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Replace obfuscated mdct in qmf_32_subbands() by ff_imdct_half(). 

Originally committed as revision 15049 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2008-08-30 10:47:13 +00:00
parent 47f0e05295
commit 89df5e95bb
1 changed files with 37 additions and 28 deletions
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65
libavcodec/dca.c
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@ -157,7 +157,7 @@ typedef struct {
/* Subband samples history (for ADPCM) */
float subband_samples_hist[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS][4];
float subband_fir_hist[DCA_PRIM_CHANNELS_MAX][512];
DECLARE_ALIGNED_16(float, subband_fir_hist[DCA_PRIM_CHANNELS_MAX][512]);
float subband_fir_noidea[DCA_PRIM_CHANNELS_MAX][32];
int hist_index[DCA_PRIM_CHANNELS_MAX];
@ -177,6 +177,7 @@ typedef struct {
int debug_flag; ///< used for suppressing repeated error messages output
DSPContext dsp;
MDCTContext imdct;
} DCAContext;
static av_cold void dca_init_vlcs(void)
@ -656,15 +657,15 @@ static void qmf_32_subbands(DCAContext * s, int chans,
float scale, float bias)
{
const float *prCoeff;
int i, j, k;
float praXin[33], *raXin = &praXin[1];
int i, j;
DECLARE_ALIGNED_16(float, raXin[32]);
int hist_index= s->hist_index[chans];
float *subband_fir_hist2 = s->subband_fir_noidea[chans];
int chindex = 0, subindex;
int subindex;
praXin[0] = 0.0;
scale *= sqrt(1/8.0);
/* Select filter */
if (!s->multirate_inter) /* Non-perfect reconstruction */
@ -676,39 +677,39 @@ static void qmf_32_subbands(DCAContext * s, int chans,
for (subindex = 0; subindex < 8; subindex++) {
float *subband_fir_hist = s->subband_fir_hist[chans] + hist_index;
/* Load in one sample from each subband and clear inactive subbands */
for (i = 0; i < s->subband_activity[chans]; i++)
raXin[i] = samples_in[i][subindex];
for (i = 0; i < s->subband_activity[chans]; i++){
if((i-1)&2) raXin[i] = -samples_in[i][subindex];
else raXin[i] = samples_in[i][subindex];
}
for (; i < 32; i++)
raXin[i] = 0.0;
/* Multiply by cosine modulation coefficients and
* create temporary arrays SUM and DIFF */
for (j = 0, k = 0; k < 16; k++) {
float t1 = 0.0;
float t2 = 0.0;
for (i = 0; i < 16; i++, j++){
t1 += (raXin[2 * i] + raXin[2 * i + 1]) * cos_mod[j];
t2 += (raXin[2 * i] + raXin[2 * i - 1]) * cos_mod[j + 256];
}
subband_fir_hist[ k ] = cos_mod[k+512 ] * (t1 + t2);
subband_fir_hist[32-k-1] = cos_mod[k+512+16] * (t1 - t2);
}
ff_imdct_half(&s->imdct, subband_fir_hist, raXin);
/* Multiply by filter coefficients */
for (k = 31, i = 0; i < 32; i++, k--){
float a= subband_fir_hist2[i];
float b= 0;
for (i = 0; i < 16; i++){
float a= subband_fir_hist2[i ];
float b= subband_fir_hist2[i+16];
float c= 0;
float d= 0;
for (j = 0; j < 512-hist_index; j += 64){
a += prCoeff[i+j ]*( subband_fir_hist[i+j] - subband_fir_hist[j+k]);
b += prCoeff[i+j+32]*(-subband_fir_hist[i+j] - subband_fir_hist[j+k]);
a += prCoeff[i+j ]*(-subband_fir_hist[15-i+j]);
b += prCoeff[i+j+16]*( subband_fir_hist[ i+j]);
c += prCoeff[i+j+32]*( subband_fir_hist[16+i+j]);
d += prCoeff[i+j+48]*( subband_fir_hist[31-i+j]);
}
for ( ; j < 512; j += 64){
a += prCoeff[i+j ]*( subband_fir_hist[i+j-512] - subband_fir_hist[j+k-512]);
b += prCoeff[i+j+32]*(-subband_fir_hist[i+j-512] - subband_fir_hist[j+k-512]);
a += prCoeff[i+j ]*(-subband_fir_hist[15-i+j-512]);
b += prCoeff[i+j+16]*( subband_fir_hist[ i+j-512]);
c += prCoeff[i+j+32]*( subband_fir_hist[16+i+j-512]);
d += prCoeff[i+j+48]*( subband_fir_hist[31-i+j-512]);
}
samples_out[chindex++] = a * scale + bias;
subband_fir_hist2[i] = b;
samples_out[i ] = a * scale + bias;
samples_out[i+16] = b * scale + bias;
subband_fir_hist2[i ] = c;
subband_fir_hist2[i+16] = d;
}
samples_out+= 32;
hist_index = (hist_index-32)&511;
}
@ -1237,6 +1238,7 @@ static av_cold int dca_decode_init(AVCodecContext * avctx)
pre_calc_cosmod(s);
dsputil_init(&s->dsp, avctx);
ff_mdct_init(&s->imdct, 6, 1);
/* allow downmixing to stereo */
if (avctx->channels > 0 && avctx->request_channels < avctx->channels &&
@ -1249,6 +1251,12 @@ static av_cold int dca_decode_init(AVCodecContext * avctx)
return 0;
}
static av_cold int dca_decode_end(AVCodecContext * avctx)
{
DCAContext *s = avctx->priv_data;
ff_mdct_end(&s->imdct);
return 0;
}
AVCodec dca_decoder = {
.name = "dca",
@ -1257,5 +1265,6 @@ AVCodec dca_decoder = {
.priv_data_size = sizeof(DCAContext),
.init = dca_decode_init,
.decode = dca_decode_frame,
.close = dca_decode_end,
.long_name = NULL_IF_CONFIG_SMALL("DCA (DTS Coherent Acoustics)"),
};