PeerStreamer

/*

 * X11 video grab interface

 *

 * This file is part of Libav.

 *

 * Libav integration:

 * Copyright (C) 2006 Clemens Fruhwirth <clemens@endorphin.org>

 *                    Edouard Gomez <ed.gomez@free.fr>

 *

 * This file contains code from grab.c:

 * Copyright (c) 2000-2001 Fabrice Bellard

 *

 * This file contains code from the xvidcap project:

 * Copyright (C) 1997-1998 Rasca, Berlin

 *               2003-2004 Karl H. Beckers, Frankfurt

 *

 * Libav 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.

 *

 * Libav 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 Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * X11 frame device demuxer by Clemens Fruhwirth <clemens@endorphin.org>

 * and Edouard Gomez <ed.gomez@free.fr>.

 */

#define _XOPEN_SOURCE 600

#include "config.h"

#include "libavformat/avformat.h"

#include <time.h>

#include <X11/X.h>

#include <X11/Xlib.h>

#include <X11/Xlibint.h>

#include <X11/Xproto.h>

#include <X11/Xutil.h>

#include <sys/shm.h>

#include <X11/extensions/XShm.h>

#include <X11/extensions/Xfixes.h>

/**

 * X11 Device Demuxer context

 */

struct x11_grab

{

    int frame_size;          /**< Size in bytes of a grabbed frame */

    AVRational time_base;    /**< Time base */

    int64_t time_frame;      /**< Current time */

    int height;              /**< Height of the grab frame */

    int width;               /**< Width of the grab frame */

    int x_off;               /**< Horizontal top-left corner coordinate */

    int y_off;               /**< Vertical top-left corner coordinate */

    Display *dpy;            /**< X11 display from which x11grab grabs frames */

    XImage *image;           /**< X11 image holding the grab */

    int use_shm;             /**< !0 when using XShm extension */

    XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */

    int nomouse;

};

/**

 * Initialize the x11 grab device demuxer (public device demuxer API).

 *

 * @param s1 Context from avformat core

 * @param ap Parameters from avformat core

 * @return <ul>

 *          <li>AVERROR(ENOMEM) no memory left</li>

 *          <li>AVERROR(EIO) other failure case</li>

 *          <li>0 success</li>

 *         </ul>

 */

static int

x11grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)

{

    struct x11_grab *x11grab = s1->priv_data;

    Display *dpy;

    AVStream *st = NULL;

    enum PixelFormat input_pixfmt;

    XImage *image;

    int x_off = 0;

    int y_off = 0;

    int use_shm;

    char *param, *offset;

    param = av_strdup(s1->filename);

    offset = strchr(param, '+');

    if (offset) {

        sscanf(offset, "%d,%d", &x_off, &y_off);

        x11grab->nomouse= strstr(offset, "nomouse");

        *offset= 0;

    }

    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);

    dpy = XOpenDisplay(param);

    if(!dpy) {

        av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");

        return AVERROR(EIO);

    }

    if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {

        av_log(s1, AV_LOG_ERROR, "AVParameters don't have video size and/or rate. Use -s and -r.\n");

        return AVERROR(EIO);

    }

    st = av_new_stream(s1, 0);

    if (!st) {

        return AVERROR(ENOMEM);

    }

    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */

    use_shm = XShmQueryExtension(dpy);

    av_log(s1, AV_LOG_INFO, "shared memory extension %s found\n", use_shm ? "" : "not");

    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 AVERROR(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(EIO);

        }

    } 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 palette\n");

        input_pixfmt = PIX_FMT_PAL8;

        break;

    case 16:

        if (       image->red_mask   == 0xf800 &&

                   image->green_mask == 0x07e0 &&

                   image->blue_mask  == 0x001f ) {

            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  == 0x001f ) {

            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(EIO);

        }

        break;

    case 24:

        if (        image->red_mask   == 0xff0000 &&

                    image->green_mask == 0x00ff00 &&

                    image->blue_mask  == 0x0000ff ) {

            input_pixfmt = PIX_FMT_BGR24;

        } else if ( image->red_mask   == 0x0000ff &&

                    image->green_mask == 0x00ff00 &&

                    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(EIO);

        }

        break;

    case 32:

#if 0

        GetColorInfo (image, &c_info);

        if ( c_info.alpha_mask == 0xff000000 && image->green_mask == 0x0000ff00) {

            /* 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(EIO);

        }

#endif

        input_pixfmt = PIX_FMT_RGB32;

        break;

    default:

        av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);

        return -1;

    }

    x11grab->frame_size = ap->width * ap->height * image->bits_per_pixel/8;

    x11grab->dpy = dpy;

    x11grab->width = ap->width;

    x11grab->height = ap->height;

    x11grab->time_base  = ap->time_base;

    x11grab->time_frame = av_gettime() / av_q2d(ap->time_base);

    x11grab->x_off = x_off;

    x11grab->y_off = y_off;

    x11grab->image = image;

    x11grab->use_shm = use_shm;

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codec->codec_id = CODEC_ID_RAWVIDEO;

    st->codec->width = ap->width;

    st->codec->height = ap->height;

    st->codec->pix_fmt = input_pixfmt;

    st->codec->time_base = ap->time_base;

    st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(ap->time_base) * 8;

    return 0;

}

/**

 * Paint a mouse pointer in an X11 image.

