_shortcut ("window")
+vlc_module_end ()
+
+/*
+ * Local prototypes
+ */
+static int Demux (demux_t *);
+static int Control (demux_t *, int, va_list);
+
+struct demux_sys_t
+{
+    xcb_connection_t *conn;
+    es_out_id_t      *es;
+    mtime_t           pts, interval;
+    xcb_window_t      window;
+    int16_t           x, y;
+    uint16_t          w, h;
+};
+
+/**
+ * Probes and initializes.
+ */
+static int Open (vlc_object_t *obj)
+{
+    demux_t *demux = (demux_t *)obj;
+    demux_sys_t *p_sys = malloc (sizeof (*p_sys));
+
+    if (p_sys == NULL)
+        return VLC_ENOMEM;
+
+    /* Connect to X server */
+    char *display = var_CreateGetNonEmptyString (obj, "x11-display");
+    int snum;
+    xcb_connection_t *conn = xcb_connect (display, &snum);
+    free (display);
+    if (xcb_connection_has_error (conn))
+    {
+        free (p_sys);
+        return VLC_EGENERIC;
+    }
+    p_sys->conn = conn;
+
+    /* Find configured screen */
+    const xcb_setup_t *setup = xcb_get_setup (conn);
+    xcb_screen_t *scr = NULL;
+    for (xcb_screen_iterator_t i = xcb_setup_roots_iterator (setup);
+         i.rem > 0; xcb_screen_next (&i))
+    {
+        if (snum == 0)
+        {
+            scr = i.data;
+            break;
+        }
+        snum--;
+    }
+    if (scr == NULL)
+    {
+        msg_Err (obj, "bad X11 screen number");
+        goto error;
+    }
+
+    /* Determine capture window */
+    if (!strcmp (demux->psz_access, "screen"))
+        p_sys->window = scr->root;
+    else
+    if (!strcmp (demux->psz_access, "window"))
+    {
+        char *end;
+        unsigned long ul = strtoul (demux->psz_path, &end, 0);
+        if (*end || ul > 0xffffffff)
+        {
+            msg_Err (obj, "bad X11 window %s", demux->psz_path);
+            goto error;
+        }
+        p_sys->window = ul;
+    }
+    else
+        goto error;
+
+    /* Window properties */
+    xcb_get_geometry_reply_t *geo;
+    geo = xcb_get_geometry_reply (conn,
+                                  xcb_get_geometry (conn, p_sys->window),
+                                  NULL);
+    if (geo == NULL)
+    {
+        msg_Err (obj, "bad X11 window 0x%08"PRIx32, p_sys->window);
+        goto error;
+    }
+
+    p_sys->x = var_CreateGetInteger (obj, "screen-left");
+    p_sys->y = var_CreateGetInteger (obj, "screen-top");
+    p_sys->w = var_CreateGetInteger (obj, "screen-width");
+    if (p_sys->w == 0)
+        p_sys->w = geo->width;
+    p_sys->h = var_CreateGetInteger (obj, "screen-height");
+    if (p_sys->h == 0)
+        p_sys->h = geo->height;
+
+    uint32_t chroma = 0;
+    uint8_t bpp = geo->depth;
+    for (const xcb_format_t *fmt = xcb_setup_pixmap_formats (setup),
+             *end = fmt + xcb_setup_pixmap_formats_length (setup);
+         fmt < end; fmt++)
+    {
+        if (fmt->depth != geo->depth)
+            continue;
+        switch (geo->depth)
+        {
+            case 32:
+                if (fmt->bits_per_pixel == 32)
+                    chroma = VLC_CODEC_RGBA;
+                break;
+            case 24:
+                if (fmt->bits_per_pixel == 32)
+                {
+                    chroma = VLC_CODEC_RGB32;
+                    bpp = 32;
+                }
+                else if (fmt->bits_per_pixel == 24)
+                    chroma = VLC_CODEC_RGB24;
+                break;
+            case 16:
+                if (fmt->bits_per_pixel == 16)
+                    chroma = VLC_CODEC_RGB16;
+                break;
+            case 15:
+                if (fmt->bits_per_pixel == 16)
+                    chroma = VLC_CODEC_RGB15;
+                break;
+            case 8: /* XXX: screw grey scale! */
+                if (fmt->bits_per_pixel == 8)
