diff --git a/CMakeLists.txt b/CMakeLists.txt
index 63f17d5aa9..6589216bb7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -481,6 +481,7 @@ src/subprocess.cpp
 src/baseutils.cpp
 src/fileutils.cpp
 src/utfutils.cpp
+src/stringutils.cpp
 
 extern/itcompress/compression.c
 
diff --git a/src/engine/engine.h b/src/engine/engine.h
index c64268dd85..167079aa13 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -499,6 +499,7 @@ class DivEngine {
   DivAudioEngines audioEngine;
   DivAudioExportModes exportMode;
   DivAudioExportFormats exportFormat;
+  String exportFileExtNoDot;
   double exportFadeOut;
   bool isFadingOut;
   int exportOutputs;
@@ -623,8 +624,8 @@ class DivEngine {
   void loadFF(SafeReader& reader, std::vector<DivInstrument*>& ret, String& stripPath);
   void loadWOPL(SafeReader& reader, std::vector<DivInstrument*>& ret, String& stripPath);
   void loadWOPN(SafeReader& reader, std::vector<DivInstrument*>& ret, String& stripPath);
- 
- //sample banks
+
+  // sample banks
   void loadP(SafeReader& reader, std::vector<DivSample*>& ret, String& stripPath);
   void loadPPC(SafeReader& reader, std::vector<DivSample*>& ret, String& stripPath);
   void loadPPS(SafeReader& reader, std::vector<DivSample*>& ret, String& stripPath);
@@ -633,8 +634,6 @@ class DivEngine {
   void loadPZI(SafeReader& reader, std::vector<DivSample*>& ret, String& stripPath);
   void loadP86(SafeReader& reader, std::vector<DivSample*>& ret, String& stripPath);
 
-
-
   int loadSampleROM(String path, ssize_t expectedSize, unsigned char*& ret);
 
   bool initAudioBackend();
@@ -734,7 +733,7 @@ class DivEngine {
     // export to text
     SafeWriter* saveText(bool separatePatterns=true);
     // export to an audio file
-    bool saveAudio(const char* path, DivAudioExportOptions options);
+    bool saveAudio(const char* path, DivAudioExportOptions options, const char *fileExt);
     // wait for audio export to finish
     void waitAudioFile();
     // stop audio file export
diff --git a/src/engine/sfWrapper.cpp b/src/engine/sfWrapper.cpp
index 18a1c0c344..dbd10d2209 100644
--- a/src/engine/sfWrapper.cpp
+++ b/src/engine/sfWrapper.cpp
@@ -75,12 +75,16 @@ int SFWrapper::doClose() {
   return ret;
 }
 
-SNDFILE* SFWrapper::doOpen(const char* path, int mode, SF_INFO* sfinfo) {
+void SFWrapper::initVio() {
   vio.get_filelen=_vioGetSize;
   vio.read=_vioRead;
   vio.seek=_vioSeek;
   vio.tell=_vioTell;
   vio.write=_vioWrite;
+}
+
+SNDFILE* SFWrapper::doOpen(const char* path, int mode, SF_INFO* sfinfo) {
+  initVio();
   logV("SFWrapper: opening %s",path);
 
