aacenc: copy PRNG from the decoder

Needed for the following PNS commits.

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

1 files changed, 9 insertions, 0 deletions

diff --git a/libavcodec/aacenc_utils.h b/libavcodec/aacenc_utils.h
index 327fbad833..0ab15a3e5e 100644
--- a/libavcodec/aacenc_utils.h
+++ b/libavcodec/aacenc_utils.h
@@ -128,6 +128,15 @@ static inline int quant_array_idx(const float val, const float *arr, const int n
     return index;
 }
 
+/*
+ * linear congruential pseudorandom number generator, copied from the decoder
+ */
+static inline int lcg_random(unsigned previous_val)
+{
+    union { unsigned u; int s; } v = { previous_val * 1664525u + 1013904223 };
+    return v.s;
+}
+
 #define ERROR_IF(cond, ...) \
     if (cond) { \
         av_log(avctx, AV_LOG_ERROR, __VA_ARGS__); \