A bitstream transmission device that transmits an audio bitstream in a given format, the bitstream transmission device comprising: an input unit configured to acquire an elementary audio stream that is obtained by coding an audio signal; an analysis unit configured to analyze a sampling frequency and a coding format of the elementary audio stream; a preamble generation unit configured to generate, based on a result of the analysis by the analysis unit, a preamble signal including information indicating a coding format of the elementary audio stream; a forming unit configured to form the audio bitstream in the given format by adding to the elementary audio stream the preamble signal generated by the preamble generation unit; and an output unit configured to output the audio bitstream formed by the forming unit, wherein based on the sampling frequency and the coding format resulting from the analysis by the analysis unit, the preamble generation unit is configured to specify, as the information included in the preamble signal and indicating the coding format, a coding format that complies with the given format of the audio bitstream and is different from the coding format of the elementary audio stream resulting from the analysis by the analysis unit, characterized in that the audio bitstream in the given format is an audio bitstream in a format defined by the IEC 61937 standard, and when the sampling frequency resulting from the analysis by the analysis unit is a predetermined first frequency and the coding format corresponding to the first frequency does not comply with the IEC 61937 standard, to generate the preamble signal that conforms the audio bitstream to the IEC 61937 standard, the preamble generation unit is configured to specify, as the information indicating the coding format, a coding format different from the analyzed coding format in terms of presence or absence of spectral band replication information in the elementary audio stream.. an input unit configured to acquire an elementary audio stream that is obtained by coding an audio signal; an analysis unit configured to analyze a sampling frequency and a coding format of the elementary audio stream; a preamble generation unit configured to generate, based on a result of the analysis by the analysis unit, a preamble signal including information indicating a coding format of the elementary audio stream; a forming unit configured to form the audio bitstream in the given format by adding to the elementary audio stream the preamble signal generated by the preamble generation unit; and an output unit configured to output the audio bitstream formed by the forming unit, wherein based on the sampling frequency and the coding format resulting from the analysis by the analysis unit, the preamble generation unit is configured to specify, as the information included in the preamble signal and indicating the coding format, a coding format that complies with the given format of the audio bitstream and is different from the coding format of the elementary audio stream resulting from the analysis by the analysis unit, characterized in that the audio bitstream in the given format is an audio bitstream in a format defined by the IEC 61937 standard, and when the sampling frequency resulting from the analysis by the analysis unit is a predetermined first frequency and the coding format corresponding to the first frequency does not comply with the IEC 61937 standard, to generate the preamble signal that conforms the audio bitstream to the IEC 61937 standard, the preamble generation unit is configured to specify, as the information indicating the coding format, a coding format different from the analyzed coding format in terms of presence or absence of spectral band replication information in the elementary audio stream..