Bit rate setting?

I've been using a Blue Snowball USB microphone for recording. The microphone has a bit rate of 16. When I'm recording with that microphone, should I change the GarageBand bit rate setting to 16 as well? I vaguely recall being prompted in GarageBand to set the bit rate, but stuck to the default (whatever that is), because at the time I had no idea what a bit rate was.

jsamuelpage wrote:
The microphone has a bit rate of 16.
16 wouldn't be a "bit rate" it would be the bit depth (bit rate would be measured in the thousands, not double digits)
jsamuelpage wrote:
should I change the GarageBand bit rate setting to 16 as well?
GB records with a sample rate of 44100 bps, and a bit depth of 16 by default, so you need not set anything.

Similar Messages

What are the best data and bit rate setting for uploading from final cut express to Youtube?

Can anyone suggest the best data rate and bit rate presets for uploading footage from final cut express 4 to Youtube? What settings will provide the best resolution, quality, and match the current youtube requirements?
Thank you in advance for your help,
Susan Kayne

It depends on whether you are using aspect ratios of 4:3 or 16:9.
Below is some simple guidance that will provide good quality with reasonably small file sizes.
The first part is for 4:3 video:-
1. File>Export Using QT Conversion.
2. The "Format" window should say, "QT Movie".
3. In "Use" select "LAN/Intranet" from the dropdown menu.
4. Click "Save" and when it has finished encoding, upload it to YouTube.
If you are making 16:9 video (Standard or High Definition) do steps 1 to 3 above.
Then when you have selected "LAN/Intranet" press the "Options" button and in the new
window that opens press the "Size" button and change the "640x480" to "853x480"
To do this you will have to click on the 640x480 and a dropdown menu appears.
Select "Custom" from the bottom of the menu and in the window that opens
you will see 2 boxes.
Put 853 in the first box and 480 in the second.
Click OK.
Then Save it.

Bit rate spikes above 7.3-maximum setting?

Hi
I have used a setting of 6.5 ave - 7.3 maximum-2 pass VBR with compressor 1.1 & AC3-192-audio. Burned a DVD-R of the DVDSP2 project and it plays fine in my set top player. However, I noticed when I watched the bit rate display (ave. & max. bit rates- which is an option on the set top player) while playing the DVD-R, the maximum bit rate spiked to 9.4 for a split second on one scene and would jump to 8 to 9 at other times for a split second on a few other scenes. Most of the time peaks were around 7. My question is will this present a problem for playback compatibility on some set top players? Or is this normal & not a problem for most set top DVD players as long as the bit rate spikes are very short in duration? I find it odd that the maximum bit rate setting of 7.3 that I used was over ridden that much to allow 9.4 as a peak-maybe the set top bit rate display is not totally accurate?
I have to burn 300 DVD-R's of this project for mail order distribution (will be burning at 1X using Taiyo Yuden media) so I need to make sure of playback compatibility with most DVD players. Can anyone shed some light on any issues that these sporadic high bit rates might present or is this not an issue for playback compatibility on most set top players?
Thanks in advance...
Della

