[Ffmpeg-devel] [RFC] X11 device demuxer

Edouard Gomez ed.gomez
Tue Nov 14 21:43:23 CET 2006


Adds X11 frame demuxer capabilities.

It's still rough on some edges. There is a quite nasty bit in
the way it gets integrated in ffmpeg.c. I send this for review
as i would like it to be included upstream eventually.

diff -r 246a0ffe5bef -r 1ef5eaa16613 configure
--- a/configure	Tue Nov 14 20:00:55 2006 +0000
+++ b/configure	Tue Nov 14 21:38:29 2006 +0100
@@ -1622,6 +1622,15 @@ struct v4l2_buffer dummy1;
 struct v4l2_buffer dummy1;
 EOF
 
+# Deal with the x11 frame grabber
+enabled gpl || disable x11_grab_device_demuxer
+check_header X11/X.h || disable x11_grab_device_demuxer
+check_header X11/Xlib.h || disable x11_grab_device_demuxer
+check_header X11/Xlibint.h || disable x11_grab_device_demuxer
+check_header X11/Xproto.h || disable x11_grab_device_demuxer
+check_header X11/extensions/XShm.h || disable x11_grab_device_demuxer
+enabled x11_grab_device_demuxer && add_extralibs "-lX11 -lXext"
+
 enabled debug && add_cflags -g
 
 # add some useful compiler flags if supported
diff -r 246a0ffe5bef -r 1ef5eaa16613 ffmpeg.c
--- a/ffmpeg.c	Tue Nov 14 20:00:55 2006 +0000
+++ b/ffmpeg.c	Tue Nov 14 21:38:29 2006 +0100
@@ -3244,6 +3244,10 @@ static void prepare_grab(void)
 
     if (has_video) {
         AVInputFormat *fmt1;
+#warning FIXME: find a better interface
+	if(!strncmp(video_device,"x11:",4)) {
+	  video_grab_format="x11grab";
+	}
         fmt1 = av_find_input_format(video_grab_format);
         vp->device  = video_device;
         vp->channel = video_channel;
diff -r 246a0ffe5bef -r 1ef5eaa16613 libavformat/Makefile
--- a/libavformat/Makefile	Tue Nov 14 20:00:55 2006 +0000
+++ b/libavformat/Makefile	Tue Nov 14 21:38:29 2006 +0100
@@ -123,6 +123,7 @@ OBJS-$(CONFIG_WSAUD_DEMUXER)            
 OBJS-$(CONFIG_WSAUD_DEMUXER)             += westwood.o
 OBJS-$(CONFIG_WSVQA_DEMUXER)             += westwood.o
 OBJS-$(CONFIG_WV_DEMUXER)                += wv.o
+OBJS-$(CONFIG_X11_GRAB_DEVICE_DEMUXER)   += x11grab.o
 OBJS-$(CONFIG_YUV4MPEGPIPE_MUXER)        += yuv4mpeg.o
 OBJS-$(CONFIG_YUV4MPEGPIPE_DEMUXER)      += yuv4mpeg.o
 
diff -r 246a0ffe5bef -r 1ef5eaa16613 libavformat/allformats.c
--- a/libavformat/allformats.c	Tue Nov 14 20:00:55 2006 +0000
+++ b/libavformat/allformats.c	Tue Nov 14 21:38:29 2006 +0100
@@ -71,6 +71,9 @@ void av_register_all(void)
 #ifdef CONFIG_AU_MUXER
     av_register_output_format(&au_muxer);
 #endif
+#ifdef CONFIG_X11_GRAB_DEVICE_DEMUXER
+    av_register_input_format(&x11_grab_device_demuxer);
+#endif
 #if defined(CONFIG_AUDIO_OSS) || defined(CONFIG_AUDIO_BEOS)
 #ifdef CONFIG_AUDIO_DEMUXER
     av_register_input_format(&audio_demuxer);
diff -r 246a0ffe5bef -r 1ef5eaa16613 libavformat/allformats.h
--- a/libavformat/allformats.h	Tue Nov 14 20:00:55 2006 +0000
+++ b/libavformat/allformats.h	Tue Nov 14 21:38:29 2006 +0100
@@ -163,6 +163,7 @@ extern AVOutputFormat yuv4mpegpipe_muxer
 extern AVOutputFormat yuv4mpegpipe_muxer;
 extern AVInputFormat yuv4mpegpipe_demuxer;
 extern AVInputFormat tiertexseq_demuxer;
+extern AVInputFormat x11_grab_device_demuxer;
 
