Audio encoder and decoder with program loudness and boundary metadata

Abstract

Apparatus and methods for generating an encoded audio bitstream, including by including program loudness metadata and audio data in the bitstream, and optionally also program boundary metadata in at least one segment (e.g., frame) of the bitstream. Other aspects are apparatus and methods for decoding such a bitstream, e.g., including by performing adaptive loudness processing of the audio data of an audio program indicated by the bitstream, or authentication and/or validation of metadata and/or audio data of such an audio program. Another aspect is an audio processing unit (e.g., an encoder, decoder, or post-processor) configured (e.g., programmed) to perform any embodiment of the method or which includes a buffer memory which stores at least one frame of an audio bitstream generated in accordance with any embodiment of the method.

What is claimed is: 
     
         1 . A non-transitory storage medium including at least a portion of a frame of an encoded audio bitstream, the frame comprising:
 a synchronization information segment including a synchronization word;   a bitstream information segment following the synchronization information segment, the bitstream information segment including a dialog normalization value, a flag indicating whether additional bit stream information is present in the frame, and a parameter indicating a length of the additional bit stream information if the flag indicates that the additional bit stream information is present;   up to six blocks of audio data following the bitstream information section, each of the up to six blocks of audio data optionally including a skip field;   an auxiliary data field following the up to six blocks of audio data;   an error correction word following the auxiliary data field; and   a metadata container located in a reserved data space of the frame selected from the group consisting the skip field, the additional bitstream information, the auxiliary data field, or a combination thereof,   wherein the metadata container includes:
 a header identifying a start of the metadata container, the header including a syncword followed by a length field specifying a length of the metadata container; 
 a format version field following the header, the format version field specifying a format version of the metadata container; and 
 a program loudness payload following the header and the format version field, wherein the program loudness payload includes a loudness regulation type field and the loudness regulation type field indicates a loudness regulation standard that was used to calculate the dialog normalization value. 
   
     
     
         2 . The non-transitory storage medium of  claim 1  wherein the syncword is a 16 bit field having a value of 0x5838. 
     
     
         3 . The non-transitory storage medium of  claim 1  wherein the program loudness payload includes a dialogue channel field, the dialogue channel field consisting of a 3-bit field indicating whether a left, right or center channel of the audio data contains spoken dialogue. 
     
     
         4 . The non-transitory storage medium of  claim 1  wherein the program loudness payload includes a loudness correction type, the loudness correction type consisting of a 1-bit field indicating whether the audio data was corrected with an infinite look-ahead or file-based loudness correction process. 
     
     
         5 . The non-transitory storage medium of  claim 1  wherein the storage medium represents an input buffer of an audio decoder. 
     
     
         6 . An audio decoder comprising the non-transitory computer readable medium of  claim 1 . 
     
     
         7 . An audio processing apparatus for processing a frame of an encoded audio bitstream, the audio processing apparatus comprising:
 an input buffer for storing at least a portion of the frame; and   an audio decoder for decoding the frame, wherein the frame includes:
 a synchronization information segment including a synchronization word; 
 a bitstream information segment following the synchronization information segment, the bitstream information segment including a dialog normalization value, a flag indicating whether additional bit stream information is present in the frame, and a parameter indicating a length of the additional bit stream information if the flag indicates that the additional bit stream information is present; 
 up to six blocks of audio data following the bitstream information section, each of the up to six blocks of audio data optionally including a skip field; 
 an auxiliary data field following the up to six blocks of audio data; 
 an error correction word following the auxiliary data field; and 
 a metadata container located in a reserved data space of the frame selected from the group consisting the skip field, the additional bitstream information, the auxiliary data field, or a combination thereof, 
   wherein the metadata container includes:
 a header identifying a start of the metadata container, the header including a syncword followed by a length field specifying a length of the metadata container; 
 a format version field following the header, the format version field specifying a format version of the metadata container; and 
 a program loudness payload following the header and the format version field, wherein the program loudness payload includes a loudness regulation type field and the loudness regulation type field indicates a loudness regulation standard that was used to calculate the dialog normalization value.