From f8a93a2036c8b1d82c39925880e9dad9bbb7c3b5 Mon Sep 17 00:00:00 2001 From: Alex Converse Date: Sat, 13 Mar 2010 21:12:10 +0000 Subject: [PATCH] aac: Don't bias output during the IMDCT if SBR will be used. Originally committed as revision 22515 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/aac.c | 27 ++++++++++++++------------- libavcodec/aacsbr.c | 8 ++++---- 2 files changed, 18 insertions(+), 17 deletions(-) diff --git a/libavcodec/aac.c b/libavcodec/aac.c index dbaffeedc..84a8cc00a 100644 --- a/libavcodec/aac.c +++ b/libavcodec/aac.c @@ -1719,7 +1719,7 @@ static void apply_tns(float coef[1024], TemporalNoiseShaping *tns, /** * Conduct IMDCT and windowing. */ -static void imdct_and_windowing(AACContext *ac, SingleChannelElement *sce) +static void imdct_and_windowing(AACContext *ac, SingleChannelElement *sce, float bias) { IndividualChannelStream *ics = &sce->ics; float *in = sce->coeffs; @@ -1751,29 +1751,29 @@ static void imdct_and_windowing(AACContext *ac, SingleChannelElement *sce) */ if ((ics->window_sequence[1] == ONLY_LONG_SEQUENCE || ics->window_sequence[1] == LONG_STOP_SEQUENCE) && (ics->window_sequence[0] == ONLY_LONG_SEQUENCE || ics->window_sequence[0] == LONG_START_SEQUENCE)) { - ac->dsp.vector_fmul_window( out, saved, buf, lwindow_prev, ac->add_bias, 512); + ac->dsp.vector_fmul_window( out, saved, buf, lwindow_prev, bias, 512); } else { for (i = 0; i < 448; i++) - out[i] = saved[i] + ac->add_bias; + out[i] = saved[i] + bias; if (ics->window_sequence[0] == EIGHT_SHORT_SEQUENCE) { - ac->dsp.vector_fmul_window(out + 448 + 0*128, saved + 448, buf + 0*128, swindow_prev, ac->add_bias, 64); - ac->dsp.vector_fmul_window(out + 448 + 1*128, buf + 0*128 + 64, buf + 1*128, swindow, ac->add_bias, 64); - ac->dsp.vector_fmul_window(out + 448 + 2*128, buf + 1*128 + 64, buf + 2*128, swindow, ac->add_bias, 64); - ac->dsp.vector_fmul_window(out + 448 + 3*128, buf + 2*128 + 64, buf + 3*128, swindow, ac->add_bias, 64); - ac->dsp.vector_fmul_window(temp, buf + 3*128 + 64, buf + 4*128, swindow, ac->add_bias, 64); + ac->dsp.vector_fmul_window(out + 448 + 0*128, saved + 448, buf + 0*128, swindow_prev, bias, 64); + ac->dsp.vector_fmul_window(out + 448 + 1*128, buf + 0*128 + 64, buf + 1*128, swindow, bias, 64); + ac->dsp.vector_fmul_window(out + 448 + 2*128, buf + 1*128 + 64, buf + 2*128, swindow, bias, 64); + ac->dsp.vector_fmul_window(out + 448 + 3*128, buf + 2*128 + 64, buf + 3*128, swindow, bias, 64); + ac->dsp.vector_fmul_window(temp, buf + 3*128 + 64, buf + 4*128, swindow, bias, 64); memcpy( out + 448 + 4*128, temp, 64 * sizeof(float)); } else { - ac->dsp.vector_fmul_window(out + 448, saved + 448, buf, swindow_prev, ac->add_bias, 64); + ac->dsp.vector_fmul_window(out + 448, saved + 448, buf, swindow_prev, bias, 64); for (i = 576; i < 1024; i++) - out[i] = buf[i-512] + ac->add_bias; + out[i] = buf[i-512] + bias; } } // buffer update if (ics->window_sequence[0] == EIGHT_SHORT_SEQUENCE) { for (i = 0; i < 64; i++) - saved[i] = temp[64 + i] - ac->add_bias; + saved[i] = temp[64 + i] - bias; ac->dsp.vector_fmul_window(saved + 64, buf + 4*128 + 64, buf + 5*128, swindow, 0, 64); ac->dsp.vector_fmul_window(saved + 192, buf + 5*128 + 64, buf + 6*128, swindow, 0, 64); ac->dsp.vector_fmul_window(saved + 320, buf + 6*128 + 64, buf + 7*128, swindow, 0, 64); @@ -1884,6 +1884,7 @@ static void apply_channel_coupling(AACContext *ac, ChannelElement *cc, static void spectral_to_sample(AACContext *ac) { int i, type; + float imdct_bias = (ac->m4ac.sbr <= 0) ? ac->add_bias : 0.0f; for (type = 3; type >= 0; type--) { for (i = 0; i < MAX_ELEM_ID; i++) { ChannelElement *che = ac->che[type][i]; @@ -1897,14 +1898,14 @@ static void spectral_to_sample(AACContext *ac) if (type <= TYPE_CPE) apply_channel_coupling(ac, che, type, i, BETWEEN_TNS_AND_IMDCT, apply_dependent_coupling); if (type != TYPE_CCE || che->coup.coupling_point == AFTER_IMDCT) { - imdct_and_windowing(ac, &che->ch[0]); + imdct_and_windowing(ac, &che->ch[0], imdct_bias); if (ac->m4ac.sbr > 0) { ff_sbr_dequant(ac, &che->sbr, type == TYPE_CPE ? TYPE_CPE : TYPE_SCE); ff_sbr_apply(ac, &che->sbr, 0, che->ch[0].ret, che->ch[0].ret); } } if (type == TYPE_CPE) { - imdct_and_windowing(ac, &che->ch[1]); + imdct_and_windowing(ac, &che->ch[1], imdct_bias); if (ac->m4ac.sbr > 0) ff_sbr_apply(ac, &che->sbr, 1, che->ch[1].ret, che->ch[1].ret); } diff --git a/libavcodec/aacsbr.c b/libavcodec/aacsbr.c index 6915152ec..23823aa71 100644 --- a/libavcodec/aacsbr.c +++ b/libavcodec/aacsbr.c @@ -1126,14 +1126,14 @@ static void sbr_dequant(SpectralBandReplication *sbr, int id_aac) */ static void sbr_qmf_analysis(DSPContext *dsp, RDFTContext *rdft, const float *in, float *x, float z[320], float W[2][32][32][2], - float bias, float scale) + float scale) { int i, k; memcpy(W[0], W[1], sizeof(W[0])); memcpy(x , x+1024, (320-32)*sizeof(x[0])); - if (scale != 1.0f || bias != 0.0f) + if (scale != 1.0f) for (i = 0; i < 1024; i++) - x[288 + i] = (in[i] - bias) * scale; + x[288 + i] = in[i] * scale; else memcpy(x+288, in, 1024*sizeof(*x)); for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames @@ -1719,7 +1719,7 @@ void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int ch, /* decode channel */ sbr_qmf_analysis(&ac->dsp, &sbr->rdft, in, sbr->data[ch].analysis_filterbank_samples, (float*)sbr->qmf_filter_scratch, - sbr->data[ch].W, ac->add_bias, 1/(-1024 * ac->sf_scale)); + sbr->data[ch].W, 1/(-1024 * ac->sf_scale)); sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W); if (sbr->start) { sbr_hf_inverse_filter(sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]); -- 2.11.0