calculate AIFF files samplerate from 80-bit float, fixes wrong playback of some AIFF files

1 files changed, 21 insertions, 1 deletions

diff --git a/src/demuxers/demux_aiff.c b/src/demuxers/demux_aiff.c
index b30b74910..8a2811ac6 100644
--- a/src/demuxers/demux_aiff.c
+++ b/src/demuxers/demux_aiff.c
@@ -84,6 +84,24 @@ typedef struct {
   demux_class_t     demux_class;
 } demux_aiff_class_t;
 
+/* converts IEEE 80bit extended into int, based on FFMPEG code */
+int extended_to_int(const unsigned char p[10])
+{
+    uint64_t m = 0;
+    int e, i;
+
+    for (i = 0; i < 8; i++)
+        m = (m<<8) + p[2+i];;
+    e = (((int)p[0]&0x7f)<<8) | p[1];
+    if (e == 0x7fff && m)
+        return 0.0/0.0;
+    e -= 16383 + 63;
+
+    if (p[0]&0x80)
+        m= -m;
+    return (int) ldexp(m, e);
+}
+
 /* returns 1 if the AIFF file was opened successfully, 0 otherwise */
 static int open_aiff_file(demux_aiff_t *this) {
 
@@ -91,6 +109,7 @@ static int open_aiff_file(demux_aiff_t *this) {
   unsigned char preamble[PREAMBLE_SIZE];
   unsigned int chunk_type;
   unsigned int chunk_size;
+  unsigned char extended_sample_rate[10];
 
   if (_x_demux_read_header(this->input, signature, AIFF_SIGNATURE_SIZE) != AIFF_SIGNATURE_SIZE)
     return 0;
@@ -139,7 +158,8 @@ static int open_aiff_file(demux_aiff_t *this) {
       this->audio_channels = _X_BE_16(&buffer[0]);
       this->audio_frames = _X_BE_32(&buffer[2]);
       this->audio_bits = _X_BE_16(&buffer[6]);
-      this->audio_sample_rate = _X_BE_16(&buffer[0x0A]);
+      memcpy(&extended_sample_rate, &buffer[8], sizeof(extended_sample_rate));
+      this->audio_sample_rate = extended_to_int(extended_sample_rate);
       this->audio_bytes_per_second = this->audio_channels *
         (this->audio_bits / 8) * this->audio_sample_rate;