A method comprising: temporally aligning sequences of temporal segments (711-714, 721-724, 731-734) across a plurality of client streams, wherein each sequence comprises a plurality of temporal segments for a respective client stream for download to a respective one of a plurality of client devices sharing a network resource, and wherein the temporal segments of each sequence are used to download segment representations of media content data to one of the plurality of client devices, the aligning comprising aligning start and end download times of segments across the streams such that respective aligned segments of each of the streams start and end downloading to the user devices at the same start and end times (tsl-ts4, te1-te4) within a threshold variance; and selecting segment representations for each temporal segment, for each sequence, in accordance with the sequence alignment and based on perceptual quality level values associated with available segment representations, wherein a combination of resulting perceptual quality levels satisfies a joint quality criterion across the sequences; wherein the perceptual quality levels are based on one of a mean-square error distortion, a peak-signal-to-noise-ratio, and a structure-similarity-index and comprise distortion values d i,m for respective segments m of respective streams i, and wherein the joint quality criterion is based on a total distortion value d T characterizing the respective distortion values d i,m associated with corresponding client devices sharing a fixed allocation of bandwidth R m; wherein a segment representation for a temporal segment m of each stream i is selected from a set of segment representations having a plurality of different available encoding bitrates r i,m, the method comprising: calculating the distortion values d i,m for available encoding rates r i,m that satisfy the total bit allocation R m shared by the client devices for the m th temporal segment; and minimizing the total distortion value d T for the segment given by the sum of distortion values d i,m computed for respective streams. temporally aligning sequences of temporal segments (711-714, 721-724, 731-734) across a plurality of client streams, wherein each sequence comprises a plurality of temporal segments for a respective client stream for download to a respective one of a plurality of client devices sharing a network resource, and wherein the temporal segments of each sequence are used to download segment representations of media content data to one of the plurality of client devices, the aligning comprising aligning start and end download times of segments across the streams such that respective aligned segments of each of the streams start and end downloading to the user devices at the same start and end times (tsl-ts4, te1-te4) within a threshold variance; and selecting segment representations for each temporal segment, for each sequence, in accordance with the sequence alignment and based on perceptual quality level values associated with available segment representations, wherein a combination of resulting perceptual quality levels satisfies a joint quality criterion across the sequences; wherein the perceptual quality levels are based on one of a mean-square error distortion, a peak-signal-to-noise-ratio, and a structure-similarity-index and comprise distortion values d i,m for respective segments m of respective streams i, and wherein the joint quality criterion is based on a total distortion value d T characterizing the respective distortion values d i,m associated with corresponding client devices sharing a fixed allocation of bandwidth R m; wherein a segment representation for a temporal segment m of each stream i is selected from a set of segment representations having a plurality of different available encoding bitrates r i,m, the method comprising: calculating the distortion values d i,m for available encoding rates r i,m that satisfy the total bit allocation R m shared by the client devices for the m th temporal segment; and minimizing the total distortion value d T for the segment given by the sum of distortion values d i,m computed for respective streams. calculating the distortion values d i,m for available encoding rates r i,m that satisfy the total bit allocation R m shared by the client devices for the m th temporal segment; and minimizing the total distortion value d T for the segment given by the sum of distortion values d i,m computed for respective streams.