   const char* modeC="rb";
@@ -103,7 +107,7 @@ SNDFILE* SFWrapper::doOpen(const char* path, int mode, SF_INFO* sfinfo) {
     f=NULL;
     return NULL;
   }
-  
+
   len=ftell(f);
   if (len==(SIZE_MAX>>1)) {
     logE("SFWrapper: failed to tell (%s)",strerror(errno));
@@ -128,3 +132,21 @@ SNDFILE* SFWrapper::doOpen(const char* path, int mode, SF_INFO* sfinfo) {
   }
   return sf;
 }
+
+SNDFILE* SFWrapper::doOpenFromWriteFd(int writeFd, SF_INFO* sfinfo) {
+  f=fdopen(writeFd,"w");
+  if (f==NULL) {
+    logE("SFWrapper: failed to open file descriptor %d (pipe) as file: %s",writeFd,strerror(errno));
+    return NULL;
+  }
+
+  initVio();
+  len=0; // I am hoping this is not used when writing
+  fileMode=SFM_WRITE;
+
+  sf=sf_open_virtual(&vio,SFM_WRITE,sfinfo,this);
+  if (sf==NULL) {
+    logE("SFWrapper: WHY IS IT NULL?!");
+  }
+  return sf;
+}
diff --git a/src/engine/sfWrapper.h b/src/engine/sfWrapper.h
index c32c8ba194..50abab6b0d 100644
--- a/src/engine/sfWrapper.h
+++ b/src/engine/sfWrapper.h
@@ -44,8 +44,10 @@ class SFWrapper {
     sf_count_t ioWrite(const void* ptr, sf_count_t count);
     sf_count_t ioTell();
 
+    void initVio();
     int doClose();
     SNDFILE* doOpen(const char* path, int mode, SF_INFO* sfinfo);
+    SNDFILE* doOpenFromWriteFd(int fd, SF_INFO* sfinfo);
     SFWrapper():
       f(NULL),
       len(0),
diff --git a/src/engine/wavOps.cpp b/src/engine/wavOps.cpp
index 0b8893f9bf..d5645222f8 100644
--- a/src/engine/wavOps.cpp
+++ b/src/engine/wavOps.cpp
@@ -20,6 +20,7 @@
 #include "engine.h"
 #include "../ta-log.h"
 #include "../subprocess.h"
+#include "../stringutils.h"
 #ifdef HAVE_SNDFILE
 #include "sfWrapper.h"
 #endif
@@ -120,92 +121,106 @@ void DivEngine::runExportThread() {
         si.format=SF_FORMAT_WAV|SF_FORMAT_FLOAT;
       }
 
-      // TODO: receive format! and check if we really need to pipe it out
-      std::vector<String> args={"echo", "hello world!"};
-      Subprocess proc(args);
-      if (!proc.start()) {
-        logE("failed to start subprocess!\n");
-        // int writeFd=proc.pipeStdin(); // TODO
-      } else {
-        proc.wait();
-      }
-
-      sf=sfWrap.doOpen(exportPath.c_str(),SFM_WRITE,&si);
-      if (sf==NULL) {
-        logE("could not open file for writing! (%s)",sf_strerror(NULL));
-        exporting=false;
-        return;
-      }
+      const auto doExport=[&](){
+        if (sf==NULL) {
+          logE("could not initialize export");
+          exporting=false;
+          return;
+        }
 
-      float* outBuf[DIV_MAX_OUTPUTS];
-      float* outBufFinal;
-      for (int i=0; i<exportOutputs; i++) {
-        outBuf[i]=new float[EXPORT_BUFSIZE];
-      }
-      outBufFinal=new float[EXPORT_BUFSIZE*exportOutputs];
+        float* outBuf[DIV_MAX_OUTPUTS];
+        float* outBufFinal;
+        for (int i=0; i<exportOutputs; i++) {
+          outBuf[i]=new float[EXPORT_BUFSIZE];
+        }
+        outBufFinal=new float[EXPORT_BUFSIZE*exportOutputs];
 
-      // take control of audio output
-      deinitAudioBackend();
-      playSub(false);
+        // take control of audio output
+        deinitAudioBackend();
+        playSub(false);
 
-      logI("rendering to file...");
+        logI("rendering to file...");
 
