Nyaaori/rockbox
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
rockbox/docs/FAQ
Linus Nielsen Feltzing 10fafb3d7c Added a link for condenser mics, and updated some links to the wiki 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4870 a1c6a512-1295-4272-9138-f99709370657
2004-07-13 09:53:36 +00:00

776 lines
37 KiB
Text
Raw Blame History

Q1. What is a FAQ?
A1. A rare small animal of the species 'Textius Electronicus'. It is known for
its helpful attitude and vicious misspellings.
Q2. Okay, fine, what is _this_ FAQ?
A2. This FAQ is for questions (that we have answers to) that have been asked
repeatedly either in emails or on IRC.
Q3. What is Rockbox? What is it's purpose?
A3. The purpose of this project is to write an Open Source replacement
firmware for the Archos Jukebox 6000, Studio 20 and Recorder MP3 players.
Q4. I want to write code for my Archos, how do I proceed?
A4. Our guide on first time (http://rockbox.haxx.se/docs/firsttime.html)
Rockbox development should answer most of your questions.
Q5: What is CVS?
A5: Concurrent Versions System (http://www.cvshome.org). We have a small
help page about how to use this to get, update and commit files on the web
at http://rockbox.haxx.se/cvs.html
Q6. What exactly is the CONTRIBUTING file?
A6. Just like the name implies, it lists conventions that the project follows,
and in turn asks you to follow, for the formating of source code in
general.
Q7. Okay, so I read CONTRIBUTING and although I don't agree with all your
conventions, I am going to be sensible and follow them anyway. Now what?
A7. Start by reading up on the information about the jukeboxes on our web page.
Then go into CVS and look at the code we've written. Then take what you
need and start writing.
Q8. I want to join the development team, but don't have a SourceForge account,
what should I do?
A8. You don't need a SourceForge account to help developing Rockbox. Just
submit patches (http://rockbox.haxx.se/twiki/bin/view/Main/WorkingWithPatches)
If your patches are consistently well-written and thus accepted, you may
ultimately be offered CVS commit access. If that should happen, you will
need to get a Sourceforge account:
http://sourceforge.net/account/register.php
Q9. Do you have a mailing list?
A9. Sure do! As a matter of fact, we have several of them for specific things.
Please check out: http://rockbox.haxx.se/mail/, and please see FAQ entry
75.
Q10. Great you have a mailing list! Is there anyway for me to catch up on
past posts?
A10. Check out the archives at: http://rockbox.haxx.se/mail/
Q11. How can I meet the developers working on the project?
A11. One way is by visiting us on IRC. Head on over to the server
irc.openprojects.net, and then join "#rockbox". There is usually at
least one person there. If you don't see any activity, feel free to post
questions anyway, several of us log the channel and will get you answers
when we unidle.
Q12: Wow, you guys talk on IRC a lot? I wish I had been around for those
conversations to see what happened.
A12: We are glad you mentioned that! http://rockbox.haxx.se/irc happens
to have a list of various logs we have recorded of events in the channel.
Feel free to read up, and ask questions on what you find.
Q13. What is this "SourceForge" you keep mentioning?
A13. http://www.sourceforge.net
Q14. Can the changes or the software that Rockbox suggests or offers
possibly damage my Archos Player?
A14. All firmware mods that are presented are still highly experimental.
Try them at your own risk. We offer no guarantee that this software, or
the hardware modifications we show, will not damage your player or void
your warranty. That said, we have not been able to damage any of our
units by modifying only the firmware. You can accidentally password
protect your hard disk, but there are ways around that. (See below.)
Q15. I want to see what the inside of my player looks like, but I would really
like to avoid voiding my warranty. Is there anything you can suggest?
A15. We have a collection of photos of both the player and recorder. Look at
http://rockbox.haxx.se/internals/
Q16. What exactly are you trying to achieve with this line of development?
(A.K.A. what's your purpose for being here?)
A16. Firstly, we wouldn't start something like this if we didn't simply enjoy
it profusely. This is great fun!
Secondly, we feel the original firmware is lacking some features and
contains a number of annoying bugs that we don't want to live with.
