JPWO2020038938A5

JPWO2020038938A5 -

Info

Publication number: JPWO2020038938A5
Application number: JP2021509899A
Authority: JP
Publication date: 2022-08-17
Anticipated expiration: 2039-08-20

Claims

1. An audio decoder for decoding a bitstream of encoded audio data, said bitstream of encoded audio data representing a succession of audio sample values and having a plurality of frames, each frame having an associated In the audio decoder having encoded audio sample values of
A determination configured to determine whether a frame of the bitstream of encoded audio data is an immediate-play frame having encoded audio sample values associated with a current frame and additional information. and the bitstream of encoded audio data is an MPEG-4 audio bitstream, and the additional information is an extension payload element of a new extension payload element type EXT_AUDIO_PRE_ROLL MPEG-4 audio bitstream extension mechanism. the determiner, wherein the extended payload element is located in a first position within the MPEG-4 audio bitstream, and the extended payload element is contained within a fill element (ID_FIL);
an initialization unit configured to initialize the decoder if the determiner determines that the frame is an immediate play frame;
The additional information comprises encoded audio sample values of a number of frames preceding the instant-play frame, wherein the encoded audio sample values of the preceding frames have the same codec setting as the current frame. is encoded using
The number of preceding frames corresponding to a pre-roll frame causes the entire signal to be in position to output valid audio sample values associated with the current frame whenever an instant-play frame is decoded. corresponding to the number of frames required by said decoder to compose;
Initializing the decoder decodes the encoded audio sample values configured with the additional information prior to decoding the encoded audio sample values associated with the current frame. has
The initialization unit, if the determination unit determines that the frame is an immediate-play frame and if the audio sample values of the current frame are encoded using a different codec setting, the configured to switch an audio decoder from a current codec setting to the different codec setting;
The decoder decodes the current frame using the current codec settings, and if the determiner determines that the frame is an instant-play frame, and the audio sample values of the current frame are configured to discard said additional information if encoded using current codec settings;
audio decoder.

The additional information includes information about codec settings used to encode audio sample values associated with the current frame, and the determining unit determines whether the codec settings of the additional information are the current frame. further configured to determine if it differs from the codec setting ; and/or
the immediate play frame comprises the additional information as an extension payload, the decision unit being configured to evaluate the extension payload of the immediate play frame ;
Audio decoder according to claim 1.

the extension payload element has a specific instance tag that conveys that the payload of the extension payload element is the additional information ; and/or
said additional information further comprises a unique identifier, optionally said unique identifier is used to detect said different codec settings ;
Audio decoder according to claim 1 or 2 .

A cross between output sample values obtained by flushing the decoder with a previous codec setting and output sample values obtained by decoding the encoded audio sample values associated with the current frame. further comprising a crossfader configured to perform fades; and/or
An earliest frame of the plurality of frames included in the additional information is not time-differentially encoded or entropy-encoded with respect to any frame prior to the earliest frame, and the immediate playback frame is: time-differentially encoding any frame prior to the earliest of the plurality of frames preceding the instant-play frame or any frame prior to the instant-play frame; or not entropy coded ,
Audio decoder according to any one of claims 1 to 3 .

A method of decoding a bitstream of encoded audio data, said bitstream of encoded audio data representing a succession of audio sample values and having a plurality of frames, each frame being associated with a The method comprising encoded audio sample values,
determining whether a frame of the bitstream of encoded audio data is an immediate-play frame having encoded audio sample values associated with the current frame and additional information; the encoded audio data bitstream is an MPEG-4 audio bitstream, said additional information being carried via an MPEG-4 audio bitstream extension mechanism, an extension payload element of a new extension payload element type EXT_AUDIO_PRE_ROLL; The extended payload element is located at a first position within the MPEG-4 audio bitstream, the extended payload element is contained within a fill element (ID_FIL), and the additional information precedes the immediate play frame. wherein the encoded audio sample values of the preceding frame are encoded using the same codec settings as the immediate-play frame and pre-roll The number of preceding frames corresponding to a frame configures the overall signal to be in position to output valid audio sample values associated with the current frame whenever an instant play frame is decoded. a step corresponding to the number of frames required by the decoder for
initializing the decoder if the frame is determined to be an immediate playback frame, the initializing decoding the encoded audio sample values associated with the current frame; previously decoding the encoded audio sample values configured by the additional information;
If the frame is determined to be an immediate-play frame, and if the audio sample values of the immediate-play frame are encoded using a different codec setting, the decoder is changed from the current codec setting to the different codec setting. switching to codec settings;
decoding the instant-play frame using the current codec settings, and if it is determined that the frame is an immediate-play frame, and the audio sample values of the immediate-play frame are determined using the current codec settings; and discarding said additional information if it is encoded.

The bitstream of encoded audio data comprises a first number of frames encoded using a first codec setting followed by the first number of frames encoded using a second codec setting. and a second number of frames;
a first frame of the second number of frames is the instant play frame;
6. The method of claim 5 .

