Stereo Encoder: Differences in TCX/HQ Core Selection for LTV at 32 kbps

Basic info

• Float reference:
  • Encoder (float): ceb8871f
  • Decoder (float): ceb8871f
• Fixed point:
  • Encoder (fixed): c89d638e
  • Decoder (fixed): n/a

Bug description

For the violin part in the LTVs (starting at 1:17.35), the BASOP encoder choses a different transform-coder mode than the floating-point code, leading to a significant degradation of the coded signal. Starting from frame 3853, the BASOP encoder switches to HQ_CORE, where Float sticks to TCX20.

Float:

BASOP:

Ways to reproduce

./IVAS_cod -stereo 32000 16 ltv16_STEREO.wav ltv16_STEREO_32kbps.192
./IVAS_dec stereo 16 ltv16_STEREO_32kbps.192 ltv16_STEREO_32kbps.wav