TWI430644B - Audio data transmission method and audio processing system thereof - Google Patents

Description

Audio data transmission method and audio processing system thereof

The present invention relates to audio data transmission, and more particularly to a method and apparatus for encrypting audio data and transmitting the encrypted audio data through a high-fidelity audio link.

More and more consumers are moving their computers to the living room or living room to enjoy digital music or movies in their daily lives, from all corners of the home, through multi-channel audio systems or large-screen TVs. Such a move would mean that the user would connect a higher-order speaker to their computer, so if the computer's sound subsystem (whether integrated or external) could not reach the same level, it could affect the overall digital media playback quality. . In addition, many consumers are also beginning to demand the simultaneous playback of two streams of audio data on a computer, such as playing a symphony in a study room, as well as playing a movie in the living room. This expectation is a realm that previous sound solutions could not achieve. The High Definition Audio (HD Audio) developed by Intel is more advanced than the previous audio specifications and can support up to eight 192 kHz/32-bit audio channels. The traditional AC97 specification can only support up to 6 A 48kHz/20 bit channel. Therefore, by introducing new high-fidelity audio specifications, people will be able to satisfy higher-quality sound effects in the future.

However, whether using the currently used AC97 audio specifications or the newly developed high-fidelity audio specifications as described above, existing computer systems or audio systems are still capable of direct decoding such as PCM (pulse code modulation). The data format being played to store and transmit audio data. The storage and transmission of audio data in this way will cause the audio data to be stolen by unscrupulous users (also known as hackers) during storage or transmission. As a result, personal privacy and intellectual property rights will be protected. Unable to be comprehensive.

One of the objects of the present invention is to use an encryption technique to encrypt audio data in a computer system or an audio system during storage or transmission of audio data to ensure that even if the audio data is stolen by unscrupulous users, It has been encrypted and cannot be known about its actual content.

In accordance with an embodiment of the present invention, an audio processing system is disclosed. The audio processing system includes: a host system and an audio device. The host system is configured to receive an audio data, and encrypt the audio data according to an encryption standard and a format of the audio data to generate an encrypted audio material. The audio device is coupled to the host system through a connection specification for receiving the encrypted audio data generated by the host system through the connection specification, and decrypting the encrypted audio signal, wherein the audio device is decrypted. The length of a data of the encrypted audio material generated by the system depends on the format of the audio material.

According to an embodiment of the present invention, an audio data transmission method is further disclosed. The method for transmitting audio data includes: encrypting the audio data according to an encryption method and a format of an audio data; transmitting the encrypted audio data to an audio device through a connection specification; and utilizing the audio information The audio device performs a decryption process on the encrypted audio data, wherein a length of the data of the encrypted audio data depends on the format of the audio data.

Please refer to FIG. 1. FIG. 1 is a schematic diagram showing an encrypted audio data transmission apparatus 100 according to an embodiment of the present invention. In this embodiment, a common personal computer system (for example, a desktop computer or a notebook computer) is taken as an example, but those skilled in the art should understand that the technology described in the present invention. It is not limited to applications on personal computer systems, and any other audio system that has been compromised by unscrupulous users (e.g., because of the connection to a network system) is within the field to be protected by the technology of the present invention. In the first embodiment, the encrypted audio data transmission device 100 includes a host system 110. In this embodiment, the host system 110 is composed of a main computing mechanism of a personal computer, and generally includes a central processing unit in the hardware portion. A central processing unit (CPU) 112, coupled to the CPU 112, is responsible for communicating with a memory 116 and other components with faster access speeds, and is coupled to the north bridge chip 114, responsible for the host system. The south bridge wafer 118 communicated with other peripheral devices of 110, and other common components not shown in FIG. 1; and the software portion usually includes the upper application 122 and the lower driver ( Drivers 124, examples of common applications 122 are multimedia processing and playback programs, or other programs that process audio data, and driver 124 is used for communication between software and hardware. The host system 110 receives an audio data from an audio data source 130, encrypts the audio data by using an encryption function in the application 122, and transmits the encrypted audio data to an audio link through an audio link 150. The audio CODEC 140 is decrypted by the audio codec chip 140 for subsequent sound playback.

In this embodiment, the audio data source 140 is a DVD optical disc storage device, including a next-generation DVD specification such as an HD-DVD or a Blu-ray disc, in which a multimedia material containing image and sound information is stored. However, the present invention is not limited thereto, and any device or signal source storing or transmitting audio data belongs to the application of the audio data source 140. In order to cooperate with the implementation of the present invention, the audio codec chip 140 is provided with the ability to decrypt the encryption operation of the audio data by the host system 110, and the decryption function 142 can be implemented by hardware, software or both hardware and software. The way to achieve this is for those who are familiar with the technology to complete. As for the audio link 150 for connecting the host system 110 (in the present embodiment, the portion of the south bridge chip 118) and the audio codec chip 140, it is preferable to use a HDA link (HDA link) having a high transmission bandwidth. In conjunction with the transmission of the encrypted audio data, those skilled in the art should understand that the present invention is not limited thereto, and other conventional or innovative audio linking technologies can also be used.