Q17. You mention supporting Ogg Vorbis and other file types on your list of
ideas. What is the status on that?
A17. Pessimist's Answer: At the current time we believe this is not very
likely. The Micronas chip (MAS3507) decoder in the Archos does not
natively support decoding and there is very little program space in the
player to implement it ourselves. The alternative would be to write a
software decoder as part of the Rockbox firmware. However, as much as we
love our players, the computing power of the Archos (SH1 microcontroller)
is not fully sufficient for this need.
Optimist's Answer: We can play any format if only we can write code for
the DSP to decode it. The MAS 3507 (and 3587) are generic DSPs that
simply have MP3 codecs in ROM. We can download new codecs in them and
we will be the first to celebrate if we can get OGG or FLAC or anything
into these DSPs. Unfortunately, we have no docs or tools for writing new
MAS DSP code and Micronas is very secretive about it. If anyone can
help, please get in touch!
The recent release of Tremor (integer Ogg decoder) indicates it uses
around 100 KB for lookup tables. That's not unreasonable for a decoder,
but we only have 4 KB for both code *and* data. So the grim reality is
that Ogg will never be supported by the Archos Players and Recorders.
Q18. What about supporting playing of WMA files?
A18. Dear Mr. Gates, you have two options. Re-read previous question, or go
buy your own project.
Q19: But you don't understand, I'm not talking about decoding here,
since the data we want may already be in the decoded format (PCM).
A19: Okay, last time. No. We have no problems whatsoever reading different
file formats, call it PCM, WAV, GRI, PQR or whatever. The problem is
that the CODEC only accepts MP3 data and nothing else. We could write a
new CODEC if we knew how to do it, but there is no documentation on the
DSP. Please note that we have no access to the DAC, so we can't send the
data directly to the DAC.
Q20. What is the most recent version of Rockbox?
A20. We recently released version 2.2, so head on over to
http://rockbox.haxx.se/download/ and pull it down.
Make sure to read the release notes.
(http://rockbox.haxx.se/download/rockbox-2.2-notes.txt).
Q21. What do you plan to add to coming versions?
A21. We don't plan versions in detail. We just write code, and when it feels
right we release a new version.
Q22. I tried one of your firmware files and now I can't access my hard disk!
When I turn on my jukebox, it says:
Part. Error
Pls Chck HD
A22. Your hard disk has been password protected. We're not 100% sure why it
happens, but you can unlock it yourself. Look at:
http://rockbox.haxx.se/lock.html
Note: This is a very rare problem. Most people who think they have a
locked disk actually just experience hardware and/or driver problems.
Q23: This FAQ doesn't answer the question I have. What should I do?
A23: You have a couple options here. You could forget the question, find an
easier question, or accept '42' as the answer no matter what. We don't
really recommend any of these (though I do opt for '42' often myself).
What we do recommend is stopping by IRC, visiting the web site
(http://rockbox.haxx.se) to see if the question was answered else where
(like our nodo http://rockbox.haxx.se/twiki/bin/view/Main/NoDo FAQ)
and just not included here, or ultimately dropping an email to the
mailing list (rockbox@cool.haxx.se) or the FAQ maintainer listed on the
project home page.
Q24: Are there other ways to contact the developers?
A24: Yes.
Q25: Are you going to tell us what they are?
A25: No. Post to the mailing list and we will get back to you.
Q26: But I _really_ want to talk with you in person.
A26: I'm sorry. My girlfriend/boyfriend/pet says I'm not allowed to, and the
doctors here won't let me have pens or pencils. They say its some rule
about us not having sharp objects. I'm sorry. Now please stop calling
me here.
Q27: Will you ever port Quake II to the Archos?
A27: If you ask that again, I'm sending your address and phone number to the
guy that mailed us with question #24.
Q28: Umm, was that sarcasm?
A28: That's it, I'm mailing him now.
Q29: Is this legal? I mean, I'd just hate to see something like that
challenged under the DMCA in all its ridiculousness. Any thoughts or
ideas?
