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ffmpeg / libavdevice / x11grab.c @ 2912e87a

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/*
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 * X11 video grab interface
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 *
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 * This file is part of Libav.
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 *
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 * Libav integration:
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 * Copyright (C) 2006 Clemens Fruhwirth <clemens@endorphin.org>
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 *                    Edouard Gomez <ed.gomez@free.fr>
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 *
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 * This file contains code from grab.c:
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 * Copyright (c) 2000-2001 Fabrice Bellard
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 *
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 * This file contains code from the xvidcap project:
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 * Copyright (C) 1997-1998 Rasca, Berlin
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 *               2003-2004 Karl H. Beckers, Frankfurt
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 *
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 * Libav is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * X11 frame device demuxer by Clemens Fruhwirth <clemens@endorphin.org>
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 * and Edouard Gomez <ed.gomez@free.fr>.
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 */
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#define _XOPEN_SOURCE 600
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#include "config.h"
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#include "libavformat/avformat.h"
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#include <time.h>
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#include <X11/X.h>
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#include <X11/Xlib.h>
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#include <X11/Xlibint.h>
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#include <X11/Xproto.h>
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#include <X11/Xutil.h>
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#include <sys/shm.h>
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#include <X11/extensions/XShm.h>
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#include <X11/extensions/Xfixes.h>
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/**
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 * X11 Device Demuxer context
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 */
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struct x11_grab
56
{
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    int frame_size;          /**< Size in bytes of a grabbed frame */
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    AVRational time_base;    /**< Time base */
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    int64_t time_frame;      /**< Current time */
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    int height;              /**< Height of the grab frame */
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    int width;               /**< Width of the grab frame */
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    int x_off;               /**< Horizontal top-left corner coordinate */
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    int y_off;               /**< Vertical top-left corner coordinate */
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    Display *dpy;            /**< X11 display from which x11grab grabs frames */
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    XImage *image;           /**< X11 image holding the grab */
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    int use_shm;             /**< !0 when using XShm extension */
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    XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
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    int nomouse;
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};
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/**
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 * Initialize the x11 grab device demuxer (public device demuxer API).
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 *
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 * @param s1 Context from avformat core
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 * @param ap Parameters from avformat core
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 * @return <ul>
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 *          <li>AVERROR(ENOMEM) no memory left</li>
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 *          <li>AVERROR(EIO) other failure case</li>
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 *          <li>0 success</li>
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 *         </ul>
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 */
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static int
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x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
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{
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    struct x11_grab *x11grab = s1->priv_data;
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    Display *dpy;
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    AVStream *st = NULL;
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    enum PixelFormat input_pixfmt;
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    XImage *image;
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    int x_off = 0;
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    int y_off = 0;
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    int use_shm;
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    char *param, *offset;
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    param = av_strdup(s1->filename);
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    offset = strchr(param, '+');
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    if (offset) {
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        sscanf(offset, "%d,%d", &x_off, &y_off);
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        x11grab->nomouse= strstr(offset, "nomouse");
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        *offset= 0;
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    }
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    av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d height: %d\n", s1->filename, param, x_off, y_off, ap->width, ap->height);
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    dpy = XOpenDisplay(param);
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    if(!dpy) {
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        av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
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        return AVERROR(EIO);
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    }
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    if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
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        av_log(s1, AV_LOG_ERROR, "AVParameters don't have video size and/or rate. Use -s and -r.\n");
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        return AVERROR(EIO);
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    }
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    st = av_new_stream(s1, 0);
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    if (!st) {
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        return AVERROR(ENOMEM);
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    }
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    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
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    use_shm = XShmQueryExtension(dpy);
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    av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");
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    if(use_shm) {
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        int scr = XDefaultScreen(dpy);
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        image = XShmCreateImage(dpy,
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                                DefaultVisual(dpy, scr),
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                                DefaultDepth(dpy, scr),
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                                ZPixmap,
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                                NULL,
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                                &x11grab->shminfo,
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                                ap->width, ap->height);
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        x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
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                                        image->bytes_per_line * image->height,
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                                        IPC_CREAT|0777);
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        if (x11grab->shminfo.shmid == -1) {
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            av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
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            return AVERROR(ENOMEM);
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        }
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        x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
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        x11grab->shminfo.readOnly = False;
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        if (!XShmAttach(dpy, &x11grab->shminfo)) {
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            av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
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            /* needs some better error subroutine :) */
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            return AVERROR(EIO);
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        }
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    } else {
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        image = XGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)),
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                          x_off,y_off,
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                          ap->width,ap->height,
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                          AllPlanes, ZPixmap);
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    }
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    switch (image->bits_per_pixel) {
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    case 8:
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        av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
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        input_pixfmt = PIX_FMT_PAL8;
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        break;
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    case 16:
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        if (       image->red_mask   == 0xf800 &&
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                   image->green_mask == 0x07e0 &&
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                   image->blue_mask  == 0x001f ) {
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            av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
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            input_pixfmt = PIX_FMT_RGB565;
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        } else if (image->red_mask   == 0x7c00 &&
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                   image->green_mask == 0x03e0 &&
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                   image->blue_mask  == 0x001f ) {
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            av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
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            input_pixfmt = PIX_FMT_RGB555;
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        } else {
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            av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
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            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);
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            return AVERROR(EIO);
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        }
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        break;
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    case 24:
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        if (        image->red_mask   == 0xff0000 &&
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                    image->green_mask == 0x00ff00 &&
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                    image->blue_mask  == 0x0000ff ) {
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            input_pixfmt = PIX_FMT_BGR24;
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        } else if ( image->red_mask   == 0x0000ff &&
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                    image->green_mask == 0x00ff00 &&
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                    image->blue_mask  == 0xff0000 ) {
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            input_pixfmt = PIX_FMT_RGB24;
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        } else {
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            av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
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            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);
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            return AVERROR(EIO);
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        }
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        break;
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    case 32:
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#if 0
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        GetColorInfo (image, &c_info);
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        if ( c_info.alpha_mask == 0xff000000 && image->green_mask == 0x0000ff00) {
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            /* byte order is relevant here, not endianness
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             * endianness is handled by avcodec, but atm no such thing
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             * as having ABGR, instead of ARGB in a word. Since we
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             * need this for Solaris/SPARC, but need to do the conversion
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             * for every frame we do it outside of this loop, cf. below
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             * this matches both ARGB32 and ABGR32 */
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            input_pixfmt = PIX_FMT_ARGB32;
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        }  else {
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            av_log(s1, AV_LOG_ERROR,"image depth %i not supported ... aborting\n", image->bits_per_pixel);
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            return AVERROR(EIO);
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        }
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#endif
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        input_pixfmt = PIX_FMT_RGB32;
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        break;
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    default:
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        av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
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        return -1;
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    }
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    x11grab->frame_size = ap->width * ap->height * image->bits_per_pixel/8;
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    x11grab->dpy = dpy;
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    x11grab->width = ap->width;
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    x11grab->height = ap->height;
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    x11grab->time_base  = ap->time_base;
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    x11grab->time_frame = av_gettime() / av_q2d(ap->time_base);
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    x11grab->x_off = x_off;
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    x11grab->y_off = y_off;
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    x11grab->image = image;
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    x11grab->use_shm = use_shm;
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    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
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    st->codec->codec_id = CODEC_ID_RAWVIDEO;
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    st->codec->width = ap->width;
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    st->codec->height = ap->height;
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    st->codec->pix_fmt = input_pixfmt;
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    st->codec->time_base = ap->time_base;
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    st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(ap->time_base) * 8;
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237
    return 0;
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}
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240
/**
241
 * Paint a mouse pointer in an X11 image.
242
 *
243
 * @param image image to paint the mouse pointer to
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 * @param s context used to retrieve original grabbing rectangle
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 *          coordinates
246
 */
247
static void
248
paint_mouse_pointer(XImage *image, struct x11_grab *s)
249
{
250
    int x_off = s->x_off;
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    int y_off = s->y_off;
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    int width = s->width;
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    int height = s->height;
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    Display *dpy = s->dpy;
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    XFixesCursorImage *xcim;
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    int x, y;
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    int line, column;
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    int to_line, to_column;
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    int pixstride = image->bits_per_pixel >> 3;
260
    /* Warning: in its insanity, xlib provides unsigned image data through a
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     * char* pointer, so we have to make it uint8_t to make things not break.
262
     * Anyone who performs further investigation of the xlib API likely risks
263
     * permanent brain damage. */
264
    uint8_t *pix = image->data;
265

