opus: fix hybrid folding indexing during band quantization

Resulted in valgrind errors due to uninitialized memory.
Also updates fate and makes it use the tron sample result.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

libavcodec/opus.c

@@ -481,13 +481,12 @@ void ff_celt_quant_bands(CeltFrame *f, OpusRangeCoder *rc)
         if (i == f->start_band + 1) {
             /* Special Hybrid Folding (RFC 8251 section 9). Copy the first band into
             the second to ensure the second band never has to use the LCG. */
-            int offset = 8 * ff_celt_freq_bands[i];
-            int count = 8 * (ff_celt_freq_range[i] - ff_celt_freq_range[i-1]);
+            int count = (ff_celt_freq_range[i] - ff_celt_freq_range[i-1]) << f->size;
 
-            memcpy(&norm1[offset], &norm1[offset - count], count * sizeof(float));
+            memcpy(&norm1[band_offset], &norm1[band_offset - count], count * sizeof(float));
 
             if (f->channels == 2)
-                memcpy(&norm2[offset], &norm2[offset - count], count * sizeof(float));
+                memcpy(&norm2[band_offset], &norm2[band_offset - count], count * sizeof(float));
         }
 
         /* Get a conservative estimate of the collapse_mask's for the bands we're

tests/fate/opus.mak

@@ -28,14 +28,15 @@ fate-opus-testvector01: CMP_TARGET = 0
 fate-opus-testvector02:      CMP_TARGET = 191
 fate-opus-testvector03:      CMP_TARGET = 139
 fate-opus-testvector04:      CMP_TARGET = 119
-fate-opus-testvector05: CMP_TARGET = 109
-fate-opus-testvector06: CMP_TARGET = 109
+fate-opus-testvector05:      CMP_TARGET = 108
+fate-opus-testvector06:      CMP_TARGET = 106
 fate-opus-testvector07:      CMP_TARGET = 0
 fate-opus-testvector08:      CMP_TARGET = 6
 fate-opus-testvector09:      CMP_TARGET = 0
 fate-opus-testvector10:      CMP_TARGET = 38
 fate-opus-testvector11:      CMP_TARGET = 0
 fate-opus-testvector12:      CMP_TARGET = 160
+fate-opus-tron.6ch.tinypkts: CMP_TARGET = 0
 
 $(FATE_OPUS_CELT): CMP = oneoff
 $(FATE_OPUS_CELT): FUZZ = 6