A29: We believe we are in the green on this. We are not violating anyone's
copyright and we are not circumventing any copy protection scheme.
This has been a big point for the project since its inception. Some
people wanted us to distribute patched versions of the original firmware,
but seeing as that _would_ have violated Archos' copyright, we didn't
follow that course of action.
Q30: On the web site [and various information postings] you state
"Every tiny bit was reverse engineered, disassembled and then
re-written from scratch".
If it was rewritten from scratch then why was it first reverse-engineered
and disassembled? Instead this sounds more like someone disassembled it
then used the understanding that they gained to create a new version,
which is not quite the same as "from scratch".
A30: Don't confuse the terms. Reverse engineering means examining a product
to find out how it works. Disassembling the firmware is merely one tool
used in that examination. Oscilloscopes and logic analyzers are other
tools we have used. We have written every single byte of the Rockbox
firmware. But we could not have written the software without first
researching how the hardware was put together, i.e. reverse engineer it.
All of this is completely legal. If you define "from scratch" as writing
software without first researching the surrounding interfaces, then no
software has ever been written from scratch.
Q31: This FAQ is great, but do you have anything with a bit more detail?
A31: Check out our website and it's documentation. Rockbox also has a user
manual you can read. http://rockbox.haxx.se/manual/manual.pdf
Q32: I've heard talk of a 'Rolo'. What is that? (Or 'All you ever wanted
to know about Rockbox boot loaders')
A32: Rolo is our bootloader. Rolo became available with our 1.4 release.
To make use of Rolo, you must have a file with the same extension as
your Rockbox firmware (.ajz on Recorder, .mod on Player) but a different
name. You can then browse to it, and you 'run' the other firmware
you wish to switch to by pressing play. Remember to set the Show Files
option to "Supported" or "All" to be able to see the firmware files in
the browser.
*Poof* You will reboot to that firmware. (Note that in order to return
to Rockbox you may need to reboot manually if the new firmware you loaded
does not have a bootloader itself.)
Q33: Can I use the Archos as an USB hard disk to store data from my PDA/
digital camera/phone etc.
A33: No. See http://rockbox.haxx.se/twiki/bin/view/Main/NoDo#4_Interfacing_with_other_USB_dev
Q34: When I use Rockbox my jukebox's red "error" light turns on a lot, but this
doesn't happen on the factory firmware. Why?
A34: Rockbox uses the red LED as harddisk activity light, not as an error
light. Relax and enjoy the music.
Q35: I have a question about the batteries...
A35: STOP! We have put together a completely different FAQ for battery
related questions.
Check out: http://rockbox.haxx.se/docs/battery-faq.html
Q36. I have a question about patches...
A36. Check out http://rockbox.haxx.se/twiki/bin/view/Main/WorkingWithPatches
as it should answer any patch related questions you may have.
Q37: What is the WPS?
A37: That is the 'While Playing Screen'. Basically this is what is shown on
your player's display while we are playing your song.
Q38: What good is the WPS? How usable/flexible is it?
A38: It is very good if you want information about the current item playing ;)
By using a WPS configuration file you can manage exactly how/what you
want displayed on your Archos Player. (Even better yet, if you want
a feature that's not there, we are _always_ open to suggestions!)
Please see http://rockbox.haxx.se/manual/wps.html for information.
Q40: So how do I load/make a .wps file?
A40: You check out http://rockbox.haxx.se/twiki/bin/view/Main/CustomWPS
to learn the format/features of a .wps file, and read the manual to
learn how to load it ;)
Q41: Does Rockbox support other languages? How do I load/use different
languages?
A41: See: http://rockbox.haxx.se/lang
Q42: Does Rockbox support other fonts/character sets?
A42: Recorders do, Players don't.
Q43: How do I use the loadable fonts?
A43: If you own a Recorder see: http://rockbox.haxx.se/fonts/ Players
cannot make use of loadable fonts.
Q44: Why can't I use loadable fonts on the Player?
