[libcamera-devel] [PATCH v8 3/4] cam: sdl_sink: Add SDL sink with initial YUYV support

Kieran Bingham kieran.bingham at ideasonboard.com
Wed May 18 01:38:20 CEST 2022


Quoting Eric Curtin via libcamera-devel (2022-05-05 16:18:50)
> This adds more portability to existing cam sinks. You can pass a
> YUYV camera buffer and SDL will handle the pixel buffer conversion
> to the display. 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 has not been
> tested. Also tested on simpledrm raspberry pi 4 framebuffer
> successfully where existing kms sink did not work. Can also be used as
> kmsdrm sink. Only supports one camera stream at present.
> 
> Signed-off-by: Eric Curtin <ecurtin at redhat.com>
> ---
>  src/cam/camera_session.cpp   |   8 ++
>  src/cam/main.cpp             |   4 +
>  src/cam/main.h               |   1 +
>  src/cam/meson.build          |  12 +++
>  src/cam/sdl_sink.cpp         | 192 +++++++++++++++++++++++++++++++++++
>  src/cam/sdl_sink.h           |  48 +++++++++
>  src/cam/sdl_texture.cpp      |  32 ++++++
>  src/cam/sdl_texture.h        |  23 +++++
>  src/cam/sdl_texture_yuyv.cpp |  13 +++
>  src/cam/sdl_texture_yuyv.h   |  10 ++

Given the number of sdl_ files here I wonder if they should be under
src/cam/sdl/.... 

But not crucial to this patch.

I can't test this right now - but I'm looking forward to seeing a
preview on cam ... so I'll hopefully test this tomorrow.


>  10 files changed, 343 insertions(+)
>  create mode 100644 src/cam/sdl_sink.cpp
>  create mode 100644 src/cam/sdl_sink.h
>  create mode 100644 src/cam/sdl_texture.cpp
>  create mode 100644 src/cam/sdl_texture.h
>  create mode 100644 src/cam/sdl_texture_yuyv.cpp
>  create mode 100644 src/cam/sdl_texture_yuyv.h
> 
> diff --git a/src/cam/camera_session.cpp b/src/cam/camera_session.cpp
> index efffafbf..71e6bd60 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"
>  
> @@ -186,6 +189,11 @@ 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
> +

It looks like the precedence of which sink really gets used if multiples
are set is simply the order in this file that they get set. But I think
that's ok for the moment. Not sure we could do much else right now
without extending to support multiple sinks which is out of scope here.

Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>


>         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..fd3108b0 100644
> --- a/src/cam/main.cpp
> +++ b/src/cam/main.cpp
> @@ -137,6 +137,10 @@ int CamApp::parseOptions(int argc, char *argv[])
>                          "Display viewfinder through DRM/KMS on specified connector",
>                          "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"
> diff --git a/src/cam/main.h b/src/cam/main.h
> index 62f7bbc9..2b285808 100644
> --- a/src/cam/main.h
> +++ b/src/cam/main.h
> @@ -18,6 +18,7 @@ enum {
>         OptListProperties = 'p',
>         OptMonitor = 'm',
>         OptStream = 's',
> +       OptSDL = 'S',
>         OptListControls = 256,
>         OptStrictFormats = 257,
>         OptMetadata = 258,
> diff --git a/src/cam/meson.build b/src/cam/meson.build
> index 5bab8c9e..3032730b 100644
> --- a/src/cam/meson.build
> +++ b/src/cam/meson.build
> @@ -32,11 +32,23 @@ if libdrm.found()
>      ])
>  endif
>  
> +libsdl2 = dependency('SDL2', required : false)
> +
> +if libsdl2.found()
> +    cam_cpp_args += ['-DHAVE_SDL']
> +    cam_sources += files([
> +        'sdl_sink.cpp',
> +        'sdl_texture.cpp',
> +        'sdl_texture_yuyv.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..6fbeaf56
> --- /dev/null
> +++ b/src/cam/sdl_sink.cpp
> @@ -0,0 +1,192 @@
> +/* 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 "sdl_texture_yuyv.h"
> +
> +#include "event_loop.h"
> +#include "image.h"
> +
> +using namespace libcamera;
> +
> +SDLSink::SDLSink()
> +       : sdlWindow_(nullptr), sdlRenderer_(nullptr), sdlRect_({}),
> +         sdlInit_(false)
> +{
> +}
> +
> +SDLSink::~SDLSink()
> +{
> +       stop();
> +}
> +
> +int SDLSink::configure(const libcamera::CameraConfiguration &config)
> +{
> +       int ret = FrameSink::configure(config);
> +       if (ret < 0)
> +               return ret;
> +
> +       if (config.size() > 1) {
> +               std::cerr
> +                       << "SDL sink only supports one camera stream at present, streaming first camera stream"
> +                       << std::endl;
> +       } else if (config.empty()) {
> +               std::cerr << "Require at least one camera stream to process"
> +                         << std::endl;
> +               return -EINVAL;
> +       }
> +
> +       const libcamera::StreamConfiguration &cfg = config.at(0);
> +       sdlRect_.w = cfg.size.width;
> +       sdlRect_.h = cfg.size.height;
> +
> +       switch (cfg.pixelFormat) {
> +       case libcamera::formats::YUYV:
> +               sdlTexture_ = std::make_unique<SDLTextureYUYV>(sdlRect_);
> +               break;
> +       default:
> +               std::cerr << "Unsupported pixel format "
> +                         << cfg.pixelFormat.toString() << std::endl;
> +               return -EINVAL;
> +       };
> +
> +       return 0;
> +}
> +
> +int SDLSink::start()
> +{
> +       int ret = SDL_Init(SDL_INIT_VIDEO);
> +       if (ret) {
> +               std::cerr << "Failed to initialize SDL: " << SDL_GetError()
> +                         << std::endl;
> +               return ret;
> +       }
> +
> +       sdlInit_ = true;
> +       sdlWindow_ = SDL_CreateWindow("", SDL_WINDOWPOS_UNDEFINED,
> +                                     SDL_WINDOWPOS_UNDEFINED, sdlRect_.w,
> +                                     sdlRect_.h,
> +                                     SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE);
> +       if (!sdlWindow_) {
> +               std::cerr << "Failed to create SDL window: " << SDL_GetError()
> +                         << std::endl;
> +               return -EINVAL;
> +       }
> +
> +       sdlRenderer_ = SDL_CreateRenderer(sdlWindow_, -1, 0);
> +       if (!sdlRenderer_) {
> +               std::cerr << "Failed to create SDL renderer: " << SDL_GetError()
> +                         << std::endl;
> +               return -EINVAL;
> +       }
> +
> +       ret = SDL_RenderSetLogicalSize(sdlRenderer_, sdlRect_.w, sdlRect_.h);
> +       if (ret) { /* Not critical to set, don't return in this case, set for scaling purposes */
> +               std::cerr << "Failed to set SDL render logical size: "
> +                         << SDL_GetError() << std::endl;
> +       }
> +
> +       ret = sdlTexture_->create(sdlRenderer_);
> +       if (ret) {
> +               return ret;
> +       }
> +
> +       EventLoop::instance()->addTimerEvent(
> +               10ms, std::bind(&SDLSink::processSDLEvents, this));
> +
> +       return 0;
> +}
> +
> +int SDLSink::stop()
> +{
> +       if (sdlTexture_) {
> +               sdlTexture_->destroy();
> +               sdlTexture_ = nullptr;
> +       }
> +
> +       if (sdlRenderer_) {
> +               SDL_DestroyRenderer(sdlRenderer_);
> +               sdlRenderer_ = nullptr;
> +       }
> +
> +       if (sdlWindow_) {
> +               SDL_DestroyWindow(sdlWindow_);
> +               sdlWindow_ = nullptr;
> +       }
> +
> +       if (sdlInit_) {
