flac格式轉換mp3格式_MP3，FLAC和其他音頻格式之間有什么區別？

flac格式轉換mp3格式

Digital audio has been around a very long time so there’s bound to be a plethora of audio formats out there.? Here are some of the more common ones, what differentiates them, and what to use them for.

數字音頻已經存在了很長時間，因此必然會有大量的音頻格式。以下是一些較常見的功能，它們的區別以及用途。

Before we talk about everyday audio formats, it’s important you understand the basics, and that means understanding PCM.? After that, we’ll tackle compressed formats.

在討論日常音頻格式之前，了解基礎知識很重要，這意味著了解PCM。之后，我們將解決壓縮格式。

PCM音頻：從哪里開始 (PCM Audio: Where It All Starts)

Pulse-Code Modulation was created back in 1937 and is the closest approximation of analog audio.? That is, an analog waveform is approximated in regular intervals.? PCM is characterized by two properties: sample rate and bit depth.? Sample rate measures how often (in times per second) the amplitude of the waveform is taken, and the bit depth measures the possible digital values.? In terms of audio formats, this is pretty much the foundation.

脈沖編碼調制創建于1937年，是模擬音頻的最接近近似值。即，以規則的間隔近似模擬波形。 PCM具有兩個特性：采樣率和位深度。采樣率測量獲取波形幅度的頻率(以每秒為單位)，位深度測量可能的數字值。就音頻格式而言，這幾乎是基礎。

True sound, in the real world, is continuous.? In the digital world, it’s not.? Somehow this is more confusing with audio than with video, so let’s look at video as a point of comparison.? What we interpret to be “motion” or think of as “fluid” and constantly-moving is, in actuality, a series of still pictures.? In that same way, the amplitude of sound waves in a digital format isn’t “fluid” or constantly changing.? It’s changing based on certain criteria at pre-defined intervals.

真實世界中的真實聲音是連續的。在數字世界中，事實并非如此。不知何故，音頻比視頻更容易混淆，因此讓我們將視頻作為比較點。實際上，我們解釋為“運動”或認為是“流暢”且不斷運動的是一系列靜止圖像。以同樣的方式，數字格式的聲波幅度不會“波動”或不斷變化。它會根據某些標準以預定義的時間間隔進行更改。

Image from Wikipedia

圖片來自維基百科

I know there’s a lot here that may not be second-nature unless you’re an engineer, physicist, or an audiophile, so let’s pare it down further with an analogy.

我知道，除非您是工程師，物理學家或發燒友，否則很多東西可能都不是第二自然的，所以讓我們用一個類比將其進一步減少。

Let’s say that the water flowing from an open faucet is your “analog” audio source.? The temperature of the water we can compare to the amplitude of an audio wave; it’s a property that needs to be measured so you can enjoy it properly.? Sampling is the number of times per second you dip your finger into the flowing water.? The more often you dip your finger into it, the more “continuous” the temperature changes become.? If you stick your finger into the running water 44,100 times per second, it’s almost like keeping your finger under there the whole time, right?? That’s the basic idea behind sampling.

假設從開放式水龍頭流出的水是您的“模擬”音頻源。我們可以將水的溫度與聲波的振幅進行比較。這是一個需要測量的屬性，以便您可以正確使用它。采樣是每秒將手指浸入流水中的次數。您將手指浸入的次數越多，溫度變化就越“連續”。如果您將手指每秒浸入流水中44,100次，那幾乎就像是始終將手指一直壓在那兒，對嗎？這是采樣背后的基本思想。

Bit depth is a little trickier.? Instead of using your finger, let’s say you used a really crapper thermometer.? It basically said “Hot” for anything above room temperature and “Cold” for anything below.? Regardless of how many times you dipped it into the water, it wouldn’t really give you much useful information.? Now, if instead of just 2 options, let’s say the thermometer had 16 possible values which you could use to gauge the water temperature.? More useful, right?? Bit depth works the same way, in that higher values allow more dynamic changes in sound amplitude to be accurately portrayed.

位深度有些棘手。假設您沒有使用手指，而是使用了一個非常實用的溫度計。對于高于室溫的溫度，基本上說“熱”，低于室溫的溫度說“冷”。無論您將其浸入水中多少次，它都不會真正為您提供有用的信息。現在，如果不是只有2個選項，可以說溫度計有16個可能的值，可用于測量水溫。更有用吧？位深度以相同的方式工作，因為更高的值可以準確描繪聲音幅度的更多動態變化。

As previously mentioned, PCM is the foundation for digital audio, along with its variants.? PCM attempts to model a waveform, in as much of its uncompressed glory as possible.? It’s special, it’s ready to be stuck in a digital signal processor, and it’s more or less universally playable.? Most other formats manipulate audio via algorithms, so they need to be decoded while playing.? PCM audio is considered “lossless,” it is uncompressed, and therefore, takes up a lot of hard drive space.