A44: This is because the Player font is character cell based (as opposed to
the Recorder's bitmap based display). This
means that we are able to choose what characters to display, but not how
to display them. We do have the ability to change/create up to 4 chars
on one model and 8 on another, however we are currently using several of
these 'letters' to store icons for the player.
Q45: Why don't you have as many games available for the Players?
A45: The display on the Players is character cell and not bitmap based.
This means there is much more limitations in the amount of graphics that
can be displayed, and thus what kind of games can be written.
Q46: I keep shutting off my player in my pocket. Can the OFF (Recorder) or
STOP (Player) key be locked?
A46: No. Unfortunately, the ON/OFF mechanisms are handled entirely in
hardware. The firmware can read the keys, but can't prevent them from
shutting off the player.
Q47: Can I record with Rockbox?
A47: You sure can. Take a look at our manual.
http://rockbox.haxx.se/manual/manual.pdf
Q48: Now that I can record, can I use custom codecs (like LAME)?
A48: The MP3 encoder is in the MAS3587F chip, and nothing we can change.
Q49: What are the max/min bitrates for recording on the Recorder's encoder?
A49: The builtin encoder is variable bit rate only with a max of 192kbit/s,
and a min of 32kbit/s.
Q50: Would it be possible to record from line in on the player?
A50: No.
Q51: I have a question about the id3v1 and id3v2 tags...
A51: Rockbox supports both id3v1 and id3v2. If you have problems,
report it to the developers and please provide an example.
Q52: Where exactly did the name 'Rockbox' come from?
A52: Well you can follow the full line of emails at
http://rockbox.haxx.se/mail/archive/rockbox-archive-2002-01/0062.shtml
However, the brief rundown is that it was recommended first by
Tome Cvitan, and put to a vote (which it lost).
Funny thing about democracies. This isn't one ;) Our beloved project
leader vetoed the winning name and chose Rockbox instead.
http://rockbox.haxx.se/mail/archive/rockbox-archive-2002-01/0134.shtml
There you have it. Recommended by users, decision by dictator.
Q53: Why is there a limit of 400 files in a directory?
A53: This is a configurable value, 400 files is just the default.
Q54: Why is there a 10,000 song limit on playlists?
A54: This is a configurable value, 10,000 songs is just the default.
Q55: How can I make playlists on my PC?
A55: There are many programs that can create .m3u playlists. WinAmp is one.
Another simple method, that requires no extra software, is to use dir:
dir /b /s X:\ > X:\allfiles.m3u
dir /b /s X:\Pop > X:\pop.m3u
...where X: is your Archos drive.
Linux users can use the 'find' command:
cd /mnt/archos
find . -name "*.mp3" > all.m3u
Remember that playlists are simple text files. You can edit them with any
normal text editor.
Q56: How does the shuffle work?
A56: It sees the playlist as a deck of cards, shuffling the entries using a
pseudo-random generator called the Mersenne Twister. After shuffling,
the list is never changed again until you re-shuffle the list, by
stopping the playback and restarting. If the repeat mode is enabled,
the list will simply start over from the first file again, without
re-shuffling.
The random seed is stored in the persistent setting area, so that the
resume feature can shuffle the playlist in exactly the same way when
resuming.
Q57: How can I find out about all the neat features that Rockbox has?
A57: This information is in our manual (It sometimes gets a bit out of
date, so please bear with us.) The information you are most likely
looking for is a bit down the tree, so the here is the url:
http://rockbox.haxx.se/manual/rec-general.html
Also, check out the features-list at:
http://rockbox.haxx.se/docs/features.html
Q58: How can I see what bugs are currently open/being worked on?
A58: Check out http://rockbox.haxx.se/bugs.shtml for a listing of bugs
that have been reported.
Q59: How can I report about bugs in Rockbox?
A59: If we were better programmers we would take that as an insult. But we
aren't, so we won't. The first step in reporting a bug is to review
the rules we ask you to follow in your submission (listed at:
http://rockbox.haxx.se/bugs.shtml#rules).
Please note that we ask reports of bugs in CVS/daily builds to be sent
to the mailing list, and bugs in released versions of Rockbox to be
submitted through SourceForge's bug tracker. (A link to the bug tracker
can be found under our bug submission rules.)
