[WIP] OpenCV-free BGRA capture using Epiphan DVI2PCIe Duo

src/CMakeLists.txt

@@ -264,7 +264,9 @@ if(USE_EPIPHANSDK)
 
     INCLUDE_DIRECTORIES(epiphansdk)
     LIST(APPEND HEADERS epiphansdk/epiphansdk_video_source.h)
+    LIST(APPEND HEADERS epiphansdk/rgb_to_bgra_converter.h)
     LIST(APPEND SOURCES epiphansdk/epiphansdk_video_source.cpp)
+    LIST(APPEND SOURCES epiphansdk/rgb_to_bgra_converter.cpp)
 endif(USE_EPIPHANSDK)
 
 # Blackmagic SDK video source

src/api/videosourcefactory.cpp

@@ -63,11 +63,12 @@ IVideoSource * VideoSourceFactory::get_device(Device device,
 
         // BGRA ========================================
         case BGRA:
-#ifdef USE_OPENCV
-            src = new VideoSourceOpenCV(0);
+#ifdef USE_EPIPHANSDK
+            src = new VideoSourceEpiphanSDK(Epiphan_DVI2PCIeDuo_DVI,
+                                            V2U_GRABFRAME_FORMAT_RGB24);
 #else
             throw VideoSourceError(
-                "BGRA colour space on Epiphan DVI2PCIe Duo supported only with OpenCV");
+                "BGRA colour space on Epiphan DVI2PCIe Duo supported only with Epiphan SDK");
 #endif
             break;
 
@@ -115,11 +116,12 @@ IVideoSource * VideoSourceFactory::get_device(Device device,
 
         // BGRA ========================================
         case BGRA:
-#ifdef USE_OPENCV
-            src = new VideoSourceOpenCV(1);
+#ifdef USE_EPIPHANSDK
+            src = new VideoSourceEpiphanSDK(Epiphan_DVI2PCIeDuo_SDI,
+                                            V2U_GRABFRAME_FORMAT_RGB24);
 #else
             throw VideoSourceError(
-                "BGRA colour space on Epiphan DVI2PCIe Duo supported only with OpenCV");
+                "BGRA colour space on Epiphan DVI2PCIe Duo supported only with Epiphan SDK");
 #endif
             break;
 

src/epiphansdk/epiphansdk_video_source.cpp

@@ -10,6 +10,8 @@ VideoSourceEpiphanSDK::VideoSourceEpiphanSDK(
     , _frame_grabber(nullptr)
     , _flags(0)
     , _daemon(nullptr)
+    , _bgra_data(nullptr)
+    , _buffer(nullptr)
 {
     FrmGrab_Init();
 
@@ -21,7 +23,7 @@ VideoSourceEpiphanSDK::VideoSourceEpiphanSDK(
         return;
     }
 
-    if (colour_space != V2U_GRABFRAME_FORMAT_I420 and colour_space != V2U_GRABFRAME_FORMAT_BGR24)
+    if (colour_space != V2U_GRABFRAME_FORMAT_I420 and colour_space != V2U_GRABFRAME_FORMAT_RGB24)
     {
         // TODO - exception GiftGrab#42
         std::cerr << "Colour space " << colour_space << " not supported" << std::endl;
@@ -30,7 +32,10 @@ VideoSourceEpiphanSDK::VideoSourceEpiphanSDK(
     else if (colour_space == V2U_GRABFRAME_FORMAT_I420)
         _colour = I420;
     else
+    {
         _colour = BGRA;
+        _flags |= V2U_GRABFRAME_BOTTOM_UP_FLAG; // for some reason without this the image is flipped
+    }
     _flags |= colour_space;
 
     VideoFrame frame(_colour);
@@ -42,6 +47,12 @@ VideoSourceEpiphanSDK::VideoSourceEpiphanSDK(
      */
     _full.width = 1920;
     _full.height = 1080;
+    if (_colour == BGRA)
+    {
+        _bgra_data = reinterpret_cast<unsigned char*>(malloc(
+            4 * _full.width * _full.height * sizeof(unsigned char)
+        ));
+    }
     get_full_frame();
     // TODO - exception GiftGrab#42
     if (not get_frame(frame)) return;
@@ -55,6 +66,11 @@ VideoSourceEpiphanSDK::~VideoSourceEpiphanSDK()
     delete _daemon;
     if (_frame_grabber) FrmGrab_Close(_frame_grabber);
     FrmGrab_Deinit();
+    if (_colour == BGRA && _bgra_data != nullptr)
+    {
+        free(_bgra_data);
+        _bgra_data = nullptr;
+    }
 }
 
 bool VideoSourceEpiphanSDK::get_frame_dimensions(int & width, int & height)
@@ -70,21 +86,42 @@ bool VideoSourceEpiphanSDK::get_frame(VideoFrame & frame)
         // TODO - exception GiftGrab#42
         return false;
 
