Lossy compression format: music MP3, OGG, WMA, etc., video, generally
Lossless compression format: music APE, WAVPACK, FLAC, video, seems to be MPG, I'm not sure, but my home DV camera video is this format, its file size per minute, with the lowest quality of the filming, it is also nearly 700MB.
I don't know about the compression efficiency.
The following are some of the more general, technical articles I've found on lossless compression formats.
Lossless music formats:
APE and FLAC formats. Are files obtained by ripping tracks directly from a CD. It is larger than other lossy formats such as MP3,WMA, and the sound quality is clearer.
FLAC is an acronym for Free Lossless Audio Codec, which can be interpreted as a lossless audio compression coding, FLAC is a famous set of free audio compression coding, which is characterized by lossless compression. Unlike other lossy compression codes such as MP3 and AAC, it does not break any original audio information, so it can restore the sound quality of music CDs. It is now supported by many software and hardware audio products.
APE is one of the most popular digital music file formats. Unlike MP3, which is a lossy compression method, APE is a lossless audio compression technology, which means that when you compress an audio data file read from an audio CD into APE format, you can also restore the APE format again, and the restored audio file is exactly the same as the one before compression, without any loss.APE's file size is roughly half of that of a CD, but with the popularity of broadband, the APE format has received a lot of attention from many users, and it has become the most popular format in the world. The APE format has become a favorite among many music lovers, especially those who want to transfer audio CDs over the Internet, and APE can help them save a lot of resources.
In a nutshell, FLAC is similar to MP3, but is lossless, meaning that no information is lost when audio is compressed in FLAC. The compression is similar to that of Zip, but FLAC will give you a much higher compression ratio because FLAC is specifically designed to compress audio, and you can play FLAC-compressed files on your player just as you normally play your MP3 files (there are now many car players and home stereo devices that support FLAC, and you can find links to the manufacturers of these devices on the FLAC Web site). can find links to the manufacturers of these devices).
Here's a knowledgeable article I came across about lossless compression.
If you want to have a deep understanding of the lossless compression format, check it out.
Lossless VS Lossy 2008-05-15 20:28Lossless VS Lossy
What are the strengths and weaknesses of lossless compression over lossy? The following comparison should give you a clear idea about lossless compression.
Advantages of lossless compression:
1. 100% preservation without any signal loss
As I said before, lossless compression format is just like Zip compression file, it can preserve 100% of the data of the WAV file, which can be proved by the "WAV Compare" function of EAC. This can be proved by EAC's "WAV Compare" function. Save the U2's "Beautiful Day" as a WAV file. Compress this WAV file into APE format, then decompress the APE file into WAV format. Using EAC's "WAV Compare" function to compare the data of these two WAV files, EAC did not report any inconsistency! If the WAV file is compressed to MP3 and then decompressed, comparing the original WAV file, it is inconsistent from beginning to end! A lot of friends want to maximize the CD "original" copy to the hard disk, but also want to reduce the amount of space occupied, which in the past seems to be only 320KbpsCBRMP3 this kind of solution, but that is far from being able to do 100%! Now, the advent of lossless compression provides an almost perfect solution.
2. High sound quality, independent of the source
Since the original audio signal is 100% preserved, the sound quality of the lossless compression format is undoubtedly the same as the original CD! Compare the spectrograms of BeautifulDay in WAV format and FLAC compressed format, and you can't see any difference. Likewise, actual listening is unlikely to make any difference! The lossy compression format, due to its innate design (which requires the loss of a portion of the signal), is only infinitely close to an acoustic CD in terms of sound quality, and it's impossible to really reach the level of a CD! And because of the limitations of the lossy compression format algorithms, when compressing symphonies and other types of music with a large dynamic range, the sound quality performance is poor. Lossless compression formats do not have this problem, and can be used for any type of music!
3. Convenient conversion
Lossless compression formats can be easily reduced to WAV, and can also be directly converted to lossy compression formats such as MP3, Ogg, etc., and can even be converted to each other between different lossless compression formats without losing any data. This is much stronger than lossy formats! Because the secondary encoding of lossy compression formats (converting from one lossy format to another, or keeping the format the same and adjusting the bitrate) means that more signal is lost and more distortion is introduced!