Della,
Did you try the BitVice demo yet?
I'd be happy to help, so that your experiments with it will be fruitful. If you contact Innobits with any questions, I promise I will answer you personally. You are right in the assumption that bitrate graphs will not tell you any real truths. At least not those you were looking for:-(
Dear you all, Della included of course,
As one of the scientists behind the Bitvice MPEG-2 encoder, I am sad about the time we spend helping people clarify the crazy things they hear. Fortunately there are forums, such as this one, where hopefully clarifying the same things multiple times is not necessary. (Thus the invention of the FAQ)
At BitVice we treat our customers very well, and we are happy to help on this topic also.
There are so many misconceptions about maximum bitrate floating around on the Internet. Therefore, in a perhaps futile attempt, I decided that this might the time for putting my foot down. Hopefully, it may shed some light on the subject, at least to some of you.
No names, but I know that some of you are far better than me to explain technical things in a more "popular" form to members of this forum. If any of you wish to "translate" the essence of it into a more human readable format, please contact me off-line to get a "complete story".
I am not aware of any publically available diagnostic tool, for momentary (peak) bitrate graph calculation, that could be seriously used for MPEG-2 video stream evaluation against what is meant by "maximum bitrate", as defined in the DVD, or MPEG-2, specifications. Please, correct me if you think I'm wrong.
Bitrate graphs are generally created upon inspection of a .m2v file and based on some (non-standardized) time interval.
Depending on how (by which intervals) you are calculating a momentary bitrate of a .m2v file, it may very well vary between 1 to 40 Mbps, even for DVD compliant constant bitrate streams. The MPEG-2 group was obviously aware of this fact and therefore didn't even try to define what "momentary bitrate" is. And, INTERESTINGLY, there is absolutely no need for such a measure anyway, at least not where MPEG-2 is concerned. I hope the following will help to explain why that would be like weighing of a truck by measuring its length instead, regardless whether it was empty or fully loaded.
The DVD spec. has a 9.8 Mbps limit to the video bitrate, and 10.08 Mbps for the total bitrate. However, this has very little to do with what many bitrate graphing applications is trying to tell you. I'd say, unless they offer you to decide which maximum bitrate it is supposed to measure against, it is just pulling your leg. I think this is really sad. You didn't ask, or pay, to be falsely comforted, did you?
It really doesn't work the way you are led to believe. Actually, the MPEG-2 specification is completely silent about how to even calculate any "peak" bitrate (just because it is really beside the point). Instead, this rate problem is handled in a far more sofisticated and clever way, namely by looking at the decoder buffer fullness at all times. This seems to be completely ignored by most bitrate graphing utilities.
Don't get me wrong here, such utilities can still be rather useful for getting a general idea of which parts of a movie requires more bits than others, but that's about all they can do. For your own mental health, don't fall into the trap of thinking that the highest peak (momentary bitrate) is telling you what the max bitrate is. Sorry, if this sounds confusing at first.
The correct way of interpreting the term "maximum" bitrate is
NOT by comparing to any kind of bitrate graph. That is simply because MPEG-2 does not even define any way to calculate such a thing.
Instead, one needs to think of the "maximum" bitrate as the maximum CONSTANT sustained rate, at which a decoder is capable of reading (or pulling) the data from e.g., a DVD disk. Just think about it for a little while and you will understand that it is more a property of the decoder/player than of the MPEG stream (file) itself. Of course, the responsibility of meeting these requirements rests solely on the MPEG-2 encoder. However, and this is very IMPORTANT, the encoder is COMPLETELY FREE to chose ANY strategy or policy to ascertain that the buffer requirements are complied with. That alone, is enough to leave bitrate graphing utilities in the dark of what is really going on.
If the time it takes to display some already buffered frames (which could amount to say 50 to 300 ms, as counted in display time, depending on the situation) is too short for the next (big) frame to be pulled in its entirety from the disk, then the decoder buffer will underflow. Meaning; that no complete frame was received in the buffer by the time next frame was supposed to be decoded. This situation is where you can honestly say that the bitrate of the stream was higher than the decoder was capable of reading.
However, this is a very tricky thing to capture in a bitrate graph just by inspecting the stream, unless you know everything about the current state of the buffers in general (meaning that its recent history is important) AND more specifically knowing at which rate the decoder is supposed to be pulling picture data from the disk, including, of course, any imperfections in the DVD media.
Given this maximum sustained "pulling" rate, which actually corresponds to the "ceiling" setting in BitVice terminology, it is up to the MPEG-2 encoder to create a stream (.m2v file) that will never, neither overlow nor underflow the decoders' buffers. For those who think a step further on this matter, it means that there exists no common time (duration, measured along the display-time axis, or a number of frames) over which one can calculate a peak bitrate. So, however you choose to do; averaging number of bits over one second, over half a second, over a certain amount of frames or whatever, you will NOT find the correct answer to how the bitrate graph should look like, if you want to be able to interpret the peaks as reflecting what the max bitrate is.
Let's agree that an MPEG-2 stream NEVER has a constant frame rate, as seen by a decoder reading at a constant "maximum" bitrate. From this follows;
Assuming a duration, as counted in display time, by which you can divide the number of bits to get a bitrate, is rather pointless, and also wrong. However, that is generally what is assumed by a bitrate graphing utility.
An MPEG-2 video stream NEVER has a constant frame rate, as seen by the decoder. One frame may be swallowed 5 ms and the next may take several hundred milliseconds to completely enter the decoder buffer.
This is because every frame has an individual size, which may vary most considerably (even for CBR), but the decoder reads the stream of them at the same (normally maximum, see the PS below) bitrate. So, while the decoder is displaying one single frame on your TV monitor, it may be receiving and decoding several successive smaller frames. On the other hand, while receiving/decoding larger frames (e.g., I-frames) it will have time to display many previous frames on your monitor, before a single later, and bigger, frame has been completely read into the decoder buffer. I hope this explains why you should be careful about how you interpret any bitrate graphs, especially when maximum bitrate is concerned. (That's the primary reason why we have not designed such a tool for our customers yet).
Instead, and contrary to many other encoders, we have designed the bitrate control in BitVice in such a way that;
1) The target bitrate that you choose (the average over the whole movie) is enforced, extremely accurately, usually less than 0.1%. I have seen files generated by other encoders which have been 200% off the desired bitrate, though. (To get the true average bitrate of an m2v file; divide its number of bits by its duration expressed in seconds. Then you'll see what I mean. Extremely simple math for a 12 year old kid, although the numbers may be big and therefore tend to have many digits in them;-))
2) The "Ceiling" bitrate is NEVER exceeded, not even by one single bit/s. Now, frankly, if your bitrate graphing tool says something else, then it is telling you more about itself than about a file generated by BitVice.
There is sort of a contract between encoder and decoder, like this, where X is the maximum bitrate:
Decoder:
"I promise you that I am able to read your video stream at X Mbps, or less, for as long as you wish."
Encoder:
"OK, then I promise you that my video stream would never need to be read any faster than X Mbps, at any time, and your buffer will never overflow or run dry. However, if your buffer is less than THIS big (the needed buffer size is written at the beginning of the stream, normally 1835008 bits or 224 kB), then you can as well stop already.
I don't know how every other MPEG-2 encoder works in this respect, or if bitrate graphs could be of any help in evaluating them. The only thing I can promise is that with BitVice you can rely on its bitrate control to deliver what you asked for. You could use BitVice in your evaluation of different bitrate graphing utilities though, if you like.
I'll stop here, because I sense that even those of you who have read this far may want me to;-), but, this topic is enough to fill one whole chapter of a book that I may never find the time to write.
I realize that this post may seem controversial at first, so I'm prepared to follow up on any questions, suggestions or comments that you might have.
Kindest
Roger Andersson / Innobits AB, makers of BitVice MPEG-2 encoder for Mac
PS.
Of course, a decoder is assumed to completely stop reading (pulling) from disk whenever its buffer gets full, but then continues at full speed (maximum bitrate) again, whenever the buffer is NOT full.
So the true bitrate graph, according to the decoders' view, is be very easy to recongize, becaue it will just alternate between two values, 0 Mbps and the max bitrate.
Ds.

