refactor(video): use a new ToxAVFrame structure instead of vpx_image

Instead of misusing an existing structure from another library, defines
a new simpler structure that reflects the capabilities of the ToxAV
transport mechanism.

src/core/coreav.cpp

@@ -361,26 +361,20 @@ void CoreAV::sendCallVideo(uint32_t callId, std::shared_ptr<VideoFrame> vframe)
     }
 
     // This frame shares vframe's buffers, we don't call vpx_img_free but just delete it
-    vpx_image* frame = vframe->toVpxImage();
+    ToxAVFrame frame = vframe->toToxAVFrame();
 
-    if(!frame)
+    if(frame.width == 0 || frame.height == 0)
     {
         return;
     }
-    if(frame->fmt == VPX_IMG_FMT_NONE)
-    {
-        qWarning() << "Invalid frame";
-        vpx_img_free(frame);
-        return;
-    }
 
     // TOXAV_ERR_SEND_FRAME_SYNC means toxav failed to lock, retry 5 times in this case
     // We don't want to be dropping iframes because of some lock held by toxav_iterate
     TOXAV_ERR_SEND_FRAME err;
     int retries = 0;
     do {
-        if (!toxav_video_send_frame(toxav, callId, frame->d_w, frame->d_h,
-                                    frame->planes[0], frame->planes[1], frame->planes[2], &err))
+        if (!toxav_video_send_frame(toxav, callId, frame.width, frame.height,
+                                    frame.y, frame.u, frame.v, &err))
         {
             if (err == TOXAV_ERR_SEND_FRAME_SYNC)
             {
@@ -395,8 +389,6 @@ void CoreAV::sendCallVideo(uint32_t callId, std::shared_ptr<VideoFrame> vframe)
     } while (err == TOXAV_ERR_SEND_FRAME_SYNC && retries < 5);
     if (err == TOXAV_ERR_SEND_FRAME_SYNC)
         qDebug() << "toxav_video_send_frame error: Lock busy, dropping frame";
-
-    vpx_img_free(frame);
 }
 
 void CoreAV::micMuteToggle(uint32_t callId)

src/video/videoframe.cpp

@@ -162,7 +162,7 @@ QImage VideoFrame::toQImage(QSize frameSize)
     return ret;
 }
 
-vpx_image* VideoFrame::toVpxImage(QSize frameSize)
+ToxAVFrame VideoFrame::toToxAVFrame(QSize frameSize)
 {
     frameLock.lockForRead();
 
@@ -170,7 +170,7 @@ vpx_image* VideoFrame::toVpxImage(QSize frameSize)
     if(frameBuffer.size() == 0)
     {
         frameLock.unlock();
-        return nullptr;
+        return {0, 0, nullptr, nullptr, nullptr};
     }
 
     if(frameSize.width() == 0 && frameSize.height() == 0)
@@ -182,20 +182,7 @@ vpx_image* VideoFrame::toVpxImage(QSize frameSize)
 
     if(frame)
     {
-        vpx_image* ret = new vpx_image {};
-        memset(ret, 0, sizeof(vpx_image));
-
-        ret->w = ret->d_w = frameSize.width();
-        ret->h = ret->d_h = frameSize.height();
-        ret->fmt = VPX_IMG_FMT_I420;
-        ret->planes[0] = frame->data[0];
-        ret->planes[1] = frame->data[1];
-        ret->planes[2] = frame->data[2];
-        ret->planes[3] = nullptr;
-        ret->stride[0] = frame->linesize[0];
-        ret->stride[1] = frame->linesize[1];
-        ret->stride[2] = frame->linesize[2];
-        ret->stride[3] = frame->linesize[3];
+        ToxAVFrame ret {frameSize.width(), frameSize.height(), frame->data[0], frame->data[1], frame->data[2]};
 
         frameLock.unlock();
         return ret;
@@ -216,20 +203,7 @@ vpx_image* VideoFrame::toVpxImage(QSize frameSize)
 
     storeAVFrame(frame, frameSize, static_cast<int>(AV_PIX_FMT_YUV420P));
 
-    vpx_image* ret = new vpx_image {};
-    memset(ret, 0, sizeof(vpx_image));
-
-    ret->w = ret->d_w = frameSize.width();
-    ret->h = ret->d_h = frameSize.height();
-    ret->fmt = VPX_IMG_FMT_I420;
-    ret->planes[0] = frame->data[0];
-    ret->planes[1] = frame->data[1];
-    ret->planes[2] = frame->data[2];
-    ret->planes[3] = nullptr;
-    ret->stride[0] = frame->linesize[0];
-    ret->stride[1] = frame->linesize[1];
-    ret->stride[2] = frame->linesize[2];
-    ret->stride[3] = frame->linesize[3];
+    ToxAVFrame ret {frameSize.width(), frameSize.height(), frame->data[0], frame->data[1], frame->data[2]};
 
     frameLock.unlock();
     return ret;

src/video/videoframe.h

@@ -29,11 +29,24 @@ extern "C"{
 #include <libavcodec/avcodec.h>
 }
 
-#include <vpx/vpx_image.h>
 #include <functional>
 #include <memory>
 #include <unordered_map>
 
+/**
+ * @brief A simple structure to represent a ToxAV frame.
+ */
+struct ToxAVFrame
+{
+public:
+    const std::uint16_t width;
+    const std::uint16_t height;
+
+    const uint8_t* y;
+    const uint8_t* u;
+    const uint8_t* v;
+};
+
 /**
  * @brief An ownernship and management class for AVFrames.
  *
@@ -145,18 +158,17 @@ public:
     QImage toQImage(QSize frameSize = {0, 0});
 
     /**
-     * @brief Converts this VideoFrame to a vpx_image that shares this VideoFrame's buffer.
+     * @brief Converts this VideoFrame to a ToxAVFrame that shares this VideoFrame's buffer.
      *
-     * Given that libvpx does not provide a way to create vpx_images that uses external buffers,
-     * the vpx_image constructed by this function is done in a non-compliant way, requiring the
-     * use of the C++ delete keyword to properly deallocate memory associated with this image.
+     * The given ToxAVFrame will be frame aligned under a pixel format of planar YUV with a chroma
+     * subsampling format of 4:2:0 (i.e. AV_PIX_FMT_YUV420P).
      *
-     * @param frameSize the given frame size of vpx_image to generate. If frame size is 0, defaults
+     * @param frameSize the given frame size of ToxAVFrame to generate. If frame size is 0, defaults
      * to source frame size.
-     * @return a vpx_image that represents this VideoFrame, sharing it's buffers or nullptr if this
-     * VideoFrame is no longer valid.
+     * @return a ToxAVFrame structure that represents this VideoFrame, sharing it's buffers or an
+     * empty structure if this VideoFrame is no longer valid.
      */
-    vpx_image* toVpxImage(QSize frameSize = {0, 0});
+    ToxAVFrame toToxAVFrame(QSize frameSize = {0, 0});
 
     /**
      * @brief Data alignment parameter used to populate AVFrame buffers.