From c1b210534b15188c964b31dc47e172f8ed4aca55 Mon Sep 17 00:00:00 2001
From: Aline Gondim Santos <aline.gondimsantos@savoirfairelinux.com>
Date: Tue, 19 Jul 2022 13:35:19 -0300
Subject: [PATCH] Screen sharing x11 fixes
+ We can now have a single stream in the x11grab, which can be updated to follow window resizing
+ Due to stream reinit, shm may cause memory issues and was removed
+ Adds one option (is_area) that defines if we are grabing a region of the display/window or the hole screen/window.
note: This is a custom patch for later rebase
---
libavdevice/xcbgrab.c | 186 ++++++++++--------------------------------
1 file changed, 45 insertions(+), 141 deletions(-)
diff --git a/libavdevice/xcbgrab.c b/libavdevice/xcbgrab.c
index 64a68ba497..76e654b424 100644
--- a/libavdevice/xcbgrab.c
+++ b/libavdevice/xcbgrab.c
@@ -29,11 +29,6 @@
#include <xcb/xfixes.h>
#endif
-#if CONFIG_LIBXCB_SHM
-#include <sys/shm.h>
-#include <xcb/shm.h>
-#endif
-
#if CONFIG_LIBXCB_SHAPE
#include <xcb/shape.h>
#endif
@@ -53,9 +48,6 @@ typedef struct XCBGrabContext {
xcb_connection_t *conn;
xcb_screen_t *screen;
xcb_window_t window;
-#if CONFIG_LIBXCB_SHM
- AVBufferPool *shm_pool;
-#endif
int64_t time_frame;
AVRational time_base;
int64_t frame_duration;
@@ -72,10 +64,9 @@ typedef struct XCBGrabContext {
int region_border;
int centered;
int select_region;
+ int is_area;
const char *framerate;
-
- int has_shm;
} XCBGrabContext;
#define FOLLOW_CENTER -1
@@ -97,6 +88,7 @@ static const AVOption options[] = {
{ "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 },
{ "select_region", "Select the grabbing region graphically using the pointer.", OFFSET(select_region), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, D },
+ { "is_area", "Define if we are grabing a region of the display/window.", OFFSET(is_area), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, D },
{ NULL },
};
@@ -216,99 +208,6 @@ static int64_t wait_frame(AVFormatContext *s, AVPacket *pkt)
return 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 free_shm_buffer(void *opaque, uint8_t *data)
-{
- shmdt(data);
-}
-
-static AVBufferRef *allocate_shm_buffer(void *opaque, size_t size)
-{
- xcb_connection_t *conn = opaque;
- xcb_shm_seg_t segment;
- AVBufferRef *ref;
- uint8_t *data;
- int id;
-
- id = shmget(IPC_PRIVATE, size, IPC_CREAT | 0777);
- if (id == -1)
- return NULL;
-
- segment = xcb_generate_id(conn);
- xcb_shm_attach(conn, segment, id, 0);
- data = shmat(id, NULL, 0);
- shmctl(id, IPC_RMID, 0);
- if ((intptr_t)data == -1 || !data)
- return NULL;
-
- ref = av_buffer_create(data, size, free_shm_buffer, (void *)(ptrdiff_t)segment, 0);
- if (!ref)
- shmdt(data);
-
- return ref;
-}
-
-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->window_id;
- xcb_generic_error_t *e = NULL;
- AVBufferRef *buf;
- xcb_shm_seg_t segment;
-
- buf = av_buffer_pool_get(c->shm_pool);
- if (!buf) {
- av_log(s, AV_LOG_ERROR, "Could not get shared memory buffer.\n");
- return AVERROR(ENOMEM);
- }
- segment = (xcb_shm_seg_t)(uintptr_t)av_buffer_pool_buffer_get_opaque(buf);
-
- iq = xcb_shm_get_image(c->conn, drawable,
- c->x, c->y, c->width, c->height, ~0,
- XCB_IMAGE_FORMAT_Z_PIXMAP, segment, 0);
- 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);
-
- free(e);
- av_buffer_unref(&buf);
- return AVERROR(EACCES);
- }
-
- free(img);
-
- pkt->buf = buf;
- pkt->data = 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)
{
@@ -462,14 +361,7 @@ static int xcbgrab_read_packet(AVFormatContext *s, AVPacket *pkt)
if (c->show_region)
xcbgrab_update_region(s, win_x, win_y);
-#if CONFIG_LIBXCB_SHM
- if (c->has_shm && xcbgrab_frame_shm(s, pkt) < 0) {
- av_log(s, AV_LOG_WARNING, "Continuing without shared memory.\n");
- c->has_shm = 0;
- }
-#endif
- if (!c->has_shm)
- ret = xcbgrab_frame(s, pkt);
+ ret = xcbgrab_frame(s, pkt);
pkt->dts = pkt->pts = pts;
pkt->duration = c->frame_duration;
@@ -488,11 +380,8 @@ static av_cold int xcbgrab_read_close(AVFormatContext *s)
{
XCBGrabContext *ctx = s->priv_data;
-#if CONFIG_LIBXCB_SHM
- av_buffer_pool_uninit(&ctx->shm_pool);
-#endif
-
xcb_disconnect(ctx->conn);
+ ctx->conn = NULL;
return 0;
}
@@ -572,7 +461,15 @@ static int pixfmt_from_pixmap_format(AVFormatContext *s, int depth,
static int create_stream(AVFormatContext *s)
{
XCBGrabContext *c = s->priv_data;
- AVStream *st = avformat_new_stream(s, NULL);
+
+ // If we try to open another stream to x11grab, there is no reason
+ // to keep more than one stream in the context.
