[vlc-devel] commit: XCB: support for MIT-SHM ( Rémi Denis-Courmont )
git version control
git at videolan.org
Sat Jan 24 18:00:30 CET 2009
vlc | branch: master | Rémi Denis-Courmont <rdenis at simphalempin.com> | Sat Jan 24 18:23:41 2009 +0200| [15c2fab78a080b22ed0599ad2df61f4900fe6d6a] | committer: Rémi Denis-Courmont
XCB: support for MIT-SHM
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=15c2fab78a080b22ed0599ad2df61f4900fe6d6a
---
modules/video_output/Modules.am | 7 ++-
modules/video_output/xcb/xcb.c | 132 +++++++++++++++++++++++++++++++++++----
2 files changed, 124 insertions(+), 15 deletions(-)
diff --git a/modules/video_output/Modules.am b/modules/video_output/Modules.am
index f91b892..b3be41c 100644
--- a/modules/video_output/Modules.am
+++ b/modules/video_output/Modules.am
@@ -22,13 +22,16 @@ SOURCES_yuv = yuv.c
# TODO: move to configure.ac once/if xcb plugin gets more functional
XCB_LIBS = -lxcb
+XCB_SHM_LIBS = -lxcb-shm
XCB_AUX_LIBS = -lxcb-aux
XCB_IMAGE_LIBS = -lxcb-image
libxcb_plugin_la_SOURCES = xcb/xcb.c
libxcb_plugin_la_CFLAGS = $(AM_CFLAGS) \
- $(XCB_CFLAGS) $(XCB_AUX_CFLAGS) $(XCB_IMAGE_CFLAGS)
+ $(XCB_CFLAGS) $(XCB_SHM) \
+ $(XCB_AUX_CFLAGS) $(XCB_IMAGE_CFLAGS)
libxcb_plugin_la_LIBADD = $(AM_LIBADD) \
- $(XCB_LIBS) $(XCB_AUX_LIBS) $(XCB_IMAGE_LIBS)
+ $(XCB_LIBS) $(XCB_SHM) \
+ $(XCB_AUX_LIBS) $(XCB_IMAGE_LIBS)
libxcb_plugin_la_DEPENDENCIES =
EXTRA_LTLIBRARIES += libxcb_plugin.la
diff --git a/modules/video_output/xcb/xcb.c b/modules/video_output/xcb/xcb.c
index a6d7992..f9a02cf 100644
--- a/modules/video_output/xcb/xcb.c
+++ b/modules/video_output/xcb/xcb.c
@@ -27,7 +27,12 @@
#include <stdlib.h>
#include <assert.h>
+#include <sys/types.h>
+#include <sys/shm.h>
+
#include <xcb/xcb.h>
+#include <xcb/shm.h>
+
#include <xcb/xcb_aux.h>
#include <xcb/xcb_image.h>
@@ -41,6 +46,10 @@
"X11 hardware display to use. By default VLC will " \
"use the value of the DISPLAY environment variable.")
+#define SHM_TEXT N_("Use shared memory")
+#define SHM_LONGTEXT N_( \
+ "Use shared memory to communicate between VLC and the X server.")
+
static int Open (vlc_object_t *);
static void Close (vlc_object_t *);
@@ -57,6 +66,7 @@ vlc_module_begin ()
add_string ("x11-display", NULL, NULL,
DISPLAY_TEXT, DISPLAY_LONGTEXT, true)
+ add_bool ("x11-shm", true, NULL, SHM_TEXT, SHM_LONGTEXT, true)
vlc_module_end ()
struct vout_sys_t
@@ -69,6 +79,7 @@ struct vout_sys_t
xcb_window_t parent; /* parent X window */
xcb_window_t window; /* drawable X window */
xcb_gcontext_t gc; /* context to put images */
+ bool shm; /* whether to use MIT-SHM */
uint8_t bpp; /* bits per pixel */
};
@@ -151,6 +162,23 @@ static int Open (vlc_object_t *obj)
}
p_sys->vid = vt->visual_id;
+ p_sys->shm = var_CreateGetBool (vout, "x11-shm") > 0;
+ if (p_sys->shm)
+ {
+ xcb_shm_query_version_cookie_t ck;
+ xcb_shm_query_version_reply_t *r;
+ xcb_generic_error_t *err;
+
+ ck = xcb_shm_query_version (p_sys->conn);
+ r = xcb_shm_query_version_reply (p_sys->conn, ck, &err);
+ if (!r)
+ {
+ msg_Err (vout, "shared memory (MIT-SHM) not available");
+ msg_Warn (vout, "display will be slow");
+ p_sys->shm = false;
+ }
+ }
+
vout->pf_init = Init;
vout->pf_end = Deinit;
vout->pf_display = Display;
@@ -179,10 +207,14 @@ static void Close (vlc_object_t *obj)
struct picture_sys_t
{
+ xcb_connection_t *conn;
xcb_image_t *image;
+ xcb_shm_seg_t segment;
};
static void PictureRelease (picture_t *pic);
+static void PictureShmRelease (picture_t *pic);
+#define SHM_ERR ((void *)(intptr_t)(-1))
static int PictureInit (vout_thread_t *vout, picture_t *pic)
{
@@ -197,6 +229,43 @@ static int PictureInit (vout_thread_t *vout, picture_t *pic)
