Hardware
MP3, the original aristocratic product, has now been accepted by the public. However, the prices of MP3s on the market are confusing. They are also 128M MP3s. Why do some cost thousands of yuan while others only cost 300 yuan? What's the reason for the huge price difference? The following will reveal the mystery for you from the aspect of MP3 decoding chip.
Before introducing the decoding chip, let’s first understand the working principle of MP3: First, take out the MP3 song file from the storage medium (flash media, hard disk media, optical disc media) and read the signal on the memory → Go to the decoding chip to decode the signal → convert the decoded digital signal into an analog signal through a digital-to-analog converter → then amplify the converted analog audio → low-pass filter it to the headphone output port, and the output is what we hear Music too.
The decoding chip, as its name suggests, is to decode the MP3 files on the storage device. It determines the final sound quality performance to a large extent. MP3 is a lossy compression format. If the MP3 player has an excellent decoding chip, it can better restore the quality of the audio signal and make up for the loss of the audio signal to a large extent. On the contrary, low-end decoding chips will cause further loss of MP3 encoded information. The most common chips in MP3 players currently on the market are: Sigmatel, Actions, Sunplus (Lingyang), MosArt (Huasi), Atmel, Telechip, PHILIPS, etc., and the following are: Philips' SAA7750/SAA7751/PNX0101ET, Sigmatel STMP3410/3420/1342, TCC730/TCC731 of telechips, and SPCA514A/SPCA751A of Sunplus, these are the mainstream models.
Edit this paragraph Micro hard drive system
PP5020
Representative products: iPod Mini, iPod Photo, iRiver H10
Main functions: < /p>
Ability to copy, view, compile and modify images without a PC;
Supports the PictBridge standard and can print directly on HP and Canon printers without a PC;
Supports On-the-Go, directly transmits images from the digital camera to the player, supports high-speed USB 2.0 transmission protocol;
Can connect to a TV and play images from the player (JPG, GIF and TIFF) and video (MPEG);
You can listen to music directly from mainstream online music services such as Musicmatch, Napster, Real Audio, etc., and listen to audio e-books (audiobooks) on Audible.com.
Automatically connect to the Internet, identify music tags and generate playlists through the online Gracenote music service;
Record captions for images collected in the player, and can be added simultaneously from background music in the same player.
Recommended headphones: Koss KSC35, PX100, ATH-CM3, ATH-EQ33, Goethe sr60, Motorola SCF5249
Representative products: iRiver H320, COWON M5, MPIO HD200
SCF5249 is a single-chip product that integrates DSP audio decoding and microcontroller system management functions. Therefore, it is more efficient than other non-single-chip products in terms of system development cost and overall power consumption performance. market competitiveness.
The battery life of this SCF5249 is 40 hours, far exceeding the current industry standard of 30 hours. It also supports a variety of different decoding and file formats, including CD-ROM, flash memory card, microcomputer, etc. Hard drives, etc.; and in this way, the portable audio device using this product can not only be used as a personal portable audio device, but also can be used as a walkman, portable MP3 and CD -ROM platform.
SCF5249 also supports various music formats including MP3, WMA, AAC, etc., to simultaneously meet consumers’ different music needs. Considering the scalability of different music formats in the future, through this The adoption of single-chip products can be further expanded through upgrades.
SCF5249 is based on Motorola's 32-bit CordFire core, which enables it to have simultaneous audio decoding and file management functions and support a variety of decoding and file formats of different specifications. It is also equipped with an integrated The SDRAM controller can simultaneously support DRAM and quickly access data content in external memory. This single-chip product can also support flash memory devices such as MMC and CF.
Recommended headphones: B&O A8, ATH-CM5 (can surpass the general quality Discman)
Texas Instruments: TMS320DA2XX
Representative product: Creative Zen Micro< /p>
I don’t need to say more about the power of this chip. If you have Money, choose it.
