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Re: kbps ratios for saving files
Posted: Sat Mar 15, 2014 3:21 am
by steve
Xerlome wrote:And just so I'm clear: Even if I save an edited 128 file at 320, will it still end up no better than 64?
It might be a little better than a 64 kbps encoding, but the point we are trying to make is that it will be worse than the 128 kbps version that you started with. MP3 encoding
always reduces the sound quality. Encoding to 320 kbps will not reduce the quality much, but it will reduce it. The lower the bit rate the more sound quality is lost and the lost sound quality is permanent - there is no way to fix it. "lossy" formats are called "lossy" because some of the information is lost ("gone and lost forever").
Xerlome wrote:How does Audacity's record feature rate in all this, if the mp3 I record is fairly high quality?
Not sure what you mean. Audacity records uncompressed (lossless) data. If you want to get an MP3 file into Audacity, don't record it, "Import" it (File menu > Import > Audio).
Xerlome wrote: I may still need to use mp3 if other formats won't read on the player.
What player is that?
Re: kbps ratios for saving files
Posted: Sat Mar 15, 2014 6:52 pm
by Xerlome
steve wrote:Xerlome wrote:How does Audacity's record feature rate in all this, if the mp3 I record is fairly high quality?
Not sure what you mean
I'm asking, what if turn on the record in Audacity to record a streaming audio. How does recording it affect the quality of the file? If the stream is at 320, what will the recording be? I'm considering whether it is better to record the stream than to download a file if the download of the same thing is only 128, for example.
steve wrote:Xerlome wrote:I may still need to use mp3 if other formats won't read on the player.
What player is that?
The one that plays the flash drive I use to play the audio at the radio station. The player does not register a WAV file, there is no readout. It will register an mp3 file.
But even if I were able to play WAV, the original of what I want to play is usually a 128 mp3 file, so I would need to convert it to WAV, and then the station converts to a 128 mp3 stream, which you've said wouldn't be good.
Re: kbps ratios for saving files
Posted: Sat Mar 15, 2014 7:13 pm
by Gale Andrews
Xerlome wrote:what if turn on the record in Audacity to record a streaming audio. How does recording it affect the quality of the file? If the stream is at 320, what will the recording be?
At the point you record, Audacity records losslessy in PCM. The recording Audacity makes is as good or bad as the streamed MP3 is, after the stream has been converted from digital to analogue (so that you can hear it playing in an analogue sound card).
That digital to analogue conversion is technically slightly lossy, but that loss is rarely noticeable - unless for example a crackle occurs during playback, in which case the crackle will be recorded.
Xerlome wrote:I'm considering whether it is better to record the stream than to download a file if the download of the same thing is only 128, for example.
If the download actually is of lower audible quality than the stream, you should still record the stream, because the losses from recording should be minimal.
If the stream and download are of equal audible quality, you should download the file.
I refer to "audible quality" rather than bit rate, because a 320 kbps MP3 can sound worse than a 128 kbps MP3 if the original audio for the 320 kbps version was worse, or if the 320 kbps version was originally 128 kbps and had been re-encoded at 320 kbps. That re-encoding would make the MP3 slightly worse than when it had been 128 kbps, but not much worse.
Gale
Re: kbps ratios for saving files
Posted: Sat Mar 15, 2014 9:11 pm
by kozikowski
You change what you can.
— The 128 quality of the station's stream is fixed. I don't see that changing any time soon because when presented with a perfect, completely undamaged show, it produces an almost perfect web stream with the smallest server cost.
— If the delivery to the station is MP3, then it's up to you to create the most perfect, high quality MP3 you can. And then call the station and find out about delivery in WAV. Like I said, if you have the only WAV of a major news event, I guarantee they'd figure out a way to play it.
— You took it in the shorts when you decided to repackage MP3 downloads (we assume free) instead of creating original content. Producers have good quality control over original content (as many multiple Audacity Forum posters with microphones can attest), but you are a complete slave to both the content provider and the delivery company. So the show will never be any better than the worst combination of both of those.
~~
What's the station?
Koz
Re: kbps ratios for saving files
Posted: Sat Mar 15, 2014 10:27 pm
by Xerlome
The info on recording is promising, though it will be more time-consuming. I try to judge the quality of the original audio I download or record. If I download an mp3 and open it in Audacity, I can see whether it was clipped, and if so I can look for one that isn't. I also usually can tell by the graphic if it was clipped but then volume reduced. If I record, it is the same thing, i keep the volume at a level not to clip, but if I see it is flattened anyway, i look for a better copy.
I'd rather not identify the station because I don't want to call attention to myself here personally. But it is a small non-commercial community station. I am doing music programming, using internet sources for music we don't have in the library, which is most of it for what I do. DJs do this commonly, and the station pays the general copyright fees and publishes the playlists.
There are already sound quality issues with the broadcast and stream, I don't think we are very good in that department. If I download a program from the archives and look at it in Audacity, it is usually clipped, which I think is because DJs don't control their volume properly. I try to keep mine within a good range, but it is touchy.
Re: kbps ratios for saving files
Posted: Sun Mar 16, 2014 1:04 am
by kozikowski
I try to keep mine within a good range, but it is touchy.
Exactly correct.
I can explain pieces of this. The "board" or mixing desk is generally split in two. One split goes to the broadcast transmitter and through the
legally required volume compressors and limiters. The other split goes to the streaming servers which everybody knows don't really matter. Since there's no electronics in server pathway, whatever the board operator feels like producing is what goes out. Overload, Dipping, Pumping, Clipping, etc. Out the door.
I begged one station to please get the data stream from the
transmitter side of the compressors rather than the raw mixing desk so at least we didn't get the wild volume swings and clipping the board op was producing. It worked. Their stream was spot-on day in and day out and sounded remarkably like the radio broadcast.
There are tricks to this.
Send the name of the station (assuming it's in the US) to me as a Private Message. I'm curious about the place, and yes I do have a General Radio FCC license and know how to drive a radio transmitter.
Koz