The Importance of Codecs in Video Compression

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The Importance of Codecs in Video Compression

Video Codec

Introduction

Video Codec

Video codecs play a vital role in video compression. The quality and size of video files depend largely on the type of codec used to compress them. In this article, we will explore the significance of video codecs in video compression and the technical aspects that determine the quality and efficiency of video files.

History of Video Codecs

The first video codec was developed in the 1970s, called H.120. This codec allowed for the transmission of video over ISDN telephone lines. Since then, video codecs have evolved significantly, and we now have a wide range of codecs available that offer different levels of compression and quality.

Understanding Video Quality

Video quality can be defined as the degree of excellence that a video possesses. This quality is determined by various factors, including the resolution, bit rate, frame rate, and compression method used.

Resolution

The resolution of a video is the number of pixels that make up the image. Higher resolution videos have more pixels, which means they are sharper and more detailed. The most common resolutions are 720p, 1080p, and 4K.

Bit Rate

The bit rate is the amount of data that is processed per second. A higher bit rate means more data is processed, resulting in a higher-quality video. However, higher bit rates also mean larger file sizes, which can be challenging for storage and transmission.

Frame Rate

The frame rate is the number of frames that are displayed per second. A higher frame rate results in a smoother video, but it also requires more data to be processed, resulting in larger file sizes.

Compression Method

Compression methods are used to reduce the size of video files without compromising on quality. Lossless compression methods preserve the original quality of the video, while lossy compression methods sacrifice some quality to achieve smaller file sizes.

Video Codecs and Formats

Video codecs can be classified into two categories: proprietary codecs and open-source codecs. Proprietary codecs are developed by companies and are generally licensed for use. Open-source codecs, on the other hand, are developed by communities and are free to use.

Proprietary Codecs

Proprietary codecs are developed by companies such as Apple, Microsoft, and Google. They are often used in popular video formats such as MP4, AVI, and MOV. These codecs are optimized for specific devices and software, resulting in high-quality videos that are compatible with a wide range of devices.

Open-Source Codecs

Open-source codecs are developed by communities and are free to use. The most popular open-source codec is the VP9 codec developed by Google. It is used in the WebM format and offers a high level of compression with minimal loss of quality.

Choosing the Right Codec

When choosing a codec, it is important to consider the factors that affect video quality, such as resolution, bit rate, frame rate, and compression method. Proprietary codecs are often optimized for specific devices and software, while open-source codecs offer more flexibility and are free to use.

Format

The format of a video file also plays a significant role in determining the quality and efficiency of the file. Popular video formats include MP4, AVI, MOV, and WebM. Each format has its own set of advantages and disadvantages, and it is important to choose the right format based on your needs.

Conclusion

Video codecs are an essential part of video compression, and they play a significant role in determining the quality and size of video files. By understanding the technical aspects of video quality and the different types of codecs and formats available, you can make informed decisions when choosing

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What is a video codec?

video codec

A codec is a program or device that encodes and decodes video. This means that it takes a video and compresses it into a smaller format so it can be streamed or stored more efficiently. Then, when you want to watch the video, the codec decodes it and plays it in its original format.

video codec

Why is a video codec important?

Video codecs are important because they make videos more accessible and easier to use. Without a codec, the videos would be too large to stream or store, which would mean that we would have to wait a long time to watch them or have a very large storage space to save them.

In addition, the codecs also make the videos look better. Some codecs use advanced techniques to compress the video without affecting its quality. This means that we can see sharp and clear videos, even when they are compressed to a smaller size.

Codecs are also important because they allow videos to be compatible with different devices and platforms. For example, if a video is encoded with a specific codec, it can be viewed on a computer, smartphone, smart TV, or game console without any problem.

What types of video codecs are there?

There are many different types of video codecs, but some of the most common are H.264, H.265, VP9, and AV1. Each codec has its own advantages and disadvantages, and some are better for certain uses than others.

For example, H.264 is a very popular codec used to compress high-definition video. It is a good option for most users as it is compatible with most devices and platforms. However, H.265 is a newer codec that is more efficient in terms of bandwidth and can offer improved video quality.

VP9 is an open source codec developed by Google that is used on some devices and platforms. AV1 is an open source codec developed by a coalition of technology companies and is a promising option for the future, offering more efficient compression and improved video quality.

It is important to note that not all codecs are created equal and some may require more processing power or bandwidth to function properly. Therefore, it is important to choose the correct codec for each situation.

Conclusion

In conclusion, a video codec is an essential program or device that allows you to compress and decode videos to make them more accessible and compatible. There are many different types of video codecs available, and it’s important to choose the one that’s best for each situation. Mp4Gain is an excellent solution for those looking to optimize and enhance their video experience.