+    std::lock_guard<std::mutex> buffer_lock_guard(_buffer_lock);
+
     _buffer = FrmGrab_Frame(_frame_grabber, _flags, &_roi);
     if (_buffer)
     {
+        unsigned char *data = static_cast<unsigned char*>(_buffer->pixbuf);
+        size_t frame_data_length = _buffer->imagelen;
+        /* TODO #54 specified _roi not always
+         * respected by FrmGrab_Frame, hence
+         * constructing with _buffer->crop
+         * instead of _roi to avoid alignment
+         * problems when saving to video files
+         */
+        size_t frame_width = _buffer->crop.width,
+               frame_height = _buffer->crop.height;
+        unsigned char *frame_data = nullptr;
+        switch(_colour)
+        {
+        case I420:
+            frame_data = data;
+            break;
+        case BGRA:
+            _rgb_to_bgra.set_frame_dimensions(frame_width, frame_height);
+            _rgb_to_bgra.convert(data, _bgra_data);
+            frame_data = _bgra_data;
+            break;
+        default:
+            // TODO
+            break;
+        }
         frame.init_from_specs(
-                    static_cast<unsigned char*>(_buffer->pixbuf),
-                    _buffer->imagelen,
-                    /* TODO #54 specified _roi not always
-                     * respected by FrmGrab_Frame, hence
-                     * constructing with _buffer->crop
-                     * instead of _roi to avoid alignment
-                     * problems when saving to video files
-                     */
-                    _buffer->crop.width, _buffer->crop.height
-                    );
+            frame_data, frame_data_length,
+            frame_width, frame_height
+        );
         FrmGrab_Release(_frame_grabber, _buffer);
+        _buffer = nullptr;
         return true;
     }
     else
@@ -93,6 +130,7 @@ bool VideoSourceEpiphanSDK::get_frame(VideoFrame & frame)
 
 double VideoSourceEpiphanSDK::get_frame_rate()
 {
+    double frame_rate = -1;
     if (_frame_grabber)
     {
 #if defined(Epiphan_DVI2PCIeDuo_DVI) and \
@@ -101,9 +139,18 @@ double VideoSourceEpiphanSDK::get_frame_rate()
     defined(Epiphan_DVI2PCIeDuo_SDI_MAX_FRAME_RATE)
         std::string port_id = FrmGrab_GetId(_frame_grabber);
         if (port_id == Epiphan_DVI2PCIeDuo_DVI)
-            return Epiphan_DVI2PCIeDuo_DVI_MAX_FRAME_RATE;
+            frame_rate = Epiphan_DVI2PCIeDuo_DVI_MAX_FRAME_RATE;
         else if (port_id == Epiphan_DVI2PCIeDuo_SDI)
-            return Epiphan_DVI2PCIeDuo_SDI_MAX_FRAME_RATE;
+            frame_rate = Epiphan_DVI2PCIeDuo_SDI_MAX_FRAME_RATE;
+        if (frame_rate > 0)
+        {
+            /* The above max frame rates are defined for I420,
+             * and are halved for BGRA, due to hardware bandwidth
+             */
+            if (_colour == BGRA)
+                frame_rate /= 2.0;
+            return frame_rate;
+        }
 #endif
     }
 

src/epiphansdk/epiphansdk_video_source.h

@@ -3,6 +3,7 @@
 #include "ivideosource.h"
 #include "macros.h"
 #include "broadcastdaemon.h"
+#include "rgb_to_bgra_converter.h"
 
 namespace gg
 {
@@ -37,11 +38,28 @@ class VideoSourceEpiphanSDK : public IVideoSource
     //!
     V2U_GrabFrame2 * _buffer;
 
+    //!
+    //! \brief This mutex to be locked when
+    //! accessing the buffer
+    //! \sa _buffer
+    //!
+    std::mutex _buffer_lock;
+
     //!
     //! \brief
     //!
     gg::BroadcastDaemon * _daemon;
 
+    //!
+    //! \brief Buffer for converting from RGB to BGRA
+    //!
+    unsigned char *_bgra_data;
+
+    //!
+    //! \brief RGB to BGRA converter
+    //!
+    RgbToBgraConverter _rgb_to_bgra;
+
 public:
     //!
     //! \brief Connects to specified port of an Epiphan
@@ -50,7 +68,7 @@ class VideoSourceEpiphanSDK : public IVideoSource
     //! as \c \#define'd in Epiphan device properties
     //! header
     //! \param colour_space \c V2U_GRABFRAME_FORMAT_I420
-    //! or \c V2U_GRABFRAME_FORMAT_BGR24
+    //! or \c V2U_GRABFRAME_FORMAT_RGB24
     //! \throw VideoSourceError if connection attempt
     //! fails, with a detailed error message
     //!

