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/*
* XCB input grabber
* Copyright (C) 2014 Luca Barbato <lu_zero@gentoo.org>
*
* This file is part of Libav.
*
* Libav 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 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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
*/
#include "config.h"
#include <stdlib.h>
#include <xcb/xcb.h>
#include <xcb/shape.h>
#if CONFIG_LIBXCB_XFIXES
#include <xcb/xfixes.h>
#endif
#if CONFIG_LIBXCB_SHM
#include <sys/shm.h>
#include <xcb/shm.h>
#endif
#include "libavutil/internal.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/time.h"
#include "libavformat/avformat.h"
#include "libavformat/internal.h"
typedef struct XCBGrabContext {
const AVClass *class;
xcb_connection_t *conn;
xcb_screen_t *screen;
xcb_window_t window;
#if CONFIG_LIBXCB_SHM
xcb_shm_seg_t segment;
#endif
int64_t time_frame;
AVRational time_base;
int x, y;
int width, height;
int frame_size;
int bpp;
int draw_mouse;
int follow_mouse;
int show_region;
int region_border;
int centered;
const char *video_size;
const char *framerate;
int has_shm;
} XCBGrabContext;
#define FOLLOW_CENTER -1
#define OFFSET(x) offsetof(XCBGrabContext, x)
#define D AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
{ "x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
{ "y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
{ "grab_x", "Initial x coordinate.", OFFSET(x), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
{ "grab_y", "Initial y coordinate.", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
{ "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = "vga" }, 0, 0, D },
{ "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc" }, 0, 0, D },
{ "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, D },
{ "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
OFFSET(follow_mouse), AV_OPT_TYPE_INT, { .i64 = 0 }, FOLLOW_CENTER, INT_MAX, D, "follow_mouse" },
{ "centered", "Keep the mouse pointer at the center of grabbing region when following.", 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, INT_MIN, INT_MAX, D, "follow_mouse" },
{ "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, D },
{ "region_border", "Set the region border thickness.", OFFSET(region_border), AV_OPT_TYPE_INT, { .i64 = 3 }, 1, 128, D },
{ NULL },
};
static const AVClass xcbgrab_class = {
.class_name = "xcbgrab indev",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
static int xcbgrab_reposition(AVFormatContext *s,
xcb_query_pointer_reply_t *p,
xcb_get_geometry_reply_t *geo)
{
XCBGrabContext *c = s->priv_data;
int x = c->x, y = c->y;
int w = c->width, h = c->height, f = c->follow_mouse;
int p_x, p_y;
if (!p || !geo)
return AVERROR(EIO);
p_x = p->win_x;
p_y = p->win_y;
if (f == FOLLOW_CENTER) {
x = p_x - w / 2;
y = p_y - h / 2;
} else {
int left = x + f;
int right = x + w - f;
int top = y + f;
int bottom = y + h + f;
if (p_x > right) {
x += p_x - right;
} else if (p_x < left) {
x -= left - p_x;
}
if (p_y > bottom) {
y += p_y - bottom;
} else if (p_y < top) {
y -= top - p_y;
}
}
c->x = FFMIN(FFMAX(0, x), geo->width - w);
c->y = FFMIN(FFMAX(0, y), geo->height - h);
return 0;
}
static int xcbgrab_frame(AVFormatContext *s, AVPacket *pkt)
{
XCBGrabContext *c = s->priv_data;
xcb_get_image_cookie_t iq;
xcb_get_image_reply_t *img;
xcb_drawable_t drawable = c->screen->root;
xcb_generic_error_t *e = NULL;
uint8_t *data;
int length, ret;
iq = xcb_get_image(c->conn, XCB_IMAGE_FORMAT_Z_PIXMAP, drawable,
c->x, c->y, c->width, c->height, ~0);
img = xcb_get_image_reply(c->conn, iq, &e);
if (e) {
av_log(s, AV_LOG_ERROR,
"Cannot get the image data "
"event_error: response_type:%u error_code:%u "
"sequence:%u resource_id:%u minor_code:%u major_code:%u.\n",
e->response_type, e->error_code,
