RE: Pros and cons of varible bit rate
Thank to you and your friend for this explanation; very useful. Amie -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Dane Trethowan Sent: 26 December 2009 22:05 To: PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate Okay, I just consulted an audio engineer abut what you wrote about minimum bit rates for VBR encoding and here's his response, it also talks about setting VBR quality and I'll have a few words to say about this after his quotation which follows: Well, basically it depends on what you're trying to do. There are several factors that contribute to VBR quality (apart from encoding quality settings of course). Most immediately noticeable is the over-all VBR quality setting, which `weights' the VBR result between the minimum and maximum you set. Imagine VBR as a set of scales swinging everywhere between min. and max. depending on what's going into the encode. VBR quality simply determines how the scales are weighted, either more towards minimum or maximum depending on what you set. The higher VBR Quality, the less the encoder will `throw away', and so the more it will weight the encode towards the higher end of the scale. If the quality is set high enough, you won't achieve *anything* by increasing the minimum; all you'll do is make your file larger for no benefit, since the encoder will waste a load of bandwidth encoding things (such as silence or low frequencies) that don't need it. Conversely, if your VBR Quality setting is too low, the encoder will throw away so much that everything will get pushed towards the lower end, and so the Minimum setting will make a great deal more difference. But even then, all it will do is make your file bigger, and probably it won't help the encode quality, since you shouldn't have set the quality so low in the first place. So, basically, for normal operation, it's a complete waste of time pushing up the minimum. The exception is if you have a hardware player that can't cope with very low bitrates (our Omni DVD players were hopeless with anything below 64KbPS), unless, _perhaps_ if the source is *very* noisy (an old dodgy cassette) where you don't want noise causing a load of artifacts, but you still want the file as small as possible. But under those circumstances, you'd be far better off processing the original source and removing as much noise as possible without damaging the audio _before_ encoding. The only other reason you might want to push up the minimum is if the encoder has a dodgy VBR algorithm that tends to push too much towards the bottom of the scale, even when the VBR Quality setting is high. LAME's `--vbr-old' algorithm is excellent, but `--vbr-New' still has problems. Unfortunately, other encoders (such as Fraunhofer) are a *hell* of a lot worse, so if you're forced to use them, it might be worth it. Anyway, hope this explains things; basically, unless you have a very specific need, don't play with Min/Max bitrates - you're likely only to get worse encodes and bigger files. Thank you kind Sir for your time and trouble smile so now to my additional notation about VBR quality and this can add to confusion. When setting VBR quality it works in the reverse as it looks, in other words the lower the number the higher the VBR quality, 3 or 4 may be a good setting for music, for mono audio or talking books, audio documentaries etc try say between 4 and 6. On 27/12/2009, at 6:38 AM, Kevin Lloyd wrote: The only point I'd add to Dane's notes is that I have read advice around not setting your variable floor too low. I'd suggest for music that you set the floor to 128kbps rather than the suggestion below of 16kbps. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Dane Trethowan grtd...@internode.on.net To: PC Audio Discussion List pc-audio@pc-audio.org Sent: Saturday, December 26, 2009 7:33 PM Subject: Re: Pros and cons of varible bit rate I suppose it comes down once again to personal preference, I've been using varriable bit rates for youears. As I understand it, encoding with a varriable bit rate takes a lot longer as the encoder looks at every sample of the song thus deciding what bit rate it should be encoded at, silence for example is encoded at a lower bit rate than a full sample of orchestra sound, minimum and maximum bit rates for variable encoding are set up with your encoding engine such as LAME so for the best and accurate results you're better off doing this sort of thing manually with a command line so use an app which supports this, Exact Audio Copy is an excellent choice here. Their are several methods of VBR encoding, Old and new, new is quicker for those jobs you want out the door fast but quality isn't quite as good if you're picky, with today's flying processor speeds you may as well use Old. Also note that some older players may not handle VBR playback though I haven't
RE: Pros and cons of varible bit rate