Q60: What's with all the different versions of Rockbox?
A60: We currently support four different hardware platforms: Players, Recorder
v1, Recorder v2 and FM Recorder.
For each platform, Rockbox is released in three versions: Release, Daily
Build and Bleeding Edge. These only differ in release frequency.
The Release version (currently 2.2) is a frozen known-good state. This
means that we are confident that few, if any, significant bugs reside
within the code for that version. This is the version for the common
user.
The Daily Builds (http://rockbox.haxx.se/daily.shtml) are automated
daily builds of the CVS (development) code. As such they contain all the
new features (and bugs) that have been introduced after the last official
release, up to this morning.
The Bleeding Edge builds (http://rockbox.haxx.se/daily.shtml#bleeding_edge)
are built from the CVS code every 20 minutes. The purpose of these builds
is to verify the code builds properly on all platforms (and simulators)
and also to allow testers to try out new features and bug fixes without
having to build the code themselves.
Please Note: Bleeding Edge builds are expected to be buggy at times. We
ask that you _do not_ submit bug reports for Bleeding Edge builds, but
would love to hear any reports you may have about Release or Daily build
versions. (see "How can I report about bugs in Rockbox?")
Q61: I am in Windows and can't create a .rockbox directory to store my
files. When are you going to fix this?
A61: We won't. The limitations of your operating system is not reason
enough for us to change how we handle things. And you _can_ create
this directory. Open a command line and type:
mkdir j:\.rockbox
You will need to correct the location for the drive letter that Windows
assigns to your drive.
Q62: I own a Mac. I can't seem to create the .rockbox file. Can you
fix this?
A62: Truth is, we don't need to fix anything. If you are using OSX then you
can just open a console, change directories to the device and just:
mkdir .rockbox
If you are in another version then you should be able to do command-N in
the Finder, then name the folder.
Q63: Will Rockbox work on any of Archos' other units?
A63: Other than the 4 currently supported models: no, probably not. If Archos
releases another rockbox-able player (such as the V2) then rockbox will
find its way onto it, but their new devices as the Gmini, MM, and AV
units are completely different hardware and probably won't be supported
by rockbox unless someone enthusiastically reverse engineers them and
submits patches to make it happen.
See also: http://rockbox.haxx.se/docs/nodo.html#7
Q64: I copied the rockbox MOD/AJZ file to the root, removed the jukebox
safely and rebooted. But Rockbox still didn't load. What is wrong?
I am running Windows.
A64: The old MOD/AJZ was not entirely deleted from the disk. It is still
there, and the boot loader finds that one instead of the new file. Here's
what you can do:
- Download and install Directory Snoop (version 4.03 in November 2002)
from http://www.briggsoft.com/dsnoop.htm.
It's shareware, the trial version can be used 25 times.
Directory Snoop can display true drive contents by bypassing the
operating system and reading the raw drive sectors directly.
- Plug the Jukebox in the PC as usual and power on
- Launch Directory snoop
- Click on the Jukebox drive letter in the [select drive] field in the
toolbar. The content of the jukebox hard drive appears in the main
window. Files which appear in red color don't seem to be present on the
hard drive, but they still here.
- Simply select the appropriate files (red color) and purge them
(Purge button). Of course, don't erase the new archos.mod file and the
.rockbox directory :)
- Safely remove (Windows unmount device function) the Jukebox.
Power it up and ...voila... Rockbox is there!
(Thanks to Olivier Rafidison for this info)
Another alternative:
- Copy the firmware file to the jukebox again. Windows will rename it to "Copy of XXXXX"
- Delete the original firmware file and remove the "Copy of" part from the new file name
- Reboot
If it doesn't load the correct firmware, do the whle procedure again until the new file is recognized.
Q65: What kind of mic can I connect to my AJBR?
A65: There are several types of microphones.
Dynamic: The one that's available from Archos is a dynamic one.
Their output level is high enough so that they don't need an
amplifier (that's the reason why the Archos mic is of this type -
it's cheap).