如前所述，PCM是數字音頻及其變體的基礎。 PCM嘗試以盡可能多的未壓縮榮耀為波形建模。這很特殊，它已經準備好被卡在數字信號處理器中，并且可以普遍播放。大多數其他格式通過算法處理音頻，因此在播放時需要對其進行解碼。 PCM音頻被認為是“無損的”，未經壓縮，因此占用了大量硬盤空間。

未壓縮的束：WAV，AIFF (The Uncompressed Bunch: WAV, AIFF)

Image by codepo8

圖片來自codepo8

Both WAV and AIFF are lossless audio container formats based on PCM, with some minor changes in data storage.? PCM audio, for most people, comes in these formats, depending on whether you use Windows or OS X, and they can be converted to and from each other without degradation of quality.? They are both also considered “lossless,” are uncompressed, and a stereo (2-channel) PCM audio file, sampled at 44.1 kHz (or 44100 times per second) at 16 bits (“CD quality”) amounts to roughly 10 MB per minute.? If you’re recording at home for the purposes of mixing, this is what you want to use because it’s full quality.

WAV和AIFF都是基于PCM的無損音頻容器格式，在數據存儲上有一些細微變化。對于大多數人而言，PCM音頻采用這些格式，具體取決于您使用的是Windows還是OS X，它們可以相互轉換而不會降低質量。它們也都被認為是“無損的”，未經壓縮，并且以44.1 kHz(或每秒44100次)的速率以16位(“ CD質量”)采樣的立體聲(2聲道)PCM音頻文件大約為每個10 MB分鐘。如果您出于混合目的在家錄制，那是您要使用的，因為它的質量很高。

Image by CyboRoZ

圖片由CyboRoZ

無損格式：FLAC，ALAC，APE (Lossless Formats: FLAC, ALAC, APE)

The Free Lossless Audio Codec, Apple Lossless Audio Codec, and Monkey’s Audio are all formats which compress audio, much in the same fashion that anything is compressed in digital world: using algorithms.? The difference between zipped files and FLAC files is that FLAC is designed specifically for audio, and so has better compression rates without any loss of data.? Typically, you’re seeing about half the size of WAVs.? That is, a FLAC file for stereo audio at “CD quality” runs roughly 5 MB per minute.

免費無損音頻編解碼器，Apple無損音頻編解碼器和Monkey's Audio都是壓縮音頻的格式，其使用方式與數字世界中壓縮任何內容的方式大致相同：使用算法。壓縮文件和FLAC文件之間的區別在于FLAC是專門為音頻設計的，因此具有更好的壓縮率，而不會丟失任何數據。通常，您會看到WAV大小的一半。也就是說，用于“ CD質量”的立體聲音頻的FLAC文件每分鐘運行大約5 MB。

The up-side is that if you want to do audio manipulation, you can convert back to a WAV without any loss of quality.? If you’re an audiophile and listen to a lot of music with dynamic ranges, these formats are for you.? If you’ve got a great set of speakers, cans, or earbuds, these formats will bring out the tones to showcase them.

有利的一面是，如果您想進行音頻處理，則可以轉換回WAV而不會降低質量。如果您是發燒友，并且聽很多動態范圍的音樂，那么這些格式適合您。如果您有大量的揚聲器，聽筒或耳塞，這些格式將帶出音色來展示它們。

有損格式：MP3，AAC，WMA，Vorbis (Lossy Formats: MP3, AAC, WMA, Vorbis)

Image by patrick h lauke

圖片由patrick h lauke

Most of the formats you see in day-to-day use are “lossy”; some degree of audio quality is sacrificed in exchange for a significant gain in file size.? An average “CD quality” MP3 runs about 1 MB per minute.? Big difference compared to PCM, no?? This is called compression, but unlike with lossless formats, you can’t really get that quality back once you strip it in lossy formats.? Different lossy formats use different algorithms to store data, and so they typically vary in file size for comparable quality.? Lossy formats also use bitrate to refer to audio quality, which usually looks like “192 kbit/s” or “192 kbps.”? Higher numbers means that more data is being pumped out, so there’s more preservation of detail.? Here are some details for the more popular formats.

您在日常使用中看到的大多數格式都是“有損的”；在某種程度上犧牲了音頻質量以換取文件大小的顯著增加。平均“ CD品質” MP3每分鐘運行大約1 MB。與PCM相比有很大的不同，不是嗎？這稱為壓縮，但是與無損格式不同，一旦以有損格式剝離它，就無法真正獲得該質量。不同的有損格式使用不同的算法來存儲數據，因此為了獲得可比的質量，它們的文件大小通常會有所不同。有損格式還使用比特率來表示音頻質量，通常看起來像是“ 192 kbit / s”或“ 192 kbps”。較高的數字意味著將抽出更多數據，因此可以保留更多細節。以下是一些較為流行的格式的詳細信息。