Shortcomings of lossless compression:
1. Large space occupation, low compression ratio
Lossless compression format is much worse than lossy compression format, which is usually around 60%. The 192Kbps lossy format is only about 14% of the original file, and the difference in compression ratio between the two is quite dramatic. As shown in the picture, I compressed a song of U2's "Beautiful Day" with different formats, including APE in Normal mode and La in High mode, but we can see that the lossless format's compression ability is better than RAR, which is specially optimized for multimedia formats, and Zip can barely compress WAV format, which is the same as 100% data preservation. Add to this the fact that Lossless has real-time playback capabilities that neither RAR nor Zip have, and we're still quite impressed with Lossless' technology!
2. Lack of hardware support
Currently, only the FLAC format is supported by a few pieces of hardware, and the only Walkman that can play lossless compression is the Karma. This is due to a number of reasons. First of all, the capacity of the mainstream flash MP3 Walkman is still only 128MB or 256MB, and it is obviously unrealistic to store lossless formats. Secondly, decoding lossless compression format requires a greater amount of computation, which puts forward higher requirements for the processing speed of the decoding chip, and at present such a decoding chip is still very little. Once again, decoding lossless formats consumes even more power than lossy formats, which is no doubt an added burden for the MP3 Walkman, whose battery life is already less than ideal!
Three, the lossless compression format at a glance
Currently more famous lossless compression format APE, FLAC, LPAC, WavPack.
1, APE (Monkey's Audio)
APE is undoubtedly the most famous lossless compression format, in the domestic application has been more widely. Its compression rate is quite excellent, and with high efficiency and speed, its comprehensive ability definitely belongs to the best today. Through BT () or electric mule (), you are able to download a large number of music in APE format. The widely used Monkey's Audio program has also contributed to the popularity of the format. However, APE has a number of drawbacks: its decoding speed is less than ideal, it can only be used on Windows platforms, and its closed source code affects its support.
2, FLAC
Very mature lossless compression format, the fame is not under APE! FLAC is the abbreviation of FreeLosslessAudioCodec, the format's source code is completely open, and is compatible with almost all operating system platforms. Its encoding algorithms are quite mature and have passed rigorous tests, and it is said that it can still be played normally in the case of file point corruption (which I have not tried). The format is not only supported by mature Windows authoring programs, but also by numerous third-party software. In addition, the format is the only lossless format already supported by hardware, with Rio's hard-disk Walkman Karma, Kenwood's in-car stereo MusicKeg, and PhatBox's digital players all supporting the FLAC format.
3, WavPack
Quite a characteristic format, it is worth trying. WavPack is not only a lossless compression format, it can also be used as a lossy compression format. In its unique "hybrid" mode, WavPack can be compressed into a combination of a wv file (a lossy compression format, generally about 23% of the size of a WAV file) + a wvc file (a correction file, generally about 41% of the size of a WAV file). With the corresponding wvc file, the lossy compressed wv file becomes lossless, and plays exactly the same as the normal lossless compressed format. If you want to reduce the file size, you can remove the wvc file, then the wv file becomes a lossy format, and plays exactly the same as a high bitrate MP3! WavPack includes both lossless and lossy formats, amazing, isn't it? Through the WavPackFrontend program, we can easily use the WavPack format.
4, LPAC
Mid-track lossless format, all indicators are relatively average. The author TilmanLiebchen is also constantly updating it, and also has a nice production program for it.
5, WMALossless
Microsoft in WindowsMediaPlayer9.0 later also began to provide lossless compression. Just click the menu "Tools" = "Options", in the "Copy Music" tab, select "WindowsMedia Audio Lossless" format. In the future, through the "Copy from CD" function of WMP, you can directly save the CD into WMALossless format, which is really very convenient to use. However, except for WindowsMediaPlayer, almost no other software can support this format.
6. AppleLossless
The latest version of Apple's iTunes music software also offers the AppleLossless lossless compression format. Like Windows MediaPlayer, iTunes can very quickly rip tracks from CDs and compress them into AppleLossless format. Again, of course, the format is supported only by its own software.