In a first embodiment, host system 110 encrypts the music material using an encryption method. For example, the encryption method used may be Advanced Encryption Standard (AES). However, the advanced encryption standard is only an example for illustrating the present invention, and is not intended to limit the scope of the present invention. Other encryption methods may also be applied to the present invention for encryption. Please refer to the table shown in Figure 2. In the high-fidelity audio specification, it can sample at a sampling frequency of 44.1 kHz, 88.2 kHz, 176.4 kHz, 48 kHz, 96 kHz, or 192 kHz, and includes 2 channels, 4 channels, 6 channels, 8 channels or even more channels of audio data, wherein for each different configuration combination, the data can be transmitted via a frame having a corresponding data bit length. The encryption process in this embodiment encrypts the audio information having different sampling frequencies and different channel numbers into 768 according to the audio data format to be processed (for example, sampling frequency, number of bits, number of channels, etc.). Encrypted audio data of the bit. In other words, in this embodiment, regardless of the format of the audio material to be encrypted, the nominal data length is a fixed number of bits (ie, 768 bits). If the length of the data before the encryption of the audio data is less than the above-mentioned amount of positioning digits (768 bits) (ie, most cases), the encryption data is first padded with a garbage data. The frame is such that the length of the data reaches the rated data length, and then the audio data is converted into six 128-bit (768-bit total) encrypted data according to the encryption standard of AES128.

It should be noted that in the architecture of high-fidelity audio, the transmission frequency of the frame is 48KHz, so additional processing must be performed for the audio data with a sampling rate of 44.1 kHz. The processing method adopted in this embodiment is as described in Section 5.4 (pages 83-86) of the High Definition Audio Specification, Revision 1.0, April 15, 2004, Intel Corporation. That is, when transmitting the audio data with a sampling rate of 44.1 kHz, it will be "12-11-11-12-11-11-12-11-11-12-11-11-11- in every 160 frames. (Repeat) mode is inserted into the cadence to transmit, where "-" means no data is sent, that is, there are 147 frames in each of the 160 frames with audio data, and there are 13 frames. No audio information. Similarly, audio data with a sampling rate of 88.2 kHz and 176.4 kHz can be processed using the same principle. The above-mentioned processing of the audio data of the sampling rate of 44.1 kHz is easily performed by those who are familiar with the technology after understanding the disclosure contents of the specification, so the detailed operation mode will not be described here.

Please refer to Figure 3, which shows when the format of the audio data to be transmitted is 48kHz/2ch/24bits, that is, when the audio data has a sampling rate of 48kHz, 2 channels and each channel. The sub-sampling is a 24-bit data length, and the encrypted audio data transmission device 100 in FIG. 1 is a schematic diagram of stuffing and encrypting the audio data. Since the rated data length is 768 bits, the audio data will only use the data length of 48 bits (24 bits × 2 channels × 1), so the remaining 720 bits will be filled with garbage data to make The length of the data reaches the rated data length (ie 768 bits), and then the above 768-bit data is encrypted to generate six 128-bit encrypted data, which are stored in a memory device for subsequent The audio codec chip 140 is transmitted through the HDA link 150. Similarly, in Figures 4, 5, and 6, the encrypted audio in Figure 1 is displayed when the format of the audio data to be transmitted is 48 kHz/8ch/24bits, 192kHz/2ch/24bits, 192kHz/8ch/24bits, respectively. The data transmission device 100 performs a method of stuffing and encrypting the audio data.

For the first embodiment described above, the nominal data length is a fixed number of bits (that is, 768 bits) regardless of the format of the audio material to be encrypted. Therefore, no matter how many bytes of audio data before encryption, the junk data padding is used to ensure that the length of the data processed by the next encryption program (such as AES128) is equal to a nominal data length, which is 768 bits. Thus, each AES128 encryption program can obtain six 128-bit encrypted data. However, the encrypted data having 768 bits will occupy a large amount of bandwidth in the audio link 150 between the host system 110 and the audio codec chip 140 and force the system to add redundant codecs. In order to improve the use efficiency of the bandwidth and reduce the number of codecs of the system, the present invention further provides a second embodiment, which selects a nominal data length from a plurality of candidate data lengths according to the format of the audio data. The audio data is encrypted, wherein the format of the audio data includes at least one of a sampling frequency, a number of bits, and a number of channels. A detailed description of this second embodiment is added.

