What is the difference between PCM and RAW in the audio settings of the projector?

[Wyatt21]

Most projectors and TVs have PCM and RAW output settings in the audio settings. For different needs, you can switch the audio output. So what is the difference between PCM and RAW? which is best digital audio output pcm or raw？Come here today to popularize it for everyone.

PCM: Pulse Code Modulation (PCM). In simple terms, it converts an analog signal with continuous time and continuous value into discrete time, and then transmits the digital signal with discrete value in the channel. Pulse code modulation is the process of first sampling the analog signal, then quantizing the sample amplitude, and encoding. The projector that supports PCM audio output is output to the next device after the decoding is completed. If the player itself is powerful, choose this. In PCM, corresponding technologies are sometimes used to reduce the data rate of digital signal sources, which is convenient for storage and data transmission.​

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RAW: It means "unprocessed". It is called BitSream in some foreign brand players. We usually call it "source code". The meaning is to output the audio format on the disc from the coaxial and optical fiber without processing, "original". This requires the user's power amplifier to have this audio format decoding function. When the audio on the projector is switched to RAW output, the audio will be output to the next device to allow the next device to decode it. Under normal circumstances, the external power amplifier chooses RAW output.​

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Through the above knowledge popularization, many netizens have a general understanding. Since the current smart projectors have their own audio equipment, the audio can be output using PCM. Users who have higher requirements for sound quality will also choose to configure A set of power amplifier sound system, then you can switch to RAW audio output. The HDMI output is the best choice for audio connections, followed by fiber and coaxial.

Dangbei F1 projector​

At present, most smart projectors support HDMI and optical fiber. When Dangbei F1 projector supports HDMI and optical fiber, of course, PCM audio output can also be used. The only difference between PCM and RAW audio output is self-decoding and non-decoding. RAW supports source code output, and PCM can decode and play by itself.

 

[akagi1945]

effect of using HDMI connection will be better, I originally used optical fiber, and later changed to HDMI

 

[guekjk]

PCM: This stands for “pulse-code modulation.” Use this setting if the external device you've connected to the HDMI port has already processed the sound, and you just want it to come out of your TV's speakers.

 

[soglkkp]

Dolby Digital is compressed so PCM is better. Dolby True HD, DTS HD MA, Atmos and DTS X are also lossless, so should be similar quality to PCM. If the source audio is stereo, it should only be coming from your front left and right speakers unless you use an up mixer.

 

[ejilliif]

PCM over optical is limited to 2 channels however bitstream (with limitations) is also supported which means DTS and Dolby Digital will also work over optical however optical has a bandwidth limitation which means you won't get DTS-HD, Dolby Digital+ or Dolby Atmos. If you are passing DTV through optical to your receiver, DTV signal usually carries Dolby Digital/DTS and your TV will send that directly through optical so you will get 5.1 discrete channels from DTV unless the content is only 2 channel, then it will pass it as RAW/PCM afaik.

 

[IUOKKI]

The differences between PCM and raw are as follows

PCM and raw are both audio output methods, and the biggest difference is that raw directly outputs audio to the next device without coding, which is the so-called audio source output; PCM is the abbreviation of pulse code modulation. The audio will be modulated and coded by the device itself and then output to the next device, which requires high performance of the device itself.

 

[IUOKKI]

The difference between PCM and raw is as follows: different decoding mode, different working principle and different dependence.

1、 Different decoding methods

1. PCM: the decoding mode of PCM is that the box decodes itself and outputs it to the back-end device.

2. Raw: raw is decoded by outputting source code to back-end devices, and back-end devices decode them themselves.

2、 Different working principles

1. PCM: the principle of PCM is to transform a continuous analog signal into discrete time, and then transmit the discrete digital signal in the channel..

2. Raw: raw works according to the received sensor photos, accepts elements, and then creates a visual image necessary for the camera sensor data information.

