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-rwxr-xr-xtinyDAV/src/codecs/g711/g711.c269
1 files changed, 141 insertions, 128 deletions
diff --git a/tinyDAV/src/codecs/g711/g711.c b/tinyDAV/src/codecs/g711/g711.c
index fa7c8be..cd599dc 100755
--- a/tinyDAV/src/codecs/g711/g711.c
+++ b/tinyDAV/src/codecs/g711/g711.c
@@ -40,7 +40,7 @@
* bli@cpk.auc.dk
*
*/
-
+
#include "tinydav/codecs/g711/g711.h"
#define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */
@@ -50,63 +50,68 @@
#define SEG_MASK (0x70) /* Segment field mask. */
static short seg_aend[8] = {0x1F, 0x3F, 0x7F, 0xFF,
- 0x1FF, 0x3FF, 0x7FF, 0xFFF};
+ 0x1FF, 0x3FF, 0x7FF, 0xFFF
+ };
static short seg_uend[8] = {0x3F, 0x7F, 0xFF, 0x1FF,
- 0x3FF, 0x7FF, 0xFFF, 0x1FFF};
+ 0x3FF, 0x7FF, 0xFFF, 0x1FFF
+ };
/* copy from CCITT G.711 specifications */
unsigned char _u2a[128] = { /* u- to A-law conversions */
- 1, 1, 2, 2, 3, 3, 4, 4,
- 5, 5, 6, 6, 7, 7, 8, 8,
- 9, 10, 11, 12, 13, 14, 15, 16,
- 17, 18, 19, 20, 21, 22, 23, 24,
- 25, 27, 29, 31, 33, 34, 35, 36,
- 37, 38, 39, 40, 41, 42, 43, 44,
- 46, 48, 49, 50, 51, 52, 53, 54,
- 55, 56, 57, 58, 59, 60, 61, 62,
- 64, 65, 66, 67, 68, 69, 70, 71,
- 72, 73, 74, 75, 76, 77, 78, 79,
-/* corrected:
- 81, 82, 83, 84, 85, 86, 87, 88,
- should be: */
- 80, 82, 83, 84, 85, 86, 87, 88,
- 89, 90, 91, 92, 93, 94, 95, 96,
- 97, 98, 99, 100, 101, 102, 103, 104,
- 105, 106, 107, 108, 109, 110, 111, 112,
- 113, 114, 115, 116, 117, 118, 119, 120,
- 121, 122, 123, 124, 125, 126, 127, 128};
+ 1, 1, 2, 2, 3, 3, 4, 4,
+ 5, 5, 6, 6, 7, 7, 8, 8,
+ 9, 10, 11, 12, 13, 14, 15, 16,
+ 17, 18, 19, 20, 21, 22, 23, 24,
+ 25, 27, 29, 31, 33, 34, 35, 36,
+ 37, 38, 39, 40, 41, 42, 43, 44,
+ 46, 48, 49, 50, 51, 52, 53, 54,
+ 55, 56, 57, 58, 59, 60, 61, 62,
+ 64, 65, 66, 67, 68, 69, 70, 71,
+ 72, 73, 74, 75, 76, 77, 78, 79,
+ /* corrected:
+ 81, 82, 83, 84, 85, 86, 87, 88,
+ should be: */
+ 80, 82, 83, 84, 85, 86, 87, 88,
+ 89, 90, 91, 92, 93, 94, 95, 96,
+ 97, 98, 99, 100, 101, 102, 103, 104,
+ 105, 106, 107, 108, 109, 110, 111, 112,
+ 113, 114, 115, 116, 117, 118, 119, 120,
+ 121, 122, 123, 124, 125, 126, 127, 128
+};
unsigned char _a2u[128] = { /* A- to u-law conversions */
- 1, 3, 5, 7, 9, 11, 13, 15,
- 16, 17, 18, 19, 20, 21, 22, 23,
- 24, 25, 26, 27, 28, 29, 30, 31,
- 32, 32, 33, 33, 34, 34, 35, 35,
- 36, 37, 38, 39, 40, 41, 42, 43,
- 44, 45, 46, 47, 48, 48, 49, 49,
- 50, 51, 52, 53, 54, 55, 56, 57,
- 58, 59, 60, 61, 62, 63, 64, 64,
- 65, 66, 67, 68, 69, 70, 71, 72,
-/* corrected:
- 73, 74, 75, 76, 77, 78, 79, 79,
- should be: */
- 73, 74, 75, 76, 77, 78, 79, 80,
+ 1, 3, 5, 7, 9, 11, 13, 15,
+ 16, 17, 18, 19, 20, 21, 22, 23,
+ 24, 25, 26, 27, 28, 29, 30, 31,
+ 32, 32, 33, 33, 34, 34, 35, 35,
+ 36, 37, 38, 39, 40, 41, 42, 43,
+ 44, 45, 46, 47, 48, 48, 49, 49,
+ 50, 51, 52, 53, 54, 55, 56, 57,
+ 58, 59, 60, 61, 62, 63, 64, 64,
+ 65, 66, 67, 68, 69, 70, 71, 72,
+ /* corrected:
+ 73, 74, 75, 76, 77, 78, 79, 79,
+ should be: */
+ 73, 74, 75, 76, 77, 78, 79, 80,
- 80, 81, 82, 83, 84, 85, 86, 87,
- 88, 89, 90, 91, 92, 93, 94, 95,
