From 4afedfd8e5c5f102d3a67c224c33b51bbed47eee Mon Sep 17 00:00:00 2001 From: Nathan Caldwell Date: Wed, 16 Mar 2011 23:35:39 -0400 Subject: aacenc: cosmetics, indentation, and comment clarification Correct bad indentation in aaccoder Clarify and correct comments in 3GPP psymodel, other cosmetics. --- libavcodec/aacpsy.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) (limited to 'libavcodec/aacpsy.c') diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c index de3b0f329e..d9896ed74f 100644 --- a/libavcodec/aacpsy.c +++ b/libavcodec/aacpsy.c @@ -39,8 +39,8 @@ * constants for 3GPP AAC psychoacoustic model * @{ */ -#define PSY_3GPP_SPREAD_HI 1.5f // spreading factor for ascending threshold spreading (15 dB/Bark) -#define PSY_3GPP_SPREAD_LOW 3.0f // spreading factor for descending threshold spreading (30 dB/Bark) +#define PSY_3GPP_THR_SPREAD_HI 1.5f // spreading factor for low-to-hi threshold spreading (15 dB/Bark) +#define PSY_3GPP_THR_SPREAD_LOW 3.0f // spreading factor for hi-to-low threshold spreading (30 dB/Bark) #define PSY_3GPP_RPEMIN 0.01f #define PSY_3GPP_RPELEV 2.0f @@ -256,8 +256,8 @@ static av_cold int psy_3gpp_init(FFPsyContext *ctx) { for (g = 0; g < ctx->num_bands[j] - 1; g++) { AacPsyCoeffs *coeff = &coeffs[g]; float bark_width = coeffs[g+1].barks - coeffs->barks; - coeff->spread_low[0] = pow(10.0, -bark_width * PSY_3GPP_SPREAD_LOW); - coeff->spread_hi [0] = pow(10.0, -bark_width * PSY_3GPP_SPREAD_HI); + coeff->spread_low[0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_LOW); + coeff->spread_hi [0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_HI); } start = 0; for (g = 0; g < ctx->num_bands[j]; g++) { @@ -395,9 +395,9 @@ static void psy_3gpp_analyze(FFPsyContext *ctx, int channel, AacPsyChannel *pch = &pctx->ch[channel]; int start = 0; int i, w, g; - const int num_bands = ctx->num_bands[wi->num_windows == 8]; - const uint8_t* band_sizes = ctx->bands[wi->num_windows == 8]; - AacPsyCoeffs *coeffs = &pctx->psy_coef[wi->num_windows == 8]; + const int num_bands = ctx->num_bands[wi->num_windows == 8]; + const uint8_t *band_sizes = ctx->bands[wi->num_windows == 8]; + AacPsyCoeffs *coeffs = &pctx->psy_coef[wi->num_windows == 8]; //calculate energies, initial thresholds and related values - 5.4.2 "Threshold Calculation" for (w = 0; w < wi->num_windows*16; w += 16) { @@ -410,17 +410,19 @@ static void psy_3gpp_analyze(FFPsyContext *ctx, int channel, start += band_sizes[g]; } } - //modify thresholds - spread, threshold in quiet - 5.4.3 "Spreaded Energy Calculation" + //modify thresholds and energies - spread, threshold in quiet, pre-echo control for (w = 0; w < wi->num_windows*16; w += 16) { - AacPsyBand *bands = &pch->band[w]; + //5.4.2.3 "Spreading" & 5.4.3 "Spreaded Energy Calculation" for (g = 1; g < num_bands; g++) bands[g].thr = FFMAX(bands[g].thr, bands[g-1].thr * coeffs[g].spread_hi[0]); for (g = num_bands - 2; g >= 0; g--) bands[g].thr = FFMAX(bands[g].thr, bands[g+1].thr * coeffs[g].spread_low[0]); + //5.4.2.4 "Threshold in quiet" for (g = 0; g < num_bands; g++) { AacPsyBand *band = &bands[g]; band->thr_quiet = band->thr = FFMAX(band->thr, coeffs[g].ath); + //5.4.2.5 "Pre-echo control" if (!(wi->window_type[0] == LONG_STOP_SEQUENCE || (wi->window_type[1] == LONG_START_SEQUENCE && !w))) band->thr = FFMAX(PSY_3GPP_RPEMIN*band->thr, FFMIN(band->thr, PSY_3GPP_RPELEV*pch->prev_band[w+g].thr_quiet)); @@ -436,6 +438,7 @@ static void psy_3gpp_analyze(FFPsyContext *ctx, int channel, psy_band->energy = band->energy; } } + memcpy(pch->prev_band, pch->band, sizeof(pch->band)); } -- cgit v1.2.3