Problem with bit rate ?

Hi there,
Using FCP7.
After compressing a FCP project with Compressor and burning DVDSP with DVDSP, I realized that scenes containing objects or people in rapid movement where showing jerked images.
The slow motion scenes are fine.
I checked the following
settings for DVDSP burning: VBR two pass;
averageBit rate 4,0,
max rate 7,0
1) the self-contained QT that I started with is not showing this problem.
2) the m2v file obtained from compressor (I use preset setting for high quality compression) does not show this problem when I view it with MPEG streamclip
3) I tried to burn directly the QT file with Toast 10 …get same problem if not worse !.
settings for Toast
automatic re-encoding
average rate 4,0 Mbps
max bit rate 8,0 Mbps
MPEG-2
I guess my problem comes from the bit rate I used ?
I am now confused and I am not sure I understood the impact of the bit rate setting on the quality of the resulting DVD, and I believe that using a high bit rate in DVDSP might result in problems for some clients to play the DVD on their player ?
Could it be something else ?
could someone please give me advice ?
Many thanks in advance
Ivan

I can only think of two possibilities based on the info available:
1. Old DVD player (choking on the bitrate spike)
2. You need to set some compression markers around the scenes while in FCP. This would flag Compressor to pay extra attention to that area. After you output the new clip, I suggest you use the standard High Quality preset (in Compressor) for your program duration e.g., "Highest Quality 90 minute". Don't get creative with the encoding set-up. And ALWAYS used AC-3 audio.