Does the PLextor handle vbr? Amie -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Dane Trethowan Sent: 27 December 2009 00:15 To: PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate So there we are, the first audio players I've heard of that won't touch VBR smile. On 27/12/2009, at 11:03 AM, Tim Noonan wrote: Also, There are devices, even modern ones, which don't reliably, or indeed at all, cope with VBR. The Olympus machines, even the DM-520 are a case in point - so use VBR with care if you want to guarantee everyone and everything can play your MP3 files. Regards Tim Tim Noonan Director, Vocal Branding Australia Transforming products, brands and experiences so they Sound as great as they look and feel! Phone: +61 419 779 669 Web: www.vocalbranding.com.au/blog Email: t...@vocalbranding.com.au Twitter: www.twitter.com/VocalEssence Skype: TimNoonan -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Dane Trethowan Sent: Sunday, December 27, 2009 9:05 AM To: PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate Okay, I just consulted an audio engineer abut what you wrote about minimum bit rates for VBR encoding and here's his response, it also talks about setting VBR quality and I'll have a few words to say about this after his quotation which follows: Well, basically it depends on what you're trying to do. There are several factors that contribute to VBR quality (apart from encoding quality settings of course). Most immediately noticeable is the over-all VBR quality setting, which `weights' the VBR result between the minimum and maximum you set. Imagine VBR as a set of scales swinging everywhere between min. and max. depending on what's going into the encode. VBR quality simply determines how the scales are weighted, either more towards minimum or maximum depending on what you set. The higher VBR Quality, the less the encoder will `throw away', and so the more it will weight the encode towards the higher end of the scale. If the quality is set high enough, you won't achieve *anything* by increasing the minimum; all you'll do is make your file larger for no benefit, since the encoder will waste a load of bandwidth encoding things (such as silence or low frequencies) that don't need it. Conversely, if your VBR Quality setting is too low, the encoder will throw away so much that everything will get pushed towards the lower end, and so the Minimum setting will make a great deal more difference. But even then, all it will do is make your file bigger, and probably it won't help the encode quality, since you shouldn't have set the quality so low in the first place. So, basically, for normal operation, it's a complete waste of time pushing up the minimum. The exception is if you have a hardware player that can't cope with very low bitrates (our Omni DVD players were hopeless with anything below 64KbPS), unless, _perhaps_ if the source is *very* noisy (an old dodgy cassette) where you don't want noise causing a load of artifacts, but you still want the file as small as possible. But under those circumstances, you'd be far better off processing the original source and removing as much noise as possible without damaging the audio _before_ encoding. The only other reason you might want to push up the minimum is if the encoder has a dodgy VBR algorithm that tends to push too much towards the bottom of the scale, even when the VBR Quality setting is high. LAME's `--vbr-old' algorithm is excellent, but `--vbr-New' still has problems. Unfortunately, other encoders (such as Fraunhofer) are a *hell* of a lot worse, so if you're forced to use them, it might be worth it. Anyway, hope this explains things; basically, unless you have a very specific need, don't play with Min/Max bitrates - you're likely only to get worse encodes and bigger files. Thank you kind Sir for your time and trouble smile so now to my additional notation about VBR quality and this can add to confusion. When setting VBR quality it works in the reverse as it looks, in other words the lower the number the higher the VBR quality, 3 or 4 may be a good setting for music, for mono audio or talking books, audio documentaries etc try say between 4 and 6. On 27/12/2009, at 6:38 AM, Kevin Lloyd wrote: The only point I'd add to Dane's notes is that I have read advice around not setting your variable floor too low. I'd suggest for music that you set the floor to 128kbps rather than the suggestion below of 16kbps. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Dane Trethowan grtd...@internode.on.net To: PC Audio Discussion List pc-audio@pc-audio.org Sent: Saturday, December 26, 2009 7:33 PM Subject: Re: Pros and cons of varible
RE: Pros and cons of varible bit rate
So is there any difference between ABR set to a higher bit rate and VBR with the quality set to the highest? Amie -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Kevin Lloyd Sent: 27 December 2009 14:00 To: Kevin Lloyd; PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate and here's a reference to the choices around minimum bit rates when using VBR: CDex Manual File Edit Bookmark Options Help Contents Index Back Print Up Bitrate Options: There are three types of bitrate options that you can specify for each the encoder (although some encoders may not allow any options). 1) Constant Bitrate (CBR) This is the default encoding mode, and also the most basic. In this mode, the bitrate will be the same throughout the whole file. So, a second of audio from one part of the file takes just as much disk space as a second from any other part of that file -- regardless of whether either part is silence, acoustically simple, or quite complex. This means that you are likely to hear distortion more in the complex parts than in the simple parts. The advantage of CBR formats is that even older players understand them, and that you can reliably predict the file size from the duration of the sound (or vice versa). 