 /* raw.c */
 int pcm_read_seek(AVFormatContext *s,
diff -r 246a0ffe5bef -r 1ef5eaa16613 libavformat/x11grab.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libavformat/x11grab.c	Tue Nov 14 21:38:29 2006 +0100
@@ -0,0 +1,527 @@
+/*
+ * X11 video grab interface
+ * Copyright (C) 2006 Clemens Fruhwirth
+ *
+ * A quick note on licensing. This file is a mixture of LGPL code
+ * (ffmpeg) and GPL code (xvidcap). The result is a file that must
+ * abid both licenses. As they are compatible and GPL is more
+ * strict, this code has an "effective" GPL license.
+ * 
+ * This file contains code from grab.c:
+ * Copyright (c) 2000, 2001 Fabrice Bellard 
+ *
+ * This library 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 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
+ * Lesser 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * This file contains code from the xvidcap project:
+ * Copyright (C) 1997-98 Rasca, Berlin
+ * Copyright (C) 2003,04 Karl H. Beckers, Frankfurt
+ *
+ * This program 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 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "avformat.h"
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#define _LINUX_TIME_H 1
+#include <time.h>
+#include <X11/X.h>
+#include <X11/Xlib.h>
+#include <X11/Xlibint.h>
+#include <X11/Xproto.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <X11/extensions/XShm.h>
+
+typedef struct
+{
+	Display *dpy;
+	int frame_format;
+	int frame_size;
+	int frame_rate;
+	int frame_rate_base;
+	int64_t time_frame;
+
+	int height;
+	int width;
+	int x_off;
+	int y_off;
+	XImage *image;
+	int use_shm;
+	XShmSegmentInfo shminfo;
+	int mouse_wanted;
+} X11Grab;
+
+static int
+x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
+{
+	X11Grab *x11grab = s1->priv_data;
+	Display *dpy;
+	AVStream *st = NULL;
+	int width, height;
+	int frame_rate, frame_rate_base, frame_size;
+	int input_pixfmt;
+	XImage *image;
+	int x_off=0; int y_off = 0;
+	int use_shm;
+
+	dpy = XOpenDisplay(NULL);
+	if(!dpy) {
+		goto fail;
+	}
+
+	sscanf(ap->device, "x11:%d,%d", &x_off, &y_off);
+	av_log(s1, AV_LOG_INFO, "device: %s -> x: %d y: %d width: %d height: %d\n", ap->device, x_off, y_off, ap->width, ap->height);
+  
+	if (!ap || ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
+		av_log(s1, AV_LOG_ERROR, "AVParameters don't have any video size. Use -s.\n");
+		return AVERROR_IO;  
+	}
+
+	width = ap->width;
+	height = ap->height;
+	frame_rate = ap->time_base.den;
+	frame_rate_base = ap->time_base.num;
+
+	st = av_new_stream(s1, 0);
+	if (!st) {
+		return -ENOMEM;
+	}
+	av_set_pts_info(st, 48, 1, 1000000); /* 48 bits pts in us */
+
+	use_shm = XShmQueryExtension(dpy);
+	av_log(s1, AV_LOG_INFO, "shared memory extension %s\n", use_shm ? "found" : "not found");
+
+	if(use_shm) {
+		int scr = XDefaultScreen(dpy);
+		image = XShmCreateImage(dpy,
+					DefaultVisual(dpy,scr),
+					DefaultDepth(dpy,scr),
+					ZPixmap,
+					NULL,
+					&x11grab->shminfo,
+					ap->width, ap->height);
+		x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
+						image->bytes_per_line * image->height,
+						IPC_CREAT|0777);
+		if (x11grab->shminfo.shmid == -1) {
+			av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
+			return -ENOMEM;
+		}
+		x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
+		x11grab->shminfo.readOnly = False;
+            
+		if (!XShmAttach(dpy, &x11grab->shminfo)) {
+			av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
+			/* needs some better error subroutine :) */
+			return AVERROR_IO;  
+		}
+	} else {
+		image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
+				  x_off,y_off,
