aac plugin WIP

1 files changed, 102 insertions, 0 deletions

diff --git a/plugins/aac/aac_parser.c b/plugins/aac/aac_parser.c
new file mode 100644
index 00000000..eea957df
--- /dev/null
+++ b/plugins/aac/aac_parser.c
@@ -0,0 +1,102 @@
+/*
+    DeaDBeeF - ultimate music player for GNU/Linux systems with X11
+    Copyright (C) 2009-2010 Alexey Yakovenko <waker@users.sourceforge.net>
+
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+    
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+    
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+#include <stdio.h>
+#include "aac_parser.h"
+
+#define min(x,y) ((x)<(y)?(x):(y))
+#define max(x,y) ((x)>(y)?(x):(y))
+
+#define trace(...) { fprintf(stderr, __VA_ARGS__); }
+//#define trace(fmt,...)
+
+static const int aac_sample_rates[16] = {
+    96000, 88200, 64000, 48000, 44100, 32000,
+    24000, 22050, 16000, 12000, 11025, 8000, 7350
+};
+
+static const int aac_channels[8] = {
+    0, 1, 2, 3, 4, 5, 6, 8
+};
+
+// buf size must be at least ADTS_HEADER_SIZE*8
+// returns frame size
+int
+aac_sync(const uint8_t *buf, int *channels, int *sample_rate, int *bit_rate, int *samples)
+{
+    int size, rdb;
+
+    // 12 sync bits
+    if (buf[0] != 0xff || (buf[1]&0xf0) != 0xf0) {
+        trace ("unsync\n");
+        return 0;
+    }
+
+    int id = (buf[1] & 0x08) >> 7;
+
+    int version = id == 0 ? 4 : 2;
+
+    int layer = (buf[1] & 0x06) >> 5;
+    int protection_abs = (buf[1] & 0x01);
+
+    int header_size = protection_abs > 0 ? 7 : 9;
+
+    int profile_objecttype = (buf[2] & 0xC0) >> 6;
+
+    //const char *profiles[4] = {
+    //    "0 Main profile AAC MAIN",
+    //    "1 Low Complexity profile (LC)AAC LC",
+    //    "2 Scalable Sample Rate profile (SSR)AAC SSR",
+    //    "3 (reserved)AAC LTP"
+    //};
+    //trace ("profile: %s\n", profiles[profile_objecttype]);
+
+    int sample_freq_index = (buf[2] & 0x3C) >> 2;
+    if (!aac_sample_rates[sample_freq_index]) {
+        //trace ("invalid samplerate\n");
+        return 0;
+    }
+    //trace ("samplerate %d (#%d)\n", aac_sample_rates[sample_freq_index], sample_freq_index);
+    int private_bit = (buf[2] & 0x02) >> 1;
+
+    int channel_conf = ((buf[2] & 0x01) << 2) | ((buf[3] & 0xC0) >> 6);
+    if (!aac_channels[channel_conf]) {
+        //trace ("invalid channels\n");
+        return 0;
+    }
+    //trace ("channels %d\n", aac_channels[channel_conf]);
+    int orig_copy = (buf[3] & 0x20) >> 5;
+    int home = (buf[3] & 0x10) >> 4;
+    int copyright_ident_bit = (buf[3] & 0x08) >> 3;
+    int copyright_ident_start = (buf[3] & 0x04) >> 2;
+    size = ((buf[3] & 0x03) << 11) | (buf[4] << 3) | ((buf[5] & 0xE0) >> 5);
+    if(size < ADTS_HEADER_SIZE) {
+        //trace ("invalid size\n");
+        return 0;
+    }
+    int adts_buffer_fullness = ((buf[5] & 0x1F) << 3) | ((buf[6] & 0xFC) >> 2);
+    rdb = buf[7] & 0x03;
+
+    *channels = aac_channels[channel_conf];
+    *sample_rate = aac_sample_rates[sample_freq_index];
+    *samples = rdb * 1024;
+    *bit_rate = size * 8 * *sample_rate / *samples;
+
+    return size;
+}
+