2) Average Bitrate (ABR) In this mode, you tell the encoder to aim for an average bitrate that you specify, skimping on the simpler parts of the music, and using higher bitrates for the parts of your music that are more complex. The result will be of higher quality than you'd get in a CBR encoded file of the same size. This mode is highly recommended over CBR. This encoding mode is similar to VBR. 3) Variable bitrate (VBR) In this mode, you say what level of quality you want in the output file, and the encoder compresses each second as best it can to get just that level of quality -- using less information to represent simpler parts of the song, and more information to represent the more complex parts. However, this mode relies heavily on the encoder's model of how you perceive quality, and could lead to a few bad choices in the encoding process. If possible, you may want to specify a minimum bitrate (e.g., 64 Kbps) to avoid those potential errors. To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.430 / Virus Database: 270.14.118/2584 - Release Date: 12/23/09 19:02:00 To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org
Re: Pros and cons of varible bit rate
Yep, there would be a difference but the higher the ABR then the smaller the difference between the resulting file and that encoded using high quality VBR. For example, if you set your ABR to 300kbps then ABR would steal a little from less complex parts of the music and use those to supplement parts of the music that are more complex and need more than 300kbps. The result is that ABR will try to maintain a jagged line around the 300kbps mark so imagine it just dropping slightly above and below the line through the music track. With VBR with a maximum of 320kbps then you are guaranteed that if a long part of the track needs 320kbps then it will get that. You don't have that guarantee with ABR because it may not have enough bits in hand from the less complex parts of the track to maintain 320kbps for the same amount of time and may instead cap it at 310kbps. ABR is a poor man's VBR where it is important that you can predict the file size. Much better than constant bit rates of less than 320kbps though. For example, a file at ABR of 256kbps will sound better than a file encoded with a constant bit rate of 256kbps. The reason being that the ABR file will be fluctuating just above and below the 256kbps mark as required whereas the constant bit rate will have been crudely chopped as soon as it needed to go above 256kbps. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Amie Slavin amie.sla...@ntlworld.com To: 'PC Audio Discussion List' pc-audio@pc-audio.org Sent: Wednesday, December 30, 2009 12:28 PM Subject: RE: Pros and cons of varible bit rate So is there any difference between ABR set to a higher bit rate and VBR with the quality set to the highest? Amie -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Kevin Lloyd Sent: 27 December 2009 14:00 To: Kevin Lloyd; PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate and here's a reference to the choices around minimum bit rates when using VBR: CDex Manual File Edit Bookmark Options Help Contents Index Back Print Up Bitrate Options: There are three types of bitrate options that you can specify for each the encoder (although some encoders may not allow any options). 1) Constant Bitrate (CBR) This is the default encoding mode, and also the most basic. In this mode, the bitrate will be the same throughout the whole file. So, a second of audio from one part of the file takes just as much disk space as a second from any other part of that file -- regardless of whether either part is silence, acoustically simple, or quite complex. This means that you are likely to hear distortion more in the complex parts than in the simple parts. The advantage of CBR formats is that even older players understand them, and that you can reliably predict the file size from the duration of the sound (or vice versa). 2) Average Bitrate (ABR) In this mode, you tell the encoder to aim for an average bitrate that you specify, skimping on the simpler parts of the music, and using higher bitrates for the parts of your music that are more complex. The result will be of higher quality than you'd get in a CBR encoded file of the same size. This mode is highly recommended over CBR. This encoding mode is similar to VBR. 3) Variable bitrate (VBR) In this mode, you say what level of quality you want in the output file, and the encoder compresses each second as best it can to get just that level of quality -- using less information to represent simpler parts of the song, and more information to represent the more complex parts. However, this mode relies heavily on the encoder's model of how you perceive quality, and could lead to a few bad choices in the encoding process. If possible, you may want to specify a minimum bitrate (e.g., 64 Kbps) to avoid those potential errors. To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.430 / Virus Database: 270.14.118/2584 - Release Date: 12/23/09 19:02:00 To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org
RE: Pros and cons of varible bit rate
