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Topic: 48Khz or 44.1Khz? (Read 8498 times) previous topic - next topic
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48Khz or 44.1Khz?

I need to reencode a AC3 file from a DVD to MP3 and I want to know what is the best choice:
- Downsampling the original 48000Hz to 44100Hz or keep it at 48000Hz?

I have to use 160Kbps CBR.

48Khz or 44.1Khz?

Reply #1 –
If you are going to use Lame, downsample it.

If not, it's better to keep the original frequency.

48Khz or 44.1Khz?

Reply #2 –
Quote
If you are going to use Lame, downsample it.

If not, it's better to keep the original frequency.

Hi ! can you explain me why it should be downsampled ? Why with lame but not with other codecs ?

sorry for my english ! i am learning the language for about three years in the school ^^
bye

48Khz or 44.1Khz?

Reply #3 –
Quote
If you are going to use Lame, downsample it.

If not, it's better to keep the original frequency.

I was under the impression that it was better to use 44,1kHz unless you want to achieve transparency? It's my impression that the higher the sample rate, the harder it is to compress the audio. Anyway, 44,1kHz should require less CPU to decode, and won't require resampling (any decent sound card should be able to play CD w/o resampling ) thus allowing you to use more CPU for other tasks, such as decoding video. This is especially useful on old machines.

Anyway, won't compressing the audio to 160kbps MP3 introduce far more audible artifacts than resampling it once (or twice)?

48Khz or 44.1Khz?

Reply #4 –
Quote
Quote
If you are going to use Lame, downsample it.

If not, it's better to keep the original frequency.

I was under the impression that it was better to use 44,1kHz unless you want to achieve transparency? It's my impression that the higher the sample rate, the harder it is to compress the audio. Anyway, 44,1kHz should require less CPU to decode, and won't require resampling (any decent sound card should be able to play CD w/o resampling ) thus allowing you to use more CPU for other tasks, such as decoding video. This is especially useful on old machines.

Anyway, won't compressing the audio to 160kbps MP3 introduce far more audible artifacts than resampling it once (or twice)?

thx !

i got enough cpu power, so it doesn't matter !
hmm, it's harder to compress ? i use aps so it should be transparency with 48khz, or not ? 

48Khz or 44.1Khz?

Reply #5 –
LAME is tuned for 44.1kHz.

48Khz or 44.1Khz?

Reply #6 –
Quote
LAME is tuned for 44.1kHz.

damn, all my ripped movies have 48khz mp3 tracks (encoded with lame) ! 

ok, but at least i've learned something new ! thx cya

48Khz or 44.1Khz?

Reply #7 –
Well 48kHz shouldn't be horrible but it's just not optimal either.

48Khz or 44.1Khz?

Reply #8 –
Quote
Well 48kHz shouldn't be horrible but it's just not optimal either.

and what's about vorbis ? should i use there 48khz ? (which version is better ? gt3b1 or 1.0 cvs ?)

48Khz or 44.1Khz?

Reply #9 –
Quote
which version is better ? gt3b1 or 1.0 cvs ?

If you are going to go above q5, it's a good idea to use GT3. If not, either one should be fine.
Hard work might not kill you, but why take any chances?

48Khz or 44.1Khz?

Reply #10 –
For below -q4, I'd disrecommend GT3. (Unstable because of 'floggy' hacks)

48Khz or 44.1Khz?

Reply #11 –
Quote
For below -q4, I'd disrecommend GT3. (Unstable because of 'floggy' hacks)

oh sorry you didn't understand me ! which version is better for 48khz encoding ? i always use (gt3b1) -q6 so should i also use your tuned version for 48khz encoding or the "original" version ? 
 

48Khz or 44.1Khz?

Reply #12 –
Quote
Anyway, 44,1kHz should require less CPU to decode, and won't require resampling (any decent sound card should be able to play CD w/o resampling ) thus allowing you to use more CPU for other tasks, such as decoding video. This is especially useful on old machines.


It is the opposite, 44.1 kHz needs to be resampled to 48 kHz !
It is not clear if the resampling process is also performed from 48 to 48 kHz (without changing the frequency) on playback. It is performed on digital recording because the clock is not in synch with the incoming stream, but this should not be required for playback, as the initial data (the sound file) is read in "burst" mode from the hard disc.