e->sequence, e->resource_id, e->minor_code, e->major_code);
return AVERROR(EACCES);
}
if (!img)
return AVERROR(EAGAIN);
data = xcb_get_image_data(img);
length = xcb_get_image_data_length(img);
ret = av_new_packet(pkt, length);
if (!ret)
memcpy(pkt->data, data, length);
free(img);
return ret;
}
static void wait_frame(AVFormatContext *s, AVPacket *pkt)
{
XCBGrabContext *c = s->priv_data;
int64_t curtime, delay;
int64_t frame_time = av_rescale_q(1, c->time_base, AV_TIME_BASE_Q);
c->time_frame += frame_time;
for (;;) {
curtime = av_gettime();
delay = c->time_frame - curtime;
if (delay <= 0)
break;
av_usleep(delay);
}
pkt->pts = curtime;
}
#if CONFIG_LIBXCB_SHM
static int check_shm(xcb_connection_t *conn)
{
xcb_shm_query_version_cookie_t cookie = xcb_shm_query_version(conn);
xcb_shm_query_version_reply_t *reply;
reply = xcb_shm_query_version_reply(conn, cookie, NULL);
if (reply) {
free(reply);
return 1;
}
return 0;
}
static void dealloc_shm(void *unused, uint8_t *data)
{
shmdt(data);
}
static int xcbgrab_frame_shm(AVFormatContext *s, AVPacket *pkt)
{
XCBGrabContext *c = s->priv_data;
xcb_shm_get_image_cookie_t iq;
xcb_shm_get_image_reply_t *img;
xcb_drawable_t drawable = c->screen->root;
uint8_t *data;
int size = c->frame_size + AV_INPUT_BUFFER_PADDING_SIZE;
int id = shmget(IPC_PRIVATE, size, IPC_CREAT | 0777);
xcb_generic_error_t *e = NULL;
if (id == -1) {
char errbuf[1024];
int err = AVERROR(errno);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(s, AV_LOG_ERROR, "Cannot get %d bytes of shared memory: %s.\n",
size, errbuf);
return err;
}
xcb_shm_attach(c->conn, c->segment, id, 0);
iq = xcb_shm_get_image(c->conn, drawable,
c->x, c->y, c->width, c->height, ~0,
XCB_IMAGE_FORMAT_Z_PIXMAP, c->segment, 0);
xcb_shm_detach(c->conn, c->segment);
img = xcb_shm_get_image_reply(c->conn, iq, &e);
xcb_flush(c->conn);
if (e) {
av_log(s, AV_LOG_ERROR,
"Cannot get the image data "
"event_error: response_type:%u error_code:%u "
"sequence:%u resource_id:%u minor_code:%u major_code:%u.\n",
e->response_type, e->error_code,
e->sequence, e->resource_id, e->minor_code, e->major_code);
shmctl(id, IPC_RMID, 0);
return AVERROR(EACCES);
}
free(img);
data = shmat(id, NULL, 0);
shmctl(id, IPC_RMID, 0);
if ((intptr_t)data == -1)
return AVERROR(errno);
pkt->buf = av_buffer_create(data, size, dealloc_shm, NULL, 0);
if (!pkt->buf) {
shmdt(data);
return AVERROR(ENOMEM);
}
pkt->data = pkt->buf->data;
pkt->size = c->frame_size;
return 0;
}
#endif /* CONFIG_LIBXCB_SHM */
#if CONFIG_LIBXCB_XFIXES
static int check_xfixes(xcb_connection_t *conn)
{
xcb_xfixes_query_version_cookie_t cookie;
xcb_xfixes_query_version_reply_t *reply;
cookie = xcb_xfixes_query_version(conn, XCB_XFIXES_MAJOR_VERSION,
XCB_XFIXES_MINOR_VERSION);
reply = xcb_xfixes_query_version_reply(conn, cookie, NULL);
if (reply) {
free(reply);
return 1;
}
return 0;
}
#define BLEND(target, source, alpha) \
(target) + ((source) * (255 - (alpha)) + 255 / 2) / 255
static void xcbgrab_draw_mouse(AVFormatContext *s, AVPacket *pkt,
xcb_query_pointer_reply_t *p,
xcb_get_geometry_reply_t *geo)
{
XCBGrabContext *gr = s->priv_data;
uint32_t *cursor;
uint8_t *image = pkt->data;
int stride = gr->bpp / 8;
xcb_xfixes_get_cursor_image_cookie_t cc;
xcb_xfixes_get_cursor_image_reply_t *ci;
int cx, cy, x, y, w, h, c_off, i_off;
cc = xcb_xfixes_get_cursor_image(gr->conn);
ci = xcb_xfixes_get_cursor_image_reply(gr->conn, cc, NULL);
if (!ci)
return;
cursor = xcb_xfixes_get_cursor_image_cursor_image(ci);
if (!cursor)
return;
cx = ci->x - ci->xhot;
cy = ci->y - ci->yhot;
x = FFMAX(cx, gr->x);
y = FFMAX(cy, gr->y);
w = FFMIN(cx + ci->width, gr->x + gr->width) - x;
h = FFMIN(cy + ci->height, gr->y + gr->height) - y;
c_off = x - cx;
i_off = x - gr->x;
cursor += (y - cy) * ci->width;
image += (y - gr->y) * gr->width * stride;
for (y = 0; y < h; y++) {
cursor += c_off;
