reecriture du deco mpeg audio

* support du layer 1 mono et stereo
* support du layer 2 stereo (j'ai pas encore fait le mono)
* support des low bitrates proposes par le mpeg2 (non teste)
* passage des tests de compliance mpeg :)
* moins de macros qu'avant, mais je dois encore propriser un peu le code.

src/audio_decoder/audio_decoder_thread.c

 /*****************************************************************************
- * audio_decoder.c: MPEG1 Layer I-II audio decoder thread
+ * audio_decoder_thread.c: MPEG1 Layer I-II audio decoder thread
  *****************************************************************************
  * Copyright (C) 1999, 2000 VideoLAN
  *
@@ -56,7 +56,6 @@
 
 #include "audio_output.h"               /* aout_fifo_t (for audio_decoder.h) */
 
-#include "audio_constants.h"
 #include "audio_decoder.h"
 #include "audio_decoder_thread.h"
 #include "audio_math.h"                                    /* DCT32(), PCM() */

src/audio_decoder/audio_math.c

@@ -313,7 +313,7 @@ void DCT32(float *x, adec_bank_t *b)
 void PCM(adec_bank_t *b, s16 **pcm, int jump)
 {
     /* scale factor */
-#define F 32768
+#define F -32768
     /* These values are not in the same order as in Annex 3-B.3 of the ISO/IEC
        DIS 11172-3 */
     static const float c[512] = {

src/audio_decoder/audio_test.c

+/*****************************************************************************
+ * audio_test.c: MPEG1 Layer I-II audio decoder test program
+ *****************************************************************************
+ * Copyright (C) 1999, 2000 VideoLAN
+ *
+ * Authors:
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *****************************************************************************/
+
+/*
+ * TODO :
+ *
+ * - optimiser les NeedBits() et les GetBits() du code l o c'est possible ;
+ * - vlc_cond_signal() / vlc_cond_wait() ;
+ *
+ */
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+
+#include <stdio.h>
+#include <string.h>
+
+#include "int_types.h"
+#include "audio_decoder.h"
+
+#define ADEC_FRAME_SIZE (2*1152)
+
+int main (void)
+{
+    audiodec_t decoder;
+    adec_sync_info_t sync_info;
+    adec_byte_stream_t * stream;
+    s16 buffer [ADEC_FRAME_SIZE];
+
+    int framenum;
+
+    memset (&decoder, 0, sizeof (decoder));
+    if (adec_init (&decoder))
+	return 1;
+
+    stream = adec_byte_stream (&decoder);
+    stream->p_byte = NULL;
+    stream->p_end = NULL;
+    stream->info = stdin;
+
+    framenum = 0;
+
+    while (1) {
+	int i;
+
+	if (adec_sync_frame (&decoder, &sync_info))
+	    return 1;
+	if (adec_decode_frame (&decoder, buffer))
+	    return 1;
+
+#if 1
+	for (i = 0; i < (2*1152); i++)
+	    printf ("%04X\n",(u16)buffer[i]);
+#endif
+    }
+
+    return 0;
+}
+
+void adec_byte_stream_next (adec_byte_stream_t * p_byte_stream)
+{
+    static u8 buffer [1024];
+    static u8 dummy = 0;
+    FILE * fd;
+    int size;
+
+    fd = p_byte_stream->info;
+    size = fread (buffer, 1, 1024, fd);
+    if (size) {
+	p_byte_stream->p_byte = buffer;
+	p_byte_stream->p_end = buffer + size;
+    } else {	/* end of stream, read dummy zeroes */
+	p_byte_stream->p_byte = &dummy;
+	p_byte_stream->p_end = &dummy + 1;
+    }
+}