Video formats and compression codecs for video editing

To understand the basics of video editing, one must consider display frame theory. For this reason, we will often use a fitting comparison in the guide: that of motion pictures and the frames that make up the film.

Video Editing

What is a video format?

We all know that you need a screen, a projector, and a movie to get a movie projection. A sequence of images is printed on the film, translucent as the negatives of the photographs, which in the projection modify the light beam of the projector, allowing only certain parts to pass through, which will generate an image on the screen. Film flows, projected images change rapidly, and a motion effect is obtained.

Let’s go back to digital video.

Let’s say we have a series of images that reproduce a movement (we will see later how the capture phase, or video capture, allows this). These images alone are not enough to show a movie on our PC. In fact, we should be able to tell the machine where these images are, what type they are, how fast they should be viewed, and in what order. For this reason, the format of a clip is defined, that is, a kind of “container”, recognizable by the PC, in which the previous information is attached, in addition to the images.
To recognize a video file format of a clip, you can access the file properties panel or observe the file extension itself (for example, AVI, MPG, QTM, etc … all video extensions).

Digital video
Each editor chooses the best video format they consider appropriate, depending on how they work, the technology they have available and the end result they want to achieve.

In fact, try to think how much a color image of about 800×600 pixels takes up. So much … too much to see 25 per second (as the theory of optics says) and save them to our HD.

What is a video codec?

This is where the codec (COmpressor DECompressor or better DECoder CODER) comes in, or the software that contains the mathematical procedure through which the images are compressed (often with loss or loss of information) to allow agile management and reproduction correct clip.
In practice, compressed video formats are obtained.

The codec is used both to capture and compress the video from an external source, and to play and process the video once it is stored on the hard drive. It could be compared to a kind of very fast Winzip that, if necessary, compresses and decompresses the images of a film.

It is useless to dwell on how a codec manages to make a noticeable decrease in the space occupied by images, reducing the loss of quality to a minimum (sometimes surprisingly!) What little indication to say which is the best video codec or the best compression Of video . The answer is always the same: it depends on what you want to achieve (and, similarly, what is the best video format is a question that has multiple answers).
The important thing is that these codecs are available to us, there are many of them and each one has peculiar characteristics that suggest its working environment.

We suggest downloading the K-Lite Codeck Pack (often also abbreviated as Klite) which contains an important collection of useful and cross-cutting codecs, tools, formats and filters.

Structure of a video format

Hardware codec and analog capture

Until recently, analog capture cards (especially M-Jpeg) were almost all equipped with a proprietary chip that allowed smooth, lossless capture as it took the computer’s processor out of compression work (it’s this chip that kept the price of the cards high).
The hardware codec is still software, but it interacts with this chip by letting the system know that it exists and that it can do the job instead of the CPU.
Without the codec installed, the card chip is useless, whereas if only the software codec is installed, the PC processor may be able to do the compression job, but this in particular cases.

Entry-level PCs are still powerful, and often analog acquisition cards only have one analog-to-digital conversion chip, while the processor does the conversion. In some cases, it is even possible to capture with very complex and elaborate software codecs like DivX or Xvid.
It is clear that choosing the hardware codec is always recommended, as in the case of the MPEG2 capture which requires a lot of resources.

Video codecs

In photography, the choice of the recording codec is quite limited: we usually fluctuate between the JPG format and the Raw format. In video, the choice is slightly wider: MPEG-1, MPEG-2, MPG-4, H264, H265, RAW, ProRes, ProRes Raw, Motion jpeg, etc.

So what are these codecs for, what uses are they designed for, and which ones should you choose?

Códecs

CONTAINERS AND CODECS are NOT the same!

Digital videos are contained in files. These files are called “containers”. The extension of these files often makes it possible to determine their type. The most common containers are MP4, MOV, AVI and MXF. The MXF container is generally used in professional camera series from manufacturers such as Sony or Panasonic.

These containers are “boxes” or “folders” that consist of several elements: video track, sound tracks, time code or subtitles. The purpose of the container is to synchronize all the elements it contains.

Therefore, you cannot know the codec of a video from the file extension: for example, an .avi file and a .mov file could use the same codec to encode the video track.

WHAT IS A CODEC?

A codec is a mathematical procedure consisting of algorithms used to encode and decode the image (codec). It helps define how sensor information is stored and the strategy for compressing and decompressing images.

The size of a one minute 4K video file is about 50 GB. Therefore, it is easy to understand the main advantage of using a codec: compression. For the same minute of 4K recording, for example, using the H264 codec reduces the file size by a factor of about 27, or a final size of about 1.8 GB.

The more “codec” a codec is, the more complex the decoding will be and it will require a powerful machine to accomplish this task. At the same time, the higher the compression, the greater the loss of information that can make post-production difficult.

