better error messages, added utility functions

include/ffmpeg_encoder_decoder/utils.hpp

@@ -175,6 +175,21 @@ std::vector<std::string> split_by_char(const std::string & str_list, const char
  * \return true if ROS encoding is single channel and color format is like NV12/yuv420p
  */
 bool encode_single_channel_as_color(const std::string & encoding, enum AVPixelFormat fmt);
+
+/**
+ * \brief splits a string with a list of decoders
+ * \param decoder_list comma-separated list of decoders
+ * \return vector of separated strings
+ */
+std::vector<std::string> split_decoders(const std::string & decoder_list);
+
+/**
+ * \brief splits a string with an encoding ("codec;fmt;fmt;fmt")
+ * \param encoding string with encoding information
+ * \return vector of separated strings
+ */
+std::vector<std::string> split_encoding(const std::string & encoding);
+
 }  // namespace utils
 }  // namespace ffmpeg_encoder_decoder
 #endif  // FFMPEG_ENCODER_DECODER__UTILS_HPP_

src/decoder.cpp

@@ -66,15 +66,10 @@ void Decoder::setOutputMessageEncoding(const std::string & output_encoding)
   outputMsgEncoding_ = output_encoding;
 }
 
-static std::vector<std::string> splitEncoding(const std::string & encoding)
-{
-  return (utils::split_by_char(encoding, ';'));
-}
-
 void Decoder::setEncoding(const std::string & encoding)
 {
   packetEncoding_ = encoding;
-  const auto split = splitEncoding(encoding);
+  const auto split = ffmpeg_encoder_decoder::utils::split_encoding(encoding);
   if (outputMsgEncoding_.empty()) {
     // assume orig was bgr8
     outputMsgEncoding_ = split.size() == 4 ? split[3] : "bgr8";

src/utils.cpp

@@ -213,7 +213,8 @@ enum AVPixelFormat ros_to_av_pix_format(const std::string & ros_pix_fmt)
   const auto it = ros_to_av_pix_map.find(ros_pix_fmt);
   if (it == ros_to_av_pix_map.end()) {
     RCLCPP_ERROR_STREAM(
-      rclcpp::get_logger("encoder"), "no AV pixel format known for ros format " << ros_pix_fmt);
+      rclcpp::get_logger("encoder/decoder"),
+      "no AV pixel format known for ros format " << ros_pix_fmt);
     throw(std::runtime_error("no matching pixel format found for: " + ros_pix_fmt));
   }
   return (it->second);
@@ -265,6 +266,16 @@ std::vector<std::string> split_by_char(const std::string & str_list, const char
   return (split);
 }
 
+std::vector<std::string> split_decoders(const std::string & decoder_list)
+{
+  return (split_by_char(decoder_list, ','));
+}
+
+std::vector<std::string> split_encoding(const std::string & encoding)
+{
+  return (split_by_char(encoding, ';'));
+}
+
 // This function finds the encoding that is the target of a given encoder.
 
 static AVCodecID find_id_for_encoder_or_encoding(const std::string & encoder)
@@ -312,13 +323,21 @@ std::string find_decoders(const std::string & codec)
 std::string filter_decoders(const std::string & codec, const std::string & decoders)
 {
   std::string filtered;
-  const auto valid_decoders = split_by_char(find_decoders(codec), ',');
-  for (const auto & dec : split_by_char(decoders, ',')) {
+  const auto valid_decoders = split_decoders(find_decoders(codec));
+  for (const auto & dec : split_decoders(decoders)) {
+    bool found = false;
     for (const auto & valid : valid_decoders) {
       if (dec == valid) {
         filtered += (filtered.empty() ? "" : ",") + dec;
+        found = true;
+        break;
       }
     }
+    if (!found) {
+      RCLCPP_WARN_STREAM(
+        rclcpp::get_logger("encoder/decoder"),
+        "ignoring invalid decoder " << dec << " for codec " << codec);
+    }
   }
   return (filtered);
 }