is bitrate the same as resolution Archives - Page 6 of 7

What is Bitrate? Bitrate of video, audio, internet and more …

Free Download Mp4Gain

What is Bitrate? Bitrate of video, audio, internet and more …

We have surely heard the word bitrate countless times when an expert user refers to some video or audio in digital format, and we have come to know that it is the element that defines the data flow. But what exactly is bitrate? The doubt arises because this parameter is not only used in these fields.

Bitrate

Like the resolution and the final format of the digital video or audio, another of the determining factors to obtain an excellent quality in an image or sound is, without a doubt, the bitrate, a parameter that perhaps is not always fully taken into account. And that not only applies to the field of audio or video. Therefore, in this article, we will find a lot of information to fully understand what bitrate is.

what-is-the-bitrate-

Bitrate: Why it is so important in our digital life
Electronic devices have reached operating speeds that were unthinkable just a few years ago, and that is why today we expect our device, be it a smartphone or tablet, a computer or a hard drive, to respond to us instantly and without hesitation. Many and varied factors have to do with it, but one of the most important is the bit rate at which it can exchange or process information.

The term bit rate, used in computing and telecommunications systems, basically refers to the amount of bits that can be transmitted in a given unit of time through a transmission system or between two digital devices. Depending on the context in which the term is used, the bitrate, or bitrate in English, is measured in Kbit / s or Mbps, kilobits per second or megabits per second, respectively.

what-is-the-bitrate-
Regardless of the unit of measurement used to define the bitrate, higher numbers always mean better and higher quality values, although we must not forget that low bitrate values can also mean less signal processing by the hardware, very convenient in equipment such as smartphones, tablets or netbooks.

Free Download Mp4Gain

Mp4Gain Main Window

Mp4Gain Features

Free Download Mp4Gain

How does the bit rate affect the quality of the music?

How does the bit rate affect the quality of the music?

Which indicator determines the bit rate of an audio file?

Bit Rate

There is a lot of talk these days that we have lost real music with the advent of compressed audio formats like MP3, AAC and the like. Is it really so? Will lossless music save music? Can an inexperienced listener tell the difference between MP3 and FLAC music? Let’s take a look at this problem.

What is Bitrate?
You’ve probably heard the term “bitrate” before, and you probably have a basic idea of what it means, but it might be a good idea to familiarize yourself with its official definition to find out how it all works.

Bit rate is the number of bits or the amount of data that is processed over a period of time. In audio, this generally means kilobits per second. For example, the music you buy from iTunes is 256 kilobytes per second, which means that every second of the song contains 256 kilobytes of data.

The higher the bit rate of the track, the more space it will take up on your computer. Audio CDs tend to take up quite a bit of space, so it has become common practice to compress these files so that you can burn more music to your hard drive (or iPod, Dropbox or whatever). This is where the “lossy” and “lossy” formats conflict.

Lossless and Lossy formats: what’s the difference?
When we say lossless, we mean that we haven’t really changed the original file. That is, we copy a track from the CD to our hard drive, but we do not compress it to the point of losing data. Essentially the same as the original CD track.

However, most of the time, you will probably extract your music in Lossy format. That is, you took a CD, copied it to your hard drive and compressed the tracks so they don’t take up much space. A typical MP3 or AAC album is probably about 100MB. The same album in a lossless format like FLAC or ALAC (aka Apple Lossless) will be around 300MB, so it has become common practice to use lossy formats for faster downloads and more hard drive savings. .

The problem is that when you compress a file to save space, you are removing chunks of data. Just like when you take a high-quality image and compress it to JPEG, your computer grabs the raw data and “tricks” certain parts of the image into being basically the same, but with some loss of clarity and quality.

Let’s take the following two images as an example: the one on the right is clearly compressed and the quality is reduced as a result.

Remember that you are saving hard drive space by compressing music in lossy formats, which can make a big difference for an iPhone with 32GB of storage, but is only a trade-off in terms of size / quality.

There are different levels of compression: 128 kbps, for example, takes up very little space, but it will also have lower playback quality than a larger 320 kbps file, which in turn is of lower quality than a 1,411 reference file kbps. 1,411 kbps is CD-level audio quality, which is more than sufficient in most cases.

The problem is not how much the music is compressed, but what equipment you listen to it on.