1. An audio encoder for generating a bitstream of encoded audio data comprising instant-play frames, said bitstream of encoded audio data representing a sequence of audio sample values and comprising a plurality of frames; In the audio encoder, each frame having an associated encoded audio sample value,
a core encoder configured to encode uncompressed audio sample values associated with the plurality of frames using predefined codec settings;
a buffer configured to store encoded audio sample values of a number of previous frames of a current frame of the plurality of frames using the predefined codec settings;
an embedder configured to write an immediate playback frame to the current frame of the plurality of frames;
The instant-play frame has encoded audio sample values associated with the current frame and additional information corresponding to the encoded audio sample values of the multiple previous frames of the current frame. death,
The generated bitstream of encoded audio data is an MPEG-4 audio bitstream, and the embedding unit uses an MPEG-4 audio bitstream extension mechanism, an extension payload element of new extension payload element type EXT_AUDIO_PRE_ROLL. embedding the additional information into the bitstream via the MPEG-4 audio bitstream, positioning the extended payload element at a first position within the MPEG-4 audio bitstream, and embedding the extended payload element within a fill element (ID_FIL). Ru
audio encoder.

The embedder is further configured to include information about the predefined codec settings in the additional information , and/or
the embedding unit is further configured to include the additional information in the immediate playback frame ;
Audio encoder according to claim 7 .

The embedder is further configured to assign a specific instance tag that conveys that the payload of the extension payload element is the additional information , and/or
the embedding unit is further configured to include a unique identifier in the additional information, optionally the unique identifier conveying a predefined codec setting ;
Audio encoder according to claim 7 or 8 .

The audio encoder does not time-differentially encode or entropy-encode the earliest frame among the multiple frames included in the additional information with respect to any frame preceding the earliest frame. further configured,
The audio encoder may perform the following for any frame before the earliest frame of the plurality of frames preceding the instant-play frame, or for any frame before the instant-play frame. further configured not to time-differentially encode or entropy-encode the instant-play frames;
Audio encoder according to any one of claims 7-9 .

comprising two or more audio encoders according to any one of claims 7 to 10 for generating a plurality of bitstreams of encoded audio data each comprising instant-play frames;
each bitstream of encoded audio data represents a sequence of audio sample values and has a plurality of frames, each frame having an associated encoded audio sample value;
system.

a predefined sampling rate is the same for each of the core encoders of the two or more audio encoders ; and/or
The system further comprises a delay alignment unit for delay aligning the multiple bitstreams .
12. The system of claim 11 .

A method for generating, by an audio encoder, a bitstream of encoded audio data having instant-play frames, wherein the bitstream of encoded audio data represents a succession of audio sample values and comprises a plurality of frames. wherein each frame has an associated encoded audio sample value,
encoding, by a core encoder, uncompressed audio sample values associated with the plurality of frames using predefined codec settings;
storing, with a buffer, encoded audio sample values of a number of previous frames of a current frame of the plurality of frames using the predefined codec settings;
writing, by an embedder, an immediate playback frame to the current frame of the plurality of frames;
The instant-play frame has encoded audio sample values associated with the current frame and additional information corresponding to the encoded audio sample values of the multiple previous frames of the current frame. death,
The generated bitstream of encoded audio data is an MPEG-4 audio bitstream, and the additional information is an extension payload element of new extension payload element type EXT_AUDIO_PRE_ROLL using the MPEG-4 audio bitstream extension mechanism. embedded in the bitstream by the embedding unit via, the extended payload element positioned by the embedding unit at a first position within the MPEG-4 audio bitstream, the extended payload element being embedded in the bitstream by the embedding unit embedded in the filler element (ID_FIL) by
Method.

1. An apparatus for generating instant-play frames in a bitstream of encoded audio data, said bitstream of encoded audio data representing a sequence of audio sample values and comprising a plurality of frames, In the apparatus, each frame having an associated encoded audio sample value,
A receiving unit configured to receive an MPEG-4 audio bitstream of encoded audio data, said bitstream of encoded audio data representing a succession of audio sample values and comprising a plurality of frames. and each frame has an associated encoded audio sample value;
a buffer configured to store encoded audio sample values for a number of previous frames of a current frame of the plurality of frames;
an embedder configured to write an instant-play frame into the current frame of the plurality of frames, the instant-play frame including encoded audio sample values associated with the current frame; additional information corresponding to encoded audio sample values of the number of previous frames of the current frame;
The embedder embeds the additional information into the bitstream via an MPEG-4 audio bitstream extension mechanism in an extension payload element of new extension payload element type EXT_AUDIO_PRE_ROLL, and embeds the extension payload element in the MPEG-4 audio bitstream. and further configured to embed the extended payload element within a filler element (ID_FIL).
Device.

1. Apparatus for excluding instant-play frames from a bitstream of encoded audio data, said bitstream of encoded audio data representing a succession of audio sample values and comprising a plurality of frames, each frame comprising: , having associated encoded audio sample values,
A receiving unit configured to receive a bitstream of encoded audio data, said bitstream of encoded audio data representing a succession of audio sample values and comprising a plurality of frames, each frame has associated encoded audio sample values;
said instant-play frame by removing from said instant-play frame additional information corresponding to encoded audio sample values of a number of preceding frames of a current frame of said plurality of frames into which said instant-play frame is written; and an embedding unit configured to transform the into a normal frame.