+				  ap->width,ap->height,
+				  AllPlanes, ZPixmap); 
+	}
+  
+	switch (image->bits_per_pixel) {
+	case 8:
+		av_log (s1, AV_LOG_DEBUG, "8 bit pallete\n");
+		input_pixfmt = PIX_FMT_PAL8;
+		break;
+	case 16:
+		if ( image->red_mask == 0xF800 && image->green_mask == 0x07E0
+		     && image->blue_mask == 0x1F ) {
+			av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
+			input_pixfmt = PIX_FMT_RGB565;
+		} else if ( image->red_mask == 0x7C00 && 
+			    image->green_mask == 0x03E0 && 
+			    image->blue_mask == 0x1F ) {
+			av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
+			input_pixfmt = PIX_FMT_RGB555;
+		} else {
+			av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
+			av_log(s1, AV_LOG_ERROR, "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n", image->red_mask, image->green_mask, image->blue_mask);
+			return AVERROR_IO;  
+		}
+		break;
+	case 24:
+		if ( image->red_mask == 0xFF0000 && 
+		     image->green_mask == 0xFF00
+		     && image->blue_mask == 0xFF ) {
+			input_pixfmt = PIX_FMT_BGR24;
+		} else if ( image->red_mask == 0xFF && image->green_mask == 0xFF00
+			    && image->blue_mask == 0xFF0000 ) {
+			input_pixfmt = PIX_FMT_RGB24;
+		} else {
+			av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
+			av_log(s1, AV_LOG_ERROR, "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n", image->red_mask, image->green_mask, image->blue_mask);
+			return AVERROR_IO;  
+		}
+		break;
+	case 32:
+#if 0
+		GetColorInfo (image, &c_info);
+		if ( c_info.alpha_mask == 0xFF000000 && image->green_mask == 0xFF00 ) {
+			/* byte order is relevant here, not endianness
+			 * endianness is handled by avcodec, but atm no such thing
+			 * as having ABGR, instead of ARGB in a word. Since we
+			 * need this for Solaris/SPARC, but need to do the conversion
+			 * for every frame we do it outside of this loop, cf. below
+			 * this matches both ARGB32 and ABGR32 */
+			input_pixfmt = PIX_FMT_ARGB32;
+		}  else {
+			av_log(s1, AV_LOG_ERROR,"image depth %i not supported ... aborting\n", image->bits_per_pixel);
+			return AVERROR_IO;  
+		}
+#endif
+		input_pixfmt = PIX_FMT_RGBA32;
+		break;
+	default:
+		av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
+		return -1;
+	}
+
+	frame_size = width * height * image->bits_per_pixel/8;
+	x11grab->frame_size = frame_size;
+	x11grab->dpy = dpy;
+	x11grab->width = ap->width;
+	x11grab->height = ap->height;
+	x11grab->frame_rate      = frame_rate;
+	x11grab->frame_rate_base = frame_rate_base;
+	x11grab->time_frame = av_gettime() * frame_rate / frame_rate_base;
+	x11grab->x_off = x_off;
+	x11grab->y_off = y_off;
+	x11grab->image = image;
+	x11grab->use_shm = use_shm;
+	x11grab->mouse_wanted = 1;
+
+	st->codec->codec_type = CODEC_TYPE_VIDEO;
+	st->codec->codec_id = CODEC_ID_RAWVIDEO;
+	st->codec->width = width;
+	st->codec->height = height;
+	st->codec->pix_fmt = input_pixfmt;
+	st->codec->time_base.den = frame_rate;
+	st->codec->time_base.num = frame_rate_base;
+	st->codec->bit_rate = frame_size * 1/av_q2d(st->codec->time_base) * 8;
+  
+	return 0;
+fail:
+	av_free(st);
+	return AVERROR_IO;  
+}
+
+static uint16_t mousePointerBlack[] =
+{
+	0, 49152, 40960, 36864, 34816, 33792, 33280, 33024, 32896, 32832,
+	33728, 37376, 43264, 51456, 1152, 1152, 576, 576, 448, 0
+};
+
+static uint16_t mousePointerWhite[] =
+{
+	0, 0, 16384, 24576, 28672, 30720, 31744, 32256, 32512, 32640, 31744,
+	27648, 17920, 1536, 768, 768, 384, 384, 0, 0
+};
+
+static void
+getCurrentPointer(AVFormatContext *s1, X11Grab *s, int *x, int *y)
+{
+	Window mrootwindow, childwindow;
+	int dummy;
+	Display *dpy = s->dpy;
+  
