libavcodec/mpegaudioenc.c File Reference

The simplest mpeg audio layer 2 encoder. More...

#include "avcodec.h"
#include "internal.h"
#include "put_bits.h"
#include "mpegaudio.h"
#include "mpegaudiodata.h"
#include "mpegaudiotab.h"

Go to the source code of this file.

Data Structures

struct  MpegAudioContext

Defines

#define FRAC_BITS   15
#define WFRAC_BITS   14
#define MUL(a, b)   (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)
#define SAMPLES_BUF_SIZE   4096
#define USE_FLOATS
#define WSHIFT   (WFRAC_BITS + 15 - FRAC_BITS)
#define SB_NOTALLOCATED   0
#define SB_ALLOCATED   1
#define SB_NOMORE   2

Functions

static av_cold int MPA_encode_init (AVCodecContext *avctx)
static void idct32 (int *out, int *tab)
static void filter (MpegAudioContext *s, int ch, const short *samples, int incr)
static void compute_scale_factors (unsigned char scale_code[SBLIMIT], unsigned char scale_factors[SBLIMIT][3], int sb_samples[3][12][SBLIMIT], int sblimit)
static void psycho_acoustic_model (MpegAudioContext *s, short smr[SBLIMIT])
static void compute_bit_allocation (MpegAudioContext *s, short smr1[MPA_MAX_CHANNELS][SBLIMIT], unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT], int *padding)
static void encode_frame (MpegAudioContext *s, unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT], int padding)
static int MPA_encode_frame (AVCodecContext *avctx, unsigned char *frame, int buf_size, void *data)
static av_cold int MPA_encode_close (AVCodecContext *avctx)

Variables

static const AVCodecDefault mp2_defaults []
AVCodec ff_mp2_encoder


Detailed Description

The simplest mpeg audio layer 2 encoder.

Definition in file mpegaudioenc.c.


Define Documentation

#define FRAC_BITS   15

Definition at line 31 of file mpegaudioenc.c.

#define MUL ( a,
 )     (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)

Definition at line 38 of file mpegaudioenc.c.

Referenced by idct32(), and idctRowCondDC().

#define SAMPLES_BUF_SIZE   4096

Definition at line 40 of file mpegaudioenc.c.

Referenced by filter().

#define SB_ALLOCATED   1

Definition at line 490 of file mpegaudioenc.c.

Referenced by compute_bit_allocation().

#define SB_NOMORE   2

Definition at line 491 of file mpegaudioenc.c.

Referenced by compute_bit_allocation().

#define SB_NOTALLOCATED   0

Definition at line 489 of file mpegaudioenc.c.

Referenced by compute_bit_allocation().

#define USE_FLOATS

Definition at line 62 of file mpegaudioenc.c.

#define WFRAC_BITS   14

Definition at line 32 of file mpegaudioenc.c.

#define WSHIFT   (WFRAC_BITS + 15 - FRAC_BITS)

Definition at line 309 of file mpegaudioenc.c.

Referenced by filter().


Function Documentation

static void compute_bit_allocation ( MpegAudioContext s,
short  smr1[MPA_MAX_CHANNELS][SBLIMIT],
unsigned char  bit_alloc[MPA_MAX_CHANNELS][SBLIMIT],
int *  padding 
) [static]

Definition at line 496 of file mpegaudioenc.c.

Referenced by MPA_encode_frame().

static void compute_scale_factors ( unsigned char  scale_code[SBLIMIT],
unsigned char  scale_factors[SBLIMIT][3],
int  sb_samples[3][12][SBLIMIT],
int  sblimit 
) [static]

Definition at line 364 of file mpegaudioenc.c.

Referenced by MPA_encode_frame().

static void encode_frame ( MpegAudioContext s,
unsigned char  bit_alloc[MPA_MAX_CHANNELS][SBLIMIT],
int  padding 
) [static]

Definition at line 592 of file mpegaudioenc.c.

static void filter ( MpegAudioContext s,
int  ch,
const short *  samples,
int  incr 
) [static]

static void idct32 ( int *  out,
int *  tab 
) [static]

Definition at line 190 of file mpegaudioenc.c.

Referenced by filter().

static av_cold int MPA_encode_close ( AVCodecContext avctx  )  [static]

Definition at line 757 of file mpegaudioenc.c.

static int MPA_encode_frame ( AVCodecContext avctx,
unsigned char *  frame,
int  buf_size,
void *  data 
) [static]

Definition at line 728 of file mpegaudioenc.c.

static av_cold int MPA_encode_init ( AVCodecContext avctx  )  [static]

Definition at line 67 of file mpegaudioenc.c.

static void psycho_acoustic_model ( MpegAudioContext s,
short  smr[SBLIMIT] 
) [static]

Definition at line 479 of file mpegaudioenc.c.

Referenced by MPA_encode_frame().


Variable Documentation

Initial value:

 {
    .name           = "mp2",
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = CODEC_ID_MP2,
    .priv_data_size = sizeof(MpegAudioContext),
    .init           = MPA_encode_init,
    .encode         = MPA_encode_frame,
    .close          = MPA_encode_close,
    .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
    .supported_samplerates= (const int[]){44100, 48000,  32000, 22050, 24000, 16000, 0},
    .long_name = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
    .defaults       = mp2_defaults,
}

Definition at line 768 of file mpegaudioenc.c.

const AVCodecDefault mp2_defaults[] [static]

Initial value:

 {
    { "b",    "128k" },
    { NULL },
}

Definition at line 763 of file mpegaudioenc.c.


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