image += i_off * stride;
for (x = 0; x < w; x++, cursor++, image += stride) {
int r, g, b, a;
r = *cursor & 0xff;
g = (*cursor >> 8) & 0xff;
b = (*cursor >> 16) & 0xff;
a = (*cursor >> 24) & 0xff;
if (!a)
continue;
if (a == 255) {
image[0] = r;
image[1] = g;
image[2] = b;
} else {
image[0] = BLEND(r, image[0], a);
image[1] = BLEND(g, image[1], a);
image[2] = BLEND(b, image[2], a);
}
}
cursor += ci->width - w - c_off;
image += (gr->width - w - i_off) * stride;
}
free(ci);
}
#endif /* CONFIG_LIBXCB_XFIXES */
static void xcbgrab_update_region(AVFormatContext *s)
{
XCBGrabContext *c = s->priv_data;
const uint32_t args[] = { c->x - c->region_border,
c->y - c->region_border };
xcb_configure_window(c->conn,
c->window,
XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y,
args);
}
static int xcbgrab_read_packet(AVFormatContext *s, AVPacket *pkt)
{
XCBGrabContext *c = s->priv_data;
xcb_query_pointer_cookie_t pc;
xcb_get_geometry_cookie_t gc;
xcb_query_pointer_reply_t *p = NULL;
xcb_get_geometry_reply_t *geo = NULL;
int ret = 0;
wait_frame(s, pkt);
if (c->follow_mouse || c->draw_mouse) {
pc = xcb_query_pointer(c->conn, c->screen->root);
gc = xcb_get_geometry(c->conn, c->screen->root);
p = xcb_query_pointer_reply(c->conn, pc, NULL);
geo = xcb_get_geometry_reply(c->conn, gc, NULL);
}
if (c->follow_mouse && p->same_screen)
xcbgrab_reposition(s, p, geo);
if (c->show_region)
xcbgrab_update_region(s);
#if CONFIG_LIBXCB_SHM
if (c->has_shm && xcbgrab_frame_shm(s, pkt) < 0)
c->has_shm = 0;
#endif
if (!c->has_shm)
ret = xcbgrab_frame(s, pkt);
#if CONFIG_LIBXCB_XFIXES
if (ret >= 0 && c->draw_mouse && p->same_screen)
xcbgrab_draw_mouse(s, pkt, p, geo);
#endif
free(p);
free(geo);
return ret;
}
static av_cold int xcbgrab_read_close(AVFormatContext *s)
{
XCBGrabContext *ctx = s->priv_data;
xcb_disconnect(ctx->conn);
return 0;
}
static xcb_screen_t *get_screen(const xcb_setup_t *setup, int screen_num)
{
xcb_screen_iterator_t it = xcb_setup_roots_iterator(setup);
xcb_screen_t *screen = NULL;
for (; it.rem > 0; xcb_screen_next (&it)) {
if (!screen_num) {
screen = it.data;
break;
}
screen_num--;
}
return screen;
}
static int pixfmt_from_pixmap_format(AVFormatContext *s, int depth,
int *pix_fmt)
{
XCBGrabContext *c = s->priv_data;
const xcb_setup_t *setup = xcb_get_setup(c->conn);
const xcb_format_t *fmt = xcb_setup_pixmap_formats(setup);
int length = xcb_setup_pixmap_formats_length(setup);
*pix_fmt = 0;
while (length--) {
if (fmt->depth == depth) {
switch (depth) {
case 32:
if (fmt->bits_per_pixel == 32)
*pix_fmt = AV_PIX_FMT_ARGB;
break;
case 24:
if (fmt->bits_per_pixel == 32)
*pix_fmt = AV_PIX_FMT_RGB32;
else if (fmt->bits_per_pixel == 24)
*pix_fmt = AV_PIX_FMT_RGB24;
break;
case 16:
if (fmt->bits_per_pixel == 16)
*pix_fmt = AV_PIX_FMT_RGB565;
break;
case 15:
if (fmt->bits_per_pixel == 16)
*pix_fmt = AV_PIX_FMT_RGB555;
break;
case 8:
if (fmt->bits_per_pixel == 8)
*pix_fmt = AV_PIX_FMT_RGB8;
break;
}
}
if (*pix_fmt) {
c->bpp = fmt->bits_per_pixel;
c->frame_size = c->width * c->height * fmt->bits_per_pixel / 8;
return 0;
}
fmt++;
}
avpriv_report_missing_feature(s, "Mapping this pixmap format");
return AVERROR_PATCHWELCOME;
}
static int create_stream(AVFormatContext *s)
{
XCBGrabContext *c = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
xcb_get_geometry_cookie_t gc;
xcb_get_geometry_reply_t *geo;
int ret;
if (!st)
return AVERROR(ENOMEM);
ret = av_parse_video_size(&c->width, &c->height, c->video_size);
if (ret < 0)
return ret;
ret = av_parse_video_rate(&st->avg_frame_rate, c->framerate);
if (ret < 0)
return ret;
avpriv_set_pts_info(st, 64, 1, 1000000);
gc = xcb_get_geometry(c->conn, c->screen->root);
geo = xcb_get_geometry_reply(c->conn, gc, NULL);
if (c->x + c->width > geo->width ||
c->y + c->height > geo->height) {
av_log(s, AV_LOG_ERROR,
"Capture area %dx%d at position %d.%d "