So VBR with highest quality setting it is then. Thank you for this full and very helpful explanation. Cheers Amie -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Kevin Lloyd Sent: 30 December 2009 13:40 To: PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate Yep, there would be a difference but the higher the ABR then the smaller the difference between the resulting file and that encoded using high quality VBR. For example, if you set your ABR to 300kbps then ABR would steal a little from less complex parts of the music and use those to supplement parts of the music that are more complex and need more than 300kbps. The result is that ABR will try to maintain a jagged line around the 300kbps mark so imagine it just dropping slightly above and below the line through the music track. With VBR with a maximum of 320kbps then you are guaranteed that if a long part of the track needs 320kbps then it will get that. You don't have that guarantee with ABR because it may not have enough bits in hand from the less complex parts of the track to maintain 320kbps for the same amount of time and may instead cap it at 310kbps. ABR is a poor man's VBR where it is important that you can predict the file size. Much better than constant bit rates of less than 320kbps though. For example, a file at ABR of 256kbps will sound better than a file encoded with a constant bit rate of 256kbps. The reason being that the ABR file will be fluctuating just above and below the 256kbps mark as required whereas the constant bit rate will have been crudely chopped as soon as it needed to go above 256kbps. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Amie Slavin amie.sla...@ntlworld.com To: 'PC Audio Discussion List' pc-audio@pc-audio.org Sent: Wednesday, December 30, 2009 12:28 PM Subject: RE: Pros and cons of varible bit rate So is there any difference between ABR set to a higher bit rate and VBR with the quality set to the highest? Amie -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Kevin Lloyd Sent: 27 December 2009 14:00 To: Kevin Lloyd; PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate and here's a reference to the choices around minimum bit rates when using VBR: CDex Manual File Edit Bookmark Options Help Contents Index Back Print Up Bitrate Options: There are three types of bitrate options that you can specify for each the encoder (although some encoders may not allow any options). 1) Constant Bitrate (CBR) This is the default encoding mode, and also the most basic. In this mode, the bitrate will be the same throughout the whole file. So, a second of audio from one part of the file takes just as much disk space as a second from any other part of that file -- regardless of whether either part is silence, acoustically simple, or quite complex. This means that you are likely to hear distortion more in the complex parts than in the simple parts. The advantage of CBR formats is that even older players understand them, and that you can reliably predict the file size from the duration of the sound (or vice versa). 2) Average Bitrate (ABR) In this mode, you tell the encoder to aim for an average bitrate that you specify, skimping on the simpler parts of the music, and using higher bitrates for the parts of your music that are more complex. The result will be of higher quality than you'd get in a CBR encoded file of the same size. This mode is highly recommended over CBR. This encoding mode is similar to VBR. 3) Variable bitrate (VBR) In this mode, you say what level of quality you want in the output file, and the encoder compresses each second as best it can to get just that level of quality -- using less information to represent simpler parts of the song, and more information to represent the more complex parts. However, this mode relies heavily on the encoder's model of how you perceive quality, and could lead to a few bad choices in the encoding process. If possible, you may want to specify a minimum bitrate (e.g., 64 Kbps) to avoid those potential errors. To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.430 / Virus Database: 270.14.118/2584 - Release Date: 12/23/09 19:02:00 To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.431 / Virus Database: 270.14.121/2589 - Release Date: 12/30/09 07:27:00 To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org
Re: Pros and cons of varible bit rate
That's pretty much how I reckon it should be but the only changes I'd make is set VBR method to old - if better quality is what you want and you're prepared to wait a little longer - and perhaps have several VBR profiles or presets, each one having a different VBR quality setting, say one for music and one for Audio Books. Make sure encoding quality is set to highest, file will take longer to encode but quality will be better and again, this is a different setting to the VBR Quality but - as I recall - all settings in Easy CD DA Extractor are clearly marked. If you feel up to it you may like to turn off all filtering if its enabled and - depending on what you're doing - you may like to disable auto sampling rate and select that for your particular projects, 44.1KHZ if you're ripping CD'S for example. On 27/12/2009, at 10:57 PM, Sunshine wrote: Dane, and others. this is how i have my vbr method set in easy cd da extracter. joint stereo.vbr method old. min bit rate 8 kbps max bit rate 320 kbps. let me know what you all think of this set up also the quality setting i have set to highest. ** Dane Trethowan From Melton Victoria Australia mailto:grtd...@internode.on.net Twitter: http://twitter.com/grtdane blog: http://www.grtdane.wordpress.com Phone United Kingdom 02032874641 Phone Australia 0390058589 Phone United States 8159261869 Fax: +61 3 9743 7954x MSN grtd...@dane-trethowan.net skype:grtdane12 ** To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org