-      while (playing) {
-        size_t total=0;
-        nextBuf(NULL,outBuf,0,exportOutputs,EXPORT_BUFSIZE);
-        if (totalProcessed>EXPORT_BUFSIZE) {
-          logE("error: total processed is bigger than export bufsize! %d>%d",totalProcessed,EXPORT_BUFSIZE);
-          totalProcessed=EXPORT_BUFSIZE;
-        }
-        int fi=0;
-        for (int i=0; i<(int)totalProcessed; i++) {
-          total++;
-          if (isFadingOut) {
-            double mul=(1.0-((double)curFadeOutSample/(double)fadeOutSamples));
-            for (int j=0; j<exportOutputs; j++) {
-              outBufFinal[fi++]=MAX(-1.0f,MIN(1.0f,outBuf[j][i]))*mul;
-            }
-            if (++curFadeOutSample>=fadeOutSamples) {
-              playing=false;
-              break;
-            }
-          } else {
-            for (int j=0; j<exportOutputs; j++) {
-              outBufFinal[fi++]=MAX(-1.0f,MIN(1.0f,outBuf[j][i]));
-            }
-            if (lastLoopPos>-1 && i>=lastLoopPos && totalLoops>=exportLoopCount) {
-              logD("start fading out...");
-              isFadingOut=true;
-              if (fadeOutSamples==0) break;
+        while (playing) {
+          size_t total=0;
+          nextBuf(NULL,outBuf,0,exportOutputs,EXPORT_BUFSIZE);
+          if (totalProcessed>EXPORT_BUFSIZE) {
+            logE("error: total processed is bigger than export bufsize! %d>%d",totalProcessed,EXPORT_BUFSIZE);
+            totalProcessed=EXPORT_BUFSIZE;
+          }
+          int fi=0;
+          for (int i=0; i<(int)totalProcessed; i++) {
+            total++;
+            if (isFadingOut) {
+              double mul=(1.0-((double)curFadeOutSample/(double)fadeOutSamples));
+              for (int j=0; j<exportOutputs; j++) {
+                outBufFinal[fi++]=MAX(-1.0f,MIN(1.0f,outBuf[j][i]))*mul;
+              }
+              if (++curFadeOutSample>=fadeOutSamples) {
+                playing=false;
+                break;
+              }
+            } else {
+              for (int j=0; j<exportOutputs; j++) {
+                outBufFinal[fi++]=MAX(-1.0f,MIN(1.0f,outBuf[j][i]));
+              }
+              if (lastLoopPos>-1 && i>=lastLoopPos && totalLoops>=exportLoopCount) {
+                logD("start fading out...");
+                isFadingOut=true;
+                if (fadeOutSamples==0) break;
+              }
             }
           }
-        }
 
-        if (sf_writef_float(sf,outBufFinal,total)!=(int)total) {
-          logE("error: failed to write entire buffer!");
-          break;
+          if (sf_writef_float(sf,outBufFinal,total)!=(int)total) {
+            logE("error: failed to write entire buffer!");
+            break;
+          }
         }
-      }
 
-      delete[] outBufFinal;
-      for (int i=0; i<exportOutputs; i++) {
-        delete[] outBuf[i];
-      }
+        delete[] outBufFinal;
+        for (int i=0; i<exportOutputs; i++) {
+          delete[] outBuf[i];
+        }
 
-      if (sfWrap.doClose()!=0) {
-        logE("could not close audio file!");
-      }
+        if (sfWrap.doClose()!=0) {
+          logE("could not close audio file!");
+        }
 
