Fixed auto zoom option when stdin is a socket

See #176

Author: chrisn

src/FileUtil.cpp

@@ -1,6 +1,6 @@
 //------------------------------------------------------------------------------
 //
-// Copyright 2022 BBC Research and Development
+// Copyright 2023 BBC Research and Development
 //
 // Author: Chris Needham
 //
@@ -45,18 +45,19 @@ bool isStdioFilename(const char* filename)
 
 //------------------------------------------------------------------------------
 
-bool isStdinFifo() {
+bool isStdinSeekable()
+{
     struct stat stat_buf;
 
     int result = fstat(fileno(stdin), &stat_buf);
 
     if (result >= 0) {
-        if (S_ISFIFO(stat_buf.st_mode)) {
-            return true;
+        if (S_ISFIFO(stat_buf.st_mode) || S_ISSOCK(stat_buf.st_mode)) {
+            return false;
         }
     }
 
-    return false;
+    return true;
 }
 
 //------------------------------------------------------------------------------

src/FileUtil.h

@@ -1,6 +1,6 @@
 //------------------------------------------------------------------------------
 //
-// Copyright 2022 BBC Research and Development
+// Copyright 2023 BBC Research and Development
 //
 // Author: Chris Needham
 //
@@ -28,7 +28,7 @@
 
 namespace FileUtil {
     bool isStdioFilename(const char* filename);
-    bool isStdinFifo();
+    bool isStdinSeekable();
     const char* getInputFilename(const char* filename);
     const char* getOutputFilename(const char* filename);
 }

src/OptionHandler.cpp

@@ -388,9 +388,13 @@ bool OptionHandler::renderWaveformImage(
         );
     }
     else {
+        // Seeking to the start of the audio won't work if reading from a pipe
+        // or a socket, so we buffer the entire audio data in memory.
+
         if (FileUtil::isStdioFilename(input_filename.string().c_str()) &&
-            FileUtil::isStdinFifo() &&
+            !FileUtil::isStdinSeekable() &&
             calculate_duration) {
+
             std::unique_ptr<AudioFileReader> audio_file_reader(
                 createAudioFileReader(input_filename, input_format)
             );
@@ -420,7 +424,6 @@ bool OptionHandler::renderWaveformImage(
             }
 
             output_samples_per_pixel = input_buffer.getSamplesPerPixel();
-
         }
         else {
             if (calculate_duration) {