#include <float.h>
#include <string.h>
#include "libavutil/mathematics.h"
#include "mathops.h"
#include "avcodec.h"
#include "put_bits.h"
#include "aac.h"
#include "aacenc.h"
#include "aactab.h"
#include "aacenctab.h"

Macros
#define	NMR_SFBITS(d) ff_aac_scalefactor_bits[av_clip((d) + SCALE_DIFF_ZERO, 0, 2*SCALE_MAX_DIFF)]
	AAC encoder NMR scalefactor coder. More...

#define	NMR_ITERS 14 /* lambda binary-search iters */

#define	NMR_IFINE 9 /* fine-pass lambda iters */

#define	NMR_CITERS 7 /* coarse-pass lambda iters */

#define	NMR_CWARM

#define	NMR_COARSE

#define	NMR_STEP 1 /* fine-pass scalefactor candidate granularity */

#define	NMR_PNS_BITS 9 /* approx cost in bits of signalling PNS */

#define	NMR_PNS_HOLE_FRAC 0.5f

#define	NMR_PNS_HOLE_SPREAD 0.5f

#define	NMR_RC_K_CBR 0.5f

#define	NMR_RC_ITERS 8 /* lambda bisection iters when clamping an over-cap frame */

#define	NMR_RC_CORR 1.5f

#define	NMR_CBR_BUF 1536

#define	NMR_SLEW 1.6f

#define	NMR_SLEW_RUN 1.15f /* within short runs */

#define	NMR_RC_CITERS 3 /* corridor coarse-pass iters */

#define	NMR_TRANS_PM 2.0f

#define	NMR_ZERO_STICKY 0.5f

#define	NMR_BURST_GAP 10

#define	NMR_BURST_GAIN 8.0f

#define	NMR_SHORT_BOOST 2.0f

#define	NMR_RC_FITERS 4 /* corridor fine-pass iters */

#define	NMR_RC_TRACK 0.1f /* per-frame pull of the corridor centre toward the realized lambda */

#define	NMR_PNS_NDGATE 4.0f

#define	NMR_PNS_MAX_ET 8.0f

#define	NMR_PNS_LAM 100.0f

#define	NMR_PNS_ENTER 0.7f

#define	NMR_PNS_STAY 1.4f

#define	NMR_PNS_ON 8

#define	NMR_PNS_OFF 4

Functions
static float	nmr_solve (AACEncContext s, const float(nd)[NMR_NCAND], const int(nb)[NMR_NCAND], const int blo, const int bnc, int step, const int act, int nact, int destbits, int *chosen, float lo_l, float hi_l, int iters)
	Viterbi over the coding sequence act0..nact-1, with lambda binary-searched so the coded size ~ destbits. More...

static int	nmr_band_curve (AACEncContext s, SingleChannelElement sce, int w, int g, int start, int lo, int step, int maxn, float invthr, float maxval, float nd_row, int nb_row)

static void	nmr_bail_channel (SingleChannelElement *sce)

static int	nmr_setup_channel (AVCodecContext avctx, AACEncContext s, SingleChannelElement sce, NMRSlot t)

static int	nmr_slot_bits (const NMRSlot t, const int(nb)[NMR_NCAND], int step)

static int	nmr_eval_slots (AACEncContext s, NMRSlot const *sl, int nsl, int step, float lam)

static float	nmr_solve_slots (AACEncContext s, NMRSlot const *sl, int nsl, int step, int destbits, float lo_l, float hi_l, int iters)

static void	nmr_commit_channel (AACEncContext s, NMRSlot t)

static void	nmr_solve_group (AVCodecContext avctx, AACEncContext s, const float lambda, NMRSlot const sl, int nsl, int chans, int rc_eligible, int rc_global, int rc_rate_frame, int rc_bmax)

static void	search_for_quantizers_nmr (AVCodecContext avctx, AACEncContext s, SingleChannelElement *sce, const float lambda)

Macro Definition Documentation

◆ NMR_SFBITS

#define NMR_SFBITS ( d ) ff_aac_scalefactor_bits[av_clip((d) + SCALE_DIFF_ZERO, 0, 2*SCALE_MAX_DIFF)]

AAC encoder NMR scalefactor coder.

Optimizes the same noise-to-mask objective as the two-loop coder, but with an optimal Viterbi search over scalefactors instead of a heuristic loop. For each coded band the per-scalefactor distortion/bits curve is precomputed, then a trellis over the (window-group, band) coding sequence minimizes sum_g = dist_g(sf_g)/threshold_g + lambda * (spectral_bits_g(sf_g) + scalefactor_differential_bits) with |sf_g - sf_{g-1}| <= SCALE_MAX_DIFF as a constraint, and lambda binary-searched so the coded size meets the per-frame bit budget

Perceptual noise substitution (PNS) is integrated into the same objective: once the trellis settles on its operating lambda, each noise-like band (flagged by mark_pns) is offered a terminal "code as noise" candidate whose cost is nmr_pns + lambda*NMR_PNS_BITS. Because NMR_PNS_BITS is far below a band's spectral bit count, this candidate only wins when lambda is large, i.e. when the encoder is struggling to hold the bitrate. The bits freed by the chosen PNS bands are then re-spent by a second trellis pass over the remaining bands.

