downmixing difference between float and fixed-point (TD - stereo)
Basic info
Bug description
while the downmixing of the DFT stereo works only with few glitches, the downmixing of the TD stereo is not working. The output of the fixed point downmixing suffers a lot of issues and also seems (or maybe some memories are not properly rescaled?).
The figures below show the comparison of the downed mixed signal an the encoder just before entering the front Pre-processing
On the 3 figures below, from top to bottom:
- original file
- floating point input_DMX ch. 0
- floating point input_DMX ch. 1
- fixed point input_DMX ch. 0
- fixed point input_DMX ch. 1
Ways to reproduce
You can obtain check it by running the following command for both float and fix and output the dmx signal as done in the floating point around lines 460 of ivas_cpe_enc.c ( here I printed out the input_fx[] unscaled by sts[n]->q_inp )
IVAS_cod -STEREO 2 16400 48.\ivas-codec\scripts\testv\stvST48c.wav bit16400