7, La
La, is short for LosslessAudio, the format is not famous, but is the current compression ratio of the champion, compression rate, no one can beat, including always known for high compression rate of APE! Limited to their own development of Winamp decoding plug-ins and Windows interface encoder LosslessAudioCompressor.
8, OptimFROG
The compression rate of the format can be comparable to La, but the speed of La is also slower than (depressed)! Not much more to say.
9, Shorten
Encoding very fast lossless format, but the compression rate is very disappointing! The format is also open source and supports both Windows and Mac, but it's been a while since the encoded version was updated, so I guess it's dead.
Lossless compression formats go far beyond the above, and include RKAU, SZIP, Bonk, Kexis, and many more, all of which are rare and imperfect, so I won't introduce them.
Four, the development of lossless compression format prospects
Although there are still some shortcomings, but the future of lossless compression format is undoubtedly bright, from the current existence of a variety of lossless compression format can be seen on this point! As time goes on, the factors that limit the lossless format will gradually be eliminated! For example, the increasing capacity of hard disk, 120GB has become the mainstream, 160GB will also be popularized, lossless formats occupy a lot of space will no longer be a problem. And faster decoding chips will also be developed, I believe there will be more and more hard disk Walkman support lossless format. In the near future, when the capacity of flash drives is measured in gigabytes (GB), the lossless compression format will become more and more important in the pursuit of higher sound quality!
Testing
First of all, I'd like to thank my friend WimSpeekenbrink from the Netherlands (he's quite famous in the audio technology world, and he's the one who wrote many of the encoder's frontend programs!) ), who gratuitously provided me with data from his review of a side-by-side comparison of lossless compression formats. This saved me a ton of time, and even if I were to do such a review, I'm sure I wouldn't be able to do it as well as he did. ok, let's take a look at this side-by-side test by WimSpeekenbrink, who has included all the common lossless formats, including: AppleLossless, FLAC, La, LPAC, Monkey' sAudio, OptimFROG, RKAU, Shorten (Shorten, ShortenEtree), TTA, WavPack, and WindowsMediaLossless.
The following ten CDs were used for this test:
1. ErykahBadu - Baduizm"
2. TheBeatles-"1967-1970" CD1
3. Dido-"NoAngel"
4. TheEagles-"Theverybestof"
5, HerbieHancock&WayneShorter-"1+1"
6. DianaKrall (Diana Krall)-"WhenIlookinyoureyes"
7. Metallica-"S&M" CD1
8, MilesDavis (Miles Davis) - "KindofBlue"
9, Nirvana (Nirvana) - "Nevermind"
10, U2 - "Allthatyoucan'tleavebehind"
Which are bands like the Beatles, the Eagles, and U2. and U2 are all familiar to us now. First of all, we will use EAC to rip these CDs into CD image files and save them on the hard disk, and then compress them with the encoders of the above formats to test their encoding speeds. Next we release them into WAV format using their respective decoders to test their decoding speed.
Note: The special WMA9Lossless uses "cscript.exewmcmd.vbs-inputfile.wav-outputfile.wma-a_codecWMA9LSL-a_mode2-a_settingQ100_44_2_16". 44_2_16" command line for compression and Foobar2000 for decoding, while AppleLossless relies on "Export->SoundtoWave" (output to Wav) in QuickTimePro 6.5.1. " (Export to Wav file) menu for encoding compression.
All ten CDs were given their own test scores, which were eventually summed up to get an average score. Taking the CD "TheEagles-Theverybestof" as an example, its test results are shown in Table I. The final results are ranked by compression rate. And the final results ranked by compression rate are shown in Table II.