Bit rate too high error

hi,
i am trying to burn my project which has 2 videos of 10 minutes each.
one of those videos has 19 sub-menus, which are very simple pages with nothing more than a button that says play (leading to the 2nd video). I also have 19 subtitle streams. all the video was encoded in compressor and the audio is ac3.
for bit rate setting i am using 6 and a max at 7. still getting error. not sure what the next step is here. the total i see as the project in terms of space looks like only 800 megs so i am not sure why i am getting this error. please help. thanks.

Try trashing your preference and getting rid of any PAR file associated with the disc and rebuild. Delete your old asset from the import window and trash it on your computer as well. If that doesn't work I would build the project from scratch and try again. Im looking for the data rates for a subtitle but I cant find it right now. But 6 mb/s CBr should be good.

Encoding error- Muxing bit rate too high

hi,
i am trying to burn my project which has 2 videos of 10 minutes each.
one of those videos has 19 subtitled tracks and simple sub-menus. All the video was encoded in compressor and i tried both a VBR and CBR. I am only using audio that is AC3. For bit rate setting i am using 6 and a max at 7. The muxing craps out about 33% though. When i open the last file in MPEG Clipstream, i can see it dumps out at about 8 minutes but there is nothing on any of the subtitle streams that appears out of place. Total project is under 1 gig in terms of space so i am not sure why i having problems. i also posted this on the dvdsp forum but so far, no one has been able to help solve the issue. please help. thanks.

Eric suggested:
"Try trashing your preference and getting rid of any PAR file associated with the disc and rebuild. Delete your old asset from the import window and trash it on your computer as well. If that doesn't work I would build the project from scratch and try again. Im looking for the data rates for a subtitle but I cant find it right now. But 6 mb/s CBr should be good."
What happened when you tried this?

Maximum Bit Rate help

I have been trying to find the best bit rate settings to display from a USB drive on an Xbox 360 or PS3. I found the recommended settings but the maximum bit rate that I set it at, is always exceeded during playback.
For example if I am using the h.264 codec with the bit rate settings of VBR and the maximum bit rate set for 10 Mbps, my bit rate will always spike way higher then 10 Mbps during scenes with more movement. A scene where I'm pointing my camera out of a moving car with houses going by displayed a bit rate of 38.8. In case anyone is wondering I use the bit rate counter on my PS3 to find the bit rate at any give time.
Now When the bit rate spiked at 38.8 for that scene, it dipslayed fine on my PS3, but when played back on my Xbox it stutters a little at that moment.
If I use a CBR of 10 Mbps the bit rate still goes quite a bit over 10 Mbps but didn't approach 40 Mbps like it does when using a variable bit rate. When using a CBR it played back flawlessly on both devices but there was a little drop in quality.
Is there something I am doing wrong or is this just how it works? I assumed the target bit rate is what you are shooting for and the maximum bit rate would never be exceeded. Is that not the case?

I took that it could be inaccurate in to consideration but when I play a blu-ray back the bit rate usually fluctuates between 25-35 Mbps so I assumed the readings were pretty accurate.
I'll try the VLC player as you suggested when I get home. Does it show you the bit rate during playback, the average bit rate, or what?
Also if I set my maximum bit rate to 10 Mbps should it never exceed that?