-      if (initAudioBackend()) {
-        for (int i=0; i<song.systemLen; i++) {
-          disCont[i].setRates(got.rate);
-          disCont[i].setQuality(lowQuality,dcHiPass);
+        if (initAudioBackend()) {
+          for (int i=0; i<song.systemLen; i++) {
+            disCont[i].setRates(got.rate);
+            disCont[i].setQuality(lowQuality,dcHiPass);
+          }
+          if (!output->setRun(true)) {
+            logE("error while activating audio!");
+          }
         }
-        if (!output->setRun(true)) {
-          logE("error while activating audio!");
+      };
+
+      if (exportFileExtNoDot=="wav") {
+        sf=sfWrap.doOpen(exportPath.c_str(),SFM_WRITE,&si);
+        doExport();
+      } else {
+        std::vector<String> args={"tee", "test.txt"}; // TODO: build args
+        Subprocess proc(args);
+        int writeFd=proc.pipeStdin();
+        if (writeFd==-1) {
+          logE("failed to create stdin pipe for subprocess");
+        } if (proc.start()) {
+          sf=sfWrap.doOpenFromWriteFd(writeFd,&si);
+          doExport();
+          logI("waiting for ffmpeg to finish...");
+          int code = proc.wait();
+          if (code!=0) {
+            logE("ffmpeg failed to export successfully"); // TODO: actually show this in the UI? (it might be a good idea to read the output from ffmpeg, in that case)
+          }
+        } else {
+          logE("failed to start subprocess");
         }
       }
-      logI("done!");
+
+      logI("exporting done!");
       exporting=false;
       break;
     }
@@ -481,7 +496,7 @@ bool DivEngine::shallSwitchCores() {
   return true;
 }
 
-bool DivEngine::saveAudio(const char* path, DivAudioExportOptions options) {
+bool DivEngine::saveAudio(const char* path, DivAudioExportOptions options, const char *fileExt) {
 #ifndef HAVE_SNDFILE
   logE("Furnace was not compiled with libsndfile. cannot export!");
   return false;
@@ -490,17 +505,15 @@ bool DivEngine::saveAudio(const char* path, DivAudioExportOptions options) {
   exportMode=options.mode;
   exportFormat=options.format;
   exportFadeOut=options.fadeOut;
+  if (fileExt[0]=='.') {
+    exportFileExtNoDot=&fileExt[1];
+  } else {
+    exportFileExtNoDot=fileExt;
+  }
+
   memcpy(exportChannelMask,options.channelMask,DIV_MAX_CHANS*sizeof(bool));
   if (exportMode!=DIV_EXPORT_MODE_ONE) {
-    // remove extension
-    String lowerCase=exportPath;
-    for (char& i: lowerCase) {
-      if (i>='A' && i<='Z') i+='a'-'A';
-    }
-    size_t extPos=lowerCase.rfind(".wav");
-    if (extPos!=String::npos) {
-      exportPath=exportPath.substr(0,extPos);
-    }
+    removeFileExt(exportPath,exportFileExtNoDot.c_str());
   }
   exporting=true;
   stopExport=false;
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 5e3461fcf0..d24448c975 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -2583,9 +2583,6 @@ int FurnaceGUI::loadStream(String path) {
 void FurnaceGUI::exportAudio(String path, DivAudioExportModes mode) {
   songOrdersLengths.clear();
 
-  const FurnaceGUIExportFormat *ef=&exportFormats[curAudioExportFormat];
-  const char *extNoDot=&ef->fileExt[1];
-
   int loopOrder=0;
   int loopRow=0;
   int loopEnd=0;
@@ -2599,7 +2596,8 @@ void FurnaceGUI::exportAudio(String path, DivAudioExportModes mode) {
   }
   songLoopedSectionLength-=loopRow;
 
-  e->saveAudio(path.c_str(),audioExportOptions);
+  const FurnaceGUIExportFormat& ef=exportFormats[curAudioExportFormat];
+  e->saveAudio(path.c_str(),audioExportOptions,ef.fileExt);
 