Highest compression ratio:
La0.4b (parameter: default)
OptimFROG4.509 (parameter: highnew)
Monkey's Audio3.99 (parameter: extrahigh)
Fastest encoding speed:
Fastest encoding speed:
Fastest encoding speed:
Fastest encoding speed:
The Eagles - Theverybestof CD: The Eagles - Theverybestof CD: The Eagles - Theverybestof CD: TheEagles - Theverybestof >Fastest encoding speed:
Shorten3.6.0
WavPack3.97(parameter: normal)
TTA3.0
Fastest decoding speed:
Shorten3.6.0
FLAC1.1.0( anycompressionlevel)
AppleLossless(iTunes4.5.0.31)
You must be asking, who should I choose? Indeed, it's hard to tell the difference between the top and the bottom is very difficult, and here I can only offer my opinion. My personal recommendation is - FLAC! Why? It is true that APE is the most compressed format available, excluding the very slow La and OptimFROG. It is true that APE has the highest compression rate, except for La and OptimFROG. However, it is important to realize that the difference in compression rate between different lossless formats is quite small, only around 3%! Converting a whole CD to APE or FLAC, the difference in file size is only about 20MB, which is nothing compared to the 80GB or even higher capacity hard disk that we all use nowadays. As for the encoding speed, both of them are better, the difference is not big. But I don't think that's the main thing, after all, encoding is only done once per CD. The most important thing is the decoding speed! Because decoding is the most frequent task, every time you play it, the format with low decoding speed will take up more CPU resources. Of course, for computers with a main frequency of 1G or more, this little bit of CPU resources may not count for much. But don't forget, if you want to convert the lossless format to MP3 or WMA to MP3, and burn the lossless format release to CD, it will be affected by the decoding speed. That's why decoding speed is the most important thing! This is the main reason I recommend FLAC. Of course, FLAC's open source and wide support is also a huge advantage!
In the field of audio compression, there are two types of compression, lossy compression and lossless compression! We commonly see MP3, WMA, OGG is called lossy compression, lossy compression as the name suggests is to reduce the audio sampling frequency and bit rate, the output audio file will be smaller than the original file. Another kind of audio compression is called lossless compression, which is what we are talking about today. Lossless compression is able to save all the data of the original file under the premise of 100%, the volume of the audio file is compressed smaller, and the compressed audio file is restored to achieve the same size as the source file, the same bit rate. The current lossless compression formats are APE, FLAC, WavPack, LPAC, WMALossless, AppleLossless, La, OptimFROG, Shorten, and the common, mainstream lossless compression format is currently only APE, FLAC. the following two lossless compression formats for a comparison!
APE is Monkey's Audio, a lossless compression format. The compression ratio of this format is much lower than that of other audio formats, but it can be truly lossless, while its open-source nature has gained the favor of many music enthusiasts. In the existing lossless compression scheme, APE is a format with outstanding performance, satisfactory compression ratio and fast compression speed, which is widely used in China, and has become one of the choices for many friends to exchange audiophile music in private.
At present, based on the domestic Torchlight ATJ 2097 decoding chip MP3 manufacturers, there are manufacturers such as: Onda's VX939, Delta Technology's C133 + support APE format!
FLAC, short for Free Lossless Audio Codec, is a very mature lossless compression format that is not as famous as APE! The format's source code is completely open and compatible with almost all operating system platforms. Its encoding algorithms are quite mature and have been rigorously tested and can still be played normally when the encoding is corrupted. In addition, the format is the first lossless format to receive widespread hardware support, and world-renowned digital products such as Rio's hard drive Walkman Karma, Kenwood's in-car stereo MusicKeg, and PhatBox's digital players all support the FLAC format.
At present, there are few Walkmans with flash memory chips that support FLAC lossless compression format, but just recently, the second-generation dual-core movie MP3 of TL-T19 from a well-known domestic manufacturer, Taito Technology, has announced its support for FLAC lossless compression format, which is so far the first movie MP3 that supports FLAC lossless compression format in China, and also one of the few in the world. But the two compression formats for the two compression algorithms, the following list of similarities and differences between the two compression formats:
Similarities:
First, the compression ratio to determine the lossless compression of the file occupied by the storage space
FLAC and AEP compression ratio is basically the same, FLAC compression ratio of 58.70%, while the compression ratio of the APE to be a little higher, for the 55.50%, both of which can be compressed to nearly half the size of the source file.
Second, the encoding speed to test the patience of the user, the speed of the superior
It is very commendable that the encoding speed of FLAC and APE are similar, this is because the two compression technology is open source, the developer can learn from the two in the encoding of the different advantages of the development, but the fastest encoding of WavPack and Shorten two Lossless compression formats, but the non-open source nature of these two formats limits their popularity.
