fix: avoid holding ic_mutex while error handling av_read_frame

Author: Julusian

src/modules/ffmpeg/producer/av_input.cpp

@@ -43,6 +43,7 @@ Input::Input(const std::string& filename, std::shared_ptr<diagnostics::graph> gr
 
             while (true) {
                 auto packet = alloc_packet();
+                int  ret    = 0;
 
                 {
                     std::unique_lock<std::mutex> lock(ic_mutex_);
@@ -53,39 +54,43 @@ Input::Input(const std::string& filename, std::shared_ptr<diagnostics::graph> gr
                     }
 
                     // TODO (perf) Non blocking av_read_frame when possible.
-                    auto ret = av_read_frame(ic_.get(), packet.get());
+                    ret = av_read_frame(ic_.get(), packet.get());
+                }
 
-                    if (ret == AVERROR_EXIT) {
-                        break;
-                    } else if (ret == AVERROR(EAGAIN)) {
-                        boost::this_thread::yield();
-                    } else if (ret == AVERROR_EOF) {
+                if (abort_request_) {
+                    break;
+                }
+
+                if (ret == AVERROR_EXIT) {
+                    break;
+                } else if (ret == AVERROR(EAGAIN)) {
+                    boost::this_thread::yield();
+                    continue;
+                } else if (ret == AVERROR_EOF) {
+                    eof_   = true;
+                    packet = nullptr;
+                } else if (ret == AVERROR(ENOMEM)) {
+                    // Transient memory allocation failure inside the demuxer; log and retry rather
+                    // than letting the exception escape and kill the read thread permanently.
+                    // Sleep briefly to give the system a chance to free memory before retrying.
+                    ++consecutive_enomem;
+                    if (consecutive_enomem == 1) {
+                        CASPAR_LOG(warning) << "av_input[" << filename_ << "] av_read_frame: out of memory, retrying";
+                    } else if (consecutive_enomem >= 20) {
+                        CASPAR_LOG(error) << "av_input[" << filename_
+                                          << "] av_read_frame: too many consecutive out-of-memory errors, aborting";
+
+                        // Pretend we reached EOF, to avoid the producer stalling expecting more packets
                         eof_   = true;
                         packet = nullptr;
-                    } else if (ret == AVERROR(ENOMEM)) {
-                        // Transient memory allocation failure inside the demuxer; log and retry rather
-                        // than letting the exception escape and kill the read thread permanently.
-                        // Sleep briefly to give the system a chance to free memory before retrying.
-                        ++consecutive_enomem;
-                        if (consecutive_enomem == 1) {
-                            CASPAR_LOG(warning)
-                                << "av_input[" << filename_ << "] av_read_frame: out of memory, retrying";
-                        } else if (consecutive_enomem >= 20) {
-                            CASPAR_LOG(error) << "av_input[" << filename_
-                                              << "] av_read_frame: too many consecutive out-of-memory errors, aborting";
-
-                            // Pretend we reached EOF, to avoid the producer stalling expecting more packets
-                            eof_   = true;
-                            packet = nullptr;
-                            buffer_.push(std::move(packet));
-                            break;
-                        }
-                        boost::this_thread::sleep_for(boost::chrono::milliseconds(5));
-                        continue;
-                    } else {
-                        consecutive_enomem = 0;
-                        FF_RET(ret, "av_read_frame");
+                        buffer_.push(std::move(packet));
+                        break;
                     }
+                    boost::this_thread::sleep_for(boost::chrono::milliseconds(5));
+                    continue;
+                } else {
+                    consecutive_enomem = 0;
+                    FF_RET(ret, "av_read_frame");
                 }
 
                 consecutive_enomem = 0;