Recommended headphones: Sony 838 or above or ATH-CM or above
Edit this paragraph Flash memory system
Sigmatel 3410/3420
Representative products: Samsung 55H, MSC ha 128, JNC SSF800
If we want to talk about the current market share of MP3 chips, then the Sigmatel family in the United States definitely deserves its reputation, but for the quality of Sigmatel chips , but it is always in the eye of the beholder and wisdom in the wise. Generally speaking, the sound quality of MP3 MP3 using Sigmatel decoder chip will be quite satisfactory. The sound is brighter, the mid-range performance is average, the bass volume is insufficient, and the treble is stiff. Its music performance is inferior to Philips and Telechips chips.
The sound quality of this chip is average, and it is mostly used in mid- to low-end products. The solution using the SigmaTel 3410 chip is now very mature, but if more designs are not added to the peripheral circuits, the sound quality will be average. This is why although there are many products using this chip, the sound quality performance is quite different.
Sigmatel 3420 is more like an upgraded version of Sigmatel 3410. Compared with STMP3410, which does not support MP3 hardware encoding and has a slower processing speed, Sigmatel 3420 adds support for USB2.0 on the basis of Sigmatel 3410. It has corrected the problem of Sigmatel 3410 being incompatible with USB2.0 on some motherboards, and added MP3 hardware encoding function. The sound quality is also improved compared to Sigmatel 3410.
It is recommended to use headphones: the original ones are sufficient. Using high-end headphones will cause a waste of resources...
Sigmatel 35XX
Compared with Sigmatel 3410, Sigmatel 3510 not only supports USB2.0, but also improves comprehensive energy management, supports battery charging function detection, and enhances digital/analog conversion It can be said that the Sigmatel family of chips has taken a big step in the development of the Sigmatel 3520.
Sigmatel 3520 has improved the shortcomings of the previous Sigmatel 3410/1342's mediocre midrange performance and stiff treble. The sound quality is clear, and the signal-to-noise ratio is said to reach 95dB; it also adds support for MP3 hardware encoding, FM radio and USB2.0 Support for other functions; Sigmatel 3520 has also improved its processing speed compared to the previous generation, reaching 75MHz (34xx series is 65MHz). Nowadays, MP3 players at various price points in the market have the shadow of Sigmatel 3520 chip, which also illustrates the great progress made by Sigmatel 3520 chip.
Sigmatel 3502, it is said that this chip aims at the high-end market and has greatly improved the design of the chip and peripheral circuits. It is known as the third generation decoding chip and increases the main frequency rate of the DSP digital signal processor. To 75MHz, the signal-to-noise ratio is as high as 95db, the output power reaches 11mW, and the total harmonic distortion rate is less than 0.05%.
The difference between Sigmatel 34XX and Sigmatel 35XX series is mainly due to improvements in the following two aspects: USB1.1 upgraded to USB2.0; battery life increased, such as the innovative TX-FM, which uses 1 cell 7 The battery can play continuously for 15 hours.
Recommended headphones: Innovation HQ-65, PHILIPS HE261, Sony E828LP
PHILIPS SAA775X/PNX0101ET/PNX0102
Representative products: WeWa King of Voice, Chao Huamaoyin Series
If we must choose the best MP3 decoding chip currently on the market, then it is undoubtedly the Philips chip. The Philips family of decoding chips has always been known in the industry for its "full functionality, good sound quality, and high price."
Philips SAA775x chip is one of the decoding chips with the most complete functions (supporting CD direct recording) and the best effect among MP3 player decoding chipsets currently on the market. The sound quality of this decoder chip is as follows: the bass is deeper, the midrange is excellent, and the treble is average in comparison.
Because SAA775x contains DSP (Digital Signal Processing, digital signal processing) and 32-bit ARM RISC processor, it can use a single ultra-highly integrated chip to perform audio decoding and speech encoding. And can add SDMI (Secure Digital Music Initiative, secure digital music) protection.
