chungae9ri
24th November 2005, 09:07
Hello everyone.
I have downloaded some AAC conformance test bitstreams from hannover, Tektronix which are linked by www.mpeg.org. But I can't parse the adts_header. According to ISO/IEC 13818-7, the adts header is composed of 7bytes(56bit, 28bit adts_fixed_header, 28bit adts_variable_header when adts_error_check doesnot exist), and the 7byte of the test bitstream is as follows.
FF FB E5 44 00 00 04...
as my parsing that bitstream, sampling frequency index is 9(=12000Hz) but the document about the bitstream says the sampling frequency is 48KHz! I think all other informations are not consistent with the 13818-7 document except syncword, ID, Layer, protection_absent bit. All other test bitstreams are the same.
Am I wrong? or Is there any other informations?
I have downloaded some AAC conformance test bitstreams from hannover, Tektronix which are linked by www.mpeg.org. But I can't parse the adts_header. According to ISO/IEC 13818-7, the adts header is composed of 7bytes(56bit, 28bit adts_fixed_header, 28bit adts_variable_header when adts_error_check doesnot exist), and the 7byte of the test bitstream is as follows.
FF FB E5 44 00 00 04...
as my parsing that bitstream, sampling frequency index is 9(=12000Hz) but the document about the bitstream says the sampling frequency is 48KHz! I think all other informations are not consistent with the 13818-7 document except syncword, ID, Layer, protection_absent bit. All other test bitstreams are the same.
Am I wrong? or Is there any other informations?