Bit rate problems

Re: Video bitrate too high
Posted: Sep 5, 2006 7:50 AM in response to: Rikk Desgres
Reply Email
Hi,
I have exported two 10 minute HDV movies as mpeg2 files, using Compressor, with the default bit rate setting of 6.2/7.7 mbps. When I try to burn a DVD, I get the "bit rate too high error message". I've used the same settings for these files before, and no problem. However, after I made minor changes to these files in FCP, and then tried to export - no luck. Should I try to export reducing the bit rate in Compressor?
Janis

A data rate of 160 or 192 is usually good, you should set Dialog Normalization to -31, preprocessing to none and dechecking Copyright Exists and Content is Original also helps prevent glitches (I had that drilled in my head awhile ago, like in DVD SP 1 time and sort of just follow it as a matter of course, pretty sure it still holds true through DVD SP 4 and Compressor 2, at least it has for me.)

Too High Bit rate error no matter how much reduce it

After Exporting an HDV 1080i 16:9 3 sequences from FCP via
compressor at Best SD DVD 90 minutes, 16:9, and burning two DVD-Rs that work, now DVDSP keeps giving me Video Bit Rate too high error and stops building shortly after starts. And no matter how much I lower bit rate won't do it! HELP

I think - and see if you agree - that I exported using a compressor bit rate setting of 6.0 and max of 7.5 on the first 56 min sucessful sequence build/burn, and then thought I could go higher on the second export so goosed the max bit rate to 9.0 since there were occassional big bits of motion. So now on the other two sequences DVD SP won't adjust that previous compression rate, and instead I will have to sacrifice the audio quality (use Dolby only)
to get it to build. I certainly DON't want to wait 26 to 28 hours again for each sequence to export!! Does that sound right?

Bit Rate settings for compressing to iPhone

Hello-
I have Compressor 3.05 and I'd like to use a bit-rate setting that is not available in the Apple-provided iPhone presets. I'm looking for something around 150. Is there a way to create a custom preset for iPhone compatible video? I can't seem to figure this out.
Thanks,
Mark

Yes there is!
*Step 1:* Create a preset will all the other settings how you want them. In my case I started with File Format: H.264 for Apple Devices, Device: iPhone (Local/Wifi) Drag the data rate down as low as it will go (700Kbps). Save it as a new custom setting.
*Step 2:* Those are stored in User>Library>Application Support>Compressor open the preset you just created (it will have the same name) in a text editor, I used TextWrangler. Find the second <data-rate> (the first one is for audio) the number in there should be 87500. Lower that number to the desired amount.
*Step 3:* Save the file. Go back into Compressor and then apply it to your source video.
That should do it!

MPEG-1 bit rates

I'm making up an MPEG-1 file in Cleaner 6 for a CDROM.
With a 2-Pass, Variable Bit Rate setting, what should I be setting as my Bit rate, (which I'm assuming is the max rate in the variable option I've chosen...?)
Default is 1.5 Mbps, but it can go up to 3 Mbps.
I'm assuming a higher bit rate will make quite a difference in final quality?
Is the limitation for playing back off the CDROM directly or are there other considerations.
I could have my client download the file from the CDROM to his hard drive if that would give better playback.
Thanks,
LEE

All very valid points...
We've had all this out with a very stuborn client who insists that the file must be playable from any laptop even if its only equipped with a basic CD reader.
Programme length is 30 mins and there's no other acceptable way of getting the media into people's computers than via CD.
I hate MPEG-1 and if you could see our beautifully crafted and graded pictures you'd see why...!
Alas it's all I'm going to be allowed to do. I've tried a 1.5 and 3Mbps transfer - both with 2-pass VBR and can't see a whole lot of difference so I'll probably use the lower rate.
If I change the size of the image at transfer will that give a better result than letting my client view the pictures larger by stretching the QT box bigger. It would be nice to have the programme start a bit bigger than just a thumbnail - although I appreciate that will degrade the quality.
LEE

Fixed bit-rate varies from song to song

after importing a cd (bit-rate set to 256 kpbs (stereo), 48 000 kHz, NOT checked the Use Variable Bit Rate Encoding box) i see thet the songs have been imported with bit-rates that change from song to song (like first song 258 kbps, second - 257 kbps, third - 251, fourth - 237 and so on).
could anyone please explain why so?
thanks in advance!