vout->output.i_width, vout->output.i_height,
vout->output.i_aspect);
+ void *shm = SHM_ERR;
+ const size_t size = pic->p->i_pitch * pic->p->i_lines;
+
+ if (p_sys->shm)
+ { /* Allocate shared memory segment */
+ int id = shmget (IPC_PRIVATE, size, IPC_CREAT | 0700);
+
+ if (id == -1)
+ {
+ msg_Err (vout, "shared memory allocation error: %m");
+ goto error;
+ }
+
+ /* Attach the segment to VLC */
+ shm = shmat (id, NULL, 0 /* read/write */);
+ if (shm == SHM_ERR)
+ {
+ msg_Err (vout, "shared memory attachment error: %m");
+ shmctl (id, IPC_RMID, 0);
+ goto error;
+ }
+
+ /* Attach the segment to X */
+ xcb_void_cookie_t ck;
+
+ priv->segment = xcb_generate_id (p_sys->conn);
+ ck = xcb_shm_attach_checked (p_sys->conn, priv->segment, id, 1);
+ shmctl (id, IPC_RMID, 0);
+
+ if (CheckError (vout, "shared memory server-side error", ck))
+ {
+ msg_Info (vout, "using buggy X (remote) server? SSH?");
+ shmdt (shm);
+ shm = SHM_ERR;
+ }
+ }
+
const unsigned real_width = pic->p->i_pitch / (p_sys->bpp >> 3);
/* FIXME: anyway to getthing more intuitive than that?? */
@@ -211,20 +280,36 @@ static int PictureInit (vout_thread_t *vout, picture_t *pic)
XCB_IMAGE_ORDER_LSB_FIRST,
#endif
XCB_IMAGE_ORDER_MSB_FIRST,
- NULL, 0, NULL);
+ NULL,
+ (shm != SHM_ERR) ? size : 0,
+ (shm != SHM_ERR) ? shm : NULL);
if (img == NULL)
+ {
+ if (shm != SHM_ERR)
+ xcb_shm_detach (p_sys->conn, priv->segment);
+ goto error;
+ }
+ if (shm != SHM_ERR && xcb_image_native (p_sys->conn, img, 0) == NULL)
+ {
+ msg_Err (vout, "incompatible X server image format");
+ xcb_image_destroy (img);
goto error;
+ }
+ priv->conn = p_sys->conn;
priv->image = img;
pic->p_sys = priv;
pic->p->p_pixels = img->data;
- pic->pf_release = PictureRelease;
+ pic->pf_release = (shm != SHM_ERR) ? PictureShmRelease
+ : PictureRelease;
pic->i_status = DESTROYED_PICTURE;
pic->i_type = DIRECT_PICTURE;
return VLC_SUCCESS;
error:
+ if (shm != SHM_ERR)
+ shmdt (shm);
free (p_sys);
return VLC_EGENERIC;
}
@@ -242,6 +327,18 @@ static void PictureRelease (picture_t *pic)
}
/**
+ * Release shared memory picture private data
+ */
+static void PictureShmRelease (picture_t *pic)
+{
+ struct picture_sys_t *p_sys = pic->p_sys;
+
+ xcb_shm_detach (p_sys->conn, p_sys->segment);
+ shmdt (p_sys->image->data);
+ PictureRelease (pic);
+}
+
+/**
* Allocate drawable window and picture buffers.
*/
static int Init (vout_thread_t *vout)
@@ -364,23 +461,32 @@ static void Deinit (vout_thread_t *vout)
static void Display (vout_thread_t *vout, picture_t *pic)
{
vout_sys_t *p_sys = vout->p_sys;
- xcb_image_t *img = pic->p_sys->image;
- xcb_image_t *native = xcb_image_native (p_sys->conn, img, 1);
+ picture_sys_t *priv = pic->p_sys;
+ xcb_image_t *img = priv->image;
- if (native == NULL)
+ if (img->base == NULL)
{
- msg_Err (vout, "image conversion failure");
- return;
+ xcb_shm_segment_info_t info = {
+ .shmseg = priv->segment,
+ .shmid = -1, /* lost track of it, unimportant */
+ .shmaddr = img->data,
+ };
+
+ xcb_image_shm_put (p_sys->conn, p_sys->window, p_sys->gc, img, info,
+ 0, 0, 0, 0, img->width, img->height, 0);
}
+ else
+ {
+ xcb_image_t *native = xcb_image_native (p_sys->conn, img, 1);
- xcb_image_put (p_sys->conn, p_sys->window, p_sys->gc, native, 0, 0, 0);
- xcb_flush (p_sys->conn);
+ if (native == NULL)
+ return;
- if (native != img)
- {
- /*msg_Warn (vout, "image not in native X11 pixmap format");*/
- xcb_image_destroy (native);
+ xcb_image_put (p_sys->conn, p_sys->window, p_sys->gc, native, 0, 0, 0);
+ if (native != img)
+ xcb_image_destroy (native);
}
+ xcb_flush (p_sys->conn);
}
/**
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