shithub: opus

Info  •  Files  •  Log  •  Branches

Make bandwidth detection more conservative to avoid low-passing frames

--- a/src/analysis.c

+++ b/src/analysis.c

@@ -242,6 +242,7 @@

    float prob_min, prob_max;

    float vad_prob;

    int mpos, vpos;

+   int bandwidth_span;

    pos = tonal->read_pos;

    curr_lookahead = tonal->write_pos-tonal->read_pos;

@@ -263,6 +264,8 @@

    OPUS_COPY(info_out, &tonal->info[pos], 1);

    tonality_max = tonality_avg = info_out->tonality;

    tonality_count = 1;

+   /* Look at the neighbouring frames and pick largest bandwidth found (to be safe). */

+   bandwidth_span = 6;

    /* If possible, look ahead for a tone to compensate for the delay in the tone detector. */

    for (i=0;i<3;i++)

    {

@@ -274,6 +277,19 @@

       tonality_max = MAX32(tonality_max, tonal->info[pos].tonality);

       tonality_avg += tonal->info[pos].tonality;

       tonality_count++;

+      info_out->bandwidth = IMAX(info_out->bandwidth, tonal->info[pos].bandwidth);

+      bandwidth_span--;

+   }

+   pos = pos0;

+   /* Look back in time to see if any has a wider bandwidth than the current frame. */

+   for (i=0;i<bandwidth_span;i++)

+   {

+      pos--;

+      if (pos < 0)

+         pos = DETECT_SIZE-1;

+      if (pos == tonal->write_pos)

+         break;

+      info_out->bandwidth = IMAX(info_out->bandwidth, tonal->info[pos].bandwidth);

    }

    info_out->tonality = MAX32(tonality_avg/tonality_count, tonality_max-.2f);