flac格式转换mp3格式_MP3，FLAC和其他音频格式之间有什么区别？

flac格式转换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.

数字音频已经存在了很长时间，因此必然会有大量的音频格式。以下是一些较常见的功能，它们的区别以及用途。

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.

在讨论日常音频格式之前，了解基础知识很重要，这意味着了解PCM。之后，我们将解决压缩格式。

PCM音频：从哪里开始 (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.

脉冲编码调制创建于1937年，是模拟音频的最接近近似值。即，以规则的间隔近似模拟波形。 PCM具有两个特性：采样率和位深度。采样率测量获取波形幅度的频率(以每秒为单位)，位深度测量可能的数字值。就音频格式而言，这几乎是基础。

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.

真实世界中的真实声音是连续的。在数字世界中，事实并非如此。不知何故，音频比视频更容易混淆，因此让我们将视频作为比较点。实际上，我们解释为“运动”或认为是“流畅”且不断运动的是一系列静止图像。以同样的方式，数字格式的声波幅度不会“波动”或不断变化。它会根据某些标准以预定义的时间间隔进行更改。

Image from Wikipedia

图片来自维基百科

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，除非您是工程师，物理学家或发烧友，否则很多东西可能都不是第二自然的，所以让我们用一个类比将其进一步减少。

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.

假设从开放式水龙头流出的水是您的“模拟”音频源。我们可以将水的温度与声波的振幅进行比较。这是一个需要测量的属性，以便您可以正确使用它。采样是每秒将手指浸入流水中的次数。您将手指浸入的次数越多，温度变化就越“连续”。如果您将手指每秒浸入流水中44,100次，那几乎就像是始终将手指一直压在那儿，对吗？这是采样背后的基本思想。

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。假设您没有使用手指，而是使用了一个非常实用的温度计。对于高于室温的温度，基本上说“热”，低于室温的温度说“冷”。无论您将其浸入水中多少次，它都不会真正为您提供有用的信息。现在，如果不是只有2个选项，可以说温度计有16个可能的值，可用于测量水温。更有用吧？位深度以相同的方式工作，因为更高的值可以准确描绘声音幅度的更多动态变化。

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是数字音频及其变体的基础。 PCM尝试以尽可能多的未压缩荣耀为波形建模。这很特殊，它已经准备好被卡在数字信号处理器中，并且可以普遍播放。大多数其他格式通过算法处理音频，因此在播放时需要对其进行解码。 PCM音频被认为是“无损的”，未经压缩，因此占用了大量硬盘空间。

未压缩的束：WAV，AIFF (The Uncompressed Bunch: WAV, AIFF)

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图片来自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的无损音频容器格式，在数据存储上有一些细微变化。对于大多数人而言，PCM音频采用这些格式，具体取决于您使用的是Windows还是OS X，它们可以相互转换而不会降低质量。它们也都被认为是“无损的”，未经压缩，并且以44.1 kHz(或每秒44100次)的速率以16位(“ CD质量”)采样的立体声(2声道)PCM音频文件大约为每个10 MB分钟。如果您出于混合目的在家录制，那是您要使用的，因为它的质量很高。

Image by CyboRoZ

图片由CyboRoZ

无损格式：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.

免费无损音频编解码器，Apple无损音频编解码器和Monkey's Audio都是压缩音频的格式，其使用方式与数字世界中压缩任何内容的方式大致相同：使用算法。压缩文件和FLAC文件之间的区别在于FLAC是专门为音频设计的，因此具有更好的压缩率，而不会丢失任何数据。通常，您会看到WAV大小的一半。也就是说，用于“ CD质量”的立体声音频的FLAC文件每分钟运行大约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，如果您想进行音频处理，则可以转换回WAV而不会降低质量。如果您是发烧友，并且听很多动态范围的音乐，那么这些格式适合您。如果您有大量的扬声器，听筒或耳塞，这些格式将带出音色来展示它们。

有损格式：MP3，AAC，WMA，Vorbis (Lossy Formats: MP3, AAC, WMA, Vorbis)

Image by patrick h lauke

图片由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数格式都是“有损的”；在某种程度上牺牲了音频质量以换取文件大小的显着增加。平均“ CD品质” MP3每分钟运行大约1 MB。与PCM相比有很大的不同，不是吗？这称为压缩，但是与无损格式不同，一旦以有损格式剥离它，就无法真正获得该质量。不同的有损格式使用不同的算法来存储数据，因此为了获得可比的质量，它们的文件大小通常会有所不同。有损格式还使用比特率来表示音频质量，通常看起来像是“ 192 kbit / s”或“ 192 kbps”。较高的数字意味着将抽出更多数据，因此可以保留更多细节。以下是一些较为流行的格式的详细信息。

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音频第3层，当今最常见的有损音频编解码器。尽管存在大量专利问题，但它仍然非常受欢迎。谁周围没有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：一种免费的开源有损格式，在诸如Unreal Tournament 3之类的PC游戏中使用更为频繁。FOSS爱好者(例如许多Linux用户)必定会看到大量这种格式。
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：高级音频编码，一种现在用于MPEG4视频的标准化格式。由于它与DRM的兼容性(例如Apple的FairPlay)，对mp3的改进以及不需要许可证即可流式传输或分发这种格式的内容，因此受到了大力支持。苹果粉丝可能会拥有大量的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的有损音频格式。它被开发并用于避免MP3格式的许可问题，但是由于重大改进和DRM兼容性以及无损实现，它仍然存在。在iTunes成为DRMed音乐的冠军之前，它确实很受欢迎。

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.

有损格式是您用于聆听和存储的所有内容的格式。它们旨在节省硬盘空间。您选择哪种格式取决于您使用的数字音频播放器，您有多少空间，质量是多少nitpicker，以及一堆over变量。如今，计算机可以播放任何内容，大多数音频播放器(当然，苹果播放器除外)都可以执行多种有损格式，而FLAC和APE则越来越多。苹果坚持使用MP3，ALAC和AAC。

音频质量不是主观的吗？ (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.

的确如此。最终，大部分的东西都是您的耳朵，但这是认真考虑质量的更多原因。刚开始创建我的数字音乐收藏时，我无法真正分辨出128kbit MP3和音频CD之间的区别。在我耳边，没有明显的区别。但是，随着时间的流逝，我注意到256 kbit的音质要好得多，当我买到一套非常好(且价格昂贵！)的耳机后，我便全职回到音频CD上！这也取决于音乐的流派。

Image by jonchoo

图片来自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.

伙计们，这里有很多变量，请不要误会。我花了一段时间才决定使用FLAC播放一些音乐，其余的使用320kbps MP3。我要说的是，您应该尝试看看哪种音乐最适合您和您的音乐，但要注意，随着口味的改变，您的看法，设备和质量的重要性也会随之改变。

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.”

当您不仅在谈论音乐，而且在谈论音轨，音效，白色和棕色噪音等问题时，所有这些东西都变得更加棘手。那里有各种各样的声音，所以不要灰心！通过学习并听自己说，您可以在以后的音频项目中使用此信息，以发挥自己的优势。我将向您提供一些我曾经获得的最佳建议：“做听起来简单的事情。”