Does bit rate really matter?
As memory gets cheaper every year, listening to sound at a higher bit rate, or even lossless formats, is starting to become more and more popular. But is it worth the time, effort, and memory usage on your phone or computer?

I don’t like answering questions this way, but sadly the answer is: it depends.

Part of the equation is the hardware you use. If you are using a good quality pair of headphones or speakers, you are used to wide frequency and dynamic range. As such, you are more likely to notice the downsides that come with compressing music into lower bitrate files.

You may notice that low-quality MP3 files lack a certain level of detail; Subtle backing tracks may be harder to hear, the highs and lows will not be as dynamic, or you may hear distortion in the lead vocal.

What is the bit rate?

What is the bit rate?

Bitrate

Bit rate refers to the data transfer rate (that is, how many bits are transmitted in a given time), generally expressed in bits per second.

Bitrate

Common units of bit rate are kilobits per second (Kbps) and megabits per second (Mbps). The term is also commonly used when talking about digital sampling and sample rates. For example, the MP3 audio compression algorithm is often configured to output files at a bit rate of 128 kbps. This means that the file contains an average of 128 kilobits for every second of audio (960 KB per minute). This is in contrast to CD audio, which is encoded as 44,100 16-bit stereo samples per second: 1411.2 kbps (16-bit x 44100 Hz x 2ch).

Often times, bytes are written in uppercase and are multipliers (for example, “KB” for kilobytes) and lowercase factors are bits (for example, “kb” for kilobytes). All modern computers use 8-bit bytes.

MP3 bit rate
The MP3 bit rate can be misleading. For example, an MP3 “constant bit rate” (CBR) of 128 kbps will use approximately 128 kilobits for every second of encoded audio (so the file size in bits divided by the length of the audio is approximately 128,000) , and headers, your frames will appear at regular intervals, but internally, from frame to frame, you can encode audio at bit rates higher or lower than 128 kbps by using a bit bucket (the ability of a frame to use bits of replacement of a previous block). However, the size of this bucket, and therefore the amount of variability, is limited, so 128 kbps will be very close to the effective bit rate throughout the file.

See also: 8D surround sound and how to do it
As another example, “128 kbps VBR MP3” is often incorrect, since the purpose of VBR is to allow each of the internal MP3 sectors to have its own bit rate. When people refer to the VBR MP3 bit rate, they are generally referring to the actual average bit rate of their frames. If the length of the encoded audio is known, then the “bit rate” can be the data size of the file divided by its duration, which will be fairly close to the same number. However, the length of an MP3 VBR cannot be accurately determined without scanning all the frames.

Let us remind you that when mixing and mastering, our engineers encode mp3s with various algorithms, and choose the best result so that the client gets the highest acceptable quality from their composition.

The higher the bit rate, the better the track?

The higher the bit rate, the better the track?

bit rate

This is not always the case.

bit rate

For starters, let me remind you what bitrate t (bitrate, instead of bitraid). In fact, this is the data rate in kilobits per second during playback. That is, if we take the size of the track in kilobits and divide it by its duration in seconds, we get its bit rate, the call. File-based bitrate (FBR), usually not too different from the bitrate of the audio stream (the reason for the differences is the presence of metadata on the track: tags, “embedded” images, etc.) .

Now let’s take an example: the uncompressed PCM audio bit rate recorded on a normal audio CD is calculated as follows: 2 (channels) × 16 (bits per sample) × 44100 (samples per second) = 1411200 (bps ) = 1411.2 kbps. .. Now let’s take and compress the track with any lossless codec (“lossless” – “lossless”, that is, one that does not lead to information loss), for example, the FLAC codec. As a result, we will get a lower bit rate than the original, but the quality will remain unchanged; here is your first rebuttal.

Something else is worth adding here. The lossless compression output bitrate can be very different (but is generally lower than uncompressed audio); It depends on the complexity of the compressed signal, or rather on data redundancy. So simpler signals will compress better (ie we have smaller file size for the same duration => lower bitrate), and more complex signals will be worse. That’s why lossless classical music has a lower bitrate than, say, rock. But it must be emphasized that the bit rate here is in no way an indicator of the quality of the sound material.

