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for #310, refine the aac profile for adts and aac object for RTMP sequence header.

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This commit is contained in:
winlin 2015-03-08 17:33:52 +08:00
parent 04f3f2a8f8
commit d3e2838fc6
10 changed files with 141 additions and 130 deletions
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18
trunk/src/kernel/srs_kernel_aac.cpp
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@ -43,6 +43,7 @@ SrsAacEncoder::SrsAacEncoder()
_fs = NULL;
got_sequence_header = false;
tag_stream = new SrsStream();
aac_profile = SrsAacProfileReserved;
}
SrsAacEncoder::~SrsAacEncoder()
@ -114,7 +115,7 @@ int SrsAacEncoder::write_audio(int64_t timestamp, char* data, int size)
// 1.6.2.1 AudioSpecificConfig, in aac-mp4a-format-ISO_IEC_14496-3+2001.pdf, page 33.
//
// only need to decode the first 2bytes:
// audioObjectType, aac_profile, 5bits.
// audioObjectType, 5bits.
// samplingFrequencyIndex, aac_sample_rate, 4bits.
// channelConfiguration, aac_channels, 4bits
if (!stream->require(2)) {
@ -123,12 +124,14 @@ int SrsAacEncoder::write_audio(int64_t timestamp, char* data, int size)
return ret;
}
aac_profile = stream->read_1bytes();
int8_t audioObjectType = stream->read_1bytes();
aac_sample_rate = stream->read_1bytes();
aac_channels = (aac_sample_rate >> 3) & 0x0f;
aac_sample_rate = ((aac_profile << 1) & 0x0e) | ((aac_sample_rate >> 7) & 0x01);
aac_profile = (aac_profile >> 3) & 0x1f;
aac_sample_rate = ((audioObjectType << 1) & 0x0e) | ((aac_sample_rate >> 7) & 0x01);
audioObjectType = (audioObjectType >> 3) & 0x1f;
aac_profile = srs_codec_aac_rtmp2ts((SrsAacObjectType)audioObjectType);
got_sequence_header = true;
@ -177,16 +180,13 @@ int SrsAacEncoder::write_audio(int64_t timestamp, char* data, int size)
// protection_absent 1 bslbf
*pp++ = 0xf1;
// Profile_ObjectType 2 uimsbf
// profile 2 uimsbf
// sampling_frequency_index 4 uimsbf
// private_bit 1 bslbf
// channel_configuration 3 uimsbf
// original/copy 1 bslbf
// home 1 bslbf
int8_t fh_Profile_ObjectType = aac_profile - 1;
*pp++ = ((fh_Profile_ObjectType << 6) & 0xc0) | ((aac_sample_rate << 2) & 0x3c) | ((aac_channels >> 2) & 0x01);
// @remark, Emphasis is removed,
// @see https://github.com/winlinvip/simple-rtmp-server/issues/212#issuecomment-64154736
*pp++ = ((aac_profile << 6) & 0xc0) | ((aac_sample_rate << 2) & 0x3c) | ((aac_channels >> 2) & 0x01);
// 4bits left.
// adts_variable_header(), 1.A.2.2.2 Variable Header of ADTS
// copyright_identification_bit 1 bslbf