+	mrootwindow = DefaultRootWindow(dpy);
+  
+	if (XQueryPointer(dpy, mrootwindow, &mrootwindow, &childwindow,
+			  x, y, &dummy, &dummy, (unsigned int*)&dummy)) {
+	} else {
+		av_log(s1, AV_LOG_INFO, "couldn't find mouse pointer\n");
+		*x = -1;
+		*y = -1;
+	}
+}
+
+static void
+paintMousePointer(AVFormatContext *s1, X11Grab *s, int *x, int *y, XImage *image)
+{
+	int x_off = s->x_off;
+	int y_off = s->y_off;
+	int width = s->width;
+	int height = s->height;
+
+	if (   (*x - x_off) >= 0 && *x < (width + x_off)
+	    && (*y - y_off) >= 0 && *y < (height + y_off) ) { 
+		int line;
+		uint8_t *im_data = (uint8_t*)image->data;
+    
+		im_data += (image->bytes_per_line * (*y - y_off)); // shift to right line
+		im_data += (image->bits_per_pixel / 8 * (*x - x_off)); // shift to right pixel
+    
+		switch(image->bits_per_pixel) {
+		case 32: 
+		{
+			uint32_t *cursor;
+			int width_cursor;
+			uint16_t bm_b, bm_w, mask;
+      
+			for (line = 0; line < min(20, (y_off + height) - *y); line++ ) {
+				if (s->mouse_wanted == 1) {
+					bm_b = mousePointerBlack[line];
+					bm_w = mousePointerWhite[line];
+				} else {
+					bm_b = mousePointerWhite[line];
+					bm_w = mousePointerBlack[line];
+				}
+				mask = ( 0x0001 << 15 );
+	  
+				for (cursor = (uint32_t*) im_data, width_cursor = 0; 
+				     ((width_cursor + *x) < (width + x_off) && width_cursor < 16);
+				     cursor++, width_cursor++) {
+					if ( ( bm_b & mask ) > 0 ) {
+						*cursor &= ((~ image->red_mask) & (~ image->green_mask) & (~image->blue_mask ));
+					} else if ( ( bm_w & mask ) > 0 ) {
+						*cursor |= (image->red_mask | image->green_mask | image->blue_mask );
+					}
+					mask >>= 1;
+				}
+				im_data += image->bytes_per_line;
+			}
+		}
+		break;
+/* A bunch of "i don't want to support" colorspaces */
+#if 0
+		case 24:
+			/* Is 24bit possible at all ? */
+			av_log(s1, AV_LOG_ERROR, "input image bits_per_pixel %i not implemented with mouse pointer capture ... aborting!\n",
+				image->bits_per_pixel);
+			av_log(s1, AV_LOG_ERROR, "Please file a bug at http://www.sourceforge.net/projects/xvidcap/\n");
+			exit(1);
+			break;
+		case 16: {
+			uint16_t *cursor;
+			int width;
+			uint16_t bm_b, bm_w, mask;
+                
+			for (line = 0; line < 16; line++ ) {
+				if (mjob->mouseWanted == 1) {
+					bm_b = mousePointerBlack[line];
+					bm_w = mousePointerWhite[line];
+				} else {
+					bm_b = mousePointerWhite[line];
+					bm_w = mousePointerBlack[line];
+				}
+				mask = ( 0x0001 << 15 );
+                    
+				for (cursor = (uint16_t*) im_data, width = 0;
+				     ((width + *x) < (mjob->area->width + mjob->area->x)&&width < 6);
+				     cursor++, width++) {
+					if ( ( bm_b & mask ) > 0 ) {
+						*cursor &= ((~ image->red_mask) & (~ image->green_mask) & (~
+													   image->blue_mask ));
+					} else if ( ( bm_w & mask ) > 0 ) {
+						*cursor |= (image->red_mask | image->green_mask | image->blue_mask );
+					}
+					mask >>= 1;
+                        
+				}
+				im_data += image->bytes_per_line;
+			}
+		}
+			break;
+		case 8: {
+			uint8_t *cursor;
+			int width;
+			uint16_t bm_b, bm_w, mask;
+                
+			for (line = 0; line < 16; line++ ) {
+				if (mjob->mouseWanted == 1) {
+					bm_b = mousePointerBlack[line];
+					bm_w = mousePointerWhite[line];
+				} else {
+					bm_b = mousePointerWhite[line];
+					bm_w = mousePointerBlack[line];
+				}
+				mask = ( 0x0001 << 15 );
+                    
+				for (cursor = im_data, width = 0;
+				     ((width + *x) < (mjob->area->width + mjob->area->x)&&width < 6);
+				     cursor++, width++) {