Now let’s talk about lossy compression. First of all, you need to understand that there are many different encoders and formats, and even within the same format, the encoding quality for different encoders can differ (for example, QuickTime AAC encodes much better than outdated FAAC), not to mention the superiority of modern formats (OGG Vorbis, AAC, Opus) on MP3. Simply put, from two identical tracks encoded by different encoders with the same bit rate, some will sound better and some will sound worse.

Also, there is upconversion. That is, you can take a track in MP3 format with 96 kbps bit rate and convert it to 320 kbps MP3. Not only will the quality not improve (after all, data lost during the previous 96kbps encoding cannot be returned), it will even get worse. It is worth noting that at each lossy encoding stage (at any bit rate and any encoder) a certain amount of distortion is introduced into the audio.

And even more. There is one more nuance. If, say, the bit rate of an audio stream is 320 kbps, this does not mean that the 320 kbps was spent encoding that very second. This is typical for constant bit rate encoding and for those cases where a person, hoping for maximum quality, forces a constant bit rate too high (for example, setting CBR to 512 kbps for Nero AAC ). As you know, the number of bits assigned to a particular frame is regulated by the psychoacoustic model. But in case the allocated amount is much lower than the set bitrate, even the bit deposit is not saved (for terms see the article “What is CBR, ABR, VBR?”) – as a result, we get useless “zero bits” that simply “wrap up” the frame size to the desired one (that is, increase the size of the stream to the specified size). By the way, this is easy to check: compress the resulting file with a filing cabinet (preferably 7z) and look at the compression ratio – the more, the more zero bits (as they lead to redundancy), the more space wasted.

Bit rate as a characteristic of digital video and audio

Bit rate as a characteristic of digital video and audio

bit rate

Concept

bit rate

Bitrate: literally, the information bit rate. It is common to use the bit rate when measuring the effective information transmission rate through the channel, that is, the “payload” transmission rate (in addition to that, the channel can transmit service information, for example symbols start and stop for asynchronous transmission or control symbols for redundant coding). The baud rate, which takes into account the total bandwidth of the channel, is measured in baud.

Bit rate is the number of units of information required to store (transmit) one second of a stream of data (generally audio and video files). It is generally measured in ‘kbps’, kilobits per second.

The term bit rate is used in two basic meanings
: channel or device characteristic: the maximum number of bits that can be transmitted per unit of time.
– The amount of data stream transmitted in real time (the minimum channel size that this stream can pass through without delay).
– A special case is the compressed video or audio bit rate.
Bit rate is expressed in bits per second (bit / s, bps), as well as values derived with the prefixes kilo, mega, etc.

The term bitrate (along with subjective quality criteria) is often used as a characteristic to evaluate the performance of lossy compression algorithms.

Bitrate characterizes both the density of the information package and its quality. For example, out of two MP3 files compressed with different bit rates, a file with a higher bit rate will have higher sound quality (close to the original). At the same time, a file of a different format, with the same bit rate, can offer both better and worse sound quality.

On audio CDs, information is losslessly encoded at a constant 1407 kbps bit rate.

The MP3 format allows encoding audio information with constant or variable bitrate from 32 to 320 kbps, that is, they provide five times the compression compared to CD.

Bitrate and its calculation Bit rate (bit rate) Part 3

Bitrate and its calculation Bit rate (bit rate) Part 3

bit rate

coding.

bit rate

Codecs and Media Containers

Since 2014, the most common high definition video format is HD (Full HD), with a screen resolution of 1920 x 1080 pixels and a screen aspect ratio of 16 x 9. (This format is compatible with most modern LCD and plasma televisions, but not all are capable of providing a high quality picture.
The fact is that most of these televisions have a lower screen resolution than is necessary for viewing in Full HD, for example 1280×720. The HD format has varieties: 1080i and 1080p. As with other formats, the letters i and p represent progressively scanned or interlaced images.

