On Wed, Sep 20, 2023 at 8:41 PM Abhishek Ojha < abhishek.o...@savoirfairelinux.com> wrote:
> This is an proof of concept for pipewire grab to enable screen capture > on wayland. Add a new Linux capture based on [1] PipeWire and the > [2] Desktop portal. > This new capture starts by asking the Desktop portal for a screencapture > session.There are quite a few D-Bus calls involved in this, but the key > points are: > > 1. A connection to org.freedesktop.portal.ScreenCast is estabilished, > and the available cursor modes are updated. Currently only embedded > and hidden currsor mode enabled. > > 2. Call CreateSession via dbus call. This is the first step of the > communication. Response callback return the status of created > session. > > 3. Call SelectSources . This is when a system dialog pops up asking > the user to either select a monitor (desktop capture).Only monitor > capture is enabled in current implementation. > > 4. Call Start . This signals the compositor that it can setup a PipeWire > stream, and start sending buffers. > > Above flow is implemented as per the [2] xdg-desktop-portal. Once flow > is completed, pipewire fd is received and using this pipewire stream is > created and receive buffer from the created stream. > > For cursor implementation, embedded cursor mode is enabled that means > cursor metadata is not handled in current implementation and has no > control over the cursor bitmap. > > gdbus/pipewire logic, this is based on obs-xdg, gstpipewire and > pipewire examples, and initial pipewire grab logic, this is based on > libavdevice/xcbgrab and libavdevice/v4l2 > > This implementation shows the skeleton implementation and enables basic > functionality. I'd like to hear opinions and suggestions to improve and > properly use this. > > [1] https://pipewire.org/ > [2] https://github.com/flatpak/xdg-desktop-portal/ > > Below are the arguments for pipewiregrab. > ffplay -f pipewiregrab -draw_mouse 1 -i :0.0 > > Signed-off-by: Abhishek Ojha <abhishek.o...@savoirfairelinux.com> > --- > configure | 9 + > libavdevice/Makefile | 1 + > libavdevice/alldevices.c | 1 + > libavdevice/pipewiregrab.c | 1836 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 1847 insertions(+) > create mode 100644 libavdevice/pipewiregrab.c > > diff --git a/configure b/configure > index e40dcce09e..325b10484f 100755 > --- a/configure > +++ b/configure > @@ -299,6 +299,7 @@ External library support: > --enable-libxcb-shm enable X11 grabbing shm communication > [autodetect] > --enable-libxcb-xfixes enable X11 grabbing mouse rendering > [autodetect] > --enable-libxcb-shape enable X11 grabbing shape rendering > [autodetect] > + --enable-libpipewire enable screen grabbing using pipewire > [autodetect] > --enable-libxvid enable Xvid encoding via xvidcore, > native MPEG-4/Xvid encoder exists [no] > --enable-libxml2 enable XML parsing using the C library > libxml2, needed > @@ -1788,6 +1789,8 @@ EXTERNAL_AUTODETECT_LIBRARY_LIST=" > libxcb_shm > libxcb_shape > libxcb_xfixes > + libpipewire > + libgio_unix > lzma > mediafoundation > metal > @@ -3621,6 +3624,7 @@ v4l2_outdev_suggest="libv4l2" > vfwcap_indev_deps="vfw32 vfwcap_defines" > xcbgrab_indev_deps="libxcb" > xcbgrab_indev_suggest="libxcb_shm libxcb_shape libxcb_xfixes" > +pipewiregrab_indev_deps="libpipewire libgio_unix pthreads" > xv_outdev_deps="xlib_xv xlib_x11 xlib_xext" > > # protocols > @@ -7041,6 +7045,11 @@ if enabled libxcb; then > enabled libxcb_xfixes && check_pkg_config libxcb_xfixes xcb-xfixes > xcb/xfixes.h xcb_xfixes_get_cursor_image > fi > > +enabled libpipewire && check_pkg_config libpipewire "libpipewire-0.3 >= > 0.3.40" pipewire/pipewire.h pw_init > +if enabled