3、 Different dependence

1. PCM: when playing files, PCM must rely on its file name to arrange them in frame order.

2. Raw: raw allows playback files to be arranged in frame order, regardless of its file name.

 

[geilkek]

If the only thing you have is the television speakers for your entertainment, the PCM setting is the best option because it lacks compression. You'll hear muted tones and less audio clarity when using the Dolby Digital setting with your stock setup.

 

[TingTing]

RAW supports source code output, and PCM can decode and play by itself.

 

[Rooeogsl]

Raw is bitstream, it is the original data, pcm is output after decoding, if your power amplifier is powerful, of course choose raw.

 

[Rooeogsl]

PCM Pros and Cons​

Advantages

• Decoding is done in the Blu-ray player.
• Less work for the receiver.
• Quicker, direct, and eliminates lag.
• Better quality access to additional audio tracks.

Disadvantages

• More work is done by the player.
• Audio quality is partially determined by the Blu-ray player.
• PCM transmits a two-channel signal over digital optical or coaxial.

Bitstream Pros and Cons​

Advantages

• The home receiver decodes audio.
• If the receiver offers higher quality audio processing, it can be used.
• Possibility of higher quality sound.
• Bitstream sends an encoded 5.1 signal over digital optical or coaxial.

Disadvantages

• More work is placed on the receiver.
• Requires a high-quality receiver to achieve better results.
• Supplemental audio is scaled down, which decreases quality.

Final Verdict​

There are a number of factors that should go into your choice, including the quality of your Blu-ray player and audio receiver. More often than not, you'll want bitstream. The potential for greater audio quality and the flexibility to use coaxial outputs puts it ahead of PCM.


The only situation where PCM comes out on top is when using secondary audio streams. If you don't plan on doing this, and your receiver isn't severely lacking in quality, go for bitstream.

original：https://www.lifewire.com/blu-ray-audio-bitstream-vs-pcm-1846396

 

[klsloo5h]

We can see the following options under S/PDIF setting items: OFF, RAW, PCM.

OFF: It means to turn off the digital audio output function of the player, that is, there is no output on the coaxial and optical fiber.

RAW: It is called BitSream in some brands of players, and we usually call it "source code". The meaning is to output the audio format on the optical disc from the coaxial and optical fiber without processing. This requires the user's power amplifier to have the decoding function of this audio format.

PCM: Named "Pulse Modulation Coding", its function is to convert the current audio format to PCM format, and then output. CD uses this audio coding format. This function is provided to take care of some users who are still using old power amplifiers. For example, in the early NTSC DVD video discs, the audio is all Dolby AC-3. If the AC-3 audio is output directly in RAW mode, many old power amplifiers in the CD player era cannot decode it. After "translating" Dolby audio to PCM, this problem is solved.

But the PCM re-encoding function of S/PDIF has a fatal flaw. The player can only perform PCM re-encoding on the audio format that it can decode. Therefore, if the DVD player cannot output the content in analog for certain audio, then when the S/PDIF is set on the PCM, the coaxial and optical fiber are not output.

 

[klsloo5h]

the difference:

RAW: The simple understanding is that this device will directly output to the next device without decoding, and let the next device decode it. Choose this if you need an external power amplifier;

PCM: It means outputting to the next device after the local decoding is completed. Choose this if the player is powerful.

Wire: HDMI cable is the best connection, followed by optical fiber and coaxial.

 

[tvholic]

If a DVD player cannot analog output the contents of a certain audio, then S/PDIF on a PCM has no output for coaxial and optical fibers.

 

[Milabobo]

wow thanks for sharing, so many information

 

[jowlgek]

Thank you for sharing

 

[sekjgfo]

Thanks so much for the very good content. Solved my problem.

 

[58129166]

good

 

[Adney]

good article

 

[Cloud745]

Use PCM setting if the external device you've connected to the HDMI port has already processed the sound, and you just want it to come out of your TV's speakers. Note: This changes the signal to 2.0 PCM as it passes through the TV