There are disclosed various methods, apparatuses and computer program products for video decoding or encoding. In some embodiments for decoding a block that contains quantized residual coefficients based on at least two color channels of a video presentation or an image is received. A first quantization parameter and an offset defining a relationship between the first quantization parameter and a second quantization parameter for the block are obtained. The value of the second quantization parameter is determined by using the first quantization parameter and the offset. The residual samples are reconstructed by dequantizing the quantized residual coefficients using the second quantization parameter, if the block has been encoded by using a cross-channel residual coding mode.