Third, platform support determines popularity
Audio compression requires not only hardware support, but also software support, so being able to be supported by a wider range of platforms means being used by a wider range of users. Now, whether you are a Windows user or one of the many versions of Linux, or even a Mac OS fan, you don't need to worry about not being able to use FLAC or APE.
Fourth, the open source nature of the two, completely free of charge technology
The open source nature of the two means that any organization or individual can use these two compression technologies for free, and that any organization or individual can modify and release new products based on the two technologies, giving many MP3 manufacturers the opportunity to make their own compressed music. This gives many MP3 manufacturers a strong guarantee to reduce costs, and consumers are able to purchase only world-class MP3 (e.g., iPod support for ALAC) supported by the lossless compression of audio, CD-level sound performance at a relatively low price!
Differences:
First, the ability to self-correct, who is more humane?
Many consumers have experienced MP3 popping problems, and then blamed on MP3 quality problems, in fact, a large part of the popping is because of the audio compression process, coding tiny damage, resulting in decoding, processing out of the data and audio inconsistencies, resulting in popping phenomenon. Lossless format compression is not good will also lead to coding damage, and in dealing with this problem, FLAC will be muted instead of the lossy part, while the APE processing with the common lossy compression format processing the same way, in order to replace the lossy part of the popping way. This is a more user-friendly design for FLAC!
Second, the optimized encoding structure determines the speed of decoding!
Due to the different encoding methods, the decoding speed of the two lossless compression formats will be affected. Usually, the decoding speed of FLAC is 30% faster than that of APE, because FLAC only needs to perform integer arithmetic, and does not need to perform floating-point arithmetic, which occupies a higher frequency of the system and a larger amount of data processing. Based on this, real-time decoding is perfectly possible with typical hardware.
Third, easy access to resources means that it can be more widely used and supported
Whether it's FLAC or APE, in terms of access to resources, both can be easily accessed through a web search!
Through the above comparison, I believe many users have a deeper understanding of FLAC and APE. From a technical point of view, FLAC is significantly better than APE, because FLAC is the first open source lossless compression format recognized by the world, and there are top-level developers from all over the world who have developed FLAC free of charge and perfected the technology. FLAC is supported by a wide range of hardware platforms, almost all high-end decoder chips with portable design can support FLAC format music, FLAC's third advantage lies in: excellent encoding makes the hardware in the decoding only need to use simple integer arithmetic can be, which will greatly reduce the occupied hardware resources! However, the two publicly available technologies are extremely complementary, and it is unlikely that either will ever fully surpass the other!
This is an article about lossy compression formats.
All of our previous work has been based on the standard audio format WAV, which is difficult to save, back up, and enjoy on the Internet, much less on the go, due to its large size. At this time you need to compress it. This is the last step in our audio processing.
Audio compression is divided into lossless compression and lossy compression. With lossy compression, you can choose the desired sampling frequency and bit rate of the digital audio file compression coding, compressed audio files will be much smaller than the original file, but the quality of the corresponding reduction in quality, and this loss is irreparable, even if it will be converted to the compression coding of the file format before the loss of part of it can not be recovered; and the use of lossless compression coding of the audio file to maintain the quality of the sound, the decompression can be restored to the compression coding of the audio file. After decompression, it can be restored to the same quality as before compression coding, but the compression ratio is smaller.
Basically, you don't need to compare lossless compression with lossy compression; they each have their own applications. For example, when you need to choose a compression format for your portable digital audio device, the large compression ratio of lossy compression is most attractive, while when you want to copy a CD to a hard disk, lossless compression is the best choice. All you need to know is what coding techniques are available for both lossless and lossy compression, and the advantages and disadvantages of each, so that you can make an informed choice when you need to.
Lossy compression coding
Lossy compression of digital audio files has evolved over the years, with formats such as VQF and other once-popular formats gradually moving away from the limelight, and replaced by OGG, MPC, ACC, and WMA formats, which are as popular as the ever-vibrant MP3 format. So which of these lossy compression coding techniques is the best? This requires a comprehensive comparison of various aspects such as compression rate, compression speed and compressed sound quality. Taking into account the technical characteristics of each compression method, we also need to compare the quality of compression at low and high bit rates, respectively, in order to get the results with reference value.
