A method comprising: implementing hybrid explicit / implicit encoding parameter control in an encoding system by: determining, by an encoder, an encoding parameter through implicit encoding parameter determination, wherein the encoding parameter is a quantization parameter for encoding a current sample; inserting an operational mode bit into an encoded data stream, the operational mode bit specifying to a decoder whether or not said decoder implicitly adjusts the encoding parameter; when the operational mode bit specifies to said decoder that said decoder not implicitly adjust the encoding parameter, inserting, into the encoded data stream, an explicit encoding parameter indicator that specifies a particular change in the encoding parameter; and performing two flatness checks on two sets of samples surrounding the current sample for specifying the particular change in the encoding parameter by: determining whether a first set of samples surrounding the current sample meets a high flatness threshold; if the first set of samples surrounding the current sample meets the high flatness threshold, adjusting the quantization parameter; if the first set of samples surrounding the current sample does not meet the high flatness threshold, determining whether a second set of samples surrounding the current sample meets the high flatness threshold; and if the second set of samples surrounding the current sample meets the high flatness threshold, adjusting the quantization parameter, wherein the particular change in the encoding parameter is the adjustment of the quantization parameter. determining, by an encoder, an encoding parameter through implicit encoding parameter determination, wherein the encoding parameter is a quantization parameter for encoding a current sample; inserting an operational mode bit into an encoded data stream, the operational mode bit specifying to a decoder whether or not said decoder implicitly adjusts the encoding parameter; when the operational mode bit specifies to said decoder that said decoder not implicitly adjust the encoding parameter, inserting, into the encoded data stream, an explicit encoding parameter indicator that specifies a particular change in the encoding parameter; and performing two flatness checks on two sets of samples surrounding the current sample for specifying the particular change in the encoding parameter by: determining whether a first set of samples surrounding the current sample meets a high flatness threshold; if the first set of samples surrounding the current sample meets the high flatness threshold, adjusting the quantization parameter; if the first set of samples surrounding the current sample does not meet the high flatness threshold, determining whether a second set of samples surrounding the current sample meets the high flatness threshold; and if the second set of samples surrounding the current sample meets the high flatness threshold, adjusting the quantization parameter, wherein the particular change in the encoding parameter is the adjustment of the quantization parameter. determining whether a first set of samples surrounding the current sample meets a high flatness threshold; if the first set of samples surrounding the current sample meets the high flatness threshold, adjusting the quantization parameter; if the first set of samples surrounding the current sample does not meet the high flatness threshold, determining whether a second set of samples surrounding the current sample meets the high flatness threshold; and if the second set of samples surrounding the current sample meets the high flatness threshold, adjusting the quantization parameter, wherein the particular change in the encoding parameter is the adjustment of the quantization parameter. <EOS>