Fix CELT deep PLC bugs

The sinc filter offset was incorrectly handled. Since it perfectly compensates
for the analysis offset, nothing has to be done.
Also, the preemphasis memory was never initialized.

1 files changed, 8 insertions, 11 deletions

diff --git a/celt/celt_decoder.c b/celt/celt_decoder.c
index f2d48028..c0c997f0 100644
--- a/celt/celt_decoder.c
+++ b/celt/celt_decoder.c
@@ -568,7 +568,7 @@ static const float sinc_filter[SINC_ORDER+1] = {
     4.2931e-05f
 };
 
-void update_plc_state(LPCNetPLCState *lpcnet, celt_sig *decode_mem[2], int CC)
+void update_plc_state(LPCNetPLCState *lpcnet, celt_sig *decode_mem[2], float *plc_preemphasis_mem, int CC)
 {
    int i;
    int tmp_read_post, tmp_fec_skip;
@@ -583,6 +583,7 @@ void update_plc_state(LPCNetPLCState *lpcnet, celt_sig *decode_mem[2], int CC)
    }
    /* Down-sample the last 40 ms. */
    for (i=1;i<DECODE_BUFFER_SIZE;i++) buf48k[i] += PREEMPHASIS*buf48k[i-1];
+   *plc_preemphasis_mem = buf48k[DECODE_BUFFER_SIZE-1];
    offset = DECODE_BUFFER_SIZE-SINC_ORDER-1 - 3*(PLC_UPDATE_SAMPLES-1);
    celt_assert(3*(PLC_UPDATE_SAMPLES-1) + SINC_ORDER + offset == DECODE_BUFFER_SIZE-1);
    for (i=0;i<PLC_UPDATE_SAMPLES;i++) {
@@ -720,7 +721,7 @@ static void celt_decode_lost(CELTDecoder * OPUS_RESTRICT st, int N, int LM
       if (loss_duration == 0)
       {
 #ifdef ENABLE_DEEP_PLC
-         update_plc_state(lpcnet, decode_mem, C);
+         update_plc_state(lpcnet, decode_mem, &st->plc_preemphasis_mem, C);
 #endif
          st->last_pitch_index = pitch_index = celt_plc_pitch_search(decode_mem, C, st->arch);
       } else {
@@ -916,7 +917,6 @@ static void celt_decode_lost(CELTDecoder * OPUS_RESTRICT st, int N, int LM
       if (st->complexity >= 5 || lpcnet->fec_fill_pos > 0) {
          float overlap_mem;
          int samples_needed16k;
-         int ignored = 0;
          celt_sig *buf;
          VARDECL(float, buf_copy);
          buf = decode_mem[0];
@@ -929,9 +929,6 @@ static void celt_decode_lost(CELTDecoder * OPUS_RESTRICT st, int N, int LM
             and the overlap at the end. */
          samples_needed16k = (N+SINC_ORDER+overlap)/3;
          if (loss_duration == 0) {
-            /* Ignore the first 8 samples due to the update resampling delay. */
-            ignored = SINC_ORDER/6;
-            samples_needed16k += ignored;
             st->plc_fill = 0;
          }
          while (st->plc_fill < samples_needed16k) {
@@ -942,15 +939,15 @@ static void celt_decode_lost(CELTDecoder * OPUS_RESTRICT st, int N, int LM
          for (i=0;i<(N+overlap)/3;i++) {
             int j;
             float sum;
-            for (sum=0, j=0;j<17;j++) sum += 3*st->plc_pcm[ignored+i+j]*sinc_filter[3*j];
+            for (sum=0, j=0;j<17;j++) sum += 3*st->plc_pcm[i+j]*sinc_filter[3*j];
             buf[DECODE_BUFFER_SIZE-N+3*i] = sum;
-            for (sum=0, j=0;j<16;j++) sum += 3*st->plc_pcm[ignored+i+j+1]*sinc_filter[3*j+2];
+            for (sum=0, j=0;j<16;j++) sum += 3*st->plc_pcm[i+j+1]*sinc_filter[3*j+2];
             buf[DECODE_BUFFER_SIZE-N+3*i+1] = sum;
-            for (sum=0, j=0;j<16;j++) sum += 3*st->plc_pcm[ignored+i+j+1]*sinc_filter[3*j+1];
+            for (sum=0, j=0;j<16;j++) sum += 3*st->plc_pcm[i+j+1]*sinc_filter[3*j+1];
             buf[DECODE_BUFFER_SIZE-N+3*i+1] = sum;
          }
-         OPUS_MOVE(st->plc_pcm, &st->plc_pcm[N/3+ignored], st->plc_fill-N/3-ignored);
-         st->plc_fill -= N/3+ignored;
+         OPUS_MOVE(st->plc_pcm, &st->plc_pcm[N/3], st->plc_fill-N/3);
+         st->plc_fill -= N/3;
          for (i=0;i<N;i++) {
             float tmp = buf[DECODE_BUFFER_SIZE-N+i];
             buf[DECODE_BUFFER_SIZE-N+i] -= PREEMPHASIS*st->plc_preemphasis_mem;