    
266
    /* Code doesn't currently support 16-bit or PAL8 */
267
    if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
268
        return;
269

    
270
    xcim = XFixesGetCursorImage(dpy);
271

    
272
    x = xcim->x - xcim->xhot;
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    y = xcim->y - xcim->yhot;
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275
    to_line = FFMIN((y + xcim->height), (height + y_off));
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    to_column = FFMIN((x + xcim->width), (width + x_off));
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278
    for (line = FFMAX(y, y_off); line < to_line; line++) {
279
        for (column = FFMAX(x, x_off); column < to_column; column++) {
280
            int  xcim_addr = (line - y) * xcim->width + column - x;
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            int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
282
            int r = (uint8_t)(xcim->pixels[xcim_addr] >>  0);
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            int g = (uint8_t)(xcim->pixels[xcim_addr] >>  8);
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            int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
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            int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
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287
            if (a == 255) {
288
                pix[image_addr+0] = r;
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                pix[image_addr+1] = g;
290
                pix[image_addr+2] = b;
291
            } else if (a) {
292
                /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
293
                pix[image_addr+0] = r + (pix[image_addr+0]*(255-a) + 255/2) / 255;
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                pix[image_addr+1] = g + (pix[image_addr+1]*(255-a) + 255/2) / 255;
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                pix[image_addr+2] = b + (pix[image_addr+2]*(255-a) + 255/2) / 255;
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            }
297
        }
298
    }
299