+ AVStream *st;
+ if (!s->nb_streams) {
+ st = avformat_new_stream(s, NULL);
+ } else {
+ st = s->streams[0];
+ }
xcb_get_geometry_cookie_t gc;
xcb_get_geometry_reply_t *geo;
int64_t frame_size_bits;
@@ -594,11 +491,26 @@ static int create_stream(AVFormatContext *s)
return AVERROR_EXTERNAL;
}
+ // av_log(s, AV_LOG_ERROR, "Capture is_area %d\n", c->is_area);
+ // Width and Height are not 0 only when we set a window area to share
+ // This if may be valid only in the first call to create_stream
if (!c->width || !c->height) {
+ // av_log(s, AV_LOG_ERROR, "Capture area!\n");
+ c->is_area = 0;
+ c->width = geo->width;
+ c->height = geo->height;
+ }
+ // If not a predefined area, then we should follow geometry changes
+ // This can be valid only on the second call onwards
+ if (!c->is_area && (c->width != geo->width || c->height != geo->height)) {
c->width = geo->width;
c->height = geo->height;
}
+ // av_log(s, AV_LOG_ERROR, "Capture area %dx%d at position %d.%d\n",
+ // c->width, c->height,
+ // c->x, c->y);
+
if (c->x + c->width > geo->width ||
c->y + c->height > geo->height) {
av_log(s, AV_LOG_ERROR,
@@ -628,13 +540,6 @@ static int create_stream(AVFormatContext *s)
}
c->frame_size = frame_size_bits / 8;
-#if CONFIG_LIBXCB_SHM
- c->shm_pool = av_buffer_pool_init2(c->frame_size + AV_INPUT_BUFFER_PADDING_SIZE,
- c->conn, allocate_shm_buffer, NULL);
- if (!c->shm_pool)
- return AVERROR(ENOMEM);
-#endif
-
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
st->codecpar->width = c->width;
@@ -829,23 +734,26 @@ static av_cold int xcbgrab_read_header(AVFormatContext *s)
sscanf(s->url, "+%d,%d", &c->x, &c->y);
}
- c->conn = xcb_connect(display_name[0] ? display_name : NULL, &screen_num);
- av_freep(&display_name);
+ if (!c->conn || !c->screen) {
+ xcbgrab_read_close(s);
+ c->conn = xcb_connect(display_name[0] ? display_name : NULL, &screen_num);
+ av_freep(&display_name);
- if ((ret = xcb_connection_has_error(c->conn))) {
- av_log(s, AV_LOG_ERROR, "Cannot open display %s, error %d.\n",
- s->url[0] ? s->url : "default", ret);
- return AVERROR(EIO);
- }
+ if ((ret = xcb_connection_has_error(c->conn))) {
+ av_log(s, AV_LOG_ERROR, "Cannot open display %s, error %d.\n",
+ s->url[0] ? s->url : "default", ret);
+ return AVERROR(EIO);
+ }
- setup = xcb_get_setup(c->conn);
+ 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);
+ 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);
+ }
}
if (c->window_id == XCB_NONE)
@@ -876,10 +784,6 @@ static av_cold int xcbgrab_read_header(AVFormatContext *s)
return ret;
}
-#if CONFIG_LIBXCB_SHM
- c->has_shm = check_shm(c->conn);
-#endif
-
#if CONFIG_LIBXCB_XFIXES
if (c->draw_mouse) {
if (!(c->draw_mouse = check_xfixes(c->conn))) {
--
2.34.1
