Patent Description:
The present disclosure relates to providing an apparatus, system and method for packetized media processing.

Document "<NPL> generally describes amendments relating to audio metadata enhancements of high efficiency coding and media delivery in heterogeneous enbironments.

For home Consumer Electronics (CE) installations, functionality can be spread over several devices (e.g., set-top boxes, TV-sets, AVR-receivers), where such devices are connected via standardized interfaces (e.g. HDMI).

A first device can receive media streams from broadcast and/or broadband connections. That first device can additionally have sophisticated intelligence (e.g. "smart speaker" functionality). A second device can be dedicated to media decoding, rendering and presentation to users.

Typically, a media program is received by device #<NUM> and sent to device #<NUM> for reproduction. This media program may be known as the "Main program". From time to time or in addition, a different media program (like an advertisement) received from a different transmission channel or media generated by the "Smart device" capability in device #<NUM>, both generally represented in a different media format, shall be inserted or overlaid into the main media program.

This can be accomplished by decoding both the main and the auxiliary program into a generalized, typically uncompressed representation, switching the streams or mixing/rendering both into a combined representation and re-encoding the generated media stream into an encoded transmission format. This method can be performed in any device, such as all performed in device #<NUM>. However, high computational power may be required while the rendering stages and the intermediate representation may not provide optimal matching of the actual reproduction system in device #<NUM>.

<FIG> illustrates an exemplary device #<NUM> and an exemplary device #<NUM>. Device #<NUM> may include a primary receiver <NUM>, a secondary receiver/local engine <NUM> and a packetized stream merger <NUM>. The packetized stream merger <NUM> may merge data streams received from the primary receiver <NUM> (e.g., the main stream) and from the secondary receiver/local engine <NUM> (e.g., the auxiliary data stream). The device #<NUM> may include a stream splitter <NUM>, a primary decoder/renderer <NUM> and a secondary decoder/renderer <NUM>. The stream splitter <NUM> may split streams such as a main stream (that may be provided then to a primary decoder/renderer <NUM>) and an auxiliary stream (that may then be provided to the secondary decoder/renderer <NUM>). Both decoder output signals may be presented to the listener simultaneously.

To overcome the limitation described above, device #<NUM> can directly send the incoming main media stream to device #<NUM>. This mode of device #<NUM> can be called "pass-through" mode. However, the downside of this approach is that standardized interfaces are only specified to convey one single data stream for video and audio, and therefore the second media stream can't be sent natively over the interface to device #<NUM> for reproduction.

The present invention may provide for methods and apparatus for a first receiver for receiving packetized media data, a secondary receiver for receiving an additional media stream and a transmitter interface for sending packetized media data.

This invention proposes to merge the second auxiliary media stream into the packetized main media stream by the following means.

Media streams represented as packetized streams typically use packet type identifiers to differentiate multiple sub-streams with the overall media stream. To convey additional (media) data not related to the main media stream, the first device #<NUM> can encapsulate the additional data in packets formatted according to the main media stream but labeled by a dedicated tag in the packet header. This dedicated tag will trigger the receiving device #<NUM> to strip out the packets carrying the additional media stream. Optionally, device #<NUM> may then provide the additional media stream to a secondary decoder/renderer <NUM> instance while the main stream simultaneously being received by the primary decoder/renderer <NUM>.

In one example, legacy receiving devices that do not recognize this new tag in the packet header for additional encapsulated media streams are already expected to disregard those packets.

The tag may be provided in any encoded audio data stream environment, such as MPEG-H, AC-<NUM>, Dolby Digital+, etc..

If additional inserted data streams exceed a substantial data rate compared to the original media stream, a receiver device should filter the incoming packetized stream and optionally strip out the additional data packets to maintain the receiver buffer model of the downstream connected (legacy) media decoder.

Further, <FIG> illustrates an exemplary device #<NUM> and an exemplary device #<NUM>. Device #<NUM> may include a primary receiver <NUM>, a secondary receiver/local engine <NUM> and a packetized stream merger <NUM>. The packetized stream merger <NUM> may merge data streams received from the primary receiver <NUM> (e.g., the main stream) and from the secondary receiver/local engine <NUM> (e.g., the auxiliary data stream). The device #<NUM> may only include a primary decoder/renderer <NUM>, but not a stream splitter. In one example, it might not be possible to provide an auxiliary stream to a secondary decoder/renderer. In this example, a modified primary decoder might decode/convert/mix an auxiliary stream with the main stream internally.