+					//							Boolean pointer_b_bit, pointer_w_bit;
+                        
+					//							pointer_b_bit = ( ( bm_b & mask ) > 0 );
+					//							pointer_w_bit = ( ( bm_w & mask ) > 0 );
+					//							printf("%i ", pointer_b_bit, pointer_w_bit );
+                        
+					if ( ( bm_b & mask ) > 0 ) {
+						*cursor = 0;
+					} else if ( ( bm_w & mask ) > 0 ) {
+						*cursor = 1;
+					}
+					mask >>= 1;
+                        
+				}
+				//						printf("\n");
+                    
+				im_data += image->bytes_per_line;
+			}
+		}
+			break;
+		default:
+			av_log(s1, AV_LOG_ERROR, "input image bits_per_pixel %i not supported with mouse pointer capture ... aborting!\n",
+			       image->bits_per_pixel);
+			exit(1);
+                
+#endif        
+		}
+	}
+}
+
+
+/*
+ * just read new data in the image structure, the image
+ * structure inclusive the data area must be allocated before
+ */
+static int
+XGetZPixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
+{
+	xGetImageReply rep;
+	xGetImageReq *req;
+	long nbytes;
+  
+	if (!image) {
+		return False;
+	}
+
+	LockDisplay(dpy);
+	GetReq(GetImage, req);
+
+	/* First set up the standard stuff in the request */
+	req->drawable = d;
+	req->x = x;
+	req->y = y;
+	req->width = image->width;
+	req->height = image->height;
+	req->planeMask = (unsigned int)AllPlanes;
+	req->format = ZPixmap;
+  
+	if (!_XReply(dpy, (xReply *) &rep, 0, xFalse) || !rep.length) {
+		UnlockDisplay(dpy);
+		SyncHandle();
+		return False;
+	}
+  
+	nbytes = (long)rep.length << 2;
+	_XReadPad(dpy, image->data, nbytes);
+  
+	UnlockDisplay(dpy);
+	SyncHandle();
+	return True;
+}
+
+static int x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
+{
+	X11Grab *s = s1->priv_data;
+	Display *dpy = s->dpy;
+	XImage *image = s->image;
+	int x_off = s->x_off;
+	int y_off = s->y_off;
+
+	int64_t curtime, delay;
+	struct timespec ts;
+  
+	/* Calculate the time of the next frame */
+	s->time_frame += int64_t_C(1000000);
+  
+	/* wait based on the frame rate */
+	for(;;) {
+		curtime = av_gettime();
+		delay = s->time_frame  * s->frame_rate_base / s->frame_rate - curtime;
+		if (delay <= 0) {
+			if (delay < int64_t_C(-1000000) * s->frame_rate_base / s->frame_rate) {
+				s->time_frame += int64_t_C(1000000);
+			}
+			break;
+		}    
+		ts.tv_sec = delay / 1000000;
+		ts.tv_nsec = (delay % 1000000) * 1000;
+		nanosleep(&ts, NULL);
+	}
+  
+	if (av_new_packet(pkt, s->frame_size) < 0) {
+		return AVERROR_IO;
+	}
+  
+	pkt->pts = curtime & ((1LL << 48) - 1);
+  
+	if(s->use_shm) {
+		if (!XShmGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off, AllPlanes)) {
+			av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
+		}
+	} else {
+		if (!XGetZPixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {
+			av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
+		}
+	}
+
+	{
+		int pointer_x, pointer_y;
+		getCurrentPointer(s1, s, &pointer_x, &pointer_y);
+		paintMousePointer(s1, s, &pointer_x, &pointer_y, image);
+	}
+
+
+	/* XXX: avoid memcpy */
+	memcpy(pkt->data, image->data, s->frame_size);
+	return s->frame_size;
+}
+
+static int x11grab_read_close(AVFormatContext *s1)
+{
+	X11Grab *x11grab = s1->priv_data;
+
+	/* Free shared mem if necessary */
+	if (x11grab->use_shm) {
+		shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
+	}
+
+	/* Free X11 display */
+	XCloseDisplay(x11grab->dpy);
+	return 0;
+}
+
+AVInputFormat x11_grab_device_demuxer =
+{
+	"x11grab",
+	"X11grab",
+	sizeof(X11Grab),
+	NULL,
+	x11grab_read_header,
+	x11grab_read_packet,
+	x11grab_read_close,
+	.flags = AVFMT_NOFILE,
+};





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