backport #103

Author: bjsowa

src/image_streamer.cpp

@@ -139,10 +139,9 @@ void ImageTransportImageStreamer::imageCallback(const sensor_msgs::msg::Image::C
     int input_width = img.cols;
     int input_height = img.rows;
 
-    if (output_width_ == -1)
-      output_width_ = input_width;
-    if (output_height_ == -1)
-      output_height_ = input_height;
+    
+    output_width_ = input_width;
+    output_height_ = input_height;
 
     if (invert_)
     {
@@ -171,8 +170,7 @@ void ImageTransportImageStreamer::imageCallback(const sensor_msgs::msg::Image::C
     }
 
     last_frame = nh_->now();
-    sendImage(output_size_image, last_frame );
-
+    sendImage(output_size_image, msg->header.stamp);
   }
   catch (cv_bridge::Exception &e)
   {

src/libav_streamer.cpp

@@ -20,13 +20,19 @@ LibavStreamer::LibavStreamer(const async_web_server_cpp::HttpRequest &request,
   bitrate_ = request.get_query_param_value_or_default<int>("bitrate", 100000);
   qmin_ = request.get_query_param_value_or_default<int>("qmin", 10);
   qmax_ = request.get_query_param_value_or_default<int>("qmax", 42);
-  gop_ = request.get_query_param_value_or_default<int>("gop", 250);
+  gop_ = request.get_query_param_value_or_default<int>("gop", 25);
 }
 
 LibavStreamer::~LibavStreamer()
 {
   if (codec_context_)
+  {
+    #if ( LIBAVCODEC_VERSION_INT  < AV_VERSION_INT(58,9,100) )
     avcodec_close(codec_context_);
+    #else
+    avcodec_free_context(&codec_context_);
+    #endif
+  }
   if (frame_)
   {
     av_frame_free(&frame_);
@@ -89,6 +95,7 @@ void LibavStreamer::initialize(const cv::Mat &img)
   }
   io_ctx->seekable = 0;                       // no seeking, it's a stream
   format_context_->pb = io_ctx;
+  format_context_->max_interleave_delta = 0;
   output_format_.flags |= AVFMT_FLAG_CUSTOM_IO;
   output_format_.flags |= AVFMT_NOFILE;
 
@@ -136,11 +143,12 @@ void LibavStreamer::initialize(const cv::Mat &img)
   codec_context_->qmin = qmin_;
   codec_context_->qmax = qmax_;
 
+  avcodec_parameters_from_context(video_stream_->codecpar, codec_context_);
+
   initializeEncoder();
 
-  // Some formats want stream headers to be separate
-  if (format_context_->oformat->flags & AVFMT_GLOBALHEADER)
-    codec_context_->flags |= CODEC_FLAG_GLOBAL_HEADER;
+  codec_context_->flags |= AV_CODEC_FLAG_LOW_DELAY;
+  codec_context_->max_b_frames = 0;
 
   // Open Codec
   if (avcodec_open2(codec_context_, codec_, NULL) < 0)
@@ -228,16 +236,38 @@ void LibavStreamer::sendImage(const cv::Mat &img, const rclcpp::Time &time)
   // Encode the frame
   AVPacket* pkt = av_packet_alloc();
 
-  if (avcodec_send_frame(codec_context_, frame_) < 0)
+  ret = avcodec_send_frame(codec_context_, frame_);
+  if (ret == AVERROR_EOF)
+  {
+    std::cerr << "avcodec_send_frame() encoder flushed\n";
+    // ROS_DEBUG_STREAM("avcodec_send_frame() encoder flushed");
+  }
+  else if (ret == AVERROR(EAGAIN))
   {
+    std::cerr << "avcodec_send_frame() need output read out\n";
+    // ROS_DEBUG_STREAM("avcodec_send_frame() need output read out");
+  }
+  if (ret < 0)
+  {
+    // std::cerr << "Error encoding video frame\n";
     throw std::runtime_error("Error encoding video frame");
   }
-  if (avcodec_receive_packet(codec_context_, pkt) < 0)
+
+  ret = avcodec_receive_packet(codec_context_, pkt);
+  bool got_packet = pkt->size > 0;
+  if (ret == AVERROR_EOF)
+  {
+    std::cerr << "avcodec_recieve_packet() encoder flushed\n";
+    // ROS_DEBUG_STREAM("avcodec_recieve_packet() encoder flushed");
+  }
+  else if (ret == AVERROR(EAGAIN))
   {
-    throw std::runtime_error("Error retrieving encoded packet");
+    std::cerr << "avcodec_recieve_packet() need more input\n";
+    // ROS_DEBUG_STREAM("avcodec_recieve_packet() need more input");
+    got_packet = false;
   }
 
-  if (pkt->size > 0)
+  if (got_packet)
   {
     std::size_t size;
     uint8_t *output_buf;