Re: Pros and cons of varible bit rate
I suppose it comes down once again to personal preference, I've been using varriable bit rates for youears. As I understand it, encoding with a varriable bit rate takes a lot longer as the encoder looks at every sample of the song thus deciding what bit rate it should be encoded at, silence for example is encoded at a lower bit rate than a full sample of orchestra sound, minimum and maximum bit rates for variable encoding are set up with your encoding engine such as LAME so for the best and accurate results you're better off doing this sort of thing manually with a command line so use an app which supports this, Exact Audio Copy is an excellent choice here. Their are several methods of VBR encoding, Old and new, new is quicker for those jobs you want out the door fast but quality isn't quite as good if you're picky, with today's flying processor speeds you may as well use Old. Also note that some older players may not handle VBR playback though I haven't struck one that doesn't yet. Suggested minimum and maximum bit rates for VBR? Well just use the minimum and maximum rates available or if you're configuring from a command line or a piece of software that takes full advantage of the LAME-ENC.dll library then 16 bits for the minimum and 320KBPS for the maximum, there are 2 quality settings you have to be aware of here, one is VBR quality and you may wish to change this for certain audio material you're encoding, say music and talking books. The other quality setting leave at maximum, will take longer but far better results. On 27/12/2009, at 6:21 AM, Jamie Pauls wrote: The subject is a question, not a statement. I have been uploading Main Menu archives as a 128KBPS MP3 file. I see that many people recommend 192KBPS, but there a parts of the show that really don't need that high a bit rate. In fact, I have also read that encoding at too high a bit rate can cause unwanted artifacts just as much as encoding at too low a bit rate. Variable bit rate seems a good choice for me to use, but I would like some thoughts from audio experts. Thanks. Jamie Pauls MSN: jamiepa...@hotmail.com Skype: jamie.pauls To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org ** Dane Trethowan From Melton Victoria Australia mailto:grtd...@internode.on.net Twitter: http://twitter.com/grtdane blog: http://www.grtdane.wordpress.com Phone United Kingdom 02032874641 Phone Australia 0390058589 Phone United States 8159261869 Fax: +61 3 9743 7954x MSN grtd...@dane-trethowan.net skype:grtdane12 ** To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org
Re: Pros and cons of varible bit rate
I've never seen any evidence to suggest that encoding at too high a bit rate can result in unwanted artifacts though I do understand that to broadcast in high bit rate is obviously more challenging in terms of available bandwidth and so this may be a consideration. As to the question in general, it's a no-brainer really. Variable bit rate is going to yield the best results at the smallest file size possible. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Jamie Pauls jamiepa...@sbcglobal.net To: PC Audio Discussion List pc-audio@pc-audio.org Sent: Saturday, December 26, 2009 7:21 PM Subject: Pros and cons of varible bit rate The subject is a question, not a statement. I have been uploading Main Menu archives as a 128KBPS MP3 file. I see that many people recommend 192KBPS, but there a parts of the show that really don't need that high a bit rate. In fact, I have also read that encoding at too high a bit rate can cause unwanted artifacts just as much as encoding at too low a bit rate. Variable bit rate seems a good choice for me to use, but I would like some thoughts from audio experts. Thanks. Jamie Pauls MSN: jamiepa...@hotmail.com Skype: jamie.pauls To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org
Re: Pros and cons of varible bit rate
The only point I'd add to Dane's notes is that I have read advice around not setting your variable floor too low. I'd suggest for music that you set the floor to 128kbps rather than the suggestion below of 16kbps. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Dane Trethowan grtd...@internode.on.net To: PC Audio Discussion List pc-audio@pc-audio.org Sent: Saturday, December 26, 2009 7:33 PM Subject: Re: Pros and cons of varible bit rate I suppose it comes down once again to personal preference, I've been using varriable bit rates for youears. As I understand it, encoding with a varriable bit rate takes a lot longer as the encoder looks at every sample of the song thus deciding what bit rate it should be encoded at, silence for example is encoded at a lower bit rate than a full sample of orchestra sound, minimum and maximum bit rates for variable encoding are set up with your encoding engine such as LAME so for the best and accurate results you're better off doing this sort of thing manually with a command line so use an app which supports this, Exact Audio Copy is an excellent choice here. Their are several methods of VBR encoding, Old and new, new is quicker for those jobs you want out the door fast but quality isn't quite as good if you're picky, with today's flying processor speeds you may as well use Old. Also note that some older players may