initial commit

1 files changed, 55 insertions, 0 deletions

diff --git a/mpa-frame.c b/mpa-frame.c
new file mode 100644
index 0000000..1d7f03f
--- /dev/null
+++ b/mpa-frame.c
@@ -0,0 +1,55 @@
+/*
+ * mpa-frame.c
+ */
+
+
+#include "mpa-frame.h"
+#include "audiorecorder.h"
+
+#include <vdr/tools.h>
+
+#include <iostream>
+
+
+using namespace std;
+
+const int sample_rates[] = { 44100, 48000, 32000, 0 };
+const int bit_rates[] = { 0, 32000, 48000, 56000, 64000, 80000, 96000, 112000,
+        128000, 160000, 192000, 224000, 256000, 320000, 384000, 0 };
+
+void get_mpa_frame(abuffer *buf, mpeg_audio_frame *mpa_frame,
+        const char *description)
+{
+        int c;
+        
+        mpa_frame->data = NULL;
+        
+        for (c = buf->offset; c < buf->length - buf->offset - 2; ++c) {
+                if ((buf->data[c] == 0xff) && (buf->data[c + 1] & 0xe0) &&
+                    (buf->data[c + 1] & 0x1e) == 0x1c) {
+                        /* mpeg v1, layer II header found */
+                        mpa_frame->bit_rate = bit_rates[buf->data[c + 2] >> 4];
+                        mpa_frame->sample_rate = sample_rates[(buf->data[c + 2]
+                                >> 2) & 0x03];
+                        if (mpa_frame->sample_rate < 1)
+                                continue;
+                        mpa_frame->channels = (buf->data[c + 3] >> 6) == 3 ?
+                                1 : 2;
+                        int p = buf->data[c + 2] & 0x01; /* padding bit */
+                        mpa_frame->length = 144 * mpa_frame->bit_rate /
+                                mpa_frame->sample_rate + p;
+                        
+                        if (c + mpa_frame->length <= buf->length)
+                                mpa_frame->data = buf->data + c;
+                        
+                        break;
+                }
+        }
+        
+        if (c > buf->offset && cPluginAudiorecorder::get_dbg_level() > 0)
+		cout << "skipped " << c - buf->offset << " byte(s) "
+			<< description << "> (" << __FILE__ << ", " << __func__
+			<< "())" << endl;
+        
+        buf->offset = c;
+}