src/epiphansdk/rgb_to_bgra_converter.cpp

@@ -0,0 +1,68 @@
+#include "rgb_to_bgra_converter.h"
+#include <assert.h>
+
+namespace gg
+{
+
+RgbToBgraConverter::RgbToBgraConverter()
+    : _width(0)
+    , _height(0)
+#ifdef USE_FFMPEG
+    , _sws_context(nullptr)
+#endif
+{
+
+}
+
+RgbToBgraConverter::~RgbToBgraConverter()
+{
+#ifdef USE_FFMPEG
+    sws_freeContext(_sws_context);
+    _sws_context = nullptr;
+#endif
+}
+
+void RgbToBgraConverter::convert(unsigned char *rgb,
+                                 unsigned char *bgra)
+{
+#ifdef USE_FFMPEG
+    _sws_srcSlice[0] = rgb;
+    _sws_srcStride[0] = 3 * _width;
+    _sws_dst[0] = bgra;
+    _sws_dstStride[0] = 4 * _width;
+    sws_scale(_sws_context,
+              _sws_srcSlice, _sws_srcStride, 0, _height,
+              _sws_dst, _sws_dstStride);
+#else
+    size_t length = 4 * _width * _height;
+    for (size_t i = 0, j = 0; i < length; i += 4, j += 3)
+    {
+        bgra[i] = rgb[j+2];
+        bgra[i+1] = rgb[j+1];
+        bgra[i+2] = rgb[j];
+        bgra[i+3] = 255;
+    }
+#endif
+}
+
+void RgbToBgraConverter::set_frame_dimensions(size_t width,
+                                              size_t height)
+{
+    assert(width > 0);
+    assert(height > 0);
+    if (_width == width and _height == height)
+        return;
+
+    _width = width;
+    _height = height;
+#ifdef USE_FFMPEG
+    _sws_context = sws_getCachedContext(
+                _sws_context,
+                _width, _height, _sws_srcFormat,
+                _width, _height, _sws_dstFormat,
+                0, nullptr, nullptr, nullptr       // advanced
+                );
+#endif
+}
+
+}

src/epiphansdk/rgb_to_bgra_converter.h

@@ -0,0 +1,77 @@
+#pragma once
+
+#include <cstdlib>
+#ifdef USE_FFMPEG
+extern "C" {
+#include <libswscale/swscale.h>
+}
+#endif
+
+namespace gg
+{
+
+//!
+//! \brief Epiphan SDK seems to support RGB but not BGRA.
+//! This class abstracts the conversion of captured RGB
+//! data to BGRA.
+//! \sa VideoSourceEpiphanSDK
+//!
+class RgbToBgraConverter
+{
+protected:
+    //!
+    //! \brief Width of frames passed for conversion
+    //!
+    size_t _width;
+
+    //!
+    //! \brief Height of frames passed for conversion
+    //!
+    size_t _height;
+
+#ifdef USE_FFMPEG
+    unsigned char *_sws_srcSlice[1];
+    int _sws_srcStride[1];
+    unsigned char *_sws_dst[1];
+    int _sws_dstStride[1];
+    AVPixelFormat _sws_srcFormat = AV_PIX_FMT_RGB24;
+    AVPixelFormat _sws_dstFormat = AV_PIX_FMT_BGRA;
+    SwsContext *_sws_context;
+#endif
+
+public:
+    //!
+    //! \brief Create a converter, which should be
+    //! initialised by informing it of the frame
+    //! dimensions
+    //! \sa set_frame_dimensions
+    //!
+    RgbToBgraConverter();
+
+    //!
+    //! \brief Free all allocated resources
+    //!
+    ~RgbToBgraConverter();
+
+public:
+    //!
+    //! \brief Convert RGB data in passed buffer to BGRA
+    //! data, saving it into the passed output buffer.
+    //! \param rgb should be in line with the frame
+    //! dimensions set before
+    //! \param bgra should be at least as large as the
+    //! input buffer
+    //! \sa set_frame_dimensions
+    //!
+    void convert(unsigned char *rgb, unsigned char *bgra);
+
+    //!
+    //! \brief Allocate all resources needed for RGB to
+    //! BGRA conversion based on passed frame dimensions
+    //! \param width
+    //! \param height
+    //!
+    void set_frame_dimensions(size_t width, size_t height);
+};
+
+}

src/tests/CMakeLists.txt

@@ -74,3 +74,6 @@ endif(USE_FILES)
 
 # VideoSourceFactory leak checker
 ADD_SUBDIRECTORY(videosourcefactory)
+
+# Simple colour space conversion profiling
+ADD_SUBDIRECTORY(rgbswap)

src/tests/rgbswap/CMakeLists.txt

@@ -0,0 +1,14 @@
+SET(RGB_TO_BGRA_PROFILER rgb_to_bgra_profiler)
+ADD_EXECUTABLE(
+    ${RGB_TO_BGRA_PROFILER}
+    ${CMAKE_SOURCE_DIR}/tests/rgbswap/profile_rgb_to_bgra.cpp
+)
+if(USE_FFMPEG)
+    LIST(APPEND RGB_TO_BGRA_PROFILER_LIBS ${FFmpeg_LIBS})
+endif(USE_FFMPEG)
+if(USE_OPENCV)
+    LIST(APPEND RGB_TO_BGRA_PROFILER_LIBS ${OpenCV_LIBS})
+endif(USE_OPENCV)
+TARGET_LINK_LIBRARIES(
+    ${RGB_TO_BGRA_PROFILER} ${RGB_TO_BGRA_PROFILER_LIBS}
+)