thenewdawg wrote:
Thanks for the thread, though it's an iTunes for Windows thread. Any info. for Mac?
Meg is correct, the issue is not specific to Windows, it is specific to QuickTime 7.3, on both platforms.
After reading through the thread, and others that it points to, I get the impression that the changes are supposed to be improvements. And probably are for the majority of people.
On the other hand, there are a number of specific cases where the new behavior is actually a problem. If you're using Doug Adams's excellent Join Together script (http://dougscripts.com/itunes/scripts/ss.php?sp=jointogether), with varying bitrates between tracks, you can no longer use the Pass-Through option, which means that the script can take much, much longer to complete.
And I've gotten reports from some people that at low bit rates, e.g., 64kbps and lower, imports using QuickTime 7.3 have some kind of static noise, that is not there when the same disc is imported / transcoded with QuickTime 7.2. So I think there are some software defects to work out, too.

Low frame rate even with high bit rate

I am using a Logitech QuickCam Pro for Notebooks (the model that supports UVC per Logitech's website) with a new Mac Pro and iChat. Whether I do a video iChat over the internet or one within my internal network, the fps per the connection doctor of my camera is about 6 fps, even if the bit rate is over 2000 (which is what is was when I did the internal network chat). I can't find any setting where I can increase the fps rate, I can only increase the bit rate in the camera preferences in iChat.
The camera is capable of up to 30 fps and when I do a video recording with it in QuickTime Pro and play it back, QuickTime Pro shows the frame rate as 30. So the camera is connected properly and is working properly. Any ideas on how to get the fps up to 15 in iChat (which seems to be the maximum, per the MacBook Pro I used for my internet network test above)? Thank you.

Thanks for the reply, Tony. Changing the bit rate limit to 500 did not cause the frame rate to change. On my test with my internal network if I had the limit set to none then bit rate was over 2000 but frame rate was only 5-6. When I limited the bit rate to 500 it dropped while the frame rate remained unchanged a 5-6 fps.
When I was doing an internet chat I also changed the bit rate limit to be none, 500, or 1Mbps to see what would happen and the connection doctor showed my frame rate staying at 5-6 and my bit rate staying below 100 (so changing the maximum bit rate setting made no difference). Meanwhile, the person I was chatting with had a frame rate of 15 and a bit rate of about 250.
I'm on a cable modem just like the person I was doing the internet chat with, so I guess the problem is something to do with iChat and my Logitech web cam, not my internet connection.

Can no longer change bit rate in AAC custom import setting

I want to change personal settings of AAC, but I can't. Still only the last setting, that was 192 Kbps Stereo. My iTunes version is 10.7

Hi, Ed. I am running iTunes 9.0.3.15. When I click custom, the settings description in the details box display what they were before this thing happened = 112 kbps (mono)/224 kbps (stereo), VBR, optimized for MMX/SSE2. The pop-up dialogue box that used to appear (where you could choose the specific bit rate from the drop down menu) does not appear at all.
However, when I choose anything other than AAC Encoder, and then pick custom, the pop-up box appears and I can choose the bit rate and adjust the other settings as usual. It's just not happening for AAC Encoder anymore. Since the total un-install (following Apple's specified order) and reinstall didn't work, I'm baffled how to fix this .... (If it makes a difference, I changed the bit rate in the custom box while a CD was being burned...Apparently that was stupid, but I had done it previously without incident.) Thanks.

Compressor: setting max bit rate for VBR audio

Hi,
I am using Compressor 3 to transcode DV to H.264. I want to encode the audio to AAC VBR wtih a max bitrate of 256. Under the Settings tab, under audio, for VBR there is a slider from good to best. what does this mean in terms of max bit rates? How can you use this slider in a meaninful way?
There is a setting for Average Bit Rate, where you can select a value. do we konw what the max bit rate would be?
thanks
dan

Good question about the slider…and I really don't know the answer. Why don't you try a test: crank it to one extreme and then the other with a representative source file and see what impact it actually makes on the properties of the respective output files.
Good luck.
Russ

Bit rate setting?

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