The hardest part is that the differences between audio files of higher quality are quite small, so how do we compare them and find the best one? In fact, each compression technique has its own supporters, and it's hard to have a single agreed-upon test result. However, here I can provide you with a table based on the test results of Hydrogen Audio, the most famous foreign audio technology forum, which is widely recognized in technology forums, and I believe it has some reference value for you.
Through Hydrogen Audio's tests, it's easy to see that all of the lossy compression technologies that are still popular have better compression rates, and the difference between them is that the quality is different at low and high bit rates, and the results of the overall comparison, MPC, QGG, and MP3 will be the most attractive digital audio lossy compression technology, so here's how to use these three compression technologies. Here's how to use these three compression techniques to encode your own audio files.
MP3
In contrast to MPC and OGG, MP3's aura is no longer as glamorous as it once was, but MP3 is able to get better results with both low and high bitrate compression, and can be played on a wide range of portable devices. For most digital audio enthusiasts, MP3 is still the most commonly used lossy codec for audio files.
Lame (Lame Ain't an Mp3 Encoder, you can download the latest version of Lame) is the best MP3 encoder in the world, and its unique auditory mental modeling combined with VBR, ABR, and other encoding modes allow you to freely choose the MP3 encoding effect and file size you need.
The Lame encoder is mostly used to be called by other software (such as EAC as mentioned earlier). If you don't want to be called by other audio software, you can encode MP3 files directly from the command line. But the most convenient way is to download a RazorLame software (URL:), which allows you to set Lame's encoding parameters in a graphical interface, which can help you to stay away from the nightmare of memorizing Lame's parameters, and easily choose the encoding scheme. Please check the version of Lame encoder that comes with the software before using it, if there is already a new version, you can copy the new version of Lame encoder to replace Lame.exe in the directory of the software.
Setting Lame encoding parameter in RazorLame
MPC
MPC has the best quality in the high-bit-rate encoding, and is the unanimously recognized high-bit-rate encoding standard in foreign countries. It is the best lossy compression coding method recognized by foreign countries for high bit rate compression. However, the quality of this encoding method is not good at low bit rates, and the number of supported devices and software is quite small. Although it is expected to improve with the increase of users, for now, it is still only suitable for storing and playing on one's own computer.
The most popular MPC encoder at the moment is MusePack Encoder (). Similar to Lame, MusePack Encoder is a command-line encoding program. Unpack the downloaded zip to get an exe program, select "Compression Options" from the "EAC" menu on the main EAC interface, and in the "External Compressor" dialog box, select "Compressor" from the drop-down menu. In the "External Compression Program" dialog box, change "Parameter Transfer Program" to "User-defined Program" through the drop-down menu, and type ". mpc" in the "Use File Extension" input box. mpc" in the "Use File Extension" input box, and then click the "Browse" button next to "Compressed Programs and Paths" to select the exe file you just downloaded. Clear the check mark on the "Add ID3 tag" checkbox below, and then define the encoding parameters of MPC encoder in the "Additional command line parameters" input box. For example: --quality 5 --xlevel --artist "%a" --title "%t" -album "%g" -year "%y" --track "%n" -genre "%m" %s, and you can encode the MPC file with EAC just as you would with Lame.
Setting MPC encoding parameters in EAC.
Like Lame, the MPC encoder has external programs that you can call from within the GUI. You can find a program called MuseDrop on the Download Encoder page, which is the most popular MPC encoder today. After running the program, you can set the parameters of the encoder with a right mouse click, and then drag the file you want to encode into the program's floating window to encode it.
OGG
OGG has the best low-bitrate compression quality, so it may be a good idea to encode speech or other less demanding audio files in OGG format. However, caution should be exercised when using this format, and while some manufacturers have begun experimenting with OGG-enabled portable audio players, this is not the mainstream after all. Those interested in OGG encoding can visit. Setting up the EAC is the same as setting up the Lame encoder, but the only difference is that "Ogg Vorbis Encoder" is selected for the "Parameter Delivery Scheme", and the encoding program is changed to the downloadable OGG encoder " oggenc.exe". The plug-ins for the various players can also be found on the website above.