Definition at line 58 of file aaccoder_nmr.h.

◆ NMR_ITERS

#define NMR_ITERS 14 /* lambda binary-search iters */

Definition at line 60 of file aaccoder_nmr.h.

◆ NMR_IFINE

#define NMR_IFINE 9 /* fine-pass lambda iters */

Definition at line 61 of file aaccoder_nmr.h.

◆ NMR_CITERS

#define NMR_CITERS 7 /* coarse-pass lambda iters */

Definition at line 62 of file aaccoder_nmr.h.

◆ NMR_CWARM

#define NMR_CWARM

Value:

                        5 /* coarse-pass iters when warm-started off the previous frame's
                        * lambda: the bracket spans 10 octaves instead of ~43, so fewer
                        * bisection steps reach the same resolution */

Definition at line 63 of file aaccoder_nmr.h.

◆ NMR_COARSE

#define NMR_COARSE

Value:

8 /* two-pass coarse->fine grid step, cuts the Viterbi ncand^2 with no

* quality loss, 0 disables it (single full-resolution pass) */

Definition at line 64 of file aaccoder_nmr.h.

◆ NMR_STEP

#define NMR_STEP 1 /* fine-pass scalefactor candidate granularity */

Definition at line 65 of file aaccoder_nmr.h.

◆ NMR_PNS_BITS

#define NMR_PNS_BITS 9 /* approx cost in bits of signalling PNS */

Definition at line 67 of file aaccoder_nmr.h.

◆ NMR_PNS_HOLE_FRAC

#define NMR_PNS_HOLE_FRAC 0.5f

Definition at line 71 of file aaccoder_nmr.h.

◆ NMR_PNS_HOLE_SPREAD

#define NMR_PNS_HOLE_SPREAD 0.5f

Definition at line 72 of file aaccoder_nmr.h.

◆ NMR_RC_K_CBR

#define NMR_RC_K_CBR 0.5f

Definition at line 76 of file aaccoder_nmr.h.

◆ NMR_RC_ITERS

#define NMR_RC_ITERS 8 /* lambda bisection iters when clamping an over-cap frame */

Definition at line 78 of file aaccoder_nmr.h.

◆ NMR_RC_CORR

#define NMR_RC_CORR 1.5f

Definition at line 81 of file aaccoder_nmr.h.

◆ NMR_CBR_BUF

#define NMR_CBR_BUF 1536

Definition at line 84 of file aaccoder_nmr.h.

◆ NMR_SLEW

#define NMR_SLEW 1.6f

Definition at line 87 of file aaccoder_nmr.h.

◆ NMR_SLEW_RUN

#define NMR_SLEW_RUN 1.15f /* within short runs */

Definition at line 88 of file aaccoder_nmr.h.

◆ NMR_RC_CITERS

#define NMR_RC_CITERS 3 /* corridor coarse-pass iters */

Definition at line 89 of file aaccoder_nmr.h.

◆ NMR_TRANS_PM

#define NMR_TRANS_PM 2.0f

Definition at line 93 of file aaccoder_nmr.h.

◆ NMR_ZERO_STICKY

#define NMR_ZERO_STICKY 0.5f

Definition at line 97 of file aaccoder_nmr.h.

◆ NMR_BURST_GAP

#define NMR_BURST_GAP 10

Definition at line 101 of file aaccoder_nmr.h.

◆ NMR_BURST_GAIN

#define NMR_BURST_GAIN 8.0f

Definition at line 102 of file aaccoder_nmr.h.

◆ NMR_SHORT_BOOST

#define NMR_SHORT_BOOST 2.0f

Definition at line 105 of file aaccoder_nmr.h.

◆ NMR_RC_FITERS

#define NMR_RC_FITERS 4 /* corridor fine-pass iters */

Definition at line 106 of file aaccoder_nmr.h.

◆ NMR_RC_TRACK

#define NMR_RC_TRACK 0.1f /* per-frame pull of the corridor centre toward the realized lambda */

Definition at line 107 of file aaccoder_nmr.h.

◆ NMR_PNS_NDGATE

#define NMR_PNS_NDGATE 4.0f

Definition at line 110 of file aaccoder_nmr.h.

◆ NMR_PNS_MAX_ET

#define NMR_PNS_MAX_ET 8.0f

Definition at line 114 of file aaccoder_nmr.h.

◆ NMR_PNS_LAM

#define NMR_PNS_LAM 100.0f

Definition at line 118 of file aaccoder_nmr.h.

◆ NMR_PNS_ENTER

#define NMR_PNS_ENTER 0.7f

Definition at line 121 of file aaccoder_nmr.h.

◆ NMR_PNS_STAY

#define NMR_PNS_STAY 1.4f

Definition at line 122 of file aaccoder_nmr.h.

◆ NMR_PNS_ON

#define NMR_PNS_ON 8

Definition at line 125 of file aaccoder_nmr.h.

◆ NMR_PNS_OFF

#define NMR_PNS_OFF 4

Definition at line 126 of file aaccoder_nmr.h.

