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
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, 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,
			b
	)			(((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.

#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.

Referenced by MPA_encode_init().

#define WSHIFT   (WFRAC_BITS + 15 - FRAC_BITS)

Definition at line 309 of file mpegaudioenc.c.

---

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 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]

Definition at line 311 of file mpegaudioenc.c.

Referenced by av_resample(), filter_name(), initFilter(), make_filters_from_proto(), MPA_encode_frame(), pick_formats(), query_formats(), show_filters(), and tta_decode_frame().

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

AVCodec ff_mp2_encoder

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.