Figure 7 is a table showing the length of a plurality of candidate data corresponding to the AES128 encryption specification, which includes 128 bits (1 × 128 bits), 256 bits (2 × 128 bits), and 384 bits (3 × 128 bits), 512 bits (4 x 128 bits), 640 bits (5 x 128 bits), 728 bits (6 x 128 bits). In this second embodiment, the encryption program selects a candidate data length that is not less than and closest to the number of bits of the audio data from the candidate data length, and encrypts the audio data according to the selected candidate data length. Therefore, the encryption program encrypts the audio data having different sampling frequencies and different channel numbers according to the format of the audio data by using different bit numbers (128, 256, 384, 512, 640, 728). Similarly, if the length of the data before encryption is less than the length of the selected candidate data (ie, most cases), the data will be padded with a junk data to make the data length. The selected rated candidate data length is reached. For those skilled in the art, it should be easy to understand how the stuffing of junk data works after reading the above paragraphs, so the details will not be repeated here. Then, the audio data together with the padding data is converted into a plurality of 128-bit encrypted data according to the AES128 encryption standard. Specifically, the AES128 encryption standard is generated when the selected candidate data length is 128 bits. A 128-bit encrypted data will generate two 128-bit encrypted data when the selected candidate data length is 256 bits. When the selected rated candidate data length is 384 bits, three pens will be generated. The encrypted data of the bit will generate four 128-bit encrypted data when the selected rated candidate data length is 512 bits, and five 128-bits will be generated when the selected rated candidate data length is 640 bits. The encrypted data and the selected nominal candidate data length of 768 bits will generate six 128-bit encrypted data.

Please refer to Figure 8. Figure 8 shows when the format of the audio data to be transmitted is 48kHz/2ch/24bits, that is, when the audio data has a sampling rate of 48kHz, 2 channels and each channel. The sub-sampling is a 24-bit data length, and the encrypted audio data transmission device 100 in FIG. 1 is a schematic diagram of filling and encrypting the audio data according to the second embodiment. Since the number of bits of the audio data is 48 (24 bits x 2 channels x 1), the length of the selected candidate data is 128 bits in accordance with an implementation aspect of the number of bits closest to the audio data. Since the selected candidate data length is 128 bits, the audio data will only use the data length of 48 bits, so the remaining 80 bits will be filled with the garbage data to make the data length reach the rated data length ( That is, 128 bits), and then encrypt the 128-bit data to generate a 128-bit encrypted data, and store it in a memory device for later transmission to the audio codec through the HDA link 150. Wafer 140. Similarly, in Figures 9, 10, and 11, the encrypted audio in Figure 1 is displayed when the format of the audio data to be transmitted is 48 kHz/8ch/24bits, 192kHz/2ch/24bits, 192kHz/8ch/24bits, respectively. The data transmission device 100 performs a method of stuffing and encrypting the audio data according to the second embodiment.

In summary, in this second embodiment, the nominal data length is a variable data length, which is not always equal to 768 bits, but depends on the format of the audio material, or can be set by the user. Therefore, the junk data stuffed into the audio data is elastically adjustable, mainly depending on the length of the candidate data selected. Compared with the first embodiment described above, the second embodiment can more effectively reduce the stuffed junk data, thereby reducing the burden on the decoding process of the audio codec chip 140 and improving the bandwidth usage efficiency of the HDA link. In order to improve the overall data throughput, the overall system power consumption can also be greatly reduced. In addition, the efficiency of the direct memory access (DMA) buffer of the host system 110 can be greatly improved. In addition, since the rated data length is not a fixed value, the encryption effect and security of the transmitted audio data are further improved. Moreover, since the audio data format is not fixed, it is not necessary to insert additional beats for the original signals of the sampling rates of 44.1 kHz, 88.2 kHz, and 176.4 kHz during the transmission process, so that the host system 110 and the audio codec chip 140 can be lightened. The load, in this way, can further reduce the overall power consumption.

The detailed operation mode of the above-mentioned AES encryption standard used in the encryption of the present invention is that the person familiar with the AES encryption technology can easily implement the disclosure of the present invention, and thus will not be described herein. Those skilled in the art of cryptography should also understand that the encrypted audio data transmission device 100 of the present invention and the encryption method used therein are not limited to use the AES encryption standard, and any other information security for storing and transmitting audio data. The purpose of the encryption method can be applied to the present invention. Moreover, although the present invention is not limited to the use of HDA links, a large amount of non-audio data (such as the junk material used for padding) is introduced to enhance encryption when audio data is encrypted by AES128 or other encryption standards. Security, so the link used to transmit data is naturally HDA links with high transmission bandwidth or other serial links. Moreover, the audio data received by the host system 110 from the audio data source 130 may have other standardized or proprietary encryption specifications, and the software component of the host system 110 at this time. (ie, application 122 and driver 124) as long as it has an encryption specification for decrypting the encryption specification belonging to the audio data source, and then designing the decrypted audio data for storage and/or transmission according to the present invention (eg, AES128) Encryption still does not hinder the implementation of the present invention.