   totalFiles=0;
   e->getTotalAudioFiles(totalFiles);
diff --git a/src/main.cpp b/src/main.cpp
index 64c8880521..b1990d38cd 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -913,7 +913,7 @@ int main(int argc, char** argv) {
     }
     if (outName!="") {
       e.setConsoleMode(true);
-      e.saveAudio(outName.c_str(),exportOptions);
+      e.saveAudio(outName.c_str(),exportOptions,"wav");
       e.waitAudioFile();
     }
     if (romOutName!="") {
diff --git a/src/stringutils.cpp b/src/stringutils.cpp
new file mode 100644
index 0000000000..f9df9e55fb
--- /dev/null
+++ b/src/stringutils.cpp
@@ -0,0 +1,45 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2024 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "stringutils.h"
+
+String lowerCaseCopy(const char* str) {
+  String lowerCase=str;
+  for (char& i: lowerCase) {
+    if (i>='A' && i<='Z') i+='a'-'A';
+  }
+  return lowerCase;
+}
+
+void removeFileExt(String& str, const char* ext) {
+  String lowerCase=lowerCaseCopy(str.c_str());
+
+  String extLowerCase;
+  if (ext[0]=='.') {
+    extLowerCase=lowerCaseCopy(ext);
+  } else {
+    extLowerCase=".";
+    extLowerCase+=lowerCaseCopy(ext);
+  }
+
+  size_t extPos=lowerCase.rfind(extLowerCase);
+  if (extPos!=String::npos) {
+    str=str.substr(0,extPos);
+  }
+}
diff --git a/src/stringutils.h b/src/stringutils.h
new file mode 100644
index 0000000000..a4ac5ac6a2
--- /dev/null
+++ b/src/stringutils.h
@@ -0,0 +1,31 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2024 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _STRINGUTILS_H
+#define _STRINGUTILS_H
+#include "ta-utils.h"
+
+// returns a lowercase copy of an ASCII string
+String lowerCaseCopy(const char* str);
+
+// removes an extension off the end of a string
+// the leading dot in `ext` is optional (e.g., both `.wav` and `wav` are accepted)
+void removeFileExt(String& str, const char* ext);
+
+#endif
diff --git a/src/subprocess.cpp b/src/subprocess.cpp
index 893dfc7e98..29c9daa81d 100644
--- a/src/subprocess.cpp
+++ b/src/subprocess.cpp
@@ -19,6 +19,7 @@
 
 #include <unistd.h>
 #include "subprocess.h"
+#include "ta-log.h"
 
 #define tryMakePipe(_arrVar) \
   int _arrVar[2]; \
@@ -27,21 +28,27 @@
     return -1; \
   }
 
-Subprocess::Pipe::~Pipe() {
-  // FIXME: should we close both ends of the pipe?
-  if (writeFd!=-1)
-    close(writeFd);
-  if (readFd!=-1)
-    close(readFd);
-}
-
 Subprocess::Subprocess(std::vector<String> args):
   args(args)
 {}
 
+Subprocess::~Subprocess() {
+  logD("closing pipes!");
+  const auto closePipe = [](Subprocess::Pipe& p){
+    if (p.readFd!=-1)
+      close(p.readFd);
+    if (p.writeFd!=-1)
+      close(p.writeFd);
+  };
+  closePipe(stdinPipe);
+  closePipe(stdoutPipe);
+  closePipe(stderrPipe);
+}
+
 int Subprocess::pipeStdin() {
   tryMakePipe(arr);
   stdinPipe=Subprocess::Pipe(arr);
+  logD("made pipe, fds (%d,%d) ~ (%d,%d)\n",arr[0],arr[1],stdinPipe.writeFd,stdinPipe.readFd);
   return stdinPipe.writeFd;
 }
 
diff --git a/src/subprocess.h b/src/subprocess.h
index 56c2cb8e0a..c2850ef0ab 100644
--- a/src/subprocess.h
+++ b/src/subprocess.h
@@ -29,7 +29,6 @@ class Subprocess {
     int writeFd;
     Pipe(): readFd(-1), writeFd(-1) {}
     Pipe(int pipeArr[2]): readFd(pipeArr[0]), writeFd(pipeArr[1]) {}
-    ~Pipe();
   };
 
 private:
@@ -40,6 +39,7 @@ class Subprocess {
 
 public:
   Subprocess(std::vector<String> args);
+  ~Subprocess();
 
   // enables stdin piping, and returns a file descriptor to the writable end
   // should only be called before start()