> +               SDL_Quit();
> +               sdlInit_ = false;
> +       }
> +
> +       return FrameSink::stop();
> +}
> +
> +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()) {
> +               renderBuffer(buffer);
> +               break; /* to be expanded to launch SDL window per buffer */
> +       }
> +
> +       return true;
> +}
> +
> +/*
> + * Process SDL events, required for things like window resize and quit button
> + */
> +void SDLSink::processSDLEvents()
> +{
> +       for (SDL_Event e; SDL_PollEvent(&e);) {
> +               if (e.type == SDL_QUIT) {
> +                       /* Click close icon then quit */
> +                       EventLoop::instance()->exit(0);
> +               }
> +       }
> +}
> +
> +void SDLSink::renderBuffer(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;
> +
> +               sdlTexture_->update(data);
> +       }
> +
> +       SDL_RenderClear(sdlRenderer_);
> +       SDL_RenderCopy(sdlRenderer_, sdlTexture_->ptr_, nullptr, nullptr);
> +       SDL_RenderPresent(sdlRenderer_);
> +}
> diff --git a/src/cam/sdl_sink.h b/src/cam/sdl_sink.h
> new file mode 100644
> index 00000000..37dd9f7e
> --- /dev/null
> +++ b/src/cam/sdl_sink.h
> @@ -0,0 +1,48 @@
> +/* 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"
> +#include "sdl_texture.h"
> +
> +class Image;
> +
> +class SDLSink : public FrameSink
> +{
> +public:
> +       SDLSink();
> +       ~SDLSink();
> +
> +       int configure(const libcamera::CameraConfiguration &config) override;
> +       int start() override;
> +       int stop() override;
> +       void mapBuffer(libcamera::FrameBuffer *buffer) override;
> +
> +       bool processRequest(libcamera::Request *request) override;
> +
> +private:
> +       void renderBuffer(libcamera::FrameBuffer *buffer);
> +       void processSDLEvents();
> +
> +       std::map<libcamera::FrameBuffer *, std::unique_ptr<Image>>
> +               mappedBuffers_;
> +
> +       std::unique_ptr<SDLTexture> sdlTexture_;
> +
> +       SDL_Window *sdlWindow_;
> +       SDL_Renderer *sdlRenderer_;
> +       SDL_Rect sdlRect_;
> +       SDL_PixelFormatEnum pixelFormat_;
> +       bool sdlInit_;
> +};
> diff --git a/src/cam/sdl_texture.cpp b/src/cam/sdl_texture.cpp
> new file mode 100644
> index 00000000..b39080c9
> --- /dev/null
> +++ b/src/cam/sdl_texture.cpp
> @@ -0,0 +1,32 @@
> +#include "sdl_texture.h"
> +
> +#include <iostream>
> +
> +SDLTexture::SDLTexture(const SDL_Rect &sdlRect, SDL_PixelFormatEnum pixelFormat,
> +                      const int pitch)
> +       : sdlRect_(sdlRect), pixelFormat_(pixelFormat), pitch_(pitch)
> +{
> +}
> +
> +SDLTexture::~SDLTexture()
> +{
> +}
> +
> +int SDLTexture::create(SDL_Renderer *sdlRenderer_)
> +{
> +       ptr_ = SDL_CreateTexture(sdlRenderer_, pixelFormat_,
> +                                SDL_TEXTUREACCESS_STREAMING, sdlRect_.w,
> +                                sdlRect_.h);
> +       if (!ptr_) {
> +               std::cerr << "Failed to create SDL texture: " << SDL_GetError()
> +                         << std::endl;
> +               return -ENOMEM;
> +       }
> +
> +       return 0;
> +}
> +
> +void SDLTexture::destroy()
> +{
> +       SDL_DestroyTexture(ptr_);
> +}
> diff --git a/src/cam/sdl_texture.h b/src/cam/sdl_texture.h
> new file mode 100644
> index 00000000..f9525f7f
> --- /dev/null
> +++ b/src/cam/sdl_texture.h
> @@ -0,0 +1,23 @@
> +#pragma once
> +
> +#include <SDL2/SDL.h>
> +
> +#include "image.h"
> +
> +class SDLTexture
> +{
> +public:
> +       SDLTexture(const SDL_Rect &sdlRect, SDL_PixelFormatEnum pixelFormat,
> +                  const int pitch);
> +       virtual ~SDLTexture();
> +       int create(SDL_Renderer *sdlRenderer_);
> +       void destroy();
> +       virtual void update(const libcamera::Span<uint8_t> &data) = 0;
> +
> +       SDL_Texture *ptr_;
> +
> +protected:
> +       const SDL_Rect &sdlRect_;
> +       SDL_PixelFormatEnum pixelFormat_;
> +       const int pitch_;
> +};
> diff --git a/src/cam/sdl_texture_yuyv.cpp b/src/cam/sdl_texture_yuyv.cpp
> new file mode 100644
> index 00000000..cf519a5d
> --- /dev/null
> +++ b/src/cam/sdl_texture_yuyv.cpp
> @@ -0,0 +1,13 @@
> +#include "sdl_texture_yuyv.h"
> +
> +using namespace libcamera;
> +
> +SDLTextureYUYV::SDLTextureYUYV(const SDL_Rect &sdlRect)
> +       : SDLTexture(sdlRect, SDL_PIXELFORMAT_YUY2, 4 * ((sdlRect.w + 1) / 2))
> +{
> +}
> +
> +void SDLTextureYUYV::update(const Span<uint8_t> &data)
> +{
> +       SDL_UpdateTexture(ptr_, &sdlRect_, data.data(), pitch_);
> +}
> diff --git a/src/cam/sdl_texture_yuyv.h b/src/cam/sdl_texture_yuyv.h
> new file mode 100644
> index 00000000..ad70f14f
> --- /dev/null
> +++ b/src/cam/sdl_texture_yuyv.h
> @@ -0,0 +1,10 @@
> +#pragma once
> +
> +#include "sdl_texture.h"
> +
> +class SDLTextureYUYV : public SDLTexture
> +{
> +public:
> +       SDLTextureYUYV(const SDL_Rect &sdlRect);
> +       void update(const libcamera::Span<uint8_t> &data) override;
> +};
> -- 
> 2.35.1
>


More information about the libcamera-devel mailing list