Among them, SAA7750 contains DSP and 32-bit ARM RISC processor, with a signal-to-noise ratio of 90dB. The chip is compatible with multi-stage and multi-level EQ intelligent sound effects, supports saving voice records in ADPCM format, synchronously displaying song titles and song information, and Line-in direct recording. In addition, it also supports USB 1.1/2.0 standards and supports multiple music formats. decoding. The SAA7751 only has a DSP core and flash memory, does not include an audio multimedia decoder, and can only be used in its own upgradeable MP3 CD player. The SAA7752 is a price-focused solution that only contains a DPS chip and uses external memory to store data, mainly for CD players. As for the SAA7753, it also only has a DSP chip, and the change is even more thorough. It simply uses embedded memory instead of flash memory, corresponding to a low-priced CD playback system, as an additional MP3 function.
The embedded processor used by Philips SAA775x has advanced energy management functions. It can control the processor running speed according to the workload needs to extend the battery life, similar to that commonly used in high-end PDAs and Energy-saving technology for laptops. Therefore, when the SAA775x chip plays 128Kbps MP3 at normal volume, the power supply time of a single AA battery can be up to 24 hours. Of course, this is the theoretical working time of the chip. For MP3 players, due to the constraints of the production process, the specific working time is another matter.
The PNX010x series of decoding chips is also a large series, including PNX0101, PNX0102 and PNX0105. Among them, PNX0102 and PNX0102 are specially developed for flash MP3 players, while PNX0105 is a product for hard disk multimedia players.
PNX0101 has embedded 4Mbit programmable FLASH and only supports USB1.1. Currently, all USB2.0 interfaces equipped with MP3 players using the PNX0101 chip are implemented by adding an additional USB2.0 control chip. (Note: Use with Molex to support USB2.0, SD/MMC expansion, etc.) PNX0102 has an embedded 8Mbit programmable FLASH and provides support for USB2.0 itself.
PNX0105 also supports USB2.0, and also supports interfaces such as GDMA and IDE (ATA/ATAPI/PC Card), but it does not have built-in programmable FLASH.
Recommended headphones: Sennheiser MX500 or above, Sony E888, Etymotic ER6
Telchips TCC73X/TCC72X
Only appeared on the market last year The Korean Telechips decoding chip on the market has received unanimous praise since its launch and has grown rapidly with the strong support of many Korean manufacturers. In terms of functions, performance, and sound quality, Telechips TCC730/731 is indeed better than chips such as Sigmatel's STMP3410, with sufficient bass, balanced performance in each frequency band, and a wider sound field; but compared with Philips SAA7750/7751 There is still a certain gap. In addition, Telechips TCC730 is a little cheaper than SAA7750, but it requires an external ROM and has more peripheral components. Therefore, it is rare for MP3 products using this chip to be compact.
The industry generally believes that the performance of Telechips chips in all aspects is between the Sigmatel STMP3410 and SAA7750/7751 series. Based on the sound quality of MP3 using this chip, if equipped with more high-end headphones, there will be a certain improvement. This type of machine is usually equipped with Sennheiser MX300 (or OEM Sennheiser) headphones as standard. These headphones are the most popular headphones in Sennheiser's popular MX series, so it is recommended for those who have higher requirements for sound quality. Friends can try Sennheiser MX500, or the more upscale KOSS SP/KOSS PP, Sennheiser PX100/PX200. Because MP3s using this chip have certain potential in terms of sound quality, and not all MP3s have improved sound quality after replacing high-end headphones, as all dealers tell you. In fact, some MP3s have limitations in their own chips, designs, and production processes. This leaves no room for excavation of sound quality.
