Add MMAL renderer for Raspberry Pi

app/app.pro

@@ -94,6 +94,11 @@ unix:!macx {
         packagesExist(vdpau) {
             CONFIG += libvdpau
         }
+
+        packagesExist(mmal) {
+            PKGCONFIG += mmal
+            CONFIG += mmal
+        }
     }
 }
 win32 {
@@ -213,6 +218,13 @@ libvdpau {
     SOURCES += streaming/video/ffmpeg-renderers/vdpau.cpp
     HEADERS += streaming/video/ffmpeg-renderers/vdpau.h
 }
+mmal {
+    message(MMAL renderer selected)
+
+    DEFINES += HAVE_MMAL
+    SOURCES += streaming/video/ffmpeg-renderers/mmal.cpp
+    HEADERS += streaming/video/ffmpeg-renderers/mmal.h
+}
 config_SL {
     message(Steam Link build configuration selected)
 

app/streaming/video/ffmpeg-renderers/mmal.cpp

@@ -0,0 +1,145 @@
+#include "mmal.h"
+
+#include "streaming/streamutils.h"
+#include "streaming/session.h"
+
+#include <Limelight.h>
+
+MmalRenderer::MmalRenderer()
+    : m_Renderer(nullptr),
+      m_InputPort(nullptr)
+{
+}
+
+MmalRenderer::~MmalRenderer()
+{
+    if (m_InputPort != nullptr) {
+        mmal_port_disable(m_InputPort);
+    }
+
+    if (m_Renderer != nullptr) {
+        mmal_component_destroy(m_Renderer);
+    }
+}
+
+bool MmalRenderer::prepareDecoderContext(AVCodecContext*)
+{
+    /* Nothing to do */
+
+    SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                "Using MMAL renderer");
+
+    return true;
+}
+
+bool MmalRenderer::initialize(PDECODER_PARAMETERS params)
+{
+    MMAL_STATUS_T status;
+
+    status = mmal_component_create(MMAL_COMPONENT_DEFAULT_VIDEO_RENDERER, &m_Renderer);
+    if (status != MMAL_SUCCESS) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "mmal_component_create() failed: %x (%s)",
+                     status, mmal_status_to_string(status));
+        return false;
+    }
+
+    m_InputPort = m_Renderer->input[0];
+
+    m_InputPort->format->encoding = MMAL_ENCODING_OPAQUE;
+    m_InputPort->format->es->video.width = params->width;
+    m_InputPort->format->es->video.height = params->height;
+    m_InputPort->format->es->video.crop.x = 0;
+    m_InputPort->format->es->video.crop.y = 0;
+    m_InputPort->format->es->video.crop.width = params->width;
+    m_InputPort->format->es->video.crop.height = params->height;
+    status = mmal_port_format_commit(m_InputPort);
+    if (status != MMAL_SUCCESS) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "mmal_port_format_commit() failed: %x (%s)",
+                     status, mmal_status_to_string(status));
+        return false;
+    }
+
+    status = mmal_component_enable(m_Renderer);
+    if (status != MMAL_SUCCESS) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "mmal_component_enable() failed: %x (%s)",
+                     status, mmal_status_to_string(status));
+        return false;
+    }
+
+    {
+        MMAL_DISPLAYREGION_T dr;
+
+        dr.hdr.id = MMAL_PARAMETER_DISPLAYREGION;
+        dr.hdr.size = sizeof(MMAL_DISPLAYREGION_T);
+
+        dr.set = MMAL_DISPLAY_SET_LAYER;
+        dr.layer = 128;
+
+        dr.set |= MMAL_DISPLAY_SET_ALPHA;
+        dr.alpha = 255;
+
+        dr.set |= MMAL_DISPLAY_SET_FULLSCREEN;
+        dr.fullscreen = (SDL_GetWindowFlags(params->window) & SDL_WINDOW_FULLSCREEN) != 0;
+
+        {
+            SDL_Rect src, dst;
+            src.x = src.y = 0;
+            src.w = params->width;
+            src.h = params->height;
+            dst.x = dst.y = 0;
+            SDL_GetWindowSize(params->window, &dst.w, &dst.h);
+
+            StreamUtils::scaleSourceToDestinationSurface(&src, &dst);
+
+            dr.set |= MMAL_DISPLAY_SET_DEST_RECT;
+            dr.dest_rect.x = dst.x;
+            dr.dest_rect.y = dst.y;
+            dr.dest_rect.width = dst.w;
+            dr.dest_rect.height = dst.h;
+        }
+    }
+
+    status = mmal_port_enable(m_InputPort, InputPortCallback);
+    if (status != MMAL_SUCCESS) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "mmal_port_enable() failed: %x (%s)",
+                     status, mmal_status_to_string(status));
+        return false;
+    }
+
+    return true;
+}
+
+void MmalRenderer::InputPortCallback(MMAL_PORT_T*, MMAL_BUFFER_HEADER_T* buffer)
+{
+    mmal_buffer_header_release(buffer);
+}
+
+enum AVPixelFormat MmalRenderer::getPreferredPixelFormat(int videoFormat)
+{
+    // Opaque MMAL buffers
+    SDL_assert(videoFormat == VIDEO_FORMAT_H264);
+    return AV_PIX_FMT_MMAL;
+}
+
+void MmalRenderer::renderFrame(AVFrame* frame)
+{
+    MMAL_BUFFER_HEADER_T* buffer = (MMAL_BUFFER_HEADER_T*)frame->data[3];
+    MMAL_STATUS_T status;
+
+    status = mmal_port_send_buffer(m_InputPort, buffer);
+    if (status != MMAL_SUCCESS) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "mmal_port_send_buffer() failed: %x (%s)",
+                     status, mmal_status_to_string(status));
+    }
+    else {
+        // Prevent the buffer from being freed during av_frame_free()
+        // until rendering is complete. The reference is dropped in
+        // InputPortCallback().
+        mmal_buffer_header_acquire(buffer);
+    }
+}

