Method and apparatus for embedding spatial information and reproducing embedded signal for an audio signal
An apparatus for encoding and decoding an audio signal and method thereof are disclosed, by which compatibility with a player of a general mono or stereo audio signal can be provided in coding an audio signal and by which spatial information for a multi-channel audio signal can be stored or transmitted without a presence of an auxiliary data area. The present invention includes extracting side information embedded in non-recognizable component of audio signal components and decoding the audio signal using the extracted side information.
1. A method of decoding an audio signal, comprising:
receiving a downmix signal embedding data including spatial information, the downmix signal including at least one frame, the frame including at least one sub-frame being comprised of a plurality of samples, the data being embedded in lower bits of each sample of the downmix signal, and the spatial information being sequentially embedded in most significant bit first within the lower bits;
obtaining header information of the data from the downmix signal, the header information being embedded in least significant bit of at least one sample of the downmix signal, the header information including an insertion bit length for each sub-frame of the downmix signal, the insertion bit length indicating a length of bits containing the spatial information;
obtaining the spatial information based on the insertion bit length; and
generating a multi-channel audio signal by applying the spatial information to the downmix signal.
2. The method of claim 1 , wherein the data are embedded in non-recognizable components of the downmix signal.
3. The method of claim 1 , wherein a length of the sub-frame is obtained by dividing a length of the frame of the downmix signal by a positive integer.
4. An apparatus for decoding an audio signal, comprising:
a receiver receiving a downmix signal embedding data including spatial information, the downmix signal including at least one frame, the frame including at least one sub-frame being comprised of a plurality of samples, the data being embedded in lower bits of each sample of the downmix signal, the spatial information being sequentially embedded in most significant bit first within the lower bits;
an embedded signal decoding unit obtaining header information of the data from the downmix signal, the header information being embedded in least significant bit of at least one sample of the downmix signal, the header information including an insertion bit length for each sub-frame of the downmix signal, the insertion bit length indicating a length of bits containing the spatial information;
a spatial information decoding unit obtaining the spatial information based on the insertion bit length; and
a multi-channel generating unit generating a multi-channel audio signal by applying the spatial information to the downmix signal.
5. The apparatus of claim 4 , wherein the data are embedded in non-recognizable components of the downmix signal.
6. The apparatus of claim 4 , wherein a length of the sub-frame is obtained by dividing a length of the frame of the downmix signal by a positive integer.
7. A method of encoding an audio signal, comprising:
generating a downmix signal by downmixing a multi-channel audio signal, the downmix signal including at least one frame, the frame including at least one sub-frame being comprised of a plurality of samples;
generating data including spatial information indicating an attribute of the multi-channel audio signal, in order to upmix the downmix signal;
embedding header information of the data in least significant bit of at least one sample of the downmix signal;
determining an insertion bit length for each sub-frame of the downmix signal, the insertion bit length indicating a length of bits containing the spatial information; and
embedding the spatial information based on the insertion bit length, the spatial information being sequentially embedded in most significant bit first.
8. An apparatus for encoding an audio signal, comprising:
an audio signal generating unit generating a downmix signal by downmixing a multi-channel audio signal, the downmix signal including at least one frame, the frame including at least one sub-frame being comprised of a plurality of samples;
a side information generating unit generating data including spatial information indicating an attribute of the multi-channel audio signal, in order to upmix the downmix signal;
a masking threshold computing unit determining an insertion bit length for each sub-frame of the downmix signal, the insertion bit length indicating a length of bits containing the spatial information; and
a bitstream reshaping unit:
embedding header information of the data in least significant bit of at least one sample of the downmix signal, and
embedding the spatial information based on the insertion bit length, the spatial information being sequentially embedded in most significant bit first.