libpipewire; then > + enabled libgio_unix && check_pkg_config libgio_unix gio-unix-2.0 > gio/gio.h g_main_loop_new > +fi > + > check_func_headers "windows.h" CreateDIBSection "$gdigrab_indev_extralibs" > > # d3d11va requires linking directly to dxgi and d3d11 if not building for > diff --git a/libavdevice/Makefile b/libavdevice/Makefile > index c30449201d..f02960782d 100644 > --- a/libavdevice/Makefile > +++ b/libavdevice/Makefile > @@ -49,6 +49,7 @@ OBJS-$(CONFIG_V4L2_INDEV) += v4l2.o > v4l2-common.o timefilter.o > OBJS-$(CONFIG_V4L2_OUTDEV) += v4l2enc.o v4l2-common.o > OBJS-$(CONFIG_VFWCAP_INDEV) += vfwcap.o > OBJS-$(CONFIG_XCBGRAB_INDEV) += xcbgrab.o > +OBJS-$(CONFIG_PIPEWIREGRAB_INDEV) += pipewiregrab.o > OBJS-$(CONFIG_XV_OUTDEV) += xv.o > > # external libraries > diff --git a/libavdevice/alldevices.c b/libavdevice/alldevices.c > index 8a90fcb5d7..1fa8563df4 100644 > --- a/libavdevice/alldevices.c > +++ b/libavdevice/alldevices.c > @@ -53,6 +53,7 @@ extern const AVInputFormat ff_v4l2_demuxer; > extern const FFOutputFormat ff_v4l2_muxer; > extern const AVInputFormat ff_vfwcap_demuxer; > extern const AVInputFormat ff_xcbgrab_demuxer; > +extern const AVInputFormat ff_pipewiregrab_demuxer; > extern const FFOutputFormat ff_xv_muxer; > > /* external libraries */ > diff --git a/libavdevice/pipewiregrab.c b/libavdevice/pipewiregrab.c > new file mode 100644 > index 0000000000..5b96d43863 > --- /dev/null > +++ b/libavdevice/pipewiregrab.c > @@ -0,0 +1,1836 @@ > +/* > + * PipeWire input grabber (ScreenCast) > + * Copyright (C) 2023 Savoir-faire Linux, Inc. > + * > + * This file is part of FFmpeg. > + * > + * FFmpeg 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. > + * > + * FFmpeg 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 FFmpeg; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA > 02110-1301 USA > + */ > + > +/** > + * @file > + * Pipewire Grab demuxer > + * @author Abhishek Ojha <abhishek.o...@savoirfairelinux.com> > + */ > + > +#include "config.h" > + > +#include <fcntl.h> > +#include <linux/dma-buf.h> > +#include <math.h> > +#include <pthread.h> > +#include <stdatomic.h> > +#include <stdlib.h> > +#include <string.h> > +#include <sys/mman.h> > +#include <sys/queue.h> > + > +#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" > + > +#include <pipewire/pipewire.h> > +#include <pipewire/thread-loop.h> > +#include <spa/debug/types.h> > +#include <spa/param/video/format-utils.h> > +#include <spa/param/video/type-info.h> > + > +#include <gio/gio.h> > +#include <gio/gunixfdlist.h> > + > +#ifndef __USE_XOPEN2K8 > +#define F_DUPFD_CLOEXEC > \ > + 1030 /* Duplicate file descriptor with close-on-exit set. */ > +#endif > + > +#define BYTES_PER_PIXEL 4 /* currently all formats assume 4 bytes per > pixel */ > +#define REQUEST_PATH "/org/freedesktop/portal/desktop/request/%s/obs%u" > +#define SESSION_PATH "/org/freedesktop/portal/desktop/session/%s/obs%u" > +#define MAX_SPA_PARAM 4 /* max number of params for spa pod */ > + > +#define CURSOR_META_SIZE(width, height) > \ > + (sizeof(struct spa_meta_cursor) + sizeof(struct spa_meta_bitmap) + > \ > + width * height * 4) > + > +/** > + * Pipewire capture types > + */ > +typedef enum { > + DESKTOP_CAPTURE = 1, > + WINDOW_CAPTURE = 2, > +} pw_capture_type; > + > +/** > + * Pipewire version structure > + */ > +struct FFmpegPwVersion { > + int major; > + int minor; > + int micro; > +}; > + > +/** > + * Pipewire structure for frame processing > + */ > +struct PwStreamAndBuffer { > + AVFormatContext *ctx; > + struct pw_stream *pw_stream; > + struct pw_buffer *pw_buf; > +}; > + > +/** > + * Pipewire supported cursor modes > + */ > +enum PortalCursorMode { > + PORTAL_CURSOR_MODE_HIDDEN = 1 << 0, > + PORTAL_CURSOR_MODE_EMBEDDED = 1 << 1, > + PORTAL_CURSOR_MODE_METADATA = 1 << 2, > +}; > + > +/** > + * PipeWire Grab main structure > + * Contains all necessary data that hold current state > + * Initial state of this struct is allocated by libavdevice > + * logic when declaring the AVInputFormat ff_pipewiregrab_demuxer. > + * This structure is priv_data of AVFormatContext instance. > + */ > +typedef struct PipewireGrabContext { > + /** thread used to intialize/start pipewire logic */ > + pthread_t pipewire_pthread; > + > + /** conditional synchronization logic elecments between pipewire > + * thread and libavdevice thread. > + */ > + pthread_cond_t avstream_codec_cond_var; > + pthread_mutex_t avstream_codec_mutex; > + atomic_int avstream_codec_flag; > + > + pthread_mutex_t current_pkt_mutex; > + AVPacket* current_pkt; > + > + GDBusConnection *connection; > + GDBusProxy *proxy; > + GCancellable *cancellable; > + > + char *sender_name; > + char *session_handle; > + > + uint32_t pipewire_node; > + int pipewire_fd; > + > + uint32_t available_cursor_modes; > + > + GMainLoop *glib_main_loop; > + struct pw_thread_loop *thread_loop; > + struct pw_context *context; > + > + struct pw_core *core; > + struct spa_hook core_listener; > + > + struct pw_stream *stream; > + struct spa_hook stream_listener; > + struct spa_video_info format; > + > + pw_capture_type capture_type; > + bool negotiated; > + > + /**< draw_mouse is to control the enable/disable mouse cursor */ > + int draw_mouse; > + > + /** cursor metadata */ > + struct { > + bool visible; > + bool valid; > + int x, y; > + int hotspot_x, hotspot_y; > + int width, height; > + } cursor; > + > + /**< Width and height of the grab frame (private option) */ > + uint32_t width, height; > + > + /**< Size in bytes of the frame pixel data */ > + uint32_t frame_size; > + uint8_t Bpp; > + enum AVPixelFormat av_pxl_format; > + AVRational user_frame_rate; > + > + int64_t time_frame; > + AVRational time_base; > + int64_t frame_duration; > + > + const AVClass *class; > + > + const char *framerate; > + struct FFmpegPwVersion server_version; > + int server_version_sync; > +} PipewireGrabContext; > + > +/** > + * dbus's method/event marshalling structure > + */ > +struct DbusCallData { > + AVFormatContext *ctx; > + char *request_path; > + guint signal_id; > + gulong cancelled_id; > +}; > + > +#define FOLLOW_CENTER -1 > + > +#define OFFSET(x) offsetof(PipewireGrabContext, x) > +#define D AV_OPT_FLAG_DECODING_PARAM > +static const AVOption options[] = { > + { "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 = 0 }, > + 0, > + 1, > + D }, > + { NULL }, > +}; > + > +/** > + * Function parse the pipewire version > + * @param dst FmpegPwVersion that contains PipeWire version info > + * @param version pipewire version > + */ > +static bool parse_pw_version(struct FFmpegPwVersion *dst, const char > *version) > +{ > + int n_matches = sscanf(version, "%d.%d.%d", &dst->major, &dst->minor, > + &dst->micro); > + return n_matches == 3; > +} > + > +/** > + * Function update the pipewire version in private data > + * params, then signal the blocked @ref pipewiregrab_read_header > + * > + * @param ctx AVFormatContext that contains PipeWire Grab main structure > + * @param version pipewire version > + */ > +static void update_pw_versions(AVFormatContext *ctx, const char *version) > +{ > + PipewireGrabContext *pw_ctx = ctx->priv_data; > + av_log(ctx, AV_LOG_DEBUG, "[pipewiregrab] Server version: %s\n", > version); > All logs appear to have this [pipewiregrab] part, but this looks unneeded as logs normally write module name out. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
