Making available a sound signal for higher order ambisonics signals
Audio signals are recorded with microphones receiving acoustic information from one or more directions. The corresponding audio signals can be pre-listened to in production studios. However, Higher Order Ambisonics (HOA) audio signals are matrixed in such a way that the matrixing prevents listening to the matrixed sound signals without dematrixing the matrixed sound signals. For enabling a sound engineer to listen to such a matrixed signal without full HOA decoding, an informative audio signal is added together with related side information data at encoding side to a selected part of the matrixed signal. This informative audio signal is removed before the inverse matrixing process at decoding side.
1. A method for processing for listening at least one sound signal that is combined with a Higher Order Ambisonics signal denoted HOA signal, said method comprising:
splitting said HOA signal into a selected signal part and a remaining signal part;
extracting from said remaining signal part at least one partial signal;
combining said at least one partial signal with said selected signal part so as to form an amended selected signal part;
outputting the amended selected signal part for listening;
outputting of said remaining signal part, said amended selected signal part, and side information data, wherein the side information is related to said at least one partial signal, the side information further related to merging said remaining signal part and said selected signal part.
2. The method according to claim 1 wherein, instead of extracting from said remaining signal part said at least one partial signal and combining said at least one partial signal with said selected signal part so as to form an amended selected signal part, one or more separate signals are combined with said selected signal part so as to form an amended selected signal part.
3. The method according to claim 1 wherein, in order to avoid overload following said combining, the original signal level of said HOA signal is reduced.
4. The method according to claim 1 , wherein said partial or additional, respectively, signal is one of original microphone signals, from which microphone signals said HOA signal was generated.
5. The method according to claim 1 , wherein said partial signal is a combination of HOA zero order type signal and HOA first order type signal.
6. A method for decoding an amended HOA signal which was processed according to the method of claim 1 , said decoding method comprising:
based on said side information data, extracting from said remaining signal part said at least one partial signal;
removing said at least one partial signal from said amended selected signal part so as to get said selected signal part;
merging said selected signal part and said remaining signal part so as to get said HOA signal;
decoding said HOA signal.
7. The method according to claim 6 wherein, instead of extracting from said remaining signal part said at least one partial signal and removing said at least one partial signal from said amended selected signal part so as to get said selected signal part, said one or more separate signals are removed from said amended selected signal part so as to get said selected signal part.
8. An apparatus for processing for listening at least one sound signal that is combined with a Higher Order Ambisonics signal denoted HOA signal, said apparatus comprising:
a splitter configured to split said HOA signal into a selected signal part and a remaining signal part;
an extractor configured to extract from said remaining signal part at least one partial signal;
a combiner configured to combine said at least one partial signal with said selected signal part so as to form an amended selected signal part
wherein the apparatus is configured to output the amended selected signal part for listening, and the apparatus is further configured to output said remaining signal part, said amended selected signal part, and side information data, wherein the side information is related to said at least one partial signal and to merging said remaining signal part and said selected signal part.
9. The apparatus according to claim 8 wherein, instead of extracting from said remaining signal part said at least one partial signal and combining said at least one partial signal with said selected signal part so as to form an amended selected signal part, one or more separate signals are combined with said selected signal part so as to form an amended selected signal part.
10. The apparatus according to claim 8 wherein, in order to avoid overload following said combining, the original signal level of said HOA signal is reduced.
11. The apparatus according to claim 8 , wherein said partial or additional, respectively, signal is one of original microphone signals, from which microphone signals said HOA signal was generated.
12. The apparatus according to claim 8 , wherein said partial signal is a combination of HOA zero order type signal and HOA first order type signal.
13. An apparatus for decoding an amended HOA signal which was processed according to the method of claim 1 , said apparatus comprising:
an extractor which extracts, based on said side information data, from said remaining signal part said at least one partial signal;
a remover which removes said at least one partial signal from said amended selected signal part so as to get said selected signal part;
a merger which merges said selected signal part and said remaining signal part so as to get said HOA signal;
a decoder for said HOA signal.
14. The apparatus according to claim 13 wherein, instead of extracting from said remaining signal part said at least one partial signal and removing said at least one partial signal from said amended selected signal part so as to get said selected signal part, said one or more separate signals are removed from said amended selected signal part so as to get said selected signal part.