mpegaudioenc.c File Reference

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

#include "libavutil/channel_layout.h"
#include "avcodec.h"
#include "internal.h"
#include "put_bits.h"
#include "mpegaudio.h"
#include "mpegaudiodsp.h"
#include "mpegaudiodata.h"
#include "mpegaudiotab.h"

Include dependency graph for mpegaudioenc.c:

Go to the source code of this file.

Data Structures
struct	MpegAudioContext

Macros
#define	FRAC_BITS   15 /* fractional bits for sb_samples and dct */
#define	WFRAC_BITS   14 /* fractional bits for window */
#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

Typedefs
typedef struct MpegAudioContext	MpegAudioContext

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, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)

Variables
static const AVCodecDefault	mp2_defaults []
AVCodec	ff_mp2_encoder

Detailed Description

The simplest mpeg audio layer 2 encoder.

Definition in file mpegaudioenc.c.

Macro Definition Documentation

#define FRAC_BITS   15 /* fractional bits for sb_samples and dct */

Definition at line 33 of file mpegaudioenc.c.

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

Definition at line 41 of file mpegaudioenc.c.

Referenced by idct32().

#define SAMPLES_BUF_SIZE   4096

Definition at line 43 of file mpegaudioenc.c.

Referenced by filter().

#define SB_ALLOCATED   1

Definition at line 491 of file mpegaudioenc.c.

Referenced by compute_bit_allocation().

#define SB_NOMORE   2

Definition at line 492 of file mpegaudioenc.c.

Referenced by compute_bit_allocation().

#define SB_NOTALLOCATED   0

Definition at line 490 of file mpegaudioenc.c.

Referenced by compute_bit_allocation().

#define USE_FLOATS

Definition at line 65 of file mpegaudioenc.c.

#define WFRAC_BITS   14 /* fractional bits for window */

Definition at line 34 of file mpegaudioenc.c.

Referenced by MPA_encode_init().

#define WSHIFT   (WFRAC_BITS + 15 - FRAC_BITS)

Definition at line 310 of file mpegaudioenc.c.

Referenced by filter().

Typedef Documentation

typedef struct MpegAudioContext MpegAudioContext

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 497 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 365 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 593 of file mpegaudioenc.c.

Referenced by MPA_encode_frame().

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

static

Definition at line 312 of file mpegaudioenc.c.

Referenced by MPA_encode_frame().

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

static

Definition at line 191 of file mpegaudioenc.c.

Referenced by filter().

static int MPA_encode_frame ( AVCodecContext *  avctx, AVPacket *  avpkt, const AVFrame *  frame, int *  got_packet_ptr  )

static

Definition at line 729 of file mpegaudioenc.c.

static av_cold int MPA_encode_init ( AVCodecContext *  avctx )

static

Definition at line 70 of file mpegaudioenc.c.

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

static

Definition at line 480 of file mpegaudioenc.c.

Referenced by MPA_encode_frame().

Variable Documentation

AVCodec ff_mp2_encoder

Initial value:

= {
    .name                  = "mp2",
    .type                  = AVMEDIA_TYPE_AUDIO,
    .id                    = AV_CODEC_ID_MP2,
    .priv_data_size        = sizeof(MpegAudioContext),
    .init                  = MPA_encode_init,
    .encode2               = MPA_encode_frame,
    .sample_fmts           = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
                                                            AV_SAMPLE_FMT_NONE },
    .supported_samplerates = (const int[]){
        44100, 48000,  32000, 22050, 24000, 16000, 0
    },
    .channel_layouts       = (const uint64_t[]){ AV_CH_LAYOUT_MONO,
                                                 AV_CH_LAYOUT_STEREO,
                                                 0 },
    .long_name             = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
    .defaults              = mp2_defaults,
}

Definition at line 771 of file mpegaudioenc.c.

const AVCodecDefault mp2_defaults[]

static

Initial value:

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

Definition at line 766 of file mpegaudioenc.c.