MPEG-H 3d Audio according to ISO/IEC <NUM>-<NUM> is encapsulated in a MHAS format. This format utilized a packetized format where each packet consists of a packet header and a packet payload. While the payload can be any binary data, the header specifies the type and the length of the payload. (The additionally available label can be used differentiate multiple instances, but is not utilized here.

By assigning a new MHAS packet type for the secondary media stream (exemplatorily named PACTYP_MEDIA), additional audio data represented either as uncompressed PCM data, optionally further specified using the RIFF/WAV format, or compressed audio data such as MPEG-<NUM> audio according to ISO/IEC <NUM>-<NUM> or any other encoded representation (e.g. according to ATSC A/<NUM> or ETSI TS <NUM><NUM>) can be encapsulated into MHAS packets and thus can be merged into the main MPEG-H 3d Audio stream. The different formats to be encapsulated can be differentiated by either different packet types (e.g. PACTYP_PCM, PACTYP_MPEG4AUDIO,. ) or, as show in the example below, by an additional specifier forming a sub-header of the MHAS packet.

Since (media) data may require configuration data but may not be represented as self-contained streams, this data may be encapsulated in the header of the container MHAS packet, or an additional MHAS packet (e.g. PACTYP_MEDIA_CONFIG or another type of MHAS packet name indicating configuration, such as PACTYP_PCMCONFIG) may be assigned, which, in addition, may also carry the information on the type of the additional data. The MHAS packet type may carry configuration information for PCM payload data for feeding the configuration information to the decoder. For example, if an MHAS packet type for configuration information (e.g., PACTYP_MEDIA_CONFIG or PACTYP_PCMCONFIG) is present in the bitstream (e.g., after PACTYP_MEDIA_CONFIG), PCT data confirguration information in the form of a data structure (e.g., pcmDataConfig()) may be fed to a decoder.

In general, an MHAS packet type (e.g., PACTYP_PCMDATA) may be used to embed PCM payload data corresponding to PCM signals defined in the configuration structure and to feed PCM data in the form of a PCM data payload structure to the decoder. If the MHAS packet type (e.g., PACTYP_PCMDATA) is present in the bitstream, the PCM data payload structure (e.g., pcmDataPayload()) may be used during decoding.

<FIG> illustrates an exemplary MPEG-H 3D audio packet stream in accordance with the present invention.

In one example, the present invention may be based on identifying information based on the following syntax amendments:.

<NUM>) Amend table <NUM> - Syntax of MHASPacketPayload() with:.

<NUM>) Assign an appropriate MHASPacketType for PACTYP_MEDIA in table <NUM>. Alternatively, the value of MHASPacketType may be vary or may depend on a preset value, e.g., a value that is published by a standards organization in the final standards document. <NUM>) The following media type should be specified using the mhasMediaDataType enumeration:.

<FIG> exemplarily shows a packetized main stream including exemplary packets according to MPEG-H 3D audio with 3D audio data (exemplarily including configuration data e.g. PACTYP_MPEGH3DACFG, as metadata, and coded audio data, e.g. PACTYP_MPEGH3DAFRAME).

Furthermore, <FIG> exemplarily shows a packetized secondary stream (auxiliary stream) including exemplary packets in accordance with the invention, as being indicated by header information referring to the above-described exemplary additional packet type PACTYP_MEDIA including additional audio data (auxiliary audio data/secondary audio data), exemplarily in compressed format, e.g. MPEG4Audio.

Alternatively or additionally, the additional audio data can be packeted into a packet having the header in accordance with the format of the packetized main stream, here exemplarily MPEG-H 3D audio, including a sub-header indicative of the different formats encapsulated as discussed above.

In accordance with exemplary aspects of the invention, the main stream and the auxiliary (secondary) stream can be merged by a stream merger, such as e.g. by a packetized stream merger <NUM>.

The outgoing stream (merged stream) includes packets relating to the encoded audio data of the main stream and packets relating to the audio data of the auxiliary stream within a single packetized bitstream of a same format (such as exemplarily MPEG-H 3D audio in <FIG>).

It may be noted that non-modified (legacy) MPEG-H 3D audio decoders may not understand the newly added packet type (e.g. PACTYP_MEDIA) and such non-modified (legacy) MPEG-H 3D audio decoders may ignore or dump packets having the newly added packet type (e.g. PACTYP_MEDIA) indicated in their header. Such non-modified (legacy) MPEG-H 3D audio decoders can still decode the audio data relating to the main stream but would not process the additional auxiliary/secondary audio data.