- cheap
- no good sound quality of cheap dynamic mics (good enough for
speech)
- no amplifier needed
Backplate Condenser: These are the professional mics. They need phantom
power (48V) for charging the condenser.
They also need an amplifier, because their output level is low.
- good sound quality
- need phantom power (48V)
- need amplifier
- expensive
Electret Condenser: These capsules are cheap and result in a good
recording quality. They don't need phantom power voltage. They need power
for the FET (field effect transistor) that's inside. If you have such a
mic with a battery in it, it is mostly because of the FET power, not
because of an amplification circuit inside the mic. These mics are in
all the consumer products like mobile phones, PC headsets and so on.
- cheap (2 EUR for a capsule)
- good sound quality
- need amplifier
- need power for the FET (1,5 - 15V)
Recommendation for do-it-yourselfers: Use electret condenser mic capsules,
solder an amplifier for them which both amplifies the output level
and feeds the power needed for the FET to the capsule.
The one on http://www.geocities.com/ferocious_1999/md/micpreamp2.html
was soldered and tested by Uwe Freese, and it works.
There are some others available from www.elv.de and other sellers.
Recommendation for others: Buy some mic + preamp combination which can be
plugged into a line in of any amplifier. Maybe such a commercially
available combination needs a power supply and doesn't work with
batteries. Some are very expensive. You might have some luck at
http://www.giant-squid-audio-lab.com/.
What does not work: Don't use an amplifier thing that is simply connected
between some mic cable. Maybe it sounds as if it could work, but I
doesn't. If the piece of (expensive) electronic doesn't have a power
source and your mic doesn't either, it does not work! A PC sound card or
md player usually has a power output (same pin where the sound goes
through, dc value) for feeding the FET of an electret condenser capsule
(see above) (and this power could also used to feed a mic amplifier), but
the Archos hasn't (it's a line in and no mic in!).
If you want to know more on microphone powering, read this:
http://www.hut.fi/Misc/Electronics/circuits/microphone_powering.html.
(As described, you also need amplification.)
Q66: I can't start rockbox when the charger is connected. What am I doing
wrong?
A66: If your device is off and you connect the charger, the Archos charger code
is started immediately. You can then start Rockbox with holding down the
ON key for several seconds. Hold the key down a really long time, until
you see the Rockbox logo!
Q67: Why can't you implement a cross-fader? That would be so cool!
A67: Please read our NODO faq. http://rockbox.haxx.se/twiki/bin/view/Main/NoDo#3_Crossfade_between_tracks_
Q68: My screen is all black/white when I run Rockbox on my Recorder!
A68: This bug has been fixed in the later versions of Rockbox. Upgrade!
Q69: Where are the FM controls for the FM Recorder?
A69: In the menu: FM Radio
Q70: I installed/renamed ajbrec.ajz (or archos.mod) but I am still booting
with another version of firmware.
A70: When looking on the hard disk the Archos firmware only matches the first
ten characters of the file name. Because of this files like
ajbrec.ajz.bak or ajbrec.ajz-20030404 match and are loaded. To
prevent this from happening, give the it a file name that differs in
the first 10 characters, e.g., ajbrec.bak.ajz.
Q71: Help! My recorder crashes when I copy files to it!
A71: Yes, the recorder can crash when you copy several gigabytes of
files to it. The explanation is simple: Copying several gigabytes
of files through USB requires a long period of sustained disk
activity and drains more power than the batteries of the recorder
can store. A long copy will eventually drain the batteries to the
point where the recorder can no longer function and it halts.
This even happens when connected to the charger, since the power
drain is more than the charger can provide! If the recorder halts
while connecter to the charger, the batteries will recover and
after a short while it will reboot the Archos firmware in charger
mode. To make it worse, depending on the USB drivers of your
system it can cause your system to crash as well, or confuse it
to the point it needs a reboot.
There is no solution, just some tips:
- Connect to the charger when copying lots of files. This will
not prevent the problem, but it will take longer to happen.
- Make sure you have "Deep Discharge" disabled.
- Switch off the "Backlight On When Plugged" option.