Recommended headphones: Sony Q55SL, Sony E888
Edit this paragraph to domestically produced MP3 chips
Rockchip products>> Digital audio and video processing chips
Rockchip digital audio and video processing chip RK26XX series chip is a digital audio and video processing chip that supports MPEG-4 video decoding and playback function. It is made with 0.18 micron process and can be used in portable MP3 players with MP4 playback function. product. The RK26XX series of chips adopts a highly integrated digital-analog hybrid design, integrating 32bit DSP Core, 16bit ADC, and 18bit DAC. This chip is a cost-effective portable digital audio and video player and digital foreign language learning machine developed by customers that supports MPEG-4 playback. and an ideal solution for other portable multimedia products. RK26XX can decode and play MPEG-4 format video files at lower frequency and power consumption, with clear and smooth picture quality. At the same time, RK26XX integrates a large number of I/O control interfaces to provide maximum application flexibility. The low power consumption performance of RK26XX can extend the battery life of portable players. Its integrated smart lithium battery charger supports voltage control (AVC), which saves system power consumption compared with similar products. The integrated power management unit includes a high-efficiency on-chip DC-DC converter and supports multiple battery configurations such as 1×AA, 1×AAA, and Li-ion batteries. In addition, AVC enables the chip to operate at a higher peak CPU operating frequency than traditional voltage control systems, resulting in a maximum operating speed of 100 MIPS. RK26XX supports digital rights management technology based on Microsoft's DRM 10. At the same time, Rockchip's software development tools have also integrated other advanced functions specifically for RK26XX to help speed up customers' Design in. RK26XX has the function of supporting multi-tasking, which can realize the product function of listening to music while reading e-books and listening to music while playing games.
The RK26XX chip integrates USB 2.0 High Speed/Full Speed ??PHY for faster transmission speed; it also integrates a controller that supports TFT/CSTN/OLED color screens.
RK27XX uses a more advanced ARM+DSP dual-core architecture, which can simultaneously carry the operating system and low-power, high-speed digital signal processing algorithms, making it the most powerful MP3 solution currently. On the basis of retaining all the functions of the RK26XX series, the RK27XX has more comprehensive video compatibility, including AVI (XVID, DIVX), WMV, and RMVB. It can support smooth playback at up to D1 (720*480) resolution and can also support FLASH animation. ; Add support for RA and ACC audio formats, and introduce a new music media library function to facilitate users to manage a large number of music files; support DC/DV, Bluetooth, and 16-bit game functions; embedded in the MiniOS operating system, can develop personalized UI ( Picture overlay, perspective, fade in and out, etc. effects). In addition, in response to the trend of portable multimedia technology developing towards 3C integration, RK27xx will have built-in HD Radio or DAB functions and will support GPS and mobile TV functions in the future.
Highlighted functions:
1. Video playback: Supports video playback in MPEG-4 format.
2. Music playback: supports MPEG1/2/2.5 Layer1/2/3 full code rate (8Kbps~384Kbps) audio playback; supports WMA audio playback, code rate 32Kbps-320Kbps.
3. Picture browsing: Supports JPEG format picture browsing.
4. Text reading: supports TXT text reading.
5. Live recording: Supports live recording with built-in microphone, noise reduction processing, long-term recording and high-quality recording are available.
6. Line recording: Supports LINE IN line direct MP3 recording function (supports multiple bit rates).
7. Lyrics display: song title, singer and LRC lyrics are displayed simultaneously.
8. Various sound effects: supports 3D surround sound effects, supports rock, pop, classical, jazz, bass and other sound effects, and provides users with DIY sound effect functions.
9. USB function: compatible with USB 2.0 High Speed/Full Speed.
10. Radio function: Provides FM radio function (75MHz~108MHz) to support campus radio and supports radio recording function.
11. Display interface: supports STN/CSTN/TFT/OLED, PWM control backlight brightness.
12. Spectrum display: It has real spectrum display function.
13. Game functions: Currently built-in games such as Tetris and Sokoban.
14. Multi-tasking function: You can listen to music while reading e-books or listening to music while playing games.
15. Firmware upgrade: Support firmware upgrade to expand the function of this machine.
16. System language: Supports Simplified Chinese, Traditional Chinese, English, Korean, Japanese, French and German.
17. Multi-storage compatibility: supports multiple brands of flash memory (Nand Flash Memory) and flash memory cards (SD card, Mini SD card and MMC card) of various capacities.