not handle VBR playback though I haven't struck one that doesn't yet. Suggested minimum and maximum bit rates for VBR? Well just use the minimum and maximum rates available or if you're configuring from a command line or a piece of software that takes full advantage of the LAME-ENC.dll library then 16 bits for the minimum and 320KBPS for the maximum, there are 2 quality settings you have to be aware of here, one is VBR quality and you may wish to change this for certain audio material you're encoding, say music and talking books. The other quality setting leave at maximum, will take longer but far better results. On 27/12/2009, at 6:21 AM, Jamie Pauls wrote: The subject is a question, not a statement. I have been uploading Main Menu archives as a 128KBPS MP3 file. I see that many people recommend 192KBPS, but there a parts of the show that really don't need that high a bit rate. In fact, I have also read that encoding at too high a bit rate can cause unwanted artifacts just as much as encoding at too low a bit rate. Variable bit rate seems a good choice for me to use, but I would like some thoughts from audio experts. Thanks. Jamie Pauls MSN: jamiepa...@hotmail.com Skype: jamie.pauls To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org ** Dane Trethowan From Melton Victoria Australia mailto:grtd...@internode.on.net Twitter: http://twitter.com/grtdane blog: http://www.grtdane.wordpress.com Phone United Kingdom 02032874641 Phone Australia 0390058589 Phone United States 8159261869 Fax: +61 3 9743 7954x MSN grtd...@dane-trethowan.net skype:grtdane12 ** To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org To unsubscribe from this list, send a blank email to: pc-audio-unsubscr...@pc-audio.org
Re: Pros and cons of varible bit rate
Okay, I just consulted an audio engineer abut what you wrote about minimum bit rates for VBR encoding and here's his response, it also talks about setting VBR quality and I'll have a few words to say about this after his quotation which follows: Well, basically it depends on what you're trying to do. There are several factors that contribute to VBR quality (apart from encoding quality settings of course). Most immediately noticeable is the over-all VBR quality setting, which `weights' the VBR result between the minimum and maximum you set. Imagine VBR as a set of scales swinging everywhere between min. and max. depending on what's going into the encode. VBR quality simply determines how the scales are weighted, either more towards minimum or maximum depending on what you set. The higher VBR Quality, the less the encoder will `throw away', and so the more it will weight the encode towards the higher end of the scale. If the quality is set high enough, you won't achieve *anything* by increasing the minimum; all you'll do is make your file larger for no benefit, since the encoder will waste a load of bandwidth encoding things (such as silence or low frequencies) that don't need it. Conversely, if your VBR Quality setting is too low, the encoder will throw away so much that everything will get pushed towards the lower end, and so the Minimum setting will make a great deal more difference. But even then, all it will do is make your file bigger, and probably it won't help the encode quality, since you shouldn't have set the quality so low in the first place. So, basically, for normal operation, it's a complete waste of time pushing up the minimum. The exception is if you have a hardware player that can't cope with very low bitrates (our Omni DVD players were hopeless with anything below 64KbPS), unless, _perhaps_ if the source is *very* noisy (an old dodgy cassette) where you don't want noise causing a load of artifacts, but you still want the file as small as possible. But under those circumstances, you'd be far better off processing the original source and removing as much noise as possible without damaging the audio _before_ encoding. The only other reason you might want to push up the minimum is if the encoder has a dodgy VBR algorithm that tends to push too much towards the bottom of the scale, even when the VBR Quality setting is high. LAME's `--vbr-old' algorithm is excellent, but `--vbr-New' still has problems. Unfortunately, other encoders (such as Fraunhofer) are a *hell* of a lot worse, so if you're forced to use them, it might be worth it. Anyway, hope this explains things; basically, unless you have a very specific need, don't play with Min/Max bitrates - you're likely only to get worse encodes and bigger files. Thank you kind Sir for your time and trouble smile so now to my additional notation about VBR quality and this can add to confusion. When setting VBR quality it works in the reverse as it looks, in other words the lower the number the higher the VBR quality, 3 or 4 may be a good setting for music, for mono audio or talking books, audio documentaries etc try say between 4 and 6. On 27/12/2009, at 6:38 AM, Kevin Lloyd wrote: The only point I'd add to Dane's notes is that I have read advice around not setting your variable floor too low. I'd suggest for music that you set the floor to 128kbps rather than the suggestion below of 16kbps. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Dane Trethowan grtd...