X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Faacpsy.c;h=71eeb3e547feca57085e499aa059388b9587074c;hb=83a04f103d387a8b7f574d97d340d90f42fc18de;hp=242df6863a302c09eb3d20d1e9f9f88b6321fded;hpb=61344c04ca89a3eeea473dd0855a47f770a3c67b;p=ffmpeg

diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c
index 242df6863a3..71eeb3e547f 100644
--- a/libavcodec/aacpsy.c
+++ b/libavcodec/aacpsy.c
@@ -80,6 +80,8 @@
 #define PSY_3GPP_AH_THR_LONG    0.5f
 #define PSY_3GPP_AH_THR_SHORT   0.63f
 
+#define PSY_PE_FORGET_SLOPE  511
+
 enum {
     PSY_3GPP_AH_NONE,
     PSY_3GPP_AH_INACTIVE,
@@ -303,7 +305,7 @@ static av_cold int psy_3gpp_init(FFPsyContext *ctx) {
     float prev, minscale, minath, minsnr, pe_min;
     int chan_bitrate = ctx->avctx->bit_rate / ((ctx->avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : ctx->avctx->channels);
 
-    const int bandwidth    = ctx->avctx->cutoff ? ctx->avctx->cutoff : AAC_CUTOFF(ctx->avctx);
+    const int bandwidth    = ctx->cutoff ? ctx->cutoff : AAC_CUTOFF(ctx->avctx);
     const float num_bark   = calc_bark((float)bandwidth);
 
     ctx->model_priv_data = av_mallocz(sizeof(AacPsyContext));
@@ -495,7 +497,7 @@ static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size,
     const float bitspend_add   = short_window ? PSY_3GPP_SPEND_ADD_S   : PSY_3GPP_SPEND_ADD_L;
     const float clip_low       = short_window ? PSY_3GPP_CLIP_LO_S     : PSY_3GPP_CLIP_LO_L;
     const float clip_high      = short_window ? PSY_3GPP_CLIP_HI_S     : PSY_3GPP_CLIP_HI_L;
-    float clipped_pe, bit_save, bit_spend, bit_factor, fill_level;
+    float clipped_pe, bit_save, bit_spend, bit_factor, fill_level, forgetful_min_pe;
 
     ctx->fill_level += ctx->frame_bits - bits;
     ctx->fill_level  = av_clip(ctx->fill_level, 0, size);
@@ -512,9 +514,14 @@ static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size,
      * Hopefully below is correct.
      */
     bit_factor = 1.0f - bit_save + ((bit_spend - bit_save) / (ctx->pe.max - ctx->pe.min)) * (clipped_pe - ctx->pe.min);
-    /* NOTE: The reference encoder attempts to center pe max/min around the current pe. */
+    /* NOTE: The reference encoder attempts to center pe max/min around the current pe.
+     * Here we do that by slowly forgetting pe.min when pe stays in a range that makes
+     * it unlikely (ie: above the mean)
+     */
     ctx->pe.max = FFMAX(pe, ctx->pe.max);
-    ctx->pe.min = FFMIN(pe, ctx->pe.min);
+    forgetful_min_pe = ((ctx->pe.min * PSY_PE_FORGET_SLOPE)
+        + FFMAX(ctx->pe.min, pe * (pe / ctx->pe.max))) / (PSY_PE_FORGET_SLOPE + 1);
+    ctx->pe.min = FFMIN(pe, forgetful_min_pe);
 
     /* NOTE: allocate a minimum of 1/8th average frame bits, to avoid
      *   reservoir starvation from producing zero-bit frames
@@ -588,26 +595,30 @@ static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr,
 
 #ifndef calc_thr_3gpp
 static void calc_thr_3gpp(const FFPsyWindowInfo *wi, const int num_bands, AacPsyChannel *pch,
-                          const uint8_t *band_sizes, const float *coefs)
+                          const uint8_t *band_sizes, const float *coefs, const int cutoff)
 {
     int i, w, g;
-    int start = 0;
+    int start = 0, wstart = 0;
     for (w = 0; w < wi->num_windows*16; w += 16) {
+        wstart = 0;
         for (g = 0; g < num_bands; g++) {
             AacPsyBand *band = &pch->band[w+g];
 
             float form_factor = 0.0f;
             float Temp;
             band->energy = 0.0f;
-            for (i = 0; i < band_sizes[g]; i++) {
-                band->energy += coefs[start+i] * coefs[start+i];
-                form_factor  += sqrtf(fabs(coefs[start+i]));
+            if (wstart < cutoff) {
+                for (i = 0; i < band_sizes[g]; i++) {
+                    band->energy += coefs[start+i] * coefs[start+i];
+                    form_factor  += sqrtf(fabs(coefs[start+i]));
+                }
             }
             Temp = band->energy > 0 ? sqrtf((float)band_sizes[g] / band->energy) : 0;
             band->thr      = band->energy * 0.001258925f;
             band->nz_lines = form_factor * sqrtf(Temp);
 
             start += band_sizes[g];
+            wstart += band_sizes[g];
         }
     }
 }
@@ -648,9 +659,11 @@ static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel,
     const uint8_t *band_sizes  = ctx->bands[wi->num_windows == 8];
     AacPsyCoeffs  *coeffs      = pctx->psy_coef[wi->num_windows == 8];
     const float avoid_hole_thr = wi->num_windows == 8 ? PSY_3GPP_AH_THR_SHORT : PSY_3GPP_AH_THR_LONG;
+    const int bandwidth        = ctx->cutoff ? ctx->cutoff : AAC_CUTOFF(ctx->avctx);
+    const int cutoff           = bandwidth * 2048 / wi->num_windows / ctx->avctx->sample_rate;
 
     //calculate energies, initial thresholds and related values - 5.4.2 "Threshold Calculation"
-    calc_thr_3gpp(wi, num_bands, pch, band_sizes, coefs);
+    calc_thr_3gpp(wi, num_bands, pch, band_sizes, coefs, cutoff);
 
     //modify thresholds and energies - spread, threshold in quiet, pre-echo control
     for (w = 0; w < wi->num_windows*16; w += 16) {