Function Documentation

◆ nmr_solve()

static float nmr_solve	(	AACEncContext *	s,
		const float(*)	nd[NMR_NCAND],
		const int(*)	nb[NMR_NCAND],
		const int *	blo,
		const int *	bnc,
		int	step,
		const int *	act,
		int	nact,
		int	destbits,
		int *	chosen,
		float	lo_l,
		float	hi_l,
		int	iters
	)

static

Viterbi over the coding sequence act0..nact-1, with lambda binary-searched so the coded size ~ destbits.

Fills chosen[band] for every band referenced by act. Returns the operating lambda. node cost = dist/threshold + lambda*spectral_bits; edge cost = lambda*sf_differential_bits; |delta sf| <= SCALE_MAX_DIFF hard.

Definition at line 135 of file aaccoder_nmr.h.

◆ nmr_band_curve()

static int nmr_band_curve	(	AACEncContext *	s,
		SingleChannelElement *	sce,
		int	w,
		int	g,
		int	start,
		int	lo,
		int	step,
		int	maxn,
		float	invthr,
		float	maxval,
		float *	nd_row,
		int *	nb_row
	)

static

Definition at line 199 of file aaccoder_nmr.h.

Referenced by nmr_setup_channel(), and nmr_solve_group().

◆ nmr_bail_channel()

static void nmr_bail_channel ( SingleChannelElement * sce )

static

Definition at line 225 of file aaccoder_nmr.h.

◆ nmr_setup_channel()

static int nmr_setup_channel	(	AVCodecContext *	avctx,
		AACEncContext *	s,
		SingleChannelElement *	sce,
		NMRSlot *	t
	)

static

Definition at line 238 of file aaccoder_nmr.h.

◆ nmr_slot_bits()

static int nmr_slot_bits	(	const NMRSlot *	t,
		const int(*)	nb[NMR_NCAND],
		int	step
	)

static

Definition at line 455 of file aaccoder_nmr.h.

Referenced by nmr_solve_group().

◆ nmr_eval_slots()

static int nmr_eval_slots	(	AACEncContext *	s,
		NMRSlot const	sl,
		int	nsl,
		int	step,
		float	lam
	)

static

Definition at line 467 of file aaccoder_nmr.h.

Referenced by nmr_solve_group(), and nmr_solve_slots().

◆ nmr_solve_slots()

static float nmr_solve_slots	(	AACEncContext *	s,
		NMRSlot const	sl,
		int	nsl,
		int	step,
		int	destbits,
		float	lo_l,
		float	hi_l,
		int	iters
	)

static

Definition at line 484 of file aaccoder_nmr.h.

Referenced by nmr_solve_group().

◆ nmr_commit_channel()

static void nmr_commit_channel	(	AACEncContext *	s,
		NMRSlot *	t
	)

static

Definition at line 504 of file aaccoder_nmr.h.

◆ nmr_solve_group()

static void nmr_solve_group	(	AVCodecContext *	avctx,
		AACEncContext *	s,
		const float	lambda,
		NMRSlot const	sl,
		int	nsl,
		int	chans,
		int	rc_eligible,
		int	rc_global,
		int	rc_rate_frame,
		int	rc_bmax
	)

static

Definition at line 592 of file aaccoder_nmr.h.

◆ search_for_quantizers_nmr()

static void search_for_quantizers_nmr	(	AVCodecContext *	avctx,
		AACEncContext *	s,
		SingleChannelElement *	sce,
		const float	lambda
	)

static

Definition at line 898 of file aaccoder_nmr.h.

Macros

Functions

Macro Definition Documentation

◆ NMR_SFBITS

◆ NMR_ITERS

◆ NMR_IFINE

◆ NMR_CITERS

◆ NMR_CWARM

◆ NMR_COARSE

◆ NMR_STEP

◆ NMR_PNS_BITS

◆ NMR_PNS_HOLE_FRAC

◆ NMR_PNS_HOLE_SPREAD

◆ NMR_RC_K_CBR

◆ NMR_RC_ITERS

◆ NMR_RC_CORR

◆ NMR_CBR_BUF

◆ NMR_SLEW

◆ NMR_SLEW_RUN

◆ NMR_RC_CITERS

◆ NMR_TRANS_PM

◆ NMR_ZERO_STICKY

◆ NMR_BURST_GAP

◆ NMR_BURST_GAIN

◆ NMR_SHORT_BOOST

◆ NMR_RC_FITERS

◆ NMR_RC_TRACK

◆ NMR_PNS_NDGATE

◆ NMR_PNS_MAX_ET

◆ NMR_PNS_LAM

◆ NMR_PNS_ENTER

◆ NMR_PNS_STAY

◆ NMR_PNS_ON

◆ NMR_PNS_OFF

Function Documentation

◆ nmr_solve()

◆ nmr_band_curve()

◆ nmr_bail_channel()

◆ nmr_setup_channel()

◆ nmr_slot_bits()

◆ nmr_eval_slots()

◆ nmr_solve_slots()

◆ nmr_commit_channel()

◆ nmr_solve_group()

◆ search_for_quantizers_nmr()