A method for processing digital multimedia data, the method comprising: encoding a segment of data associated with the digital multimedia data using a set of encoding parameters comprising an encoding bitrate and a quantization parameter; computing a perceived quality metric of the encoded segment of data, wherein the perceived quality metric is an observed peak signal to noise ratio, PSNR, a weighted PSNR, or Mean Opinion Score, MOS, metric; associating the segment of data with one of a plurality of content classes, wherein each of the content classes corresponds to a different quality-rate curve generated modelling perceived quality metric as a function of a bitrate, wherein the segment of data is associated with a content class by normalizing the resultant bitrate of the encoded segment of data to correspond with the encoding parameters used to generate a plurality of quality-rate curves when the encoding parameters used to encode the segment of data are different than the encoding parameters such as frame types, frame rate and quantization parameter used to generate the plurality of quality-rate curves; and selecting one of the plurality of quality-rate curves based on the computed perceived quality metric and the normalized resultant bitrate of the encoded segment of data by computing, for each of the plurality of quality-rate curves, a difference between the computed perceived quality metric and a quality metric on the respective quality-rate curve corresponding to the normalized resultant bitrate; and selecting the one of the quality-rate curve that corresponds to a smallest difference of the computed differences; adjusting at least one of the encoding parameters used to encode the segment of data based at least on the computed perceived quality metric of the encoded segment of data and a target quality metric, which corresponds to the associated content class, wherein adjusting the at least one of the encoding parameters comprises increasing the quantization parameter when the computed perceived quality metric is greater than the target quality metric by a threshold, wherein adjusting the at least one of the encoding parameters comprises decreasing the quantization parameter when the computed perceived quality metric is less than the target quality metric by a threshold; and re-encoding the segment of data using the adjusted encoding parameters. encoding a segment of data associated with the digital multimedia data using a set of encoding parameters comprising an encoding bitrate and a quantization parameter; computing a perceived quality metric of the encoded segment of data, wherein the perceived quality metric is an observed peak signal to noise ratio, PSNR, a weighted PSNR, or Mean Opinion Score, MOS, metric; associating the segment of data with one of a plurality of content classes, wherein each of the content classes corresponds to a different quality-rate curve generated modelling perceived quality metric as a function of a bitrate, wherein the segment of data is associated with a content class by normalizing the resultant bitrate of the encoded segment of data to correspond with the encoding parameters used to generate a plurality of quality-rate curves when the encoding parameters used to encode the segment of data are different than the encoding parameters such as frame types, frame rate and quantization parameter used to generate the plurality of quality-rate curves; and selecting one of the plurality of quality-rate curves based on the computed perceived quality metric and the normalized resultant bitrate of the encoded segment of data by computing, for each of the plurality of quality-rate curves, a difference between the computed perceived quality metric and a quality metric on the respective quality-rate curve corresponding to the normalized resultant bitrate; and selecting the one of the quality-rate curve that corresponds to a smallest difference of the computed differences; adjusting at least one of the encoding parameters used to encode the segment of data based at least on the computed perceived quality metric of the encoded segment of data and a target quality metric, which corresponds to the associated content class, wherein adjusting the at least one of the encoding parameters comprises increasing the quantization parameter when the computed perceived quality metric is greater than the target quality metric by a threshold, wherein adjusting the at least one of the encoding parameters comprises decreasing the quantization parameter when the computed perceived quality metric is less than the target quality metric by a threshold; and re-encoding the segment of data using the adjusted encoding parameters.