    
300
    XFree(xcim);
301
    xcim = NULL;
302
}
303

    
304

    
305
/**
306
 * Read new data in the image structure.
307
 *
308
 * @param dpy X11 display to grab from
309
 * @param d
310
 * @param image Image where the grab will be put
311
 * @param x Top-Left grabbing rectangle horizontal coordinate
312
 * @param y Top-Left grabbing rectangle vertical coordinate
313
 * @return 0 if error, !0 if successful
314
 */
315
static int
316
xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
317
{
318
    xGetImageReply rep;
319
    xGetImageReq *req;
320
    long nbytes;
321

    
322
    if (!image) {
323
        return 0;
324
    }
325

    
326
    LockDisplay(dpy);
327
    GetReq(GetImage, req);
328

    
329
    /* First set up the standard stuff in the request */
330
    req->drawable = d;
331
    req->x = x;
332
    req->y = y;
333
    req->width = image->width;
334
    req->height = image->height;
335
    req->planeMask = (unsigned int)AllPlanes;
336
    req->format = ZPixmap;
337

    
338
    if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
339
        UnlockDisplay(dpy);
340
        SyncHandle();
341
        return 0;
342
    }
343

    
344
    nbytes = (long)rep.length << 2;
345
    _XReadPad(dpy, image->data, nbytes);
346

    
347
    UnlockDisplay(dpy);
348
    SyncHandle();
349
    return 1;
350
}
351

    
352
/**
353
 * Grab a frame from x11 (public device demuxer API).
354
 *
355
 * @param s1 Context from avformat core
356
 * @param pkt Packet holding the brabbed frame
357
 * @return frame size in bytes
358
 */
359
static int
360
x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
361
{
362
    struct x11_grab *s = s1->priv_data;
363
    Display *dpy = s->dpy;
364
    XImage *image = s->image;
365
    int x_off = s->x_off;
366
    int y_off = s->y_off;
367

    
368
    int64_t curtime, delay;
369
    struct timespec ts;
370

    
371
    /* Calculate the time of the next frame */
372
    s->time_frame += INT64_C(1000000);
373

    
374
    /* wait based on the frame rate */
375
    for(;;) {
376
        curtime = av_gettime();
377
        delay = s->time_frame * av_q2d(s->time_base) - curtime;
378
        if (delay <= 0) {
379
            if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
380
                s->time_frame += INT64_C(1000000);
381
            }
382
            break;
383
        }
384
        ts.tv_sec = delay / 1000000;
385
        ts.tv_nsec = (delay % 1000000) * 1000;
386
        nanosleep(&ts, NULL);
387
    }
388

    
389
    if (av_new_packet(pkt, s->frame_size) < 0) {
390
        return AVERROR(EIO);
391
    }
392

    
393
    pkt->pts = curtime;
394

    
395
    if(s->use_shm) {
396
        if (!XShmGetImage(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off, AllPlanes)) {
397
            av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
398
        }
399
    } else {
400
        if (!xget_zpixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {
401
            av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
402
        }
403
    }
404

    
405
    if(!s->nomouse){
406
        paint_mouse_pointer(image, s);
407
    }
408

    
409

    
410
    /* XXX: avoid memcpy */
411
    memcpy(pkt->data, image->data, s->frame_size);
412
    return s->frame_size;
413
}
414

    
415
/**
416
 * Close x11 frame grabber (public device demuxer API).
417
 *
418
 * @param s1 Context from avformat core
419
 * @return 0 success, !0 failure
420
 */
421
static int
422
x11grab_read_close(AVFormatContext *s1)
423
{
424
    struct x11_grab *x11grab = s1->priv_data;
425

    
426
    /* Detach cleanly from shared mem */
427
    if (x11grab->use_shm) {
428
        XShmDetach(x11grab->dpy, &x11grab->shminfo);
429
        shmdt(x11grab->shminfo.shmaddr);
430
        shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
431
    }
432

    
433
    /* Destroy X11 image */
434
    if (x11grab->image) {
435
        XDestroyImage(x11grab->image);
436
        x11grab->image = NULL;
437
    }
438

    
439
    /* Free X11 display */
440
    XCloseDisplay(x11grab->dpy);
441
    return 0;
442
}
443

    
444
/** x11 grabber device demuxer declaration */
445
AVInputFormat ff_x11_grab_device_demuxer =
446
{
447
    "x11grab",
448
    NULL_IF_CONFIG_SMALL("X11grab"),
449
    sizeof(struct x11_grab),
450
    NULL,
451
    x11grab_read_header,
452
    x11grab_read_packet,
453
    x11grab_read_close,
454
    .flags = AVFMT_NOFILE,
455
};