But, unlike the usual PAL and NTSC formats, here with interlaced scanning the frame rate is 60 and with progressive scanning 50 frames per second. This is a standard, you can stick to it, but you can work around it too. The fact is that today a full HD format can only be played on a computer, there are no special devices (players) to watch it (HD DVD (gradually dying) and Blu-Ray disc players do not provide Full HD quality, but more on that later), therefore full compliance with the rules is no longer as important. The next most common high definition video quality and format is HDV, with a screen resolution of 1440 x 1080, but also with a 16×9 aspect ratio. This ratio is achieved by “stretching the pixels” horizontally, from 1440 to 1920. Therefore, for a Full HDV display, a FullHD television with a screen resolution of 1920×1080 is also required. Of course, the video quality in HDV format is lower than HD, but still, HDV format is quite common among users. The reason is that the HDV format was invented before HD, and even before the latter came out, a lot of video equipment was developed and released that only supports 1440×1080. High definition movies, generally recorded on HD DVD and Blu-Ray discs, also have an HDV resolution of 1440 x 1080. Even before the advent of HDV and HD, the 720p “high definition” format appeared. The resolution is 1280×720, the aspect ratio is 16×9. It is essentially a transitional format, from standard PAL to HDV and HD. The world’s first “high definition” hobby camcorder produced by JVC recorded at 720p. Even earlier, the PAL television format appeared in 720×576 resolution with 50 Hz interlaced scan. Now, this format is used in digital and satellite television (not HD). Now (2014-2017) I use mp4 format: mp4 – Full HD – 1920 x 1280, 16×9 variable bit rate 10 – 15 mbps for home viewing on 64 inch Full HD TV, this is enough. mp4 – HD – 1280 x 720, 16×9, variable bit rate 4-6 mbps. – if you need to save disk space, or if quality doesn’t really matter (or if you need to speed up rendering).
Источник: https://vseprost.ru/vybor-bitrejta-dlya-zapisi-multimedia.html

Bitrate and its calculation Bit rate (bit rate) Part 2

Bitrate and its calculation Bit rate (bit rate) Part 2

bit rate

Let’s go back to the DVD story for a moment.

bit rate

When the first analog-to-digital converters appeared in capture card form, it was claimed that 60 minutes of video could be put on a DVD-R with no loss of quality. In the claimed presentation data of the DVD format, the maximum bit rate of the multiplexed stream is 9.8 Mbit / s. When DVD recorders appeared that were capable of digitizing an analog signal in high quality, it was said that the recorder could fit up to 125 minutes on a disc without losing quality and up to 90 minutes if you wanted to save sound in PCM format.

We test, we verify, we write from both disk and videotapes; there is no visual difference even during pauses and in frame by frame mode (if the recorder is good). The bit rate that the recorders give to the output of the digitized image is 9000 Kbps and sometimes a little more. Why is the math not the same as the DVD burner result?

Probably because we do the calculation for a constant bit rate, and the recorders can already digitize video with a variable bit rate and have appropriate compression algorithms. By setting the upper limit of the bit rate at 9000 Kbps, you can achieve a good picture in video segments with dynamic actions, while in other parts of the same video the value of the bit rate can reach 2000 Kbps. noticed that when you record a video or a photo with a digital camera, the files have different sizes? Once the initial parameter is set, the codec itself chooses the value of the bit rate. Optimal bit rate for DVD video Considering the fact that up to 120 minutes of video can be recorded on DVD-R without quality loss, we ask ourselves: how to do this? Let’s consider 2 ways: 1. If you are using a DVD burner, set it to “lossless quality” mode and set to record. If your video is 60 minutes long, the recorder will not stretch it by 4. 36GB and it will only take up half the free space. 2. If you use a capture card or TV tuner, first capture as described here and then compress the resulting file with a quality program with modern codecs and multiple passes (at least the same Freemake Video Converter) at the speed of dvd5 for 120 minutes (don’t forget the menu). Consider an option when your video is short and you are not going to burn it to DVD-ROM or if you want to burn multiple MPEG-2 files to disc at once without losing quality. Below is a table calculated mathematically on the basis that you can fit 120 minutes of video on 4464MB of disk space (no menus). There are a few things to keep in mind: The table is written for MPEG-2 files. The table is not written for previously compressed videos. These values do not include a menu. Using different programs, you can get different results. The values in the table may vary depending on the content of the video. If the program has a bit rate option then you need to set “VBR” (variable). The values in the table are based on “lossless compression”. In this article, “lossless compression” refers to the viewing experience. In fact, in the analytical version, the word “compression” already denotes a loss of quality.
Источник: https://vseprost.ru/vybor-bitrejta-dlya-zapisi-multimedia.html