+                    chroma = VLC_CODEC_RGB8;
+                break;
+        }
+        if (chroma != 0)
+            break;
+    }
+    free (geo);
+
+    if (!chroma)
+    {
+        msg_Err (obj, "unsupported pixmap formats");
+        goto error;
+    }
+
+    /* Initializes format */
+    float rate = var_CreateGetFloat (obj, "screen-fps");
+    if (!rate)
+        goto error;
+    p_sys->interval = (float)CLOCK_FREQ / rate;
+    if (!p_sys->interval)
+        goto error;
+    var_Create (obj, "screen-caching", VLC_VAR_INTEGER|VLC_VAR_DOINHERIT);
+
+    es_format_t fmt;
+    es_format_Init (&fmt, VIDEO_ES, chroma);
+    fmt.video.i_chroma = chroma;
+    fmt.video.i_visible_width =
+    fmt.video.i_width = p_sys->w;
+    fmt.video.i_visible_height =
+    fmt.video.i_height = p_sys->h;
+    fmt.video.i_bits_per_pixel = bpp;
+    fmt.video.i_sar_num = fmt.video.i_sar_den = 1;
+    fmt.video.i_frame_rate = 1000 * rate;
+    fmt.video.i_frame_rate_base = 1000;
+    p_sys->es = es_out_Add (demux->out, &fmt);
+    if (p_sys->es == NULL)
+        goto error;
+    p_sys->pts = VLC_TS_INVALID;
+
+    /* Initializes demux */
+    demux->pf_demux   = Demux;
+    demux->pf_control = Control;
+    demux->p_sys      = p_sys;
+    return VLC_SUCCESS;
+
+error:
+    Close (obj);
+    return VLC_EGENERIC;
+}
+
+
+/**
+ * Releases resources
+ */
+static void Close (vlc_object_t *obj)
+{
+    demux_t *demux = (demux_t *)obj;
+    demux_sys_t *p_sys = demux->p_sys;
+
+    xcb_disconnect (p_sys->conn);
+    free (p_sys);
+}
+
+
+/**
+ * Control callback
+ */
+static int Control (demux_t *demux, int query, va_list args)
+{
+    switch (query)
+    {
+        case DEMUX_GET_POSITION:
+        {
+            float *v = va_arg (args, float *);
+            *v = 0.;
+            return VLC_SUCCESS;
+        }
+
+        case DEMUX_GET_LENGTH:
+        case DEMUX_GET_TIME:
+        {
+            int64_t *v = va_arg (args, int64_t *);
+            *v = 0;
+            return VLC_SUCCESS;
+        }
+
+        /* TODO: get title info -> crawl visible windows */
+
+        case DEMUX_GET_PTS_DELAY:
+        {
+            int64_t *v = va_arg (args, int64_t *);
+            *v = var_GetInteger (demux, "screen-caching") * UINT64_C(1000);
+            return VLC_SUCCESS;
+        }
+
+        case DEMUX_CAN_PAUSE:
+        case DEMUX_CAN_CONTROL_PACE:
+        {
+            bool *v = (bool*)va_arg( args, bool * );
+            *v = true;
+            return VLC_SUCCESS;
+        }
+
+        case DEMUX_SET_PAUSE_STATE:
+            es_out_Control (demux->out, ES_OUT_RESET_PCR);
+            return VLC_SUCCESS;
+
+        case DEMUX_CAN_CONTROL_RATE:
+        case DEMUX_CAN_SEEK:
+        {
+            bool *v = (bool*)va_arg( args, bool * );
+            *v = false;
+            return VLC_SUCCESS;
+        }
+    }
+
+    return VLC_EGENERIC;
+}
+
+
+/**
+ * Processing callback
+ */
+static int Demux (demux_t *demux)
+{
+    demux_sys_t *p_sys = demux->p_sys;
+    xcb_get_image_reply_t *img;
+
+    /* Capture screen */
+    img = xcb_get_image_reply (p_sys->conn,
+        xcb_get_image (p_sys->conn, XCB_IMAGE_FORMAT_Z_PIXMAP, p_sys->window,
+                       p_sys->x, p_sys->y, p_sys->w, p_sys->h, ~0), NULL);
+    if (img == NULL)
+    {
+        msg_Warn (demux, "no image - halting capture");
+        return 0;
+    }
+
+    /* Send block - zero copy */
+    mtime_t now = mdate ();
+    block_t *block = block_heap_Alloc (img, xcb_get_image_data (img),
+                                       xcb_get_image_data_length (img));
+    if (block == NULL)
+        return 0;
+    block->i_pts = block->i_dts = now;
+
+    es_out_Control (demux->out, ES_OUT_SET_PCR, now);
+    es_out_Send (demux->out, p_sys->es, block);
+    return 1;
+}