libavcodec/psymodel.c File Reference

#include "avcodec.h"
#include "psymodel.h"
#include "iirfilter.h"

Go to the source code of this file.

Data Structures
struct	FFPsyPreprocessContext
Defines
#define	FILT_ORDER   4
Typedefs
typedef struct FFPsyPreprocessContext	FFPsyPreprocessContext
Functions
av_cold int	ff_psy_init (FFPsyContext *ctx, AVCodecContext *avctx, int num_lens, const uint8_t **bands, const int *num_bands)
	Initialize psychoacoustic model.
FFPsyWindowInfo	ff_psy_suggest_window (FFPsyContext *ctx, const int16_t *audio, const int16_t *la, int channel, int prev_type)
	Suggest window sequence for channel.
void	ff_psy_set_band_info (FFPsyContext *ctx, int channel, const float *coeffs, FFPsyWindowInfo *wi)
	Perform psychoacoustic analysis and set band info (threshold, energy).
av_cold void	ff_psy_end (FFPsyContext *ctx)
	Cleanup model context at the end.
av_cold struct FFPsyPreprocessContext *	ff_psy_preprocess_init (AVCodecContext *avctx)
	psychoacoustic model audio preprocessing initialization
void	ff_psy_preprocess (struct FFPsyPreprocessContext *ctx, const int16_t *audio, int16_t *dest, int tag, int channels)
	Preprocess several channel in audio frame in order to compress it better.
av_cold void	ff_psy_preprocess_end (struct FFPsyPreprocessContext *ctx)
	Cleanup audio preprocessing module.
Variables
const FFPsyModel	ff_aac_psy_model

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Define Documentation

#define FILT_ORDER   4

Definition at line 77 of file psymodel.c.

Referenced by ff_psy_preprocess_init().

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Typedef Documentation

typedef struct FFPsyPreprocessContext FFPsyPreprocessContext

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Function Documentation

av_cold void ff_psy_end

(

FFPsyContext *

ctx

)

Cleanup model context at the end.

Parameters:

ctx	model context

Definition at line 61 of file psymodel.c.

Referenced by aac_encode_end().

av_cold int ff_psy_init	(	FFPsyContext *	ctx,
		AVCodecContext *	avctx,
		int	num_lens,
		const uint8_t **	bands,
		const int *	num_bands
	)

Initialize psychoacoustic model.

Parameters:

ctx	model context
avctx	codec context
num_lens	number of possible frame lengths
bands	scalefactor band lengths for all frame lengths
num_bands	number of scalefactor bands for all frame lengths

Returns:

zero if successful, a negative value if not

Definition at line 28 of file psymodel.c.

Referenced by aac_encode_init().

void ff_psy_preprocess	(	struct FFPsyPreprocessContext *	ctx,
		const int16_t *	audio,
		int16_t *	dest,
		int	tag,
		int	channels
	)

Preprocess several channel in audio frame in order to compress it better.

Parameters:

ctx	preprocessing context
audio	samples to preprocess
dest	place to put filtered samples
tag	channel number
channels	number of channel to preprocess (some additional work may be done on stereo pair)

Definition at line 101 of file psymodel.c.

Referenced by aac_encode_frame().

av_cold void ff_psy_preprocess_end

(

struct FFPsyPreprocessContext *

ctx

)

Cleanup audio preprocessing module.

Definition at line 118 of file psymodel.c.

Referenced by aac_encode_end().

av_cold struct FFPsyPreprocessContext* ff_psy_preprocess_init

(

AVCodecContext *

avctx

)

[read]

psychoacoustic model audio preprocessing initialization

Definition at line 79 of file psymodel.c.

Referenced by aac_encode_init().

void ff_psy_set_band_info	(	FFPsyContext *	ctx,
		int	channel,
		const float *	coeffs,
		FFPsyWindowInfo *	wi
	)

Perform psychoacoustic analysis and set band info (threshold, energy).

Parameters:

ctx	model context
channel	audio channel number
coeffs	pointer to the transformed coefficients
wi	window information

Definition at line 55 of file psymodel.c.

Referenced by aac_encode_frame().

FFPsyWindowInfo ff_psy_suggest_window	(	FFPsyContext *	ctx,
		const int16_t *	audio,
		const int16_t *	la,
		int	channel,
		int	prev_type
	)

Suggest window sequence for channel.

Parameters:

ctx	model context
audio	samples for the current frame
la	lookahead samples (NULL when unavailable)
channel	number of channel element to analyze
prev_type	previous window type

Returns:

suggested window information in a structure

Definition at line 48 of file psymodel.c.

Referenced by aac_encode_frame().

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Variable Documentation

const FFPsyModel ff_aac_psy_model

Definition at line 311 of file aacpsy.c.

Referenced by ff_psy_init().