"outside the screen size %dx%d\n",
c->width, c->height,
c->x, c->y,
geo->width, geo->height);
return AVERROR(EINVAL);
}
c->time_base = (AVRational){ st->avg_frame_rate.den,
st->avg_frame_rate.num };
c->time_frame = av_gettime();
lavf: replace AVStream.codec with AVStream.codecpar Currently, AVStream contains an embedded AVCodecContext instance, which is used by demuxers to export stream parameters to the caller and by muxers to receive stream parameters from the caller. It is also used internally as the codec context that is passed to parsers. In addition, it is also widely used by the callers as the decoding (when demuxer) or encoding (when muxing) context, though this has been officially discouraged since Libav 11. There are multiple important problems with this approach: - the fields in AVCodecContext are in general one of * stream parameters * codec options * codec state However, it's not clear which ones are which. It is consequently unclear which fields are a demuxer allowed to set or a muxer allowed to read. This leads to erratic behaviour depending on whether decoding or encoding is being performed or not (and whether it uses the AVStream embedded codec context). - various synchronization issues arising from the fact that the same context is used by several different APIs (muxers/demuxers, parsers, bitstream filters and encoders/decoders) simultaneously, with there being no clear rules for who can modify what and the different processes being typically delayed with respect to each other. - avformat_find_stream_info() making it necessary to support opening and closing a single codec context multiple times, thus complicating the semantics of freeing various allocated objects in the codec context. Those problems are resolved by replacing the AVStream embedded codec context with a newly added AVCodecParameters instance, which stores only the stream parameters exported by the demuxers or read by the muxers.
11 years ago
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
st->codecpar->width = c->width;
st->codecpar->height = c->height;
lavf: replace AVStream.codec with AVStream.codecpar Currently, AVStream contains an embedded AVCodecContext instance, which is used by demuxers to export stream parameters to the caller and by muxers to receive stream parameters from the caller. It is also used internally as the codec context that is passed to parsers. In addition, it is also widely used by the callers as the decoding (when demuxer) or encoding (when muxing) context, though this has been officially discouraged since Libav 11. There are multiple important problems with this approach: - the fields in AVCodecContext are in general one of * stream parameters * codec options * codec state However, it's not clear which ones are which. It is consequently unclear which fields are a demuxer allowed to set or a muxer allowed to read. This leads to erratic behaviour depending on whether decoding or encoding is being performed or not (and whether it uses the AVStream embedded codec context). - various synchronization issues arising from the fact that the same context is used by several different APIs (muxers/demuxers, parsers, bitstream filters and encoders/decoders) simultaneously, with there being no clear rules for who can modify what and the different processes being typically delayed with respect to each other. - avformat_find_stream_info() making it necessary to support opening and closing a single codec context multiple times, thus complicating the semantics of freeing various allocated objects in the codec context. Those problems are resolved by replacing the AVStream embedded codec context with a newly added AVCodecParameters instance, which stores only the stream parameters exported by the demuxers or read by the muxers.
