SampleEncoderLinear.cpp File Reference

#include "config.h"
#include <stdio.h>
#include <sys/types.h>
#include <QtGlobal>
#include "libkwave/Sample.h"
#include "libkwave/SampleEncoderLinear.h"
#include "libkwave/SampleFormat.h"
#include "libkwave/Utils.h"

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Macros
#define	MAKE_ENCODER(bits)

Functions
static void	encode_NULL (const sample_t *src, quint8 *dst, unsigned int count)
template<const unsigned int bits, const bool is_signed, const bool is_little_endian>
void	encode_linear (const sample_t *src, quint8 *dst, unsigned int count)

Macro Definition Documentation

MAKE_ENCODER

#define MAKE_ENCODER

(

bits

)

Value:

if (sample_format != Kwave::SampleFormat::Unsigned) {  \
    if (endianness != Kwave::BigEndian) {              \
        m_encoder = encode_linear<bits, true, true>;   \
    } else {                                           \
        m_encoder = encode_linear<bits, true, false>;  \
    }                                                  \
} else {                                               \
    if (endianness != Kwave::BigEndian) {              \
        m_encoder = encode_linear<bits, false, true>;  \
    } else {                                           \
        m_encoder = encode_linear<bits, false, false>; \
    }                                                  \
}

Definition at line 92 of file SampleEncoderLinear.cpp.

Referenced by Kwave::SampleEncoderLinear::SampleEncoderLinear().

Function Documentation

encode_linear()

template<const unsigned int bits, const bool is_signed, const bool is_little_endian>

void encode_linear	(	const sample_t *	src,
		quint8 *	dst,
		unsigned int	count
	)

Template for encoding a buffer with linear samples. The tricky part is done in the compiler which optimizes away all unused parts of current variant and does nice loop optimizing!

Parameters

src	array with samples in Kwave's format
dst	array that receives the raw data
count	the number of samples to be encoded

Definition at line 50 of file SampleEncoderLinear.cpp.

References SAMPLE_BITS.

{
    for ( ; count; --count) {
        // read from source buffer
        sample_t s = *(src++);

        // convert to unsigned if necessary
        if (!is_signed)
            s += 1 << (SAMPLE_BITS-1);

        // shrink 18/20 bits and similar down, otherwise it does not work
        // with ALSA for some dubious reason !?
        if (bits == 20)
            s >>= 4;
        if (bits == 18) // don't ask me why... !!!???
            s >>= 6;

        if (is_little_endian) {
            // little endian
            if (bits > 24)
                *(dst++) = 0x00;
            if (bits > 16)
                *(dst++) = static_cast<quint8>(s & 0xFF);
            if (bits > 8)
                *(dst++) = static_cast<quint8>(s >> 8);
            if (bits >= 8)
                *(dst++) = static_cast<quint8>(s >> 16);
        } else {
            // big endian
            if (bits >= 8)
                *(dst++) = static_cast<quint8>(s >> 16);
            if (bits > 8)
                *(dst++) = static_cast<quint8>(s >> 8);
            if (bits > 16)
                *(dst++) = static_cast<quint8>(s & 0xFF);
            if (bits > 24)
                *(dst++) = 0x00;
        }
    }
}

encode_NULL()

static void encode_NULL ( const sample_t *  src, quint8 *  dst, unsigned int  count  )

static

Definition at line 31 of file SampleEncoderLinear.cpp.

Referenced by Kwave::SampleEncoderLinear::SampleEncoderLinear().

{
    (void)src;
    (void)dst;
    (void)count;
//     qWarning("call to encode_NULL");
}

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