Bitrate and its calculation Bit rate (bit rate)

Bitrate and its calculation Bit rate (bit rate)

bit rate

Flow rate data per unit of time.

bit rate

Information flow is normally measured in bits and transit time in seconds (bit / s, bps). There are other quantities derived with the prefixes kilo- and mega- (kbit / s, kbit / s, kbps, Mbit / s, Mbps, Mbps). Bit rate is one of the main parameters of a video. Its value affects the size and quality of the video file. The bit rate is directly proportional to the quality and size of the file. The higher the bit rate, the better its quality and the larger the file size. Two types of speed must be distinguished: maximum bit rate: the maximum number of bits that can pass per unit of time, and bit rate: the bandwidth of the channel without delay.

Data stream compression modes

Constant Bit Rate Constant Bit Rate (CBR) is the encoding of the data stream, specified by the user and has a constant value throughout the length of the file. This mode improves compatibility and the ability to calculate more accurately, but can increase the size of the output file. Do not use this mode for dynamic scenes (sports programs, action movies, etc.) and when objects are moving in different directions. Variable Bit Rate (VBR) Variable Bit Rate is a mode in which the codec determines the amount of information stream transmitted based on the complexity of a given file segment. This mode produces the best quality in an optimal size and prevents flickering. The disadvantages of this method include only the unpredictability of the output file size and the possibility of incompatibility. Variable bit rate is actively used for burning Blu-Ray and DVD discs, where there is no limitation on the size of the file as such. Average Bit Rate (ABR) Average Bit Rate is a combination of variable and constant bit rates set by the user. Unlike variable bitrate, the data stream varies within strict limits and does not reach the minimum and maximum values. This allows you to predict the output file size much more accurately than VBR and improve video quality in fast-moving video scenes. The method was applied in the network. This mode is sometimes used to compress audio.

Bitrate calculation

Having mastered what the bit rate is and having disassembled the compression modes of the flow of information, we can proceed to the independent calculation of the bit rate. Let’s establish the conditions of the problem: video: home video 120 minutes long sound: present; menu: necessary; DVD-R Media (DVD + R) 4.36 GB; Output format: DVD (MPEG-2) DVD-R size: 4.36GB = 4464MB. Size is critical, so we will be calculating from 4300MB for several reasons: 1. Bitrate cannot be accurately calculated and the file may be larger than planned. All full disk space sometimes leads to improper disk startup. 3. Many programs are recoding based on this value. We subtract another 300MB for the menu and the audio track (if your sound is not in PCM format, whose bit rate is much higher, and if you don’t plan to create multiple audio tracks) and we get 4000MB. 4000: (120 * 60) = 0.556 Mbps = 0.556 * 8 = 4.444 Mbps = 4.444 * 1024 = 4551 Kbps. For a high-quality DVD-Rip, this value is ideal, but for MPEG-2 it is barely supportable. The fact is, different video formats need different bitrate values for an acceptable picture. You can try to play this video and if there are dynamic moments, you will see artifacts in the shape of squares in the video. It follows from this that you need to reduce the length of the file to about 60 minutes or look for other compression methods.

But what role does the bit rate play?

This term is known primarily for describing the quality of lossy compressed audio (eg MP3). Unfortunately, this makes it even more difficult than with channel-separated compression, the bit rate is split between the two channels: stereo MP3 (not to be confused with dual channel) with a 320 kBit / sec bit rate. uses only 160 kBit / sec per channel.

Bit Rate

Or different bit rates per channel: set stereo (mono signal calculated with additional stereo information), on the other hand, it works with volume differences between the two channels and therefore can use the bit rate much more efficiently .

Bitrate

DAC, bit rate

What exactly is the obviously so essential bit rate? For a CD based on the Red Book standard, the bit rate is calculated as follows: 2 channels * 44,100 Hz sample rate * 16 bit depth per sample results in 1,411,200 bits / sec., That is, 1.4112 Mbit / sec. Bit rate. Obviously, this is considerably more than what compressed formats (should) provide. You can see how the compression processes work: last but not least, they more or less cleverly reduce the bit depth per sample at a given sample rate of 44.1 kHz, for example. The amount of data decreases, and that is exactly the goal of every data compression: halving the bit rate means exactly halving the amount of data.

