fix: VideoReader bugs — stride, memory, audio detection, UB

Pass MXL grain stride (from sliceSizes[0]) into get_next_frame so
YUV422P10toV210 writes with the correct line width instead of a
self-computed value that may not match the MXL buffer.

Fix audio stream detection: condition was inverted (!= -1 → == -1),
so the first audio stream was never picked up.

Add return false at end of get_next_frame to fix UB when g_running
goes false and the loop exits without returning.

Replace av_frame_unref/av_packet_unref with av_frame_free/av_packet_free
in destructor — unref only releases data, not the struct itself.

Add av_freep(&p10_data[0]) in destructor to free av_image_alloc memory.

Remove unused p10_buffer and v210_buffer allocations.

Read filename from config("file") instead of hardcoded path.
Add early return if mxlCreateFlowWriter fails.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nodes/videoin/main.cpp

@@ -15,12 +15,10 @@ extern "C" {
 #include "NodeBase.hpp"
 #include "VideoReader.hpp"
 
-#include <iostream>
-
-
 class VideoInNode : public dmf::NodeBase {
-    void run() override {    
-        std::string filename = "/home/itten/test-vid/0.ts";
+    void run() override {
+        const std::string filename = config().value("file", std::string{});
+        if (filename.empty()) { log("config missing 'file'"); return; }
         log("VideoIn Node started with file: %s", filename.c_str());
         dmf::VideoReader video_reader(filename);
 
@@ -51,8 +49,10 @@ class VideoInNode : public dmf::NodeBase {
             &created
         );
         if (vst != MXL_STATUS_OK) {
-            log("MXL flow writer is not created. Reason: %s", dmf::mxl_status_str(vst));
+            log("mxlCreateFlowWriter failed (%s)", dmf::mxl_status_str(vst));
+            return;
         }
+        const uint32_t video_stride = video_config.discrete.sliceSizes[0];
 
         mxlRational video_rate = {fps_num, fps_den};
         uint64_t video_index = mxlGetCurrentIndex(&video_rate);
@@ -62,7 +62,7 @@ class VideoInNode : public dmf::NodeBase {
             mxlGrainInfo grain{};
             vst = mxlFlowWriterOpenGrain(video_writer, video_index, &grain, &buf);
             if (vst == MXL_STATUS_OK) {
-                if (!video_reader.get_next_frame(buf, nullptr)) continue;
+                if (!video_reader.get_next_frame(buf, video_stride, nullptr)) continue;
                 grain.flags = 0;
                 grain.validSlices = grain.totalSlices;
                 mxlFlowWriterCommitGrain(video_writer, &grain);