libavcodec/ac3enc_float.c File Reference

floating-point AC-3 encoder. More...

#include "ac3enc.c"
#include "kbdwin.h"

Go to the source code of this file.

Defines
#define	CONFIG_AC3ENC_FLOAT   1
Functions
static av_cold void	mdct_end (AC3MDCTContext *mdct)
	Finalize MDCT and free allocated memory.
static av_cold int	mdct_init (AVCodecContext *avctx, AC3MDCTContext *mdct, int nbits)
	Initialize MDCT tables.
static void	mdct512 (AC3MDCTContext *mdct, float *out, float *in)
	Calculate a 512-point MDCT.
static void	apply_window (DSPContext *dsp, float *output, const float *input, const float *window, int n)
	Apply KBD window to input samples prior to MDCT.
static int	normalize_samples (AC3EncodeContext *s)
	Normalize the input samples to use the maximum available precision.
static void	scale_coefficients (AC3EncodeContext *s)
	Scale MDCT coefficients from float to 24-bit fixed-point.
Variables
AVCodec	ff_ac3_encoder

---

Detailed Description

floating-point AC-3 encoder.

Definition in file ac3enc_float.c.

---

Define Documentation

#define CONFIG_AC3ENC_FLOAT   1

Definition at line 29 of file ac3enc_float.c.

---

Function Documentation

static void apply_window	(	DSPContext *	dsp,
		float *	output,
		const float *	input,
		const float *	window,
		int	n
	)			[static]

Apply KBD window to input samples prior to MDCT.

Definition at line 85 of file ac3enc_float.c.

static void mdct512	(	AC3MDCTContext *	mdct,
		float *	out,
		float *	in
	)			[static]

Calculate a 512-point MDCT.

Parameters:

	out	256 output frequency coefficients
	in	512 windowed input audio samples

Definition at line 76 of file ac3enc_float.c.

static av_cold void mdct_end

(

AC3MDCTContext *

mdct

)

[static]

Finalize MDCT and free allocated memory.

Definition at line 37 of file ac3enc_float.c.

static av_cold int mdct_init	(	AVCodecContext *	avctx,
		AC3MDCTContext *	mdct,
		int	nbits
	)			[static]

Initialize MDCT tables.

Parameters:

nbits

log2(MDCT size)

Definition at line 48 of file ac3enc_float.c.

static int normalize_samples

(

AC3EncodeContext *

s

)

[static]

Normalize the input samples to use the maximum available precision.

Definition at line 95 of file ac3enc_float.c.

static void scale_coefficients

(

AC3EncodeContext *

s

)

[static]

Scale MDCT coefficients from float to 24-bit fixed-point.

Definition at line 105 of file ac3enc_float.c.

---

Variable Documentation

AVCodec ff_ac3_encoder

Initial value:

 {
    "ac3",
    AVMEDIA_TYPE_AUDIO,
    CODEC_ID_AC3,
    sizeof(AC3EncodeContext),
    ac3_encode_init,
    ac3_encode_frame,
    ac3_encode_close,
    NULL,
    .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_FLT,AV_SAMPLE_FMT_NONE},
    .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
    .channel_layouts = ac3_channel_layouts,
}

Definition at line 112 of file ac3enc_float.c.