 *

 * @param image image to paint the mouse pointer to

 * @param s context used to retrieve original grabbing rectangle

 *          coordinates

 */

static void

paint_mouse_pointer(XImage *image, struct x11_grab *s)

{

    int x_off = s->x_off;

    int y_off = s->y_off;

    int width = s->width;

    int height = s->height;

    Display *dpy = s->dpy;

    XFixesCursorImage *xcim;

    int x, y;

    int line, column;

    int to_line, to_column;

    int pixstride = image->bits_per_pixel >> 3;

    /* Warning: in its insanity, xlib provides unsigned image data through a

     * char* pointer, so we have to make it uint8_t to make things not break.

     * Anyone who performs further investigation of the xlib API likely risks

     * permanent brain damage. */

    uint8_t *pix = image->data;

    /* Code doesn't currently support 16-bit or PAL8 */

    if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)

        return;

    xcim = XFixesGetCursorImage(dpy);

    x = xcim->x - xcim->xhot;

    y = xcim->y - xcim->yhot;

    to_line = FFMIN((y + xcim->height), (height + y_off));

    to_column = FFMIN((x + xcim->width), (width + x_off));

    for (line = FFMAX(y, y_off); line < to_line; line++) {

        for (column = FFMAX(x, x_off); column < to_column; column++) {

            int  xcim_addr = (line - y) * xcim->width + column - x;

            int image_addr = ((line - y_off) * width + column - x_off) * pixstride;

            int r = (uint8_t)(xcim->pixels[xcim_addr] >>  0);

            int g = (uint8_t)(xcim->pixels[xcim_addr] >>  8);

            int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);

            int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);

            if (a == 255) {

                pix[image_addr+0] = r;

                pix[image_addr+1] = g;

                pix[image_addr+2] = b;

            } else if (a) {

                /* pixel values from XFixesGetCursorImage come premultiplied by alpha */

                pix[image_addr+0] = r + (pix[image_addr+0]*(255-a) + 255/2) / 255;

                pix[image_addr+1] = g + (pix[image_addr+1]*(255-a) + 255/2) / 255;

                pix[image_addr+2] = b + (pix[image_addr+2]*(255-a) + 255/2) / 255;

            }

        }

    }

    XFree(xcim);

    xcim = NULL;

}

/**

 * Read new data in the image structure.

 *

 * @param dpy X11 display to grab from

 * @param d

 * @param image Image where the grab will be put

 * @param x Top-Left grabbing rectangle horizontal coordinate

 * @param y Top-Left grabbing rectangle vertical coordinate

 * @return 0 if error, !0 if successful

 */

static int

xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)

{

    xGetImageReply rep;

    xGetImageReq *req;

    long nbytes;

    if (!image) {

        return 0;

    }

    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 0;

    }

    nbytes = (long)rep.length << 2;

    _XReadPad(dpy, image->data, nbytes);

    UnlockDisplay(dpy);

    SyncHandle();

    return 1;

}

/**

 * Grab a frame from x11 (public device demuxer API).

 *

 * @param s1 Context from avformat core

 * @param pkt Packet holding the brabbed frame

 * @return frame size in bytes

 */

static int

x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)

{

    struct x11_grab *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_C(1000000);

    /* wait based on the frame rate */

    for(;;) {

        curtime = av_gettime();

        delay = s->time_frame * av_q2d(s->time_base) - curtime;

        if (delay <= 0) {

            if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {

                s->time_frame += INT64_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(EIO);

    }

    pkt->pts = curtime;

    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 (!xget_zpixmap(dpy, RootWindow(dpy, DefaultScreen(dpy)), image, x_off, y_off)) {

            av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");

        }

    }

    if(!s->nomouse){

        paint_mouse_pointer(image, s);

    }

    /* XXX: avoid memcpy */

    memcpy(pkt->data, image->data, s->frame_size);

    return s->frame_size;

}

/**

 * Close x11 frame grabber (public device demuxer API).

 *

 * @param s1 Context from avformat core

 * @return 0 success, !0 failure

 */

static int

x11grab_read_close(AVFormatContext *s1)

{

    struct x11_grab *x11grab = s1->priv_data;

    /* Detach cleanly from shared mem */

    if (x11grab->use_shm) {

        XShmDetach(x11grab->dpy, &x11grab->shminfo);

        shmdt(x11grab->shminfo.shmaddr);

        shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);

    }

    /* Destroy X11 image */

    if (x11grab->image) {

        XDestroyImage(x11grab->image);

        x11grab->image = NULL;

    }

    /* Free X11 display */

    XCloseDisplay(x11grab->dpy);

    return 0;

}

/** x11 grabber device demuxer declaration */

AVInputFormat ff_x11_grab_device_demuxer =

{

    "x11grab",

    NULL_IF_CONFIG_SMALL("X11grab"),

    sizeof(struct x11_grab),

    NULL,

    x11grab_read_header,

    x11grab_read_packet,

    x11grab_read_close,

    .flags = AVFMT_NOFILE,

};