![\"Samplerate\"](\"https:\/\/manual.audacityteam.org\/m\/images\/0\/0e\/waveform_sample_rates.png\")
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Sample size, sample rate, bit rate<\/p>\n
![\"digital](\"https:\/\/i.pinimg.com\/originals\/da\/30\/0b\/da300b5fce5cf07c7f451e5a72ecded2.png\")
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Sound is an integral part of video.
\nAs was the case with the author, initially I will handle the video with the stance that it is only necessary to make a sound.<\/p>\n
However, as I went over and over again, I gradually began to wonder “how can I make a good sound” and “what kind of knowledge do I need to have to optimize the sound parameters?” I will come.<\/p>\n
In this article, we will explain the sound of videos, learn how to make it “sound good” and what kind of knowledge should be used to control the sound quality and amount of audio data.<\/p>\n
What is “video sound”?
\nThere are several types of voice data.
\nParameters related to the sound quality of audio data
\nSample size (bit depth)
\nSampling rate
\nBit rate
\nresume
\nPoints to build a video distribution service Free distribution
\nVideo Recording And Live Distribution Guide You Can Do In-House For Free<\/p>\n
What is “video sound”?
\nVideo is a combination of video and audio data.
\nVideo and audio are separate, and a video file is a combination of different data methods (codecs).<\/p>\n
Since the video file has the above structure, the image quality and sound quality can be adjusted separately.
\nTherefore, the sound quality of the video depends on the audio data part.<\/p>\n
There are several types of voice data.
\nThere are several data methods for voice data.
\nThere are two main types, each of which has multiple codecs (data methods).<\/p>\n
lossless codec
\nA data method that has a low compression rate but can restore the original sound quality.
\nFLAC, ALAC, etc<\/p>\n
lossy codec
\nA data method that has a high compression rate but cannot restore the original sound quality when played back.
\nMP3, AAC, WMA, etc<\/p>\n
What is used in Internet video is a lossy codec with a high compression ratio.
\nThere is a lot of AAC and MP3, and it seems that most of the videos that are generally seen these days are AAC.
\nTherefore, to aim for high sound quality in Internet video distribution, it is important to understand how the sound quality of AAC or MP3 (lossy codec) goes up or down.<\/p>\n
Parameters related to the sound quality of audio data
\nThe factors that affect the sound quality of audio data are listed below.
\nBy understanding and understanding the following and setting them properly when creating audio data, you will be able to control sound quality properly.<\/p>\n
Sample size (bit depth)
\nThe larger the sample size, the finer the volume of the sound, so it sounds softer. If the sample size is small, it sounds harsh to the ear.
\nIf it is 16-bit, it is played by dividing the loudness of 65536 by 2 to the 16th power.
\nIf it is 24 bits, it will be 2 to the power of 24, which is 16777216 division.<\/p>\n
Actually, when you create a 32-bit MP3 file and an 8-bit MP3 file from the same WAV file and compare them, the 8-bit has a “sir” noise and the 32-bit has the same level of fluency. sounds like the original rice field file. (The bit rate and sample rate of the two files are the same.)
\nIn the case of MP3 and AAC, the bit rate also greatly affects the sound quality.
\nSampling rate
\nThis is the frame rate on the video.<\/p>\n
It is a numerical value that indicates how many times a second is divided into data, and if it is 44.1 kHz, it means that the sound is divided into 44100 times and converted into data.
\nThe finer the cut, the higher the sound reproducibility and the better the sound quality.<\/p>\n
CD is 44.1 kHz, and it seems that the range said to be audible to the human ear can be almost covered by this 44.1 kHz. So even if the sampling rate is higher than that, the human ear can’t feel it.<\/p>\n
However, many people feel that the sound is different at high sample rates, so there are audio files with higher sample rates.<\/p>\n
44.1kHz or 48kHz is often used for the audio of Internet videos.
\nSince the music industry uses 44.1kHz and the video industry uses 48kHz, it is recommended to use 48kHz for audio used for video unless there is a particular problem.<\/p>\n
When collecting audio materials with different sampling rates into one video, problems such as sound deviation will occur.<\/p>\n","protected":false},"excerpt":{"rendered":"