@internode.on.net To: PC Audio Discussion List pc-audio@pc-audio.org Sent: Saturday, December 26, 2009 7:33 PM Subject: Re: Pros and cons of varible bit rate I suppose it comes down once again to personal preference, I've been using varriable bit rates for youears. As I understand it, encoding with a varriable bit rate takes a lot longer as the encoder looks at every sample of the song thus deciding what bit rate it should be encoded at, silence for example is encoded at a lower bit rate than a full sample of orchestra sound, minimum and maximum bit rates for variable encoding are set up with your encoding engine such as LAME so for the best and accurate results you're better off doing this sort of thing manually with a command line so use an app which supports this, Exact Audio Copy is an excellent choice here. Their are several methods of VBR encoding, Old and new, new is quicker for those jobs you want out the door fast but quality isn't quite as good if you're picky, with today's flying processor speeds you may as well use Old. Also note that some older players may not handle VBR playback though I haven't struck one that doesn't yet. Suggested minimum and maximum bit rates for VBR? Well just use the minimum and maximum rates available or if you're configuring from a command line or a piece of software
RE: Pros and cons of varible bit rate
Also, There are devices, even modern ones, which don't reliably, or indeed at all, cope with VBR. The Olympus machines, even the DM-520 are a case in point - so use VBR with care if you want to guarantee everyone and everything can play your MP3 files. Regards Tim Tim Noonan Director, Vocal Branding Australia Transforming products, brands and experiences so they Sound as great as they look and feel! Phone: +61 419 779 669 Web: www.vocalbranding.com.au/blog Email: t...@vocalbranding.com.au Twitter: www.twitter.com/VocalEssence Skype: TimNoonan -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Dane Trethowan Sent: Sunday, December 27, 2009 9:05 AM To: PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate Okay, I just consulted an audio engineer abut what you wrote about minimum bit rates for VBR encoding and here's his response, it also talks about setting VBR quality and I'll have a few words to say about this after his quotation which follows: Well, basically it depends on what you're trying to do. There are several factors that contribute to VBR quality (apart from encoding quality settings of course). Most immediately noticeable is the over-all VBR quality setting, which `weights' the VBR result between the minimum and maximum you set. Imagine VBR as a set of scales swinging everywhere between min. and max. depending on what's going into the encode. VBR quality simply determines how the scales are weighted, either more towards minimum or maximum depending on what you set. The higher VBR Quality, the less the encoder will `throw away', and so the more it will weight the encode towards the higher end of the scale. If the quality is set high enough, you won't achieve *anything* by increasing the minimum; all you'll do is make your file larger for no benefit, since the encoder will waste a load of bandwidth encoding things (such as silence or low frequencies) that don't need it. Conversely, if your VBR Quality setting is too low, the encoder will throw away so much that everything will get pushed towards the lower end, and so the Minimum setting will make a great deal more difference. But even then, all it will do is make your file bigger, and probably it won't help the encode quality, since you shouldn't have set the quality so low in the first place. So, basically, for normal operation, it's a complete waste of time pushing up the minimum. The exception is if you have a hardware player that can't cope with very low bitrates (our Omni DVD players were hopeless with anything below 64KbPS), unless, _perhaps_ if the source is *very* noisy (an old dodgy cassette) where you don't want noise causing a load of artifacts, but you still want the file as small as possible. But under those circumstances, you'd be far better off processing the original source and removing as much noise as possible without damaging the audio _before_ encoding. The only other reason you might want to push up the minimum is if the encoder has a dodgy VBR algorithm that tends to push too much towards the bottom of the scale, even when the VBR Quality setting is high. LAME's `--vbr-old' algorithm is excellent, but `--vbr-New' still has problems. Unfortunately, other encoders (such as Fraunhofer) are a *hell* of a lot worse, so if you're forced to use them, it might be worth it. Anyway, hope this explains things; basically, unless you have a very specific need, don't play with Min/Max bitrates - you're likely only to get worse encodes and bigger files. Thank you kind Sir for your time and trouble smile so now to my additional notation about VBR quality and this can add to confusion. When setting VBR quality it works in the reverse as it looks, in other words the lower the number the higher the VBR quality, 3 or 4 may be a good setting for music, for mono audio or talking books, audio documentaries etc try say between 4 and 6. On 27/12/2009, at 6:38 AM, Kevin Lloyd wrote: The only point I'd add to Dane's notes is that I have read advice around not setting your variable floor too low. I'd suggest for music that you set the floor to 128kbps rather than the suggestion below of 16kbps. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Dane Trethowan grtd...@internode.on.net To: PC Audio Discussion List pc-audio@pc-audio.org Sent: Saturday, December 26, 2009 7:33 PM Subject: Re: Pros and cons of varible bit rate I suppose it comes down once again to personal preference, I've been using varriable bit rates for youears. As I understand it, encoding with a varriable bit rate takes a lot longer as the encoder looks at every sample of the song thus deciding what bit rate it should be encoded at, silence for example is encoded at a lower bit rate than a full sample of orchestra sound, minimum and maximum bit rates for variable encoding are set up with your encoding engine
