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| author | Alex Converse <alex.converse@gmail.com> | 2010-07-24 02:41:47 +0000 |
|---|---|---|
| committer | Alex Converse <alex.converse@gmail.com> | 2010-07-24 02:41:47 +0000 |
| commit | 70c99adb48d00ac85c436f01c66276345124fb2d (patch) | |
| tree | 9755509399db8f7e34995abbfba90b1fcd56ceac /libavcodec/aacdec.c | |
| parent | 51ffd3a62fbd77dc6cf334a8fc896f1f56214773 (diff) | |
| download | ffmpeg-70c99adb48d00ac85c436f01c66276345124fb2d.tar.gz | |
aacdec: 4% faster main profile decoding.
Originally committed as revision 24474 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/aacdec.c')
| -rw-r--r-- | libavcodec/aacdec.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c index a302876176..413055e1f0 100644 --- a/libavcodec/aacdec.c +++ b/libavcodec/aacdec.c @@ -1231,7 +1231,8 @@ static av_always_inline float flt16_trunc(float pf) return pun.f; } -static av_always_inline void predict(AACContext *ac, PredictorState *ps, float *coef, +static av_always_inline void predict(PredictorState *ps, float *coef, + float sf_scale, float inv_sf_scale, int output_enable) { const float a = 0.953125; // 61.0 / 64 @@ -1245,9 +1246,9 @@ static av_always_inline void predict(AACContext *ac, PredictorState *ps, float * pv = flt16_round(k1 * ps->r0 + k2 * ps->r1); if (output_enable) - *coef += pv * ac->sf_scale; + *coef += pv * sf_scale; - e0 = *coef / ac->sf_scale; + e0 = *coef * inv_sf_scale; e1 = e0 - k1 * ps->r0; ps->cor1 = flt16_trunc(alpha * ps->cor1 + ps->r1 * e1); @@ -1265,6 +1266,7 @@ static av_always_inline void predict(AACContext *ac, PredictorState *ps, float * static void apply_prediction(AACContext *ac, SingleChannelElement *sce) { int sfb, k; + float sf_scale = ac->sf_scale, inv_sf_scale = 1 / ac->sf_scale; if (!sce->ics.predictor_initialized) { reset_all_predictors(sce->predictor_state); @@ -1274,7 +1276,8 @@ static void apply_prediction(AACContext *ac, SingleChannelElement *sce) if (sce->ics.window_sequence[0] != EIGHT_SHORT_SEQUENCE) { for (sfb = 0; sfb < ff_aac_pred_sfb_max[ac->m4ac.sampling_index]; sfb++) { for (k = sce->ics.swb_offset[sfb]; k < sce->ics.swb_offset[sfb + 1]; k++) { - predict(ac, &sce->predictor_state[k], &sce->coeffs[k], + predict(&sce->predictor_state[k], &sce->coeffs[k], + sf_scale, inv_sf_scale, sce->ics.predictor_present && sce->ics.prediction_used[sfb]); } } |