Initial revision

CVS patchset: 1
CVS date: 2001/04/18 22:33:39

1 files changed, 181 insertions, 0 deletions

diff --git a/src/libmpg123/common.c b/src/libmpg123/common.c
new file mode 100644
index 000000000..0112cbc58
--- /dev/null
+++ b/src/libmpg123/common.c
@@ -0,0 +1,181 @@
+#include <ctype.h>
+#include <stdlib.h>
+#include <signal.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "mpg123.h"
+
+struct parameter mpg123_param = { 1 , 1 , 0 , 0 };
+
+int tabsel_123[2][3][16] = {
+   { {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,},
+     {0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,},
+     {0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,} },
+
+   { {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,},
+     {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,},
+     {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,} }
+};
+
+long freqs[9] = { 44100, 48000, 32000,
+                  22050, 24000, 16000 ,
+                  11025 , 12000 , 8000 };
+
+int            mpg123_bitindex;
+unsigned char *mpg123_wordpointer;
+unsigned char *pcm_sample;
+int            pcm_point = 0;
+
+
+#define HDRCMPMASK 0xfffffd00
+
+/*
+ * the code a header and write the information
+ * into the frame structure
+ */
+int decode_header(struct frame *fr,unsigned long newhead)
+{
+    if( newhead & (1<<20) ) {
+      fr->lsf = (newhead & (1<<19)) ? 0x0 : 0x1;
+      fr->mpeg25 = 0;
+    }
+    else {
+      fr->lsf = 1;
+      fr->mpeg25 = 1;
+    }
+    
+    fr->lay = 4-((newhead>>17)&3);
+    if( ((newhead>>10)&0x3) == 0x3) {
+      fprintf(stderr,"Stream error\n");
+      exit(1);
+    }
+    if(fr->mpeg25) {
+      fr->sampling_frequency = 6 + ((newhead>>10)&0x3);
+    }
+    else {
+      int dummy;
+      fr->sampling_frequency = ((newhead>>10)&0x3) + (fr->lsf*3); 
+      dummy = (newhead>>10)&0x3;
+      switch (dummy) {
+      case 0:
+        fr->sample_rate = 44100;
+        break;
+      case 1:
+        fr->sample_rate = 48000;
+        break;
+      case 2:
+        fr->sample_rate = 32000;
+        break;
+      case 3:
+        fprintf (stderr, "invalid sampling rate\n");
+        fr->sample_rate = 44100;
+        break;
+      }
+    }
+
+    fr->error_protection = ((newhead>>16)&0x1)^0x1;
+
+    if(fr->mpeg25) /* allow Bitrate change for 2.5 ... */
+      fr->bitrate_index = ((newhead>>12)&0xf);
+
+    fr->bitrate_index = ((newhead>>12)&0xf);
+    fr->padding   = ((newhead>>9)&0x1);
+    fr->extension = ((newhead>>8)&0x1);
+    fr->mode      = ((newhead>>6)&0x3);
+    fr->mode_ext  = ((newhead>>4)&0x3);
+    fr->copyright = ((newhead>>3)&0x1);
+    fr->original  = ((newhead>>2)&0x1);
+    fr->emphasis  = newhead & 0x3;
+
+    fr->stereo    = (fr->mode == MPG_MD_MONO) ? 1 : 2;
+
+    if(!fr->bitrate_index)
+    {
+      fprintf(stderr,"Free format not supported.\n");
+      return (0);
+    }
+
+    switch(fr->lay)
+    {
+      case 1:
+        fr->framesize  = (long) tabsel_123[fr->lsf][0][fr->bitrate_index] * 12000;
+        fr->framesize /= freqs[fr->sampling_frequency];
+        fr->framesize  = ((fr->framesize+fr->padding)<<2)-4;
+        break;
+      case 2:
+        fr->framesize = (long) tabsel_123[fr->lsf][1][fr->bitrate_index] * 144000;
+        fr->framesize /= freqs[fr->sampling_frequency];
+        fr->framesize += fr->padding - 4;
+        break;
+      case 3:
+	fr->framesize  = (long) tabsel_123[fr->lsf][2][fr->bitrate_index] * 144000;
+	fr->framesize /= freqs[fr->sampling_frequency]<<(fr->lsf);
+	fr->framesize = fr->framesize + fr->padding - 4;
+        break; 
+    default:
+      fprintf(stderr,"Sorry, unknown layer type.\n"); 
+      return (0);
+    }
+    return 1;
+}
+
+unsigned int getbits(int number_of_bits)
+{
+  unsigned long rval;
+
+  if(!number_of_bits)
+    return 0;
+
+  {
+    rval = mpg123_wordpointer[0];
+    rval <<= 8;
+    rval |= mpg123_wordpointer[1];
+    rval <<= 8;
+    rval |= mpg123_wordpointer[2];
+    rval <<= mpg123_bitindex;
+    rval &= 0xffffff;
+
+    mpg123_bitindex += number_of_bits;
+
+    rval >>= (24-number_of_bits);
+
+    mpg123_wordpointer += (mpg123_bitindex>>3);
+    mpg123_bitindex &= 7;
+  }
+  return rval;
+}
+
+unsigned int getbits_fast(int number_of_bits)
+{
+  unsigned long rval;
+
+  {
+    rval = mpg123_wordpointer[0];
+    rval <<= 8;	
+    rval |= mpg123_wordpointer[1];
+    rval <<= mpg123_bitindex;
+    rval &= 0xffff;
+    mpg123_bitindex += number_of_bits;
+
+    rval >>= (16-number_of_bits);
+
+    mpg123_wordpointer += (mpg123_bitindex>>3);
+    mpg123_bitindex &= 7;
+  }
+  return rval;
+}
+
+unsigned int get1bit(void)
+{
+  unsigned char rval;
+  rval = *mpg123_wordpointer << mpg123_bitindex;
+
+  mpg123_bitindex++;
+  mpg123_wordpointer += (mpg123_bitindex>>3);
+  mpg123_bitindex &= 7;
+
+  return rval>>7;
+}