Re: Pros and cons of varible bit rate
So there we are, the first audio players I've heard of that won't touch VBR smile. On 27/12/2009, at 11:03 AM, Tim Noonan wrote: Also, There are devices, even modern ones, which don't reliably, or indeed at all, cope with VBR. The Olympus machines, even the DM-520 are a case in point - so use VBR with care if you want to guarantee everyone and everything can play your MP3 files. Regards Tim Tim Noonan Director, Vocal Branding Australia Transforming products, brands and experiences so they Sound as great as they look and feel! Phone: +61 419 779 669 Web: www.vocalbranding.com.au/blog Email: t...@vocalbranding.com.au Twitter: www.twitter.com/VocalEssence Skype: TimNoonan -Original Message- From: pc-audio-boun...@pc-audio.org [mailto:pc-audio-boun...@pc-audio.org] On Behalf Of Dane Trethowan Sent: Sunday, December 27, 2009 9:05 AM To: PC Audio Discussion List Subject: Re: Pros and cons of varible bit rate Okay, I just consulted an audio engineer abut what you wrote about minimum bit rates for VBR encoding and here's his response, it also talks about setting VBR quality and I'll have a few words to say about this after his quotation which follows: Well, basically it depends on what you're trying to do. There are several factors that contribute to VBR quality (apart from encoding quality settings of course). Most immediately noticeable is the over-all VBR quality setting, which `weights' the VBR result between the minimum and maximum you set. Imagine VBR as a set of scales swinging everywhere between min. and max. depending on what's going into the encode. VBR quality simply determines how the scales are weighted, either more towards minimum or maximum depending on what you set. The higher VBR Quality, the less the encoder will `throw away', and so the more it will weight the encode towards the higher end of the scale. If the quality is set high enough, you won't achieve *anything* by increasing the minimum; all you'll do is make your file larger for no benefit, since the encoder will waste a load of bandwidth encoding things (such as silence or low frequencies) that don't need it. Conversely, if your VBR Quality setting is too low, the encoder will throw away so much that everything will get pushed towards the lower end, and so the Minimum setting will make a great deal more difference. But even then, all it will do is make your file bigger, and probably it won't help the encode quality, since you shouldn't have set the quality so low in the first place. So, basically, for normal operation, it's a complete waste of time pushing up the minimum. The exception is if you have a hardware player that can't cope with very low bitrates (our Omni DVD players were hopeless with anything below 64KbPS), unless, _perhaps_ if the source is *very* noisy (an old dodgy cassette) where you don't want noise causing a load of artifacts, but you still want the file as small as possible. But under those circumstances, you'd be far better off processing the original source and removing as much noise as possible without damaging the audio _before_ encoding. The only other reason you might want to push up the minimum is if the encoder has a dodgy VBR algorithm that tends to push too much towards the bottom of the scale, even when the VBR Quality setting is high. LAME's `--vbr-old' algorithm is excellent, but `--vbr-New' still has problems. Unfortunately, other encoders (such as Fraunhofer) are a *hell* of a lot worse, so if you're forced to use them, it might be worth it. Anyway, hope this explains things; basically, unless you have a very specific need, don't play with Min/Max bitrates - you're likely only to get worse encodes and bigger files. Thank you kind Sir for your time and trouble smile so now to my additional notation about VBR quality and this can add to confusion. When setting VBR quality it works in the reverse as it looks, in other words the lower the number the higher the VBR quality, 3 or 4 may be a good setting for music, for mono audio or talking books, audio documentaries etc try say between 4 and 6. On 27/12/2009, at 6:38 AM, Kevin Lloyd wrote: The only point I'd add to Dane's notes is that I have read advice around not setting your variable floor too low. I'd suggest for music that you set the floor to 128kbps rather than the suggestion below of 16kbps. Regards. Kevin E-mail: kevin.llo...@sky.com - Original Message - From: Dane Trethowan grtd...@internode.on.net To: PC Audio Discussion List pc-audio@pc-audio.org Sent: Saturday, December 26, 2009 7:33 PM Subject: Re: Pros and cons of varible bit rate I suppose it comes down once again to personal preference, I've been using varriable bit rates for youears. As I understand it, encoding with a varriable bit rate takes a lot longer as the encoder looks at every sample of the song thus deciding what bit
