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aac: Reset some state variables when turning SBR off 

This makes sure the reset flag gets set when SBR gets turned back on
and sets control variables for unguided mode back to their defaults.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
This commit is contained in:
Alex Converse 2012-03-21 12:00:56 -07:00
parent a237b38021
commit 0cb93dacee
2 changed files with 27 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
libavcodec/aacsbr.c
View File

@ -127,11 +127,22 @@ av_cold void ff_aac_sbr_init(void)
ff_ps_init();
}
/** Places SBR in pure upsampling mode. */
static void sbr_turnoff(SpectralBandReplication *sbr) {
sbr->start = 0;
// Init defults used in pure upsampling mode
sbr->kx[1] = 32; //Typo in spec, kx' inits to 32
sbr->m[1] = 0;
// Reset values for first SBR header
sbr->data[0].e_a[1] = sbr->data[1].e_a[1] = -1;
memset(&sbr->spectrum_params, -1, sizeof(SpectrumParameters));
}
av_cold void ff_aac_sbr_ctx_init(AACContext *ac, SpectralBandReplication *sbr)
{
float mdct_scale;
sbr->kx[0] = sbr->kx[1] = 32; //Typo in spec, kx' inits to 32
sbr->data[0].e_a[1] = sbr->data[1].e_a[1] = -1;
sbr->kx[0] = sbr->kx[1];
sbr_turnoff(sbr);
sbr->data[0].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
sbr->data[1].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
/* SBR requires samples to be scaled to +/-32768.0 to work correctly.
@ -994,18 +1005,18 @@ static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,
if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {
if (read_sbr_single_channel_element(ac, sbr, gb)) {
sbr->start = 0;
sbr_turnoff(sbr);
return get_bits_count(gb) - cnt;
}
} else if (id_aac == TYPE_CPE) {
if (read_sbr_channel_pair_element(ac, sbr, gb)) {
sbr->start = 0;
sbr_turnoff(sbr);
return get_bits_count(gb) - cnt;
}
} else {
av_log(ac->avctx, AV_LOG_ERROR,
"Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);
sbr->start = 0;
sbr_turnoff(sbr);
return get_bits_count(gb) - cnt;
}
if (get_bits1(gb)) { // bs_extended_data
@ -1037,7 +1048,7 @@ static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)
if (err < 0) {
av_log(ac->avctx, AV_LOG_ERROR,
"SBR reset failed. Switching SBR to pure upsampling mode.\n");
sbr->start = 0;
sbr_turnoff(sbr);
}
}
@ -1072,6 +1083,7 @@ int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
//Save some state from the previous frame.
sbr->kx[0] = sbr->kx[1];
sbr->m[0] = sbr->m[1];
sbr->kx_and_m_pushed = 1;
num_sbr_bits++;
if (get_bits1(gb)) // bs_header_flag
@ -1633,6 +1645,13 @@ void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,
int ch;
int nch = (id_aac == TYPE_CPE) ? 2 : 1;
if (!sbr->kx_and_m_pushed) {
sbr->kx[0] = sbr->kx[1];
sbr->m[0] = sbr->m[1];
} else {
sbr->kx_and_m_pushed = 0;
}
if (sbr->start) {
sbr_dequant(sbr, id_aac);
}
@ -1642,6 +1661,7 @@ void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,
(float*)sbr->qmf_filter_scratch,
sbr->data[ch].W);
sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W);
sbr->data[ch].Ypos ^= 1;
if (sbr->start) {
sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);
sbr_chirp(sbr, &sbr->data[ch]);
@ -1653,7 +1673,6 @@ void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,
sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);
sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
sbr->data[ch].Ypos ^= 1;
sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],
sbr->X_high, sbr, &sbr->data[ch],
sbr->data[ch].e_a);

1
libavcodec/sbr.h
View File

@ -133,6 +133,7 @@ typedef struct {
unsigned kx[2];
///M' and M respectively, M is the number of QMF subbands that use SBR.
unsigned m[2];
unsigned kx_and_m_pushed;
///The number of frequency bands in f_master
unsigned n_master;
SBRData data[2];