MP3: MPEG 1 Audio Layer 3, the most common lossy audio codec today.? Despite a heap of patent issues, it’s still incredibly popular.? Who doesn’t have MP3s lying around?
MP3：MPEG 1音頻第3層，當今最常見的有損音頻編解碼器。盡管存在大量專利問題，但它仍然非常受歡迎。誰周圍沒有MP3？
Vorbis:? A free and open-source lossy format used more often in PC games such as Unreal Tournament 3.? FOSS fans, such as many Linux users, are bound to see plenty of this format.
Vorbis：一種免費的開源有損格式，在諸如Unreal Tournament 3之類的PC游戲中使用更為頻繁。FOSS愛好者(例如許多Linux用戶)必定會看到大量這種格式。
AAC:? Advanced Audio Coding, a standardized format now used with MPEG4 video.? It’s heavily supported because of its compatibility with DRM (e.g. Apple’s FairPlay), its improvements over mp3, and because no license is needed in order to stream or distribute content in this format.? Apple fans will probably have plenty in AAC.
AAC：高級音頻編碼，一種現在用于MPEG4視頻的標準化格式。由于它與DRM的兼容性(例如Apple的FairPlay)，對mp3的改進以及不需要許可證即可流式傳輸或分發這種格式的內容，因此受到了大力支持。蘋果粉絲可能會擁有大量的AAC。
WMA:? Windows Media Audio, Microsoft’s lossy audio format.? It was developed and used to avoid licensing issues with the MP3 format, but because of major improvements and DRM compatibility, as well as a lossless implementation, it’s still around.? It was really popular before iTunes became champion of DRMed music.
WMA：Windows Media Audio，Microsoft的有損音頻格式。它被開發并用于避免MP3格式的許可問題，但是由于重大改進和DRM兼容性以及無損實現，它仍然存在。在iTunes成為DRMed音樂的冠軍之前，它確實很受歡迎。

Lossy formats are what you use for all of the stuff you listen to and store.? They’re designed to be an economy of hard drive space.? Which format you choose depends on what digital audio player you use, how much space you have, how big of a quality nitpicker you are, and a bunch of over variables.? Nowadays, computers will play anything, most audio players (except Apple’s, of course) will do multiple lossy formats, and more and more do FLAC and APE.? Apple sticks to MP3, ALAC, and AAC.

有損格式是您用于聆聽和存儲的所有內容的格式。它們旨在節省硬盤空間。您選擇哪種格式取決于您使用的數字音頻播放器，您有多少空間，質量是多少nitpicker，以及一堆over變量。如今，計算機可以播放任何內容，大多數音頻播放器(當然，蘋果播放器除外)都可以執行多種有損格式，而FLAC和APE則越來越多。蘋果堅持使用MP3，ALAC和AAC。

音頻質量不是主觀的嗎？ (Isn’t Audio Quality Subjective?)

Absolutely, it is.? Ultimately, it’s your ears that are consuming most of this stuff, but that’s more reason to think of quality seriously.? When I first started creating my digital music collection, I couldn’t really tell the difference between 128kbit MP3s and audio CDs.? To my ears, there was no noticeable difference.? Over time, however, I noticed that 256 kbit sounded much better, and after I got a really nice (and expensive!) set of headphones, I went back to audio CDs full time!? It also depends on the genre of music.

的確如此。最終，大部分的東西都是您的耳朵，但這是認真考慮質量的更多原因。剛開始創建我的數字音樂收藏時，我無法真正分辨出128kbit MP3和音頻CD之間的區別。在我耳邊，沒有明顯的區別。但是，隨著時間的流逝，我注意到256 kbit的音質要好得多，當我買到一套非常好(且價格昂貴！)的耳機后，我便全職回到音頻CD上！這也取決于音樂的流派。

Image by jonchoo

圖片來自jonchoo

There are a LOT of variables here, folks, make no mistake about that.? It took a while before I settled on using FLAC for some music and 320kbps MP3 for the rest.? The point I’m trying to make is that you should experiment to see what works best for you and your music, but be aware that as your tastes change, your perceptions, your equipment, and the importance of quality will, too.

伙計們，這里有很多變量，請不要誤會。我花了一段時間才決定使用FLAC播放一些音樂，其余的使用320kbps MP3。我要說的是，您應該嘗試看看哪種音樂最適合您和您的音樂，但要注意，隨著口味的改變，您的看法，設備和質量的重要性也會隨之改變。

And all of this stuff get even trickier when you’re not just talking about music, but about voice tracks, sound effects, white and brown noise, etc.? There’s a whole world of sound out there, so don’t get discouraged!? By learning what you can and listening for yourself, you can use this info to your advantage in your future audio projects.? I’ll leave you with some of the best advice I’ve ever gotten: “do what just plain sounds good.”

當您不僅在談論音樂，而且在談論音軌，音效，白色和棕色噪音等問題時，所有這些東西都變得更加棘手。那里有各種各樣的聲音，所以不要灰心！通過學習并聽自己說，您可以在以后的音頻項目中使用此信息，以發揮自己的優勢。我將向您提供一些我曾經獲得的最佳建議：“做聽起來簡單的事情。”