dstdec.c File Reference

Direct Stream Transfer (DST) decoder ISO/IEC 14496-3 Part 3 Subpart 10: Technical description of lossless coding of oversampled audio. More...

#include "libavutil/avassert.h"
#include "libavutil/intreadwrite.h"
#include "internal.h"
#include "get_bits.h"
#include "avcodec.h"
#include "golomb.h"
#include "mathops.h"
#include "dsd.h"

Go to the source code of this file.

Data Structures
struct	ArithCoder
struct	Table
struct	DSTContext

Macros
#define	DST_MAX_CHANNELS   6
#define	DST_MAX_ELEMENTS   (2 * DST_MAX_CHANNELS)
#define	DSD_FS44(sample_rate)   (sample_rate * 8 / 44100)
#define	DST_SAMPLES_PER_FRAME(sample_rate)   (588 * DSD_FS44(sample_rate))
#define	F(x)   filter[(x)][status[(x)]]

Functions
static av_cold int	decode_init (AVCodecContext *avctx)
static int	read_map (GetBitContext *gb, Table *t, unsigned int map[DST_MAX_CHANNELS], int channels)
static av_always_inline int	get_sr_golomb_dst (GetBitContext *gb, unsigned int k)
static void	read_uncoded_coeff (GetBitContext *gb, int *dst, unsigned int elements, int coeff_bits, int is_signed, int offset)
static int	read_table (GetBitContext *gb, Table *t, const int8_t code_pred_coeff[3][3], int length_bits, int coeff_bits, int is_signed, int offset)
static void	ac_init (ArithCoder *ac, GetBitContext *gb)
static av_always_inline void	ac_get (ArithCoder *ac, GetBitContext *gb, int p, int *e)
static uint8_t	prob_dst_x_bit (int c)
static void	build_filter (int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
static int	decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)

Variables
static const int8_t	fsets_code_pred_coeff [3][3]
static const int8_t	probs_code_pred_coeff [3][3]
AVCodec	ff_dst_decoder

Detailed Description

Direct Stream Transfer (DST) decoder ISO/IEC 14496-3 Part 3 Subpart 10: Technical description of lossless coding of oversampled audio.

Definition in file dstdec.c.

Macro Definition Documentation

#define DST_MAX_CHANNELS   6

Definition at line 37 of file dstdec.c.

Referenced by decode_frame(), and decode_init().

#define DST_MAX_ELEMENTS   (2 * DST_MAX_CHANNELS)

Definition at line 38 of file dstdec.c.

Referenced by read_map().

#define DSD_FS44

(

sample_rate

)

(sample_rate * 8 / 44100)

Definition at line 40 of file dstdec.c.

#define DST_SAMPLES_PER_FRAME

(

sample_rate

)

(588 * DSD_FS44(sample_rate))

Definition at line 42 of file dstdec.c.

Referenced by decode_frame().

#define F

(

x

)

filter[(x)][status[(x)]]

Referenced by check_loopfilter(), decode_frame(), idct(), and loop_filter().

Function Documentation

static av_cold int decode_init ( AVCodecContext *  avctx )

static

Definition at line 78 of file dstdec.c.

static int read_map ( GetBitContext *  gb, Table *  t, unsigned int  map[DST_MAX_CHANNELS], int  channels  )

static

Definition at line 98 of file dstdec.c.

Referenced by decode_frame().

static av_always_inline int get_sr_golomb_dst ( GetBitContext *  gb, unsigned int  k  )

static

Definition at line 121 of file dstdec.c.

Referenced by read_table().

static void read_uncoded_coeff ( GetBitContext *  gb, int *  dst, unsigned int  elements, int  coeff_bits, int  is_signed, int  offset  )

static

Definition at line 129 of file dstdec.c.

Referenced by read_table().

static int read_table ( GetBitContext *  gb, Table *  t, const int8_t  code_pred_coeff[3][3], int  length_bits, int  coeff_bits, int  is_signed, int  offset  )

static

Definition at line 139 of file dstdec.c.

Referenced by decode_frame().

static void ac_init ( ArithCoder *  ac, GetBitContext *  gb  )

static

Definition at line 171 of file dstdec.c.

Referenced by decode_frame().

static av_always_inline void ac_get ( ArithCoder *  ac, GetBitContext *  gb, int  p, int *  e  )

static

Definition at line 177 of file dstdec.c.

Referenced by decode_frame().

static uint8_t prob_dst_x_bit ( int  c )

static

Definition at line 198 of file dstdec.c.

Referenced by decode_frame().

static void build_filter ( int16_t  table[DST_MAX_ELEMENTS][16][256], const Table *  fsets  )

static

Definition at line 203 of file dstdec.c.

Referenced by decode_frame().

static int decode_frame ( AVCodecContext *  avctx, void *  data, int *  got_frame_ptr, AVPacket *  avpkt  )

static

Definition at line 224 of file dstdec.c.

Variable Documentation

const int8_t fsets_code_pred_coeff[3][3]

static

Initial value:

= {
    {  -8 },
    { -16,  8 },
    {  -9, -5, 6 },
}

Definition at line 44 of file dstdec.c.

Referenced by decode_frame().

const int8_t probs_code_pred_coeff[3][3]

static

Initial value:

= {
    {  -8 },
    { -16,  8 },
    { -24, 24, -8 },
}

Definition at line 50 of file dstdec.c.

Referenced by decode_frame().

AVCodec ff_dst_decoder

Initial value:

= {
    .name           = "dst",
    .long_name      = NULL_IF_CONFIG_SMALL("DST (Digital Stream Transfer)"),
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_DST,
    .priv_data_size = sizeof(DSTContext),
    .init           = decode_init,
    .decode         = decode_frame,
    .capabilities   = AV_CODEC_CAP_DR1,
    .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
                                                      AV_SAMPLE_FMT_NONE },
}

Definition at line 363 of file dstdec.c.