app/streaming/video/ffmpeg-renderers/mmal.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include "renderer.h"
+
+#include <interface/mmal/mmal.h>
+#include <interface/mmal/util/mmal_util.h>
+#include <interface/mmal/util/mmal_util_params.h>
+#include <interface/mmal/util/mmal_default_components.h>
+
+class MmalRenderer : public IFFmpegRenderer {
+public:
+    MmalRenderer();
+    virtual ~MmalRenderer() override;
+    virtual bool initialize(PDECODER_PARAMETERS params) override;
+    virtual bool prepareDecoderContext(AVCodecContext* context) override;
+    virtual void renderFrame(AVFrame* frame) override;
+    virtual enum AVPixelFormat getPreferredPixelFormat(int videoFormat) override;
+
+private:
+    static void InputPortCallback(MMAL_PORT_T* port, MMAL_BUFFER_HEADER_T* buffer);
+
+    MMAL_COMPONENT_T* m_Renderer;
+    MMAL_PORT_T* m_InputPort;
+};
+

app/streaming/video/ffmpeg.cpp

@@ -23,6 +23,10 @@
 #include "ffmpeg-renderers/vdpau.h"
 #endif
 
+#ifdef HAVE_MMAL
+#include "ffmpeg-renderers/mmal.h"
+#endif
+
 // This is gross but it allows us to use sizeof()
 #include "ffmpeg_videosamples.cpp"
 
@@ -463,6 +467,23 @@ bool FFmpegVideoDecoder::initialize(PDECODER_PARAMETERS params)
         }
     }
 
+#ifdef HAVE_MMAL
+    if ((params->videoFormat & VIDEO_FORMAT_MASK_H264) &&
+        (params->vds != StreamingPreferences::VDS_FORCE_SOFTWARE)) {
+        AVCodec* mmalDecoder = avcodec_find_decoder_by_name("h264_mmal");
+        if (mmalDecoder) {
+            m_BackendRenderer = new MmalRenderer();
+            if (m_BackendRenderer->initialize(params) &&
+                completeInitialization(mmalDecoder, params, m_TestOnly)) {
+                return true;
+            }
+            else {
+                reset();
+            }
+        }
+    }
+#endif
+
     // We must fall back to a non-hardware accelerated decoder as
     // all other possibilities have been exhausted.
     m_HwDecodeCfg = nullptr;