#define BIAS (0x84) /* Bias for linear code. */
+#define VIDC_SIGN_BIT (1)
+#define VIDC_QUANT_MASK (0x1E)
+#define VIDC_QUANT_SHIFT (1)
+#define VIDC_SEG_SHIFT (5)
+#define VIDC_SEG_MASK (0xE0)
+
/* alaw2linear() - Convert an A-law value to 16-bit linear PCM */
static av_cold int alaw2linear(unsigned char a_val)
{
- int t;
- int seg;
+ int t;
+ int seg;
- a_val ^= 0x55;
+ a_val ^= 0x55;
- t = a_val & QUANT_MASK;
- seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
- if(seg) t= (t + t + 1 + 32) << (seg + 2);
- else t= (t + t + 1 ) << 3;
+ t = a_val & QUANT_MASK;
+ seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
+ if(seg) t= (t + t + 1 + 32) << (seg + 2);
+ else t= (t + t + 1 ) << 3;
- return (a_val & SIGN_BIT) ? t : -t;
+ return (a_val & SIGN_BIT) ? t : -t;
}
static av_cold int ulaw2linear(unsigned char u_val)
{
- int t;
+ int 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);
+}
+
+static av_cold int vidc2linear(unsigned char u_val)
+{
+ int t;
+
+ /*
+ * Extract and bias the quantization bits. Then
+ * shift up by the segment number and subtract out the bias.
+ */
+ t = (((u_val & VIDC_QUANT_MASK) >> VIDC_QUANT_SHIFT) << 3) + BIAS;
+ t <<= ((unsigned)u_val & VIDC_SEG_MASK) >> VIDC_SEG_SHIFT;
+
+ return (u_val & VIDC_SIGN_BIT) ? (BIAS - t) : (t - BIAS);
}
#if CONFIG_HARDCODED_TABLES
#define pcm_alaw_tableinit()
#define pcm_ulaw_tableinit()
+#define pcm_vidc_tableinit()
#include "libavcodec/pcm_tables.h"
#else
/* 16384 entries per table */
static uint8_t linear_to_alaw[16384];
static uint8_t linear_to_ulaw[16384];
+static uint8_t linear_to_vidc[16384];
static av_cold void build_xlaw_table(uint8_t *linear_to_xlaw,
int (*xlaw2linear)(unsigned char),
{
build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
}
+
+static void pcm_vidc_tableinit(void)
+{
+ build_xlaw_table(linear_to_vidc, vidc2linear, 0xff);
+}
#endif /* CONFIG_HARDCODED_TABLES */
#endif /* AVCODEC_PCM_TABLEGEN_H */