For decoding and processing the merged stream with main and auxiliary stream, decoder devices can be modified to include a modified decoder enabled to filter and decode/process the packets related to the auxiliary audio data.

Schematically illustrates another example of a primary decoder/renderer in accordance with the present invention.

<FIG> illustrates how this might be achieved in an MPEG-H 3D Audio decoder, where the media format is PCM data. Exemplarily, the primary decoder/renderer <NUM> is realized as including an MPEG-H 3D Audio Core Decoder M1 and related rendering units such as object renderer M2, e.g. such as defined according to MPEG-H 3D audio (ISO/IEC <NUM>-<NUM>) standard.

The modified decoder <NUM> might additionally filter and strip out the MHAS packets having a header indicating the new additional packet type (e.g. PACTYP_MEDIA), and input the packets having the auxiliary audio data to a format conversion unit 301c1 and then to a sample rate converter (such as exemplarily the sample rate converter M3 present in the decoder architecture downstream of the MPEG-H 3D Audio Core Decoder M1 as defined according to MPEG-H 3D audio (ISO/IEC <NUM>-<NUM>) standard).

Accordingly, the modified decoder <NUM> might perform sample rate conversion (e.g. by sample rate converter M3) and format conversion (e.g. by format conversion unit 301c1) on the input media data (MHASPacketType == PACTYP_MEDIA) in order to match the media sampling rate and channel layout to the output sampling rate and channel configuration of the decoder. Further, a modified decoder might mix input media data or the sampling-rate-converted input media data with the audio media data that have been created by the MPEG-H 3D Audio Core Decoder M1 in a mixer (such as exemplarily the mixer unit M4 present in the decoder architecture downstream of the MPEG-H 3D Audio Core Decoder M1 as defined according to MPEG-H 3D audio (ISO/IEC <NUM>-<NUM>) standard).

The above example of <FIG> exemplarily relates to auxiliary media data including uncompressed media data, such as PCM data or the like. It is to be noted that, if the uncompressed media data, such as PCM data or the like, further includes positional information or is related to corresponding positional metadata, e.g. for 3D audio appliances, the auxiliary data can be further processed by a positional data processing object renderer, such as the object renderer M2 present in the decoder architecture downstream of the MPEG-H 3D Audio Core Decoder M1 as defined according to MPEG-H 3D audio (ISO/IEC <NUM>-<NUM>) standard.

Schematically illustrates yet another example of a primary decoder/renderer in accordance with the present invention. Exemplarily, the primary decoder/renderer <NUM> is realized as including an MPEG-H 3D Audio Core Decoder M1 and related rendering units such as object renderer M2, e.g. such as defined according to MPEG-H 3D audio (ISO/IEC <NUM>-<NUM>) standard.

<FIG> exemplarily illustrates how the above might be achieved in an MPEG-H 3D Audio decoder, where the media format is encoded data (such as MPEG-<NUM> Audio). A modified decoder <NUM> might decode the input media data (MHASPacketType == PACTYP_ MEDIA) using an additional decoder 301c2 (converter and/or decoder configured to convert and/or decode the auxiliary media data), not necessarily specified within ISO/IEC <NUM>-<NUM>. Further, a modified decoder might mix those decoded media data with the audio media data that have been created by the MPEG-H 3D Audio Core Decoder M1 as defined according to MPEG-H 3D audio (ISO/IEC <NUM>-<NUM>) standard.

In exemplary aspects in accordance with the present invention, additional time-alignment units may be provided for time-alignment of the packets of the auxiliary stream, e.g. to provide time-alignment of multiple MHAS substreams originating from different sources.

Per section <NUM> of ISO/IEC <NUM>-<NUM>, MHAS "sub-streams are generated by the same encoder [and therefore] it is presumed that various incoming streams [. ] are completely aligned and have no phase offset". In this case, alignment of a frame may be accomplished using the MHASPacketLabel number. With the proposed method in this invention, the above constraint can no longer be taken for granted. With different frame durations for different codecs or sampling rates, the time offset of consecutive MHAS packets of the secondary stream that is merged with the MHAS main stream varies over time. In each particular time slot, the timing offset of the secondary stream to the main stream needs to be signaled. For example, in associated packets of the auxiliary stream indicating a packet type relating to metadata associated with media data contained in the payload of packets of the auxiliary stream as shown in <FIG>.

