shithub: opus

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Fixes glithes when switching between SILK-only and hybrid

We now reset the CELT state when swithing to hybrid and we "drain"
the CELT MDCT overlap when switching away from hybrid.

--- a/src/opus_decoder.c

+++ b/src/opus_decoder.c

@@ -390,11 +390,21 @@

     if (mode != MODE_SILK_ONLY)

     {

     	int celt_frame_size = IMIN(F20, frame_size);

+    	/* Make sure to discard any previous CELT state */

+    	if (st->prev_mode == MODE_SILK_ONLY)

+    	   celt_decoder_ctl(celt_dec, OPUS_RESET_STATE);

         /* Decode CELT */

         celt_ret = celt_decode_with_ec(celt_dec, decode_fec?NULL:data, len, pcm, celt_frame_size, &dec);

     } else {

+       unsigned char silence[2] = {0xFF, 0xFF};

        for (i=0;i<frame_size*st->channels;i++)

           pcm[i] = 0;

+       /* For hybrid -> SILK transitions, we let the CELT MDCT do a fade-out by decoding a silence frame */

+       if (st->prev_mode == MODE_HYBRID)

+       {

+          celt_decoder_ctl(celt_dec, CELT_SET_START_BAND(0));

+          celt_decode_with_ec(celt_dec, silence, 2, pcm, F2_5, NULL);

+       }

     }

     if (mode != MODE_CELT_ONLY)

--- a/src/opus_encoder.c

+++ b/src/opus_encoder.c

@@ -891,7 +891,7 @@

     if (st->mode != MODE_HYBRID || st->stream_channels==1)

-       st->silk_mode.stereoWidth_Q14 = 1<<14;

+       st->hybrid_stereo_width_Q14 = st->silk_mode.stereoWidth_Q14 = 1<<14;

     if( st->channels == 2 ) {

         /* Apply stereo width reduction (at low bitrates) */

         if( st->hybrid_stereo_width_Q14 < (1 << 14) || st->silk_mode.stereoWidth_Q14 < (1 << 14) ) {