After discussing with Wu Hengyuan, Wang Lili, and Kang Yaoxiang, Hu Yiting returned to his office, felt relaxed, and turned on the computer to leisurely check the progress of his work in the past two days.

This is an epoch-making innovative product "core" dirty, is another milestone in Chongguang's development of flash memory chip applications, compared to repeaters, this will be a more global product.

Despite its importance, Hu Yiting gave it a very simple name, CPHIFIJ1, which means Chongguang portable high-fidelity decoder chip No. 1.

As an MP3 audio file decoding chip, it is not too much to include the word HIFI in the name, after all, the MP3 format audio file is the MPEG1 format, that is, the audio part of the VCD format audio and video file.

The sampling frequency in MPEG1 format multimedia files can be 32kHz, 44.1kHz and 48kHz, and the sound quality of 44.1KHz is equivalent to the sampling frequency of ordinary CD, so compared with the combination of ordinary commercial tapes and cheap magnetic heads on the market, the sound quality of MP3 will be better than that of tape players, and closer to CD sound quality.

Of course, as a prerequisite for comparison, both need to be recorded from the same sound source, and if the MP3 is transcribed from a tape and is a second-hand sound source, it is a different matter.

Although MP3 format is a kind of lossy compression, it can be exchanged for a very high compression ratio at the cost of minimal sound distortion, because the human auditory system distinguishes sound energy according to frequency, and any sound with a small frequency will be covered by the higher volume sound in the critical frequency band due to the masking effect, MP3 does not quantify this coverage, so as to remove those sounds that cannot be detected by the human auditory system, so as to achieve the purpose of compression.

And according to the sampling frequency, the fidelity of MP3 files is also different, if you record with the sampling frequency of the standard CD format 44.1KHz, it is difficult for the average human ear to hear the difference between MP3 and CD sound source, of course, if you use 48KHz for recording, the sound quality and CD are even more difficult to distinguish. However, some of the best Golden Ears can still tell the difference between the two, but even these listeners admit that the differences are too subtle to affect the musical experience.

One of the key aspects that really affect the sound quality of MP3 is the sound source, whether the same song is taken from a tape, or from a CD, or from the original sound source file of hundreds of megabytes in the recording studio, the difference in sound quality will be more obvious here.

On the other hand, it is also related to the encoding rate, because the encoding method of MP3 is open, under 128Kbps and 380Kbps, the file size is very different, and many developers in the world also have their own unique algorithms, such as the algorithm of variable encoding rate, which can encode the complex part of a song with a high bitrate, and the simple part with a low bitrate, so as to achieve a higher balance of sound quality and file volume, so MP3 is still a very promising music format.

Hu Yiting was not a HIFI fan in his previous life, mainly because he couldn't afford to burn money, some people said that he played SLR for three generations, but it is also possible to play HIFI directly and go bankrupt, millions or even tens of millions of sets of high-fidelity audio, with a large area of professionally decorated music appreciation room, is not something that ordinary people can afford.

Although some HIFI fans often disdain MP3, Hu Yiting never discriminates against MP3, and the songs in his mobile phone are also in this format, like many HIFI fans, the portable music equipment he usually brings when he goes out is also MP3.

Because the listening environment of portable products is very complex, and the sound insulation effect of professional monitoring rooms is completely incomparable, you can't even tell the difference between MP3 and CD under the noise of the outside world, what else is there to pretend? What is really needed in life is to enjoy music anytime and anywhere, rather than nitpicking and forcing yourself out of mental illness.

On this chip, Hu Yiting chose Philips's chip solution, that is, the SAA7750 and SAA7751 generally used by those high-end MP3 players in later generations.

The reason is very simple, Philips SAA7750/7751 was born in 03 years, when it was just launched, it was proud of its excellent high performance, surpassing TELECHIPS before South Korea and SIGMATEL in the United States, becoming the best and most expensive product in the field of MP3 chips, and it was the most high-end MP3 decoding chip at that time.

Therefore, if Chongguang can come up with the product seven or eight years in advance, it will be a hit in the world for MP3, an unprecedented product, which can be said to have laid the foundation in terms of quality, and it will undoubtedly be a bombshell for the market, this starting point is very high, and if the opponent wants to imitate and enter the MP3 decoding chip industry, it will be difficult to surpass in the short term.

You know,At the beginning, the first to launch MP3 products was the South Korean company Saehan,The company separated from Samsung launched the world's first MP3 product MPman-F10 in 98,But because the signal-to-noise ratio is nominal 70db,You must know that this is a distortion critical point,The sound quality below 70db is basically terrible when you listen to it,So as a front-end output,This value is not enough,Later high-end MP3 is basically above eighty or ninety,Even higher than 100。

If the signal-to-noise ratio of the front-end output is too low, the sound quality will be unstable, which is like if you take a kettle and pour water into a cup, your hands are weak, the kettle is shaking, the water flow will tremble, the water flow will not be aligned with the mouth of the cup, and the water will spill out.

In addition, the sound quality of ordinary headphones was not good in those years, in order to reduce the cost of products, the quality of the original earphones of MPman-F10 was mediocre, and the signal-to-noise ratio was only 70db, which means that the back-end is also unstable.

It's broken, it's the equivalent of you holding the pot and shaking with your hand, and then the other hand holding the cup is shaking, hehe, you know how much water can be poured into it. Therefore, the unanimous opinion of the music evaluation community on this model is———— "The sound quality is a mess, and the tone is unknown!"

Hehe......

Therefore, Sehan's MPman-F10 is a great drag on the product in terms of sound quality, although it is an epoch-making innovation, but the response after being introduced to the market is extremely flat, and there is no praise, and there is no hot sales, only some fashionable electronic product lovers will buy it. But fortunately, Sehan applied for a product patent for the MP3 player, so each MP3 player in later generations had to pay an average of $1 patent fee to Sehan, and Sehan also made a lot of money because of his innovation.

But having said that, it is the advent of this product that has made electronic equipment manufacturers all over the world see the huge business opportunities, and then several major manufacturers in South Korea immediately began to develop MP3, as the world's leading country in the electronics industry, the United States Imperial Alliance Company at the end of 98 years in one fell swoop to come up with the Rio-PMP300 This powerful MP3 product, its gorgeous sound quality and its $170 price is as impressive.

Next, the MP3 market began to compete with a hundred flowers, and all the heroes came up with their own MP3 decoding chip design schemes, and various manufacturers bought various chips to produce hundreds of new products to the market.