<FIG> illustrates exemplary packet types for achieving the means of this invention based on MHAS, for example where another MHAS packet type is defined to carry appropriate time offset signaling. To link this signaling to the corresponding stream, the time offset packet needs to have the same MHASPacketLabel number assigned as the MHASPacket of type PACTYP_MEDIA it refers to. From <FIG>, it is obvious that a direct one-to-one relation of stream data corresponding to one particular time slot of each stream is not guaranteed, but two or more time slots from one stream may correspond to one time slot from the other stream in a timely manner.

Another option for signaling time offset is to add this time offset to the MHAS packet of type PACTYP_MEDIA itself.

In view of the above, in some exemplary aspects in accordance with the present invention, the conversion and/or decoding unit of the modified primary decoder/renderer <NUM> of the examples of <FIG> and/or <NUM> may include a time-alignment unit for time-alignment of the auxiliary stream data with the main stream data, e.g. upstream of the mixer such as mixer unit M4 of the examples of <FIG> and <FIG>, or also upstream of the sampler (e.g. sample rate converter M3) of the examples of <FIG> and <FIG>, or also as a part of the secondary decoder/renderer <NUM> of the.

Additional data to control the mixing of the secondary (auxiliary) audio stream to the main audio streams may be required. Among other options, this data may include static gains or a dynamic gain sequences, examplatory formed as ISO/IEC <NUM>-<NUM> DynamicRangeControl data to process the main stream when the secondary audio stream is reproduced. Those data are typically generated by device #<NUM> and may be incorporated into the stream by either separate MHAS packets (e.g. with the identifier PACTYP_MPEGH_MEDIA_CFG), as further addition to the secondary stream header or by any other kind of stream encapsulation.

In view of the above, in some exemplary aspects in accordance with the present invention, the conversion and/or decoding unit of the modified decoder <NUM> of the examples of <FIG> and/or <NUM> may include a gain adjustment unit for applying static and/or dynamic gains (e.g. for loudness adjustment), e.g. upstream of the mixer such as mixer unit M4 of the examples of <FIG> and <FIG>, or also upstream of the sampler (e.g. sample rate converter M3) of the examples of <FIG> and <FIG>, or also as a part of the secondary decoder/renderer <NUM> of the example of <FIG>.

Further, Dolby AC-<NUM> (ETSI TS <NUM><NUM>) and Dolby Digital and Dolby Digital Plus (ETSI TS <NUM><NUM>) offer the possibility to carry any binary data in EMDF Payloads, which can be used to carry the same or similar data as defined in the above section (MPEG-H Ecosystem).

For such purposes, the syntax element emdf_info() as defined in ETSI TS <NUM><NUM> or the syntax element emdf_container() as defined in ETSI TS <NUM><NUM>, Annex H and their underlying elements may be used. In order to do this, one can simply define on or more emdf_payload_id definitions, which can be used in order to identify the binary data which has the same or similar format as described above under PACTYP_MEDIA and/or PACTYP_MPEGH_MEDIA_CFG.

System sound mixing for media streams containing uncompressed/uncoded data may be achieved similar in Dolby AC-<NUM> or Dolby Digital/Dolby Digital Plus as shown in <FIG> and <FIG>, with the difference that the distinction which signal path to use would not be taken based on the MHASPacketType, but on the emdf_payload_id-value.

Media streams addressed by this invention, both the main stream and the side-data streams may be of the following type:.

Claim 1:
An apparatus comprising:
a receiver configured to receive a merged packetized media bitstream which includes packets associated with a main stream and packets associated with an auxiliary stream, wherein the main stream comprises MPEG-H 3D audio data encapsulated as packets in an MHAS format according to ISO/IEC <NUM>-<NUM>, and wherein the auxiliary stream comprises additional audio data encapsulated as packets in the MHAS format, wherein a format of a packet payload of the packets associated with the auxiliary stream is different from the MPEG-H 3D audio format, and time offset packets in the MHAS format signaling an indication of a time offset of the auxiliary stream to the main stream and having a same packet label number assigned as the MHAS packets carrying the additional audio data said time offset packets refer to;
a splitter (<NUM>) configured to identify a packet type encapsulated in a header of the packets in the merged packetized media bitstream and configured to split, based on the identification of the packet type, the merged packetized media bitstream into the main stream and the auxiliary stream, wherein the packet types of the packets associated with the auxiliary stream are new MHAS packet types encapsulated in the packet header, wherein the new MHAS packet types are different from the packet type according to ISO/IEC <NUM>-<NUM>, and
a time-alignment unit for time-aligning the additional audio data with the main audio data based on the signaled time offset.