Update scorealign to SVN r227.

lib-src/libscorealign/audiofilereader-snd.cpp

@@ -0,0 +1,83 @@
+/* audiofilereader.cpp -- implements a class to read samples
+ *
+ * 14-Jun-08  RBD
+ */
+#include "assert.h"
+#include "stdio.h"
+#include "string.h"
+#include "snd.h"
+#include "audioreader.h"
+#include "audiofilereader.h"
+
+double Audio_file_reader::get_sample_rate()
+{
+    return snd.format.srate;
+}
+
+
+long Audio_file_reader::get_frames()
+{
+    return (snd.u.file.end_offset - snd.u.file.byte_offset) /
+           snd_bytes_per_frame(&snd);
+}
+
+
+long Audio_file_reader::read(float *data, long n)
+{
+    // note that "samples_per_frame" is really "frames_per_window" in this
+    // context, so we're computing bytes per window
+    char *input_data = (char *) alloca(bytes_per_frame * samples_per_frame);
+    assert(input_data != NULL) ;
+	
+    // read into the end of data
+    long frames_read = snd_read(&snd, input_data, n);
+    // now convert and move to beginning of data
+    snd_node float_sound;
+    float_sound.format = snd.format;
+    float_sound.format.channels = 1; // make sure we convert to mono
+    float_sound.format.mode = SND_MODE_FLOAT; // and convert to float
+    float_sound.format.bits = 32;
+    // note: snd_convert takes a frame count; divide samples by channels
+    int converted = snd_convert(&float_sound, data, &snd, input_data, n);
+    if (frames_read == n) assert(converted == n);
+    return frames_read;
+}
+
+
+bool Audio_file_reader::open(char *filename, Scorealign &sa, bool verbose)
+{
+    bytes_per_frame = 0; // initialize now in case an error occurs
+    snd.device = SND_DEVICE_FILE;
+    snd.write_flag = SND_READ;
+    strcpy(snd.u.file.filename, filename);
+    long flags;
+    int infile = snd_open(&snd, &flags);
+    if (infile == SND_SUCCESS) {
+        bytes_per_frame = snd_bytes_per_frame(&snd);
+        calculate_parameters(sa, verbose);
+        return true;
+    }
+    return false;
+}
+
+
+void Audio_file_reader::close()
+{
+    snd_close(&snd);
+}
+
+
+void Audio_file_reader::print_info()
+{
+    printf("   file name = %s\n", snd.u.file.filename);
+    double sample_rate = snd.format.srate;
+    printf("   sample rate = %g\n", sample_rate);
+    printf("   channels = %d\n", snd.format.channels);
+    /*=============================================================*/
+    long frames =(snd.u.file.end_offset - snd.u.file.byte_offset) / 
+            snd_bytes_per_frame(&snd);
+    printf("   total frames number is = %d\n", frames);
+    printf("   bits per sample is  %d\n", snd.format.bits);
+    printf("   audio duration = %g seconds\n", (frames) / sample_rate);
+    /*=============================================================*/
+}