[libcamera-devel] [PATCH] cam: sdl_sink: Add SDL sink
Eric Curtin
ecurtin at redhat.com
Tue Mar 22 19:35:14 CET 2022
This adds more portability to existing cam sinks. You can pass a
YUYV camera buffer for example and SDL will handle the pixel buffer
conversion, although SDL does not support decompression for pixelformats
like MJPEG. This allows cam reference implementation to display images
on VMs, Mac M1, Raspberry Pi, etc. This also enables cam reference
implementation, to run as a desktop application in wayland or x11.
SDL also has support for Android and ChromeOS which I have not tested.
Also tested on simpledrm raspberry pi 4 framebuffer successfully where
existing kms sink did not work.
Signed-off-by: Eric Curtin <ecurtin at redhat.com>
---
src/cam/camera_session.cpp | 8 +++
src/cam/main.cpp | 6 ++
src/cam/main.h | 1 +
src/cam/meson.build | 10 +++
src/cam/sdl_sink.cpp | 125 +++++++++++++++++++++++++++++++++++++
src/cam/sdl_sink.h | 40 ++++++++++++
6 files changed, 190 insertions(+)
create mode 100644 src/cam/sdl_sink.cpp
create mode 100644 src/cam/sdl_sink.h
diff --git a/src/cam/camera_session.cpp b/src/cam/camera_session.cpp
index 0428b538..30162dbd 100644
--- a/src/cam/camera_session.cpp
+++ b/src/cam/camera_session.cpp
@@ -19,6 +19,9 @@
#ifdef HAVE_KMS
#include "kms_sink.h"
#endif
+#ifdef HAVE_SDL
+#include "sdl_sink.h"
+#endif
#include "main.h"
#include "stream_options.h"
@@ -187,6 +190,11 @@ int CameraSession::start()
sink_ = std::make_unique<KMSSink>(options_[OptDisplay].toString());
#endif
+#ifdef HAVE_SDL
+ if (options_.isSet(OptSDL))
+ sink_ = std::make_unique<SDLSink>();
+#endif
+
if (options_.isSet(OptFile)) {
if (!options_[OptFile].toString().empty())
sink_ = std::make_unique<FileSink>(streamNames_,
diff --git a/src/cam/main.cpp b/src/cam/main.cpp
index c7f664b9..406d61bc 100644
--- a/src/cam/main.cpp
+++ b/src/cam/main.cpp
@@ -138,6 +138,12 @@ int CamApp::parseOptions(int argc, char *argv[])
"display", ArgumentOptional, "connector", false,
OptCamera);
#endif
+
+#ifdef HAVE_SDL
+ parser.addOption(OptSDL, OptionNone,
+ "Display viewfinder through SDL",
+ "sdl", ArgumentNone, "", false, OptCamera);
+#endif
parser.addOption(OptFile, OptionString,
"Write captured frames to disk\n"
"If the file name ends with a '/', it sets the directory in which\n"
diff --git a/src/cam/main.h b/src/cam/main.h
index 62f7bbc9..a64f95a0 100644
--- a/src/cam/main.h
+++ b/src/cam/main.h
@@ -11,6 +11,7 @@ enum {
OptCamera = 'c',
OptCapture = 'C',
OptDisplay = 'D',
+ OptSDL = 'S',
OptFile = 'F',
OptHelp = 'h',
OptInfo = 'I',
diff --git a/src/cam/meson.build b/src/cam/meson.build
index e8e2ae57..44202ef0 100644
--- a/src/cam/meson.build
+++ b/src/cam/meson.build
@@ -32,11 +32,21 @@ cam_sources += files([
])
endif
+libsdl2 = dependency('SDL2', required : false)
+
+if libsdl2.found()
+cam_cpp_args += [ '-DHAVE_SDL' ]
+cam_sources += files([
+ 'sdl_sink.cpp'
+])
+endif
+
cam = executable('cam', cam_sources,
dependencies : [
libatomic,
libcamera_public,
libdrm,
+ libsdl2,
libevent,
],
cpp_args : cam_cpp_args,
diff --git a/src/cam/sdl_sink.cpp b/src/cam/sdl_sink.cpp
new file mode 100644
index 00000000..6de1493b
--- /dev/null
+++ b/src/cam/sdl_sink.cpp
@@ -0,0 +1,125 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * sdl_sink.cpp - SDL Sink
+ */
+
+#include "sdl_sink.h"
+
+#include <assert.h>
+#include <fcntl.h>
+#include <iomanip>
+#include <iostream>
+#include <signal.h>
+#include <sstream>
+#include <string.h>
+#include <unistd.h>
+
+#include <libcamera/camera.h>
+#include <libcamera/formats.h>
+
+#include "image.h"
+
+using namespace libcamera;
+
+SDLSink::SDLSink()
+{
