g723_1dec.c File Reference

G.723.1 compatible decoder. More...

#include "libavutil/channel_layout.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "acelp_vectors.h"
#include "avcodec.h"
#include "celp_filters.h"
#include "celp_math.h"
#include "get_bits.h"
#include "internal.h"
#include "g723_1.h"

Macros
#define	BITSTREAM_READER_LE
#define	CNG_RANDOM_SEED   12345
#define	iir_filter(fir_coef, iir_coef, src, dest, width)
	Perform IIR filtering. More...
#define	OFFSET(x)   offsetof(G723_1_Context, x)
#define	AD   AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM

Variables
AVCodec	ff_g723_1_decoder

Detailed Description

G.723.1 compatible decoder.

Macro Definition Documentation

iir_filter

#define iir_filter	(		fir_coef,
			iir_coef,
			src,
			dest,
			width
	)

Value:

{\
    int m, n;\
    int res_shift = 16 & ~-(width);\
    int in_shift  = 16 - res_shift;\
\
    for (m = 0; m < SUBFRAME_LEN; m++) {\
        int64_t filter = 0;\
        for (n = 1; n <= LPC_ORDER; n++) {\
            filter -= (fir_coef)[n - 1] * (src)[m - n] -\
                      (iir_coef)[n - 1] * ((dest)[m - n] >> in_shift);\
        }\
\
        (dest)[m] = av_clipl_int32(((src)[m] * 65536) + (filter * 8) +\
                                   (1 << 15)) >> res_shift;\
    }\
}

Perform IIR filtering.

Parameters

fir_coef	FIR coefficients
iir_coef	IIR coefficients
src	source vector
dest	destination vector
width	width of the output, 16 bits(0) / 32 bits(1)

Variable Documentation

ff_g723_1_decoder

AVCodec ff_g723_1_decoder

Initial value:

= {
    .name           = "g723_1",
    .long_name      = NULL_IF_CONFIG_SMALL("G.723.1"),
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_G723_1,
    .priv_data_size = sizeof(G723_1_Context),
    .init           = g723_1_decode_init,
    .decode         = g723_1_decode_frame,
    .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
    .priv_class     = &g723_1dec_class,
}