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binkaudio: use a different value for the coefficient scale for the DCT codec

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Eliminates the need for vector_fmul_scalar() in each frame.
This commit is contained in:
Justin Ruggles 2012-09-17 16:13:24 -04:00
parent 6a08955c10
commit 0801b5979b
1 changed files with 4 additions and 4 deletions
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8
libavcodec/binkaudio.c
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@ -47,7 +47,6 @@ static float quant_table[96];
typedef struct {
AVFrame frame;
GetBitContext gb;
DSPContext dsp;
FmtConvertContext fmt_conv;
int version_b; ///< Bink version 'b'
int first;
@ -79,7 +78,6 @@ static av_cold int decode_init(AVCodecContext *avctx)
int i;
int frame_len_bits;
ff_dsputil_init(&s->dsp, avctx);
ff_fmt_convert_init(&s->fmt_conv, avctx);
/* determine frame length */
@ -112,7 +110,10 @@ static av_cold int decode_init(AVCodecContext *avctx)
s->overlap_len = s->frame_len / 16;
s->block_size = (s->frame_len - s->overlap_len) * s->channels;
sample_rate_half = (sample_rate + 1) / 2;
s->root = 2.0 / sqrt(s->frame_len);
if (avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
s->root = 2.0 / sqrt(s->frame_len);
else
s->root = s->frame_len / sqrt(s->frame_len);
for (i = 0; i < 96; i++) {
/* constant is result of 0.066399999/log10(M_E) */
quant_table[i] = expf(i * 0.15289164787221953823f) * s->root;
@ -259,7 +260,6 @@ static int decode_block(BinkAudioContext *s, int16_t *out, int use_dct)
if (CONFIG_BINKAUDIO_DCT_DECODER && use_dct) {
coeffs[0] /= 0.5;
s->trans.dct.dct_calc(&s->trans.dct, coeffs);
s->dsp.vector_fmul_scalar(coeffs, coeffs, s->frame_len / 2, s->frame_len);
}
else if (CONFIG_BINKAUDIO_RDFT_DECODER)
s->trans.rdft.rdft_calc(&s->trans.rdft, coeffs);