Enable audio encryption unless on a slow CPU

src/config.c

@@ -18,6 +18,7 @@
  */
 
 #include "config.h"
+#include "util.h"
 
 #include "input/evdev.h"
 #include "audio/audio.h"
@@ -328,6 +329,20 @@ void config_parse(int argc, char* argv[], PCONFIGURATION config) {
   config->stream.streamingRemotely = STREAM_CFG_AUTO;
   config->stream.audioConfiguration = AUDIO_CONFIGURATION_STEREO;
   config->stream.supportsHevc = false;
+  config->stream.encryptionFlags = ENCFLG_AUDIO;
+
+#ifdef __arm__
+  char cpuinfo[4096] = {};
+  if (read_file("/proc/cpuinfo", cpuinfo, sizeof(cpuinfo)) > 0) {
+    // If this is a ARMv6 CPU (like the Pi 1), we'll assume it's not
+    // powerful enough to handle audio encryption. The Pi 1 could
+    // barely handle Opus decoding alone.
+    if (strstr(cpuinfo, "ARMv6")) {
+      config->stream.encryptionFlags = ENCFLG_NONE;
+      printf("Disabling audio encryption on low performance CPU\n");
+    }
+  }
+#endif
 
   config->debug_level = 0;
   config->platform = "auto";

src/util.c

@@ -38,3 +38,15 @@ int blank_fb(char *path, bool clear) {
   } else
     return -1;
 }
+
+int read_file(char *path, char* output, int output_len) {
+  int fd = open(path, O_RDONLY);
+
+  if(fd >= 0) {
+    output_len = read(fd, output, output_len);
+    close(fd);
+    return output_len;
+  } else
+    return -1;
+}
+

src/util.h

@@ -20,3 +20,4 @@
 #include <stdbool.h>
 
 int blank_fb(char *path, bool clear);
+int read_file(char *path, char *output, int output_len);