+ memset(&sdlRect_, 0, sizeof(sdlRect_));
+}
+
+SDLSink::~SDLSink()
+{
+ SDL_Quit();
+}
+
+int SDLSink::configure(const libcamera::CameraConfiguration &cfg)
+{
+ int ret = FrameSink::configure(cfg);
+ if (ret < 0)
+ return ret;
+
+ if ((ret = SDL_Init(SDL_INIT_VIDEO))) {
+ std::cout << "Could not initialize SDL - " << SDL_GetError() << "\n";
+ return ret;
+ }
+
+ const libcamera::StreamConfiguration &sCfg = cfg.at(0);
+ sdlScreen_ = SDL_CreateWindow("", SDL_WINDOWPOS_UNDEFINED,
+ SDL_WINDOWPOS_UNDEFINED, sCfg.size.width,
+ sCfg.size.height, SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE);
+ if (!sdlScreen_) {
+ std::cerr << "SDL: could not create window - exiting: " << SDL_GetError() << "\n";
+ return -1;
+ }
+
+ sdlRenderer_ = SDL_CreateRenderer(
+ sdlScreen_, -1, 0);
+ if (!sdlRenderer_) {
+ std::cerr << "SDL_CreateRenderer Error\n";
+ return -2;
+ }
+
+ SDL_RenderSetLogicalSize(sdlRenderer_, sCfg.size.width,
+ sCfg.size.height);
+
+ SDL_PixelFormatEnum pf = (SDL_PixelFormatEnum)sCfg.pixelFormat.fourcc();
+ if (pf == SDL_DEFINE_PIXELFOURCC('Y', 'U', 'Y', 'V')) {
+ pf = SDL_PIXELFORMAT_YUY2;
+ }
+
+ if (!(ret = strcmp(SDL_GetPixelFormatName(pf), "SDL_PIXELFORMAT_UNKNOWN"))) {
+ std::cerr << "error: SDL_PIXELFORMAT_UNKNOWN, no " << sCfg.pixelFormat.toString() << " support\n";
+ return -3;
+ }
+
+ sdlTexture_ =
+ SDL_CreateTexture(sdlRenderer_, SDL_PIXELFORMAT_YUY2,
+ SDL_TEXTUREACCESS_STREAMING, sCfg.size.width,
+ sCfg.size.height);
+ sdlRect_.w = sCfg.size.width;
+ sdlRect_.h = sCfg.size.height;
+
+ return 0;
+}
+
+void SDLSink::mapBuffer(FrameBuffer *buffer)
+{
+ std::unique_ptr<Image> image =
+ Image::fromFrameBuffer(buffer, Image::MapMode::ReadOnly);
+ assert(image != nullptr);
+
+ mappedBuffers_[buffer] = std::move(image);
+}
+
+bool SDLSink::processRequest(Request *request)
+{
+ for (auto [stream, buffer] : request->buffers())
+ writeBuffer(buffer);
+
+ return true;
+}
+
+void SDLSink::writeBuffer(FrameBuffer *buffer)
+{
+ Image *image = mappedBuffers_[buffer].get();
+
+ for (unsigned int i = 0; i < buffer->planes().size(); ++i) {
+ const FrameMetadata::Plane &meta = buffer->metadata().planes()[i];
+
+ Span<uint8_t> data = image->data(i);
+ if (meta.bytesused > data.size())
+ std::cerr << "payload size " << meta.bytesused
+ << " larger than plane size " << data.size()
+ << std::endl;
+
+ SDL_UpdateTexture(sdlTexture_, &sdlRect_, data.data(), sdlRect_.w * 2);
+ SDL_RenderClear(sdlRenderer_);
+ SDL_RenderCopy(sdlRenderer_, sdlTexture_, NULL, NULL);
+ SDL_RenderPresent(sdlRenderer_);
+ SDL_Event e;
+ while (SDL_PollEvent(&e)) {
+ if (e.type == SDL_QUIT) { // click close icon then quit
+ kill(getpid(), SIGINT);
+ }
+ };
+ }
+}
diff --git a/src/cam/sdl_sink.h b/src/cam/sdl_sink.h
new file mode 100644
index 00000000..f4f843fa
--- /dev/null
+++ b/src/cam/sdl_sink.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * sdl_sink.h - SDL Sink
+ */
+
+#pragma once
+
+#include <map>
+#include <memory>
+#include <string>
+
+#include <libcamera/stream.h>
+
+#include <SDL2/SDL.h>
+
+#include "frame_sink.h"
+
+class Image;
+
+class SDLSink : public FrameSink
+{
+public:
+ SDLSink();
+ ~SDLSink();
+
+ int configure(const libcamera::CameraConfiguration &cfg) override;
+
+ void mapBuffer(libcamera::FrameBuffer *buffer) override;
+
+ bool processRequest(libcamera::Request *request) override;
+
+private:
+ void writeBuffer(libcamera::FrameBuffer *buffer);
+
+ std::map<libcamera::FrameBuffer *, std::unique_ptr<Image>> mappedBuffers_;
+ SDL_Window *sdlScreen_;
+ SDL_Renderer *sdlRenderer_;
+ SDL_Texture *sdlTexture_;
+ SDL_Rect sdlRect_;
+};
--
2.35.1
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