To achieve this optimization, most codecs use spatial compression: each image is compressed independently of the other images; This is known as an “intra” codec. For more compression, more complex codecs add temporary compression: we’re talking LONG GOP (GOP for “Group of Pictures” or “Long Group of Pictures”); Codecs of this type record only one full image per x images (often 12) and retain only what has changed between these images.

What are the most used video formats?

Choosing audio and video codecs and containers affects video quality and file size. Here we show you how to find the format that best suits your needs.

Decades and decades of developments in the audiovisual field have led to a result that, in some way, can be considered curious. While in other sectors, continuous development has led to a very marked standardization (think of the .doc or .pdf format), in multimedia the situation is at least compound.

An example is the world of audio formats, animated by strong “competition” and a multitude of available options. It is no less than that of video formats, in fact. In this case, in fact, we have to deal with a division between codecs and containers (we will see in a moment what they are and what function they perform) that ends up complicating things even more. Therefore, in case you want to convert a movie, you have to be careful to choose the correct codec and the correct video format, to avoid creating files that are too large or simply unreadable. In short, the error is just around the corner.

Differences between containers and codecs

Before analyzing the situation and seeing what are the most used video formats, it is necessary to clarify some fundamental concepts: first, what is the difference between the codec and the container. If in the audio world, the codec used to digitize the audio track matches the “final” file format, in the video, on the other hand, the codecs used are different from the file format that the video file will assume at the end of the digitization process. The reason is soon explained and lies in the multimedia nature of a video.

A movie, in fact, contains video and audio data: the conversion or playback software must be able to analyze both multimedia streams, and therefore will need different algorithms that work in one or another type of data stream. Codecs do exactly this: as the name, code, and decoding of data (audio and video) are made from movies, so you can convert them to another video format or play them back with a media player. Even with regard to containers, it is enough to resort to the literal meaning of the word: these are files that contain both the video and audio sequences within them and “make them available” to codecs for reading and playback.

What are the most used codecs?

A codec, as mentioned, is in charge of compressing and decompressing the video files and determines how they are played on the screen of the PC or smart TV. Each operating system provides the user with dozens and dozens of different codecs, each useful for encoding and decoding a specific type of file, even if a new one can be installed by downloading special software or packages from the web. Among the most used codecs we find the FFmpeg, Divx, Xvid, H.264 and its evolution H.265, VP9 and VP 10 (also known as the name of the Google codec).

-Divx and Xvid. As the name also suggests, these are two “mirror” codecs, created in the late 20th and early 21st centuries to meet the initial demand for online multimedia content. Since bandwidth and browsing speed were very limited, these are codecs that can guarantee good video quality even at high levels of image compression. In this way, it was possible to obtain files of contained dimensions even with very long movies (such as full movies)

-264 and H.265. Created by the Motion Picture Expert Group, they can be considered as industry standards. Among the most popular and used in all areas (you can find H.264 encoded movies on Blu-ray discs, for example, but also movies downloaded from the network) thanks to its versatility and ability to guarantee an excellent quality ratio / File size. The H.265 codec, in particular, can guarantee, with the same quality, a compression factor twice as high as that of its predecessor: files “treated” with this codec will therefore weigh half compared to their counterparts processed with H.264 codec

-VP9 and VP10. Also known as “Google Codec”, they are the codecs used by the giant Moutnain View to compress and decompress the movies uploaded to YouTube. These are algorithms optimized for online video playback, capable of offering excellent resolution and high quality even with small files. The VP10 in particular is the all’H.265 answer and is designed for resolutions up to 4K
Mpeg-H.

Video Formats: Everything You Should Know

There is currently a wide variety of video formats available to store multimedia content in a file and play it on our devices. Depending on this format (and other multiple factors) the video will basically have a different video quality and a smaller or smaller file size.

However, if you are not up to date on these issues, you may get lost since we enter concepts such as formats, codecs, containers or related terminology such as AVI, MP3, MP4, DIVX, XVID, OGG, MKV, OGG , FLV, MPG, VP9, HEVC, AAC, H.264, AVC and much more.

Guide to convert video formats

In this brief but detailed guide, our objective will be to explain the difference between all these concepts, often confusing, clearly separating terms such as “container video format” and “video codec”, in addition to learning along the way a simple and practical way of Convert videos to different formats.

Outline of a container format

To begin, we must be clear about the difference between these two concepts that are often confused very often: the container format and the video codec. The first one is really the format of the file, the one that surrounds everything (audio, video, etc …), while the second is the format directly related to the video part:

Container format

But let’s see a description of each concept to make it even clearer:

Container format: A video file usually has a specific container format, such as AVI, MP4 or MKV, for example. As the name implies, a file with this format contains several elements (usually and at least, video and audio). However, it is possible that it only includes one of them, or for example multiple audio channels (to have several languages of the same file). Some container formats also allow you to include other elements such as images or integrated subtitles, without the need for external files.