- 96, 97, 98, 99, 100, 101, 102, 103,
- 104, 105, 106, 107, 108, 109, 110, 111,
- 112, 113, 114, 115, 116, 117, 118, 119,
- 120, 121, 122, 123, 124, 125, 126, 127};
+ 80, 81, 82, 83, 84, 85, 86, 87,
+ 88, 89, 90, 91, 92, 93, 94, 95,
+ 96, 97, 98, 99, 100, 101, 102, 103,
+ 104, 105, 106, 107, 108, 109, 110, 111,
+ 112, 113, 114, 115, 116, 117, 118, 119,
+ 120, 121, 122, 123, 124, 125, 126, 127
+};
static short search(short val, short *table, short size)
{
- short i;
+ short i;
- for (i = 0; i < size; i++) {
- if (val <= *table++)
- return (i);
- }
- return (size);
+ for (i = 0; i < size; i++) {
+ if (val <= *table++) {
+ return (i);
+ }
+ }
+ return (size);
}
/*
@@ -130,34 +135,38 @@ static short search(short val, short *table, short size)
*/
unsigned char linear2alaw(short pcm_val) /* 2's complement (16-bit range) */
{
- short mask;
- short seg;
- unsigned char aval;
+ short mask;
+ short seg;
+ unsigned char aval;
- pcm_val = pcm_val >> 3;
+ pcm_val = pcm_val >> 3;
- if (pcm_val >= 0) {
- mask = 0xD5; /* sign (7th) bit = 1 */
- } else {
- mask = 0x55; /* sign bit = 0 */
- pcm_val = -pcm_val - 1;
- }
+ if (pcm_val >= 0) {
+ mask = 0xD5; /* sign (7th) bit = 1 */
+ }
+ else {
+ mask = 0x55; /* sign bit = 0 */
+ pcm_val = -pcm_val - 1;
+ }
- /* Convert the scaled magnitude to segment number. */
- seg = search(pcm_val, seg_aend, 8);
+ /* Convert the scaled magnitude to segment number. */
+ seg = search(pcm_val, seg_aend, 8);
- /* Combine the sign, segment, and quantization bits. */
+ /* Combine the sign, segment, and quantization bits. */
- if (seg >= 8) /* out of range, return maximum value. */
- return (unsigned char) (0x7F ^ mask);
- else {
- aval = (unsigned char) seg << SEG_SHIFT;
- if (seg < 2)
- aval |= (pcm_val >> 1) & QUANT_MASK;
- else
- aval |= (pcm_val >> seg) & QUANT_MASK;
- return (aval ^ mask);
- }
+ if (seg >= 8) { /* out of range, return maximum value. */
+ return (unsigned char) (0x7F ^ mask);
+ }
+ else {
+ aval = (unsigned char) seg << SEG_SHIFT;
+ if (seg < 2) {
+ aval |= (pcm_val >> 1) & QUANT_MASK;
+ }
+ else {
+ aval |= (pcm_val >> seg) & QUANT_MASK;
+ }
+ return (aval ^ mask);
+ }
}
/*
@@ -166,25 +175,25 @@ unsigned char linear2alaw(short pcm_val) /* 2's complement (16-bit range) */
*/
short alaw2linear(unsigned char a_val)
{
- short t;
- short seg;
+ short t;
+ short seg;
- a_val ^= 0x55;
+ a_val ^= 0x55;
- t = (a_val & QUANT_MASK) << 4;
- seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
- switch (seg) {
- case 0:
- t += 8;
- break;
- case 1:
- t += 0x108;
- break;
- default:
- t += 0x108;
- t <<= seg - 1;
- }
- return ((a_val & SIGN_BIT) ? t : -t);
+ t = (a_val & QUANT_MASK) << 4;
+ seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
+ switch (seg) {
+ case 0:
+ t += 8;
+ break;
+ case 1:
+ t += 0x108;
+ break;
+ default:
+ t += 0x108;
+ t <<= seg - 1;
+ }
+ return ((a_val & SIGN_BIT) ? t : -t);
}
#define BIAS (0x84) /* Bias for linear code. */
@@ -221,34 +230,38 @@ short alaw2linear(unsigned char a_val)
*/
unsigned char linear2ulaw(short pcm_val) /* 2's complement (16-bit range) */
