loss in nonlossy encodings?

[wavydave]

hello, audio mavens.

if i import 32-bit float, 14.4 pcm into audacity, then cut a few seconds off the beginning, and some more off the end, then export as the same type of pcm, does audacity resample the data, or does it just rewrite a subsection of the source bytes?

if it resamples, am i likely to notice loss of quality?

many thanks for your expertise,
-dave

[steve]

if i import 32-bit float, 14.4 pcm

What do you mean "32-bit float, 14.4 pcm"?

If you just mean Import "32 bit float", edit, then Export as "32 bit float", then there will be no resampling and no loss of sound quality (as long as you do not change the sample rate).

[wavydave]

if i import 32-bit float, 14.4 pcm

What do you mean "32-bit float, 14.4 pcm"?

If you just mean Import "32 bit float", edit, then Export as "32 bit float", then there will be no resampling and no loss of sound quality (as long as you do not change the sample rate).

since my last post i have discovered that the audio data in question, which is coming from a usb turntable, is actually in normal cd audio format. the reason i thought i was importing 32-bit float was because audacity was converting it according to the default sample format under quality preferences, and i was seeing "32-bit float" to the left of the track display. as far as "14.4", i guess i was thinking of old modems. i meant "44.1" funny! sorry for the confusion.

anyway, i get it -- don't change the sample rate and don't decrease the width of the format -- ***excellent*** exactly what i wanted to hear.

many thanks,
dave

[steve]

i guess i was thinking of old modems.

lol

Unless you plan to do a lot of processing of the audio you can keep it all as 16 bit (saves on disk space) and I doubt that you will be able to hear any difference (especially if you are just trimming the length).

[harmann]

Hi

I have a question on this also.

I'm trying to trim the start and end of flac files. The result came out with a larger file size than the original, both at the same compression level. I set the default sample rate/format to 44.1/16, which is the same as the source, then loaded the original again and just exported it without any editing. The result was still bigger. Seems like there's some internal processing inside audacity.

Is there any way to cut flac or audio in audacity losslessly? (as in not changing the rest of the file)

Thank you.

[steve]

Is there any way to cut flac or audio in audacity losslessly? (as in not changing the rest of the file)

I think you are doing that already. Just open the file, cut it and Export it in the same format. In some situations you may notice that the audio file is shown to be a different bit depth when in Audacity - to avoid that, go into Preferences (from the Edit menu) and in the "Quality" tab set the default sample rate to the same as the audio file that you are using.

The difference in the size of the Flac file is probably just due to the compression level setting of the flac encoder. In Audacity 1.3.x you can change that in the "Options" section of the Export dialogue. With Flac, higher compression levels do not change the sound quality (it is still lossless), but higher compression levels will be a bit slower to encode.