11 years ago
ret = pixfmt_from_pixmap_format(s, geo->depth, &st->codecpar->format);
free(geo);
return ret;
}
static void draw_rectangle(AVFormatContext *s)
{
XCBGrabContext *c = s->priv_data;
xcb_gcontext_t gc = xcb_generate_id(c->conn);
uint32_t mask = XCB_GC_FOREGROUND |
XCB_GC_BACKGROUND |
XCB_GC_LINE_WIDTH |
XCB_GC_LINE_STYLE |
XCB_GC_FILL_STYLE;
uint32_t values[] = { c->screen->black_pixel,
c->screen->white_pixel,
c->region_border,
XCB_LINE_STYLE_DOUBLE_DASH,
XCB_FILL_STYLE_SOLID };
xcb_rectangle_t r = { 1, 1,
c->width + c->region_border * 2 - 3,
c->height + c->region_border * 2 - 3 };
xcb_create_gc(c->conn, gc, c->window, mask, values);
xcb_poly_rectangle(c->conn, c->window, gc, 1, &r);
}
static void setup_window(AVFormatContext *s)
{
XCBGrabContext *c = s->priv_data;
uint32_t mask = XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK;
uint32_t values[] = { 1,
XCB_EVENT_MASK_EXPOSURE |
XCB_EVENT_MASK_STRUCTURE_NOTIFY };
xcb_rectangle_t rect = { 0, 0, c->width, c->height };
c->window = xcb_generate_id(c->conn);
xcb_create_window(c->conn, XCB_COPY_FROM_PARENT,
c->window,
c->screen->root,
c->x - c->region_border,
c->y - c->region_border,
c->width + c->region_border * 2,
c->height + c->region_border * 2,
0,
XCB_WINDOW_CLASS_INPUT_OUTPUT,
XCB_COPY_FROM_PARENT,
mask, values);
xcb_shape_rectangles(c->conn, XCB_SHAPE_SO_SUBTRACT,
XCB_SHAPE_SK_BOUNDING, XCB_CLIP_ORDERING_UNSORTED,
c->window,
c->region_border, c->region_border,
1, &rect);
xcb_map_window(c->conn, c->window);
draw_rectangle(s);
}
static av_cold int xcbgrab_read_header(AVFormatContext *s)
{
XCBGrabContext *c = s->priv_data;
int screen_num, ret;
const xcb_setup_t *setup;
char *host = s->filename[0] ? s->filename : NULL;
const char *opts = strchr(s->filename, '+');
if (opts) {
sscanf(opts, "%d,%d", &c->x, &c->y);
host = av_strdup(s->filename);
if (!host)
return AVERROR(ENOMEM);
host[opts - s->filename] = '\0';
}
c->conn = xcb_connect(host, &screen_num);
if ((ret = xcb_connection_has_error(c->conn))) {
av_log(s, AV_LOG_ERROR, "Cannot open display %s, error %d.\n",
s->filename[0] ? host : "default", ret);
if (opts)
av_freep(&host);
return AVERROR(EIO);
}
if (opts)
av_freep(&host);
setup = xcb_get_setup(c->conn);
c->screen = get_screen(setup, screen_num);
if (!c->screen) {
av_log(s, AV_LOG_ERROR, "The screen %d does not exist.\n",
screen_num);
xcbgrab_read_close(s);
return AVERROR(EIO);
}
ret = create_stream(s);
if (ret < 0) {
xcbgrab_read_close(s);
return ret;
}
#if CONFIG_LIBXCB_SHM
if ((c->has_shm = check_shm(c->conn)))
c->segment = xcb_generate_id(c->conn);
#endif
#if CONFIG_LIBXCB_XFIXES
if (c->draw_mouse) {
if (!(c->draw_mouse = check_xfixes(c->conn))) {
av_log(s, AV_LOG_WARNING,
"XFixes not available, cannot draw the mouse.\n");
}
if (c->bpp < 24) {
avpriv_report_missing_feature(s, "%d bits per pixel screen",
c->bpp);
c->draw_mouse = 0;
}
}
#endif
if (c->show_region)
setup_window(s);
return 0;
}
AVInputFormat ff_xcbgrab_demuxer = {
.name = "x11grab",
.long_name = NULL_IF_CONFIG_SMALL("X11 screen capture, using XCB"),
.priv_data_size = sizeof(XCBGrabContext),
.read_header = xcbgrab_read_header,
.read_packet = xcbgrab_read_packet,
.read_close = xcbgrab_read_close,
.flags = AVFMT_NOFILE,
.priv_class = &xcbgrab_class,
};