+--- ffmpeg-4.4/libavcodec/opus_pvq.c.orig 2021-05-08 12:19:49.996985421 +0300
++++ ffmpeg-4.4/libavcodec/opus_pvq.c 2021-05-08 12:21:12.440985425 +0300
+@@ -495,12 +495,12 @@
+ uint32_t N0 = N;
+ int N_B = N / blocks;
+ int N_B0 = N_B;
+- int B0 = blocks;
++ int B0_ = blocks;
+ int time_divide = 0;
+ int recombine = 0;
+ int inv = 0;
+ float mid = 0, side = 0;
+- int longblocks = (B0 == 1);
++ int longblocks = (B0_ == 1);
+ uint32_t cm = 0;
+
+ if (N == 1) {
+@@ -532,7 +532,7 @@
+ /* Band recombining to increase frequency resolution */
+
+ if (lowband &&
+- (recombine || ((N_B & 1) == 0 && tf_change < 0) || B0 > 1)) {
++ (recombine || ((N_B & 1) == 0 && tf_change < 0) || B0_ > 1)) {
+ for (i = 0; i < N; i++)
+ lowband_scratch[i] = lowband[i];
+ lowband = lowband_scratch;
+@@ -556,13 +556,13 @@
+ time_divide++;
+ tf_change++;
+ }
+- B0 = blocks;
++ B0_ = blocks;
+ N_B0 = N_B;
+
+ /* Reorganize the samples in time order instead of frequency order */
+- if (B0 > 1 && (quant || lowband))
++ if (B0_ > 1 && (quant || lowband))
+ celt_deinterleave_hadamard(pvq->hadamard_tmp, quant ? X : lowband,
+- N_B >> recombine, B0 << recombine,
++ N_B >> recombine, B0_ << recombine,
+ longblocks);
+ }
+
+@@ -604,7 +604,7 @@
+ if (quant) {
+ if (stereo && N > 2)
+ ff_opus_rc_enc_uint_step(rc, itheta, qn / 2);
+- else if (stereo || B0 > 1)
++ else if (stereo || B0_ > 1)
+ ff_opus_rc_enc_uint(rc, itheta, qn + 1);
+ else
+ ff_opus_rc_enc_uint_tri(rc, itheta, qn);
+@@ -619,7 +619,7 @@
+ } else {
+ if (stereo && N > 2)
+ itheta = ff_opus_rc_dec_uint_step(rc, qn / 2);
+- else if (stereo || B0 > 1)
++ else if (stereo || B0_ > 1)
+ itheta = ff_opus_rc_dec_uint(rc, qn+1);
+ else
+ itheta = ff_opus_rc_dec_uint_tri(rc, qn);
+@@ -725,7 +725,7 @@
+
+ /* Give more bits to low-energy MDCTs than they would
+ * otherwise deserve */
+- if (B0 > 1 && !stereo && (itheta & 0x3fff)) {
++ if (B0_ > 1 && !stereo && (itheta & 0x3fff)) {
+ if (itheta > 8192)
+ /* Rough approximation for pre-echo masking */
+ delta -= delta >> (4 - duration);
+@@ -764,14 +764,14 @@
+ cmt = pvq->quant_band(pvq, f, rc, band, Y, NULL, N, sbits, blocks,
+ next_lowband2, duration, NULL, next_level,
+ gain * side, NULL, fill >> blocks);
+- cm |= cmt << ((B0 >> 1) & (stereo - 1));
++ cm |= cmt << ((B0_ >> 1) & (stereo - 1));
+ } else {
+ /* For a stereo split, the high bits of fill are always zero,
+ * so no folding will be done to the side. */
+ cm = pvq->quant_band(pvq, f, rc, band, Y, NULL, N, sbits, blocks,
+ next_lowband2, duration, NULL, next_level,
+ gain * side, NULL, fill >> blocks);
+- cm <<= ((B0 >> 1) & (stereo - 1));
++ cm <<= ((B0_ >> 1) & (stereo - 1));
+ rebalance = sbits - (rebalance - f->remaining2);
+ if (rebalance > 3 << 3 && itheta != 16384)
+ mbits += rebalance - (3 << 3);
+@@ -842,13 +842,13 @@
+ int k;
+
+ /* Undo the sample reorganization going from time order to frequency order */
+- if (B0 > 1)
++ if (B0_ > 1)
+ celt_interleave_hadamard(pvq->hadamard_tmp, X, N_B >> recombine,
+- B0 << recombine, longblocks);
++ B0_ << recombine, longblocks);
+
+ /* Undo time-freq changes that we did earlier */
+ N_B = N_B0;
+- blocks = B0;
++ blocks = B0_;
+ for (k = 0; k < time_divide; k++) {
+ blocks >>= 1;
+ N_B <<= 1;