- Use USB 2.0. Transfers will be much faster.
- Copy incrementally. With fully charged standard batteries it
should be capable of sustained copying for 2 - 2.5 hours.
Q72: What should I know about digital I/O connector on my jukebox?
A72: The Recorder models have a connector for digital audio output using the
common S/PDIF standard (Sony/Phillips Digital Interface). This jack is
not present on the Studio/Player/FM Recorder models. By using the digital
output in combination with high class external equipment, you can get
much better sound quality out of your jukebox. This is because you can
use better DA-converters and better amplifiers, plus you eliminate the
analog audio connections between the jukebox and your equipment that can
introduce noise and distortion.
The Recorder and the FM Recorder models are able to record from digital
sources, too. The digital inputs don't have the 15kHz lowpass filter like
the analog inputs and you are sure to minimize the noise floor.
Although S/PDIF can be an electrical or an optical signal and there are
many devices that support both, the socket on the jukebox is for
electrical signals only! Some devices have sockets that look the same,
and can take either an optical or an electrical cable, but sadly this is
not true with the Jukebox.
If you want to connect your amp with digital input (RCA type) to the
output of your Recorder you need an adapter cable (3.5mm stereo jack to
dual RCA jack). Plug the 3.5mm stero jack into the digital I/O socket of
your jukebox and the red RCA jack (right channel) into the digital input
socket of your amp and that's it. You don't have to enable the digital
output, since it's always on. The sound settings on the digital output
are always flat, your volume, bass, treble, bass boost, loudness settings
won't have any effect here, that's why fade in/out won't work,
either. The sampling frequency of the digital output is the same as the
sampling frequency of the mp3. It's therefore possible that your external
equipment won't be able to synchronize to the output of your jukebox if
you have mp3's with sampling frequencies other than 32, 44.1 or 48kHz
(The pitch shift function also modifies the sampling frequency!).
For recording digital signals on the Recorder, use the white RCA jack
(left channel) and plug it into the digital output of your CD player, MD
player or whatever. Don't forget to select digital input in the recording
settings!
Note that some adapter cables exist with different color coding, so if it
doesn't work try to swap red and white. The tip of the 3.5mm jack is the
digital input, the ring is the ouput. For recording digital signals on
the FM Recorder, you need a special 4-pole 3.5mm plug (shaft = ground,
tip = left channel analog line in, first ring (next to tip) = right
channel analog line in, second ring = digital in).
If you want to connect devices with optical inputs/outputs, you need a
small converter box which converts your signal from electrical to optical
(for digital output from the Archos) or optical to electrical (for
digital recording in to the Archos).
Q73: How do I unsubscribe from the rockbox mailing list?
A73: The same way you subscribed, but you send an 'unsubscribe' request to the
mailing list server instead of the 'subscribe' one you sent before.
This is all mentioned on the same web page: http://rockbox.haxx.se/mail/
Please please please pretty please with sugar on top, DO NOT attempt to
mail unsubscribe requests to the mailing list itself. That will only
annoy more than 400 readers and will have no effect on your subscription.
In fact, you NEVER unsubscribe to ANY mailing lists by mailing unsubscribe
to the list's address. You might as well take the opportunity to learn
this right away.
When you first subscribed to the mailing list, you were sent a welcome
mail from the server. It contained information about the mailing list and
instructions on how to unsubscribe. It is considered a good habit to keep
such welcome messages from mailing lists.
In addition to all this, every mail that is sent out to the rockbox
mailing list has a set of standard headers that offer info about the
mailing list: how to post, how to unsubscribe, where to find the mailing
list archives etc. Sensible mail clients can display these headers.
Q74: What is the Recorder V2?
A74: The Recorder V2 is essentially an FM Recorder without the radio. It looks
and works like the FM Recorder except for the radio, and has LiIon
batteries. It is meant to replace the older Recorder model.
NOTE! The first V2 Recorders were in fact real FM Recorders with the
radio parts still mounted. If you are lucky, the FM radio might work in
your V2, try it!
Q75: Why is there a Radio option in my Rockbox for V2?