In summary, the present invention utilizes software for encryption to protect audio data to avoid being stolen by unscrupulous users during storage and/or transmission, and as a sound effect device for processing and playing sound, such as an audio codec chip. After receiving the encrypted audio data, the 140 can use the decryption technology to restore the original audio data, thereby achieving the protection effect.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

100. . . Encrypted audio data transmission device

110. . . Host system

112. . . Central processing unit

114. . . North Bridge Chip

116. . . Memory

118. . . South Bridge Chip

122. . . application

124. . . Driver

140. . . Audio decoding chip

142. . . Decryption function

FIG. 1 is a schematic diagram of an encrypted audio data transmission apparatus according to an embodiment of the present invention.

Figure 2 is a schematic diagram of the music material under the high-fidelity sound architecture.

FIG. 3 is a schematic diagram of the encrypted audio data transmission apparatus in FIG. 1 for filling and encrypting the junk data to be transmitted with the format of 48 kHz/2ch/24 bits according to the first embodiment.

FIG. 4 is a schematic diagram of the encrypted audio data transmission apparatus in FIG. 1 for filling and encrypting the garbage data to be transmitted with the format of 48 kHz/8ch/24 bits according to the first embodiment.

FIG. 5 is a schematic diagram of the encrypted audio data transmission apparatus in FIG. 1 for filling and encrypting the junk data to be transmitted with the format of 192 kHz/2ch/24 bits according to the first embodiment.

FIG. 6 is a schematic diagram of the encrypted audio data transmission device in FIG. 1 for filling and encrypting the junk data to be transmitted with the format of 192 kHz/8 ch/24 bits according to the first embodiment.

Figure 7 is a schematic diagram of a table containing a plurality of candidate data lengths.

FIG. 8 is a schematic diagram of the encrypted audio data transmission apparatus in FIG. 1 for filling and encrypting the garbage data to be transmitted with the format of 48 kHz/2ch/24 bits according to the second embodiment.

FIG. 9 is a schematic diagram of the encrypted audio data transmission device in FIG. 1 for filling and encrypting the junk data to be transmitted with the format of 48 kHz/8 ch/24 bits in accordance with the second embodiment.

FIG. 10 is a schematic diagram of the encrypted audio data transmission apparatus in FIG. 1 for filling and encrypting the junk data to be transmitted with the format of 192 kHz/2ch/24 bits according to the second embodiment.

FIG. 11 is a schematic diagram of the encrypted audio data transmission apparatus in FIG. 1 for filling and encrypting the garbage data to be transmitted with the format of 192 kHz/8ch/24 bits according to the second embodiment.

100. . . Encrypted audio data transmission device

110. . . Host system

112. . . Central processing unit

114. . . North Bridge Chip

116. . . Memory

118. . . South Bridge Chip

122. . . application

124. . . Driver

140. . . Audio decoding chip

142. . . Decryption function

150. . . Audio link

Claims (10)

An audio processing system includes: a host system for receiving an audio data, encrypting the audio data with a format of the audio data according to an encryption method to generate an encrypted audio material; and an audio device, The interface is coupled to the host system for receiving the encrypted audio data through the interface, and decrypting the encrypted audio data; wherein the encrypted audio data generated by the host system is The length of the data depends on the format of the audio material. The audio processing system of claim 1, wherein the format of the audio data comprises at least one of a sampling frequency, a number of bits, and a number of channels. The audio processing system of claim 1, wherein the host system selects a data length from the plurality of candidate data lengths according to the format of the audio data, and according to the encryption method and the length of the selected data. The audio data is encrypted. The audio processing system of claim 3, wherein the length of the data selected by the host system is the length of the data of the candidate data that is closest to the audio data. The audio processing system of claim 4, wherein the host system further comprises an application for performing the encryption process. An audio data transmission method includes: encrypting an audio data according to an encryption method and a format of an audio data to generate an encrypted audio data; and transmitting the encrypted audio data according to a link specification to And a sound effect device; and the decrypted audio data is decrypted by the sound effect device; wherein the data length of the encrypted audio data is a variable data length. The method of transmitting audio data according to claim 6, wherein the length of the data of the encrypted audio data depends on the format of the audio data. The audio data transmission method of claim 7, wherein the format of the audio data comprises at least one of a sampling frequency, a number of bits, and a number of channels. The method for transmitting audio data according to claim 7, wherein the step of performing the encryption processing on the audio data comprises: selecting a data length from a plurality of candidate data lengths according to the format of the audio data; The encryption method encrypts the audio data with the length of the selected data. The method of transmitting audio data according to claim 6, wherein the length of the encrypted audio data depends on a user setting.