Video codec: It is often confused with the video format, but it really is not the same, since it is related to the video content and not to the container format. It is not a mandatory element, since if a codec is not specified, the video is contained in RAW (uncompressed), taking up a lot of space (for example, 200MB about 10sec). For that reason, a codec is usually chosen to compress the video. Depending on the codec’s choice, better or worse quality will be achieved, and in turn, larger or smaller.

Video specification: Each video codec is usually based on a specific video specification (H.262, H.263, H.264 …), which is nothing more than a set of rules that define how it should behave. This can guide us to know if one codec is more or less recent than another.

Audio codec: In the same way as with the video, we have possible audio channels included in the file. They are also usually compressed with a certain codec to save space: MP3, OGG Vorbis, WMA …

Once this is clear, we will review the most popular container formats and the video codecs that they usually use (this does not imply that they cannot also be used in other container formats):

AVI format (Microsoft, 1992)

Perhaps, in all likelihood, one of the best known container formats is the AVI (Audio video interleave). It was developed by Microsoft in 1992 and is one of the most popular formats, perhaps because of its wide use on Windows platforms. Being one of the first container formats it is the most basic and only allows audio and video channels (although multiple of them can be included, if desired).

If we focus on video codecs, the AVI format accepts almost any VFW-compatible codec, but the most commonly used are the well-known DivX or XviD (which is a bifronte of the previous one).

DivX codec

DivX became popular in version 3.11 and was nothing more than a modified version of a Microsoft codec. Subsequently, and due to its success, they rewrote the code so as not to violate Microsoft patents. However, the DivX project became proprietary, generating a tremendous difference of ideas and causing the birth of a free brother codec: XviD.

Related to DivX was the Stage6 platform which was a kind of YouTube that allowed uploading high quality videos for the time. However, it did not have the necessary financing and failed economically.

XviD codec

XviD became popular as a result of the detriment DivX experienced, surpassing it due to its good quality, efficiency and its open source character. In addition, it also began to be supported on a large number of homemade DVD players, where perhaps, one of the first that stood out was the KISS DP-450.

Although there are currently technically better codecs, XviD is still updated and is still used due to its popularity, compression speed and good performance.

MKV format (Matroska, 2002)

MKV format (Matroska)
MKV format (Matroska)
Matroska, better known by MKV, the extension used in its archives, is an open-source container format that bases its name on the classic Russian Matrioskas dolls that fit inside each other. In addition to the MKV extension (used for video, audio and possible subtitles), there are other extensions used such as MKA (audio only), MKS (subtitles only) or MK3D (3-dimensional video).

Codec x264

This format usually uses some H.264 implementation (codec specification) as a video codec, such as x264. On the other hand, for the audio section you usually use the Vorbis audio codec.

WebM format (Google, 2010)

One of the most recent container formats is WebM (WebMovie), a project slightly based on Matroska. Initially it was developed by the company On2 Technologies, but in 2010 it was purchased by Google, which released the project as a source code, orienting it to the objective of using it with HTML5 as a free standard.

The format has excellent performance and, together with the VP9 codec, make it a very interesting option that seems to have a lot of future.

VP9 codec

The video codec used by WebM is known by VP8, developed by the company On2 Technologies (after a long evolution from TrueMotion S, used in games like Final Fantasy VII). Originally, WebM used VP8 video codec alongside Vorbis audio codec, however, it currently uses VP9 video codec alongside Opus audio codec.

URL | VP9

MPG format (ISO, 1993/1995)

Probably, MPEG-1 and MPEG-2 are one of the most complex concepts to understand. First of all, it must be made clear that these are specifications, and not a format in itself, so each specification is made up of several different concepts:

MPEG-1 / MPEG-2 specification
MPEG-1 / MPEG-2 specification
MPEG-1 Specification (ISO, 1993)

The first one, MPEG-1, is the one used to define the first container format (MPEG-PS) and the VCD storage format (VideoCD, based on H.261). Subsequently, some modifications compatible with VCD that used MPEG-2, such as SVCD (SuperVCD) or KVCD, would also appear.

As a curiosity, mention that contrary to what many people believe, the famous MP3 audio files are not MPEG-3, but MPEG-1 and are defined in the third part of the specification.

MPEG-2 Specification (ISO, 1996)

The second specification, MPEG-2, is the one used to define the container formats (MPEG-PS / MPEG-TS) and the new DVD storage format (H.262). Some MP3 features were also improved and AAC (Advanced Audio Coding), an advanced audio format with numerous improvements over MP3, was introduced.