Quote
Anyway, won't compressing the audio to 160kbps MP3 introduce far more audible artifacts than resampling it once (or twice)?


Yes, exactly. But the point is that the alt-presets having been tuned on 44.1 kHz sources only, and the sample rate having been showned to have a noticeable influence on the encoding quality, encoding non resampled files (48 kHz) at 160 kbps may introduce more artifacts than encoding 44.1 kHz resampled ones (optimal presets tuning).

EDIT : Well it depends if the machine is very old. With SB16 soundcards for example, 48 kHz is resampled at 44.1 kHz, and with SB Live soundcards, 44.1 kHz is resampled at 48 kHz.

48Khz or 44.1Khz?

Reply #13 –
Quote
It is the opposite, 44.1 kHz needs to be resampled to 48 kHz !
It is not clear if the resampling process is also performed from 48 to 48 kHz (without changing the frequency) on playback. It is performed on digital recording because the clock is not in synch with the incoming stream, but this should not be required for playback, as the initial data (the sound file) is read in "burst" mode from the hard disc.

Many sound cards do not support other sampling frequencies than 44,1kHz - especially not built in sound cards. My computer certainly doesn't playback 48kHz audio natively.

44,1kHz is what is used in CDs - and generally anything other than DVD. Are there really sound cards out there which can't play 99% of all audio without software resampling?

48Khz or 44.1Khz?

Reply #14 –
Quote
Are there really sound cards out there which can't play 99% of all audio without software resampling?

I don't know if they perform software or hardware resampling. But yes, all currently available Creative, Turtle Beach, Hercules soundcards, most lower end Terratec, Guillemot soundcards, all AC97 onboard audio... resample everything to 48 kHz (recommended in the Intel AC97 specifications), because they clock their DAC at 48 kHz. This is not much of an issue, since the process is nearly inaudible, and hidden to the user.
Note that with soundcards that can change their DAC frequency according to the file played, WindowsXP resamples your audio playback anyway, so that the card doesn't have to do so.

48Khz or 44.1Khz?

Reply #15 –
Quote
Note that with soundcards that can change their DAC frequency according to the file played, WindowsXP resamples your audio playback anyway, so that the card doesn't have to do so.

Not always. Certainly, not in case of M-Audio cards when playing a single stream. It depends on the drivers of each card.

48Khz or 44.1Khz?

Reply #16 –
Quote
Quote
Are there really sound cards out there which can't play 99% of all audio without software resampling?

I don't know if they perform software or hardware resampling. But yes, all currently available Creative, Turtle Beach, Hercules soundcards, most lower end Terratec, Guillemot soundcards, all AC97 onboard audio... resample everything to 48 kHz (recommended in the Intel AC97 specifications), because they clock their DAC at 48 kHz. This is not much of an issue, since the process is nearly inaudible, and hidden to the user.
Note that with soundcards that can change their DAC frequency according to the file played, WindowsXP resamples your audio playback anyway, so that the card doesn't have to do so.

I use the C-media chipset on my Soyo dragon motherboard as my soundcard, and it has SPDIF outputs.  It provides an option, however, to switch the SPDIF output sampling rate to 48khz or 44.1khz though.  I notice though if I choose 48khz, that my receiver seems to cut the first second or so off a song with winamp.

Also, if I had the sampling rate set to 44.1khz, and played a Dolby Digital or DTS stream through my computer, would it resample it to 44.1khz or leave it at its original 48khz?

Thanks!

48Khz or 44.1Khz?

Reply #17 –
I thought there was a bond between the sample rate and the time resolution...
It seemed to me that it was better to work in 48 kHz 

48Khz or 44.1Khz?

Reply #18 –
Quote
I thought there was a bond between the sample rate and the time resolution...
It seemed to me that it was better to work in 48 kHz 

That's true if you are recording. But if you are compressing to mp3,each sample has to be addressed by the encoder,so at 48 your available bits will be spread thinner.

48Khz or 44.1Khz?

Reply #19 –
Mez >  and what's about vorbis ? should i use there 48khz ? (which version is better ? gt3b1 or 1.0 cvs ?)

I'd leave them @ 48 kHz. Make sure you use the -r 48000 switch or it will encode at 44.1 kHz and thus, sound funny (unless your trippin). Still using Vorbis 1.0 here.

xen-uno
No one can be told what Ogg Vorbis is...you have to hear it for yourself
- Morpheus