A method for obtaining multiple scaled compressed bitstreams from a single plenary file, comprising: separately encoding a plurality of audio object files to obtain a plurality of encoded audio object files at a plenary bitrate using a scalable bitstream encoder having fine-grained scalability that ranks bits in each data frame of the encoded audio object files in an order of psychoacoustic importance to human hearing, wherein an audio object is a source signal of a particular sound or combination of sounds; generating the plenary file at the plenary bitrate by combining the plurality of independently encoded audio object files and corresponding hierarchical metadata, wherein each of the plurality of encoded audio object files is persistent and present for an entire duration of the plenary file; constructing a first scaled compressed bitstream at a first target bitrate from the plenary file; and constructing a second scaled compressed bitstream at a second target bitrate from the plenary file, wherein multiple scaled bitstreams at different target bitrates are obtained from the single plenary file without any re-encoding of the plurality of encoded audio object files; wherein the first target bitrate and the second target bitrate are different from each other and are both less than the plenary bitrate; wherein the first target bitrate is a maximum bitrate at which the first scaled compressed bitstream will be transmitted; the method further comprising: comparing a data frame activity of data frames of each of the plurality of encoded audio files at a selected time period to each other to obtain a data frame activity comparison; assigning bits to each of the data frames of the encoded audio object files at the selected time period based on the data frame activity comparison and the first target bitrate to obtain a bit allocation for the selected time period; scaling down the plenary file by truncating bits of the data frames in accordance with the bit allocation to achieve the first target bitrate and obtain bit-reduced encoded audio object files; and multiplexing together and packing the bit-reduced audio object files into the first scaled compressed bitstream at the first target bitrate. separately encoding a plurality of audio object files to obtain a plurality of encoded audio object files at a plenary bitrate using a scalable bitstream encoder having fine-grained scalability that ranks bits in each data frame of the encoded audio object files in an order of psychoacoustic importance to human hearing, wherein an audio object is a source signal of a particular sound or combination of sounds; generating the plenary file at the plenary bitrate by combining the plurality of independently encoded audio object files and corresponding hierarchical metadata, wherein each of the plurality of encoded audio object files is persistent and present for an entire duration of the plenary file; constructing a first scaled compressed bitstream at a first target bitrate from the plenary file; and constructing a second scaled compressed bitstream at a second target bitrate from the plenary file, wherein multiple scaled bitstreams at different target bitrates are obtained from the single plenary file without any re-encoding of the plurality of encoded audio object files; wherein the first target bitrate and the second target bitrate are different from each other and are both less than the plenary bitrate; wherein the first target bitrate is a maximum bitrate at which the first scaled compressed bitstream will be transmitted; the method further comprising: comparing a data frame activity of data frames of each of the plurality of encoded audio files at a selected time period to each other to obtain a data frame activity comparison; assigning bits to each of the data frames of the encoded audio object files at the selected time period based on the data frame activity comparison and the first target bitrate to obtain a bit allocation for the selected time period; scaling down the plenary file by truncating bits of the data frames in accordance with the bit allocation to achieve the first target bitrate and obtain bit-reduced encoded audio object files; and multiplexing together and packing the bit-reduced audio object files into the first scaled compressed bitstream at the first target bitrate. comparing a data frame activity of data frames of each of the plurality of encoded audio files at a selected time period to each other to obtain a data frame activity comparison; assigning bits to each of the data frames of the encoded audio object files at the selected time period based on the data frame activity comparison and the first target bitrate to obtain a bit allocation for the selected time period; scaling down the plenary file by truncating bits of the data frames in accordance with the bit allocation to achieve the first target bitrate and obtain bit-reduced encoded audio object files; and multiplexing together and packing the bit-reduced audio object files into the first scaled compressed bitstream at the first target bitrate.