A75: Some of the first V2 units had an FM radio in there, so if you're one of
the few lucky ones, you can use the radio fine. If you aren't lucky, you
just won't get any sound when trying the radio screen.
UPDATE: The daily builds now auto-detect the FM radio hardware.
Q76: What does "dir buffer is full" mean?
A76: It means you have more files in a single directory than you have
configured Rockbox to support. See Q53.
Solution: Increase the "max files in dir browser" setting.
The current official release (2.2) contains a bug that sets
the default buffer setting to 0, giving the dir buffer full error.
Solution:
1) Change the limit in the settings
2) Exit the menu back to the browser
3) Force a disk spinup. There are several ways: either select
another setting for the file filter, or insert the USB and extract
it again
4) Turn it off and on again
Q77: Why are you developing X when you should be doing Y?
A77: You make the common mistake of confusing Rockbox development with that of
commercial projects. There is not much of an agenda for the development
of Rockbox. Anyone who wants to write new features can do that.
If there is a current "huge emphasis" on the X functionality, it is
because one or more developers, decided he/they wanted to write it. It's
not because "Rockbox project management" decided function X is a more
important feature than anything else.
That is the nature of Free Software: People write code that scratches
their own itches, or that simply is fun to write. Everybody working with
Rockbox is doing it for fun. A wide or narrow audience actually has only
little bearing on the choice of features to implement.
The moment someone with a bit of time to spare and the necessary
programming skills (or a will to learn them) feels function Y is a
sufficiently useful feature, it will be written.
(That could be you.)
Q78: How do I control the recording frequency and quality?
A78: Linus Nielsen Feltzing replied to a similar question on April 17th 2004,
and this is a cut'n paste of his reply that can be read on the following
URL:
http://rockbox.haxx.se/mail/archive/rockbox-archive-2004-04/0814.shtml
SAMPLE RATE
Controls the amount of samples per second, basically which frequencies
that can accurately be reproduced during playback. Lower frequencies
produce smaller files, for two reasons: 1) The amount of data to be
compressed is smaller and 2) the data is easier to compress, since higher
frequencies are not present.
BIT RATE
Controls how many bits per second that is required for accurate live
transmission of the compressed audio. When you compress the data harder
(meaning worse sound quality), the bitrate gets lower.
STEREO VS MONO
A mono file doesn't necessarily have to be smaller than a stereo file.
It all depends on the encoder. The MAS does produce smaller files with
mono.
MAS QUALITY
The MAS uses VBR for compression (yes always), which means that the
bitrate varies from frame to frame, depending on how compressable the
data was at that point in time. This allows for a more even quality, and
also smaller files if the data is easily compressed. The MAS can generate
frames with bit rates ranging from 32kbit/s to 192kbit/s (MPEG1) or
8kbit/s to 160kbit/s (MPEG2).
The MAS quality setting is just a way of selecting an average bit rate
according to the following table (quality 0 is on the far left):
FREQUENCY BITRATE IN KBIT/S
------------------------------------------------------
44100Hz stereo: 75, 80, 90, 100, 120, 140, 160, 170
22050Hz stereo: 39, 41, 45, 50, 60, 80, 110, 130
44100Hz mono: 65, 68, 73, 80, 90, 105, 125, 140
22050Hz mono: 35, 38, 40, 45, 50, 60, 75, 90
(This table can be found on page 38 in the MAS3587 data sheet.)
MPEG VERSIONS
The different MPEG versions use different sample rates:
44100, 48000, 32000: MPEG version 1
22050, 24000, 16000: MPEG version 2
11025, 12000, 8000: MPEG version 2.5 (not an official standard)
Q79: How can I make rockbox play tracks in CD order?
A79: You have two options.
1: You can rename all tracks to have the track number in front of them
(01 - track1.mp3, 02 - track2.mp3, ...). Just make sure to zero-prefix
the number properly so that 10 will play after 09.
2: Make a playlist for each album and play that instead of the .mp3
files.
No, you can't make Rockbox use the track number id3 info for this.
Reference in a new issue View git blame Copy permalink