As an example, I have compared some common file formats for digital audio:

Format

Codec (s)

Multichannel

Sampling rate

Bit depth or resulting bit depth from bit rate

Compression
/
subject to acoustic losses

Wav

PCM et al.

yes

any

Optionally, depending on the codec, also lossless

AIFF

PCM et al.

Not

any

Not

FLAC

FLAC (Free Lossless Audio Codec)

yes

0.001 kHz-655.350 kHz

4, 8, 16, 20, 24, 32

without losses

Apple loses
less
MP4

ALAC (Apple Lossless Audio Codec)

yes

0.001 kHz-384,000 kHz

16, 20, 24, 32

without losses

MP3

MPEG I Layer 3 in various incarnations
as B. LAME

Not

8-48 kHz

8-320 kBit / sec. CBR / VBR or 640 CBR for free MP3 format

with mandatory loss

Most readers will know that lossy compression is often based on psychoacoustic models or natural limitations of human hearing: what humans cannot (should) hear is not stored in the musical signal and is irretrievably lost, apparently not. you need it. The most popular example of this is the old MP3 format already mentioned. For some audiophiles, lossy compression is by definition useless for serious music listening, regardless of whether or not they would notice the loss of compression. For others, the sound is 320 kBit / sec. MP3 encoded for pop music are identical to CDs, they are satisfied.

DAC bit rate

Lossless compression, on the other hand, has become increasingly popular since Internet bandwidths and storage capacities have steadily increased. An example is the FLAC format, which fortunately is also “open source”, which means that it can be used freely and even changed in terms of the program. Meanwhile, most of the time it is directly compatible with proprietary audio hardware, so FLAC files can be played without the help of a computer, and in some cases even created (ripped CDs). As the table above shows, FLAC supports very high sample rates and bit depths, as well as multi-channel sound.

With FLAC, the audio signal is encoded based on computable fixed-point algorithms that conserve computational power, in which blocks are formed step by step and stereo separation is converted to mid-side separation and performed the remodeling of the signal with differential storage. No information is lost, it is stored more efficiently than, for example, on a CD; Depending on the complexity of the audio signal, compression rates of up to 30% can be achieved.

FLAC

It should be clear once again that FLAC or MP3 are file formats and therefore cannot be directly compared to the PCM of the Red Book encoding of a CD or DSD (see next section). Let’s leave it at that on the subject of data compression.

What does “bit rate” mean in a video?

When downloading videos from the Internet or copying videos from disc to your computer, you may have the option of choosing a different bitrate. Even DVDs have specific bit rates. As technology has advanced, video media are able to achieve higher quality, such as high definition DVD, and this is achieved by increasing the video bit rate.

Bitrate

Definition

Bit rate, sometimes referred to as “bit rate”, is the term used to define compression of audio, video, or other multimedia compression in terms of the amount of data, measured in bits, per unit of time in the printed material. Bit rate is the ratio of quality to time. Bit rate is also often measured in kilobits or megabits per second.

Bitrate

Sense

Videos with a higher bit rate will have a larger file size. For example, it will take longer to download or stream from the Internet and upload to a device or computer, and you can burn fewer videos to DVD. However, a higher bit rate usually indicates a higher quality. In this way, your video can be clearer and sharper. When browsing for video or importing it to computer from DVD or camera, choose the highest bit rate for higher quality. However, if space is your main concern, choose the lowest bitrate when downloading or compressing video files.

bit rate factors

Programs will have different bit rates depending on different factors. For example, the output material may have more depth and quality, thus producing a higher bit rate. High definition movies have a higher bit rate than standard definition, for example. Different types of video files have different bit rates and you can also choose different bit rates for the same file. For example, iTunes allows you to compress audio files with a bit rate greater than 128 kilobytes per second to save space on your iPod.

Standard bit rates

Most standard definition DVDs have a maximum bit rate of 9.8 megabits. High definition television has a bit rate range between eight and 15 megabits per second, while the standard for 720p high definition video is approximately 19 megabits per second. At the time of publication, Blu-Ray DVDs have the highest bit rate of all consumer videos with a maximum of 40 megabits per second. This makes the content of Blu-Ray DVDs more than four times that of standard DVDs.