{
- short mask;
- short seg;
- unsigned char uval;
+ short mask;
+ short seg;
+ unsigned char uval;
- /* Get the sign and the magnitude of the value. */
- pcm_val = pcm_val >> 2;
- if (pcm_val < 0) {
- pcm_val = -pcm_val;
- mask = 0x7F;
- } else {
- mask = 0xFF;
- }
- if ( pcm_val > CLIP ) pcm_val = CLIP; /* clip the magnitude */
- pcm_val += (BIAS >> 2);
+ /* Get the sign and the magnitude of the value. */
+ pcm_val = pcm_val >> 2;
+ if (pcm_val < 0) {
+ pcm_val = -pcm_val;
+ mask = 0x7F;
+ }
+ else {
+ mask = 0xFF;
+ }
+ if ( pcm_val > CLIP ) {
+ pcm_val = CLIP; /* clip the magnitude */
+ }
+ pcm_val += (BIAS >> 2);
- /* Convert the scaled magnitude to segment number. */
- seg = search(pcm_val, seg_uend, 8);
+ /* Convert the scaled magnitude to segment number. */
+ seg = search(pcm_val, seg_uend, 8);
- /*
- * Combine the sign, segment, quantization bits;
- * and complement the code word.
- */
- if (seg >= 8) /* out of range, return maximum value. */
- return (unsigned char) (0x7F ^ mask);
- else {
- uval = (unsigned char) (seg << 4) | ((pcm_val >> (seg + 1)) & 0xF);
- return (uval ^ mask);
- }
+ /*
+ * Combine the sign, segment, quantization bits;
+ * and complement the code word.
+ */
+ if (seg >= 8) { /* out of range, return maximum value. */
+ return (unsigned char) (0x7F ^ mask);
+ }
+ else {
+ uval = (unsigned char) (seg << 4) | ((pcm_val >> (seg + 1)) & 0xF);
+ return (uval ^ mask);
+ }
}
@@ -263,33 +276,33 @@ unsigned char linear2ulaw(short pcm_val) /* 2's complement (16-bit range) */
*/
short ulaw2linear(unsigned char u_val)
{
- short t;
+ short t;
- /* Complement to obtain normal u-law value. */
- u_val = ~u_val;
+ /* Complement to obtain normal u-law value. */
+ u_val = ~u_val;
- /*
- * Extract and bias the quantization bits. Then
- * shift up by the segment number and subtract out the bias.
- */
- t = ((u_val & QUANT_MASK) << 3) + BIAS;
- t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
+ /*
+ * Extract and bias the quantization bits. Then
+ * shift up by the segment number and subtract out the bias.
+ */
+ t = ((u_val & QUANT_MASK) << 3) + BIAS;
+ t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
- return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
+ return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
}
/* A-law to u-law conversion */
unsigned char alaw2ulaw(unsigned char aval)
{
- aval &= 0xff;
- return (unsigned char) ((aval & 0x80) ? (0xFF ^ _a2u[aval ^ 0xD5]) :
- (0x7F ^ _a2u[aval ^ 0x55]));
+ aval &= 0xff;
+ return (unsigned char) ((aval & 0x80) ? (0xFF ^ _a2u[aval ^ 0xD5]) :
+ (0x7F ^ _a2u[aval ^ 0x55]));
}
/* u-law to A-law conversion */
unsigned char ulaw2alaw(unsigned char uval)
{
- uval &= 0xff;
- return (unsigned char) ((uval & 0x80) ? (0xD5 ^ (_u2a[0xFF ^ uval] - 1)) :
- (unsigned char) (0x55 ^ (_u2a[0x7F ^ uval] - 1)));
+ uval &= 0xff;
+ return (unsigned char) ((uval & 0x80) ? (0xD5 ^ (_u2a[0xFF ^ uval] - 1)) :
+ (unsigned char) (0x55 ^ (_u2a[0x7F ^ uval] - 1)));
}
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