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  #1141  
Old 10-09-2013, 06:08 PM
cyclist cyclist is offline
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my R0 use the last mod dualboot firmware, 2.51. but recently i added file to the device, but in the rockbox library, it doesnt show up. why? how can i update my library in rockbox? thanks

btw, how long is the battery last? me only last for about 11-13 hours after a full charge

SOLVED. sorry. i hold the database, and there is the option to update the library. im using 32 gb microsd, and it works perfectly

Last edited by cyclist; 10-09-2013 at 06:22 PM.
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  #1142  
Old 10-12-2013, 12:59 PM
VanniX VanniX is offline
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Quote:
Originally Posted by stbi View Post
I also think that it was a filesystem issue, as the card wasn't damaged physically. Automounting NTFS filesystems should be possible via /etc/fstab (at least this works on other Linux systems like Raspbian etc.).

P.S.: Why do I get a ...



... when I write "/etc/fstab" without obfuscating it...?
I'm pretty sure that using the fstab cause a kernel panic and complete fs corruption if you extract and plug in again a microsd-card when the player is powered on.
You should try to mount it usint the "-t ntfs" option in a startup script with the last LR or MD rom.



P.S: It's a vbullettin's bug.. I also told about it to lebellium some months ago, but he couldn't do nothing
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  #1143  
Old 10-13-2013, 08:39 AM
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lebellium lebellium is offline
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Quote:
Originally Posted by VanniX View Post
P.S: It's a vbullettin's bug.. I also told about it to lebellium some months ago, but he couldn't do nothing
Really? I don't remember hum
I'll see if our tech support can do something about that.
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  #1144  
Old 11-11-2013, 11:23 AM
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Hi, sometimes while playing MP3s, the left & right channel swaps. A bit later, they swap back (maybe). Am I the only one who noticed this?
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  #1145  
Old 11-11-2013, 12:05 PM
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lebellium lebellium is offline
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From the internal memory or from the SD card?

As regards the SD card, we already discussed that long time ago. At the time I reported it to Samsung and they partially fixed it in firmware 1.22 (see changelog here).

But I guess it can still occurs sometimes and IIRC (lorenzo correct me if I'm wrong) it's due to a bug in the old and outdated Linux 2.6.24 kernel.

edit: actually the bug is not in the linux kernel but in the Samsung audio driver
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Last edited by lebellium; 11-11-2013 at 04:03 PM.
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  #1146  
Old 11-11-2013, 05:15 PM
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stbi stbi is offline
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I'm playing files from the SD card only.

I never noticed this channel swap with the original Samsung firmware, so I thought it might be a bug in Rockbox.

So if it's a bug in the Samsung audio driver, does this mean there's no hope to get this fixed with Rockbox?
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  #1147  
Old 11-11-2013, 10:26 PM
cyclist cyclist is offline
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Quote:
Originally Posted by stbi View Post
Hi, sometimes while playing MP3s, the left & right channel swaps. A bit later, they swap back (maybe). Am I the only one who noticed this?
yeah, it happens with my samsung R0 rockboxed. what can i do to fix this?
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  #1148  
Old 11-12-2013, 03:34 AM
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lebellium lebellium is offline
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Theoretically the bug should be present in both the OF and Rockbox since the same audio driver is used.

The only solution would be to look into the audio driver code, try to find out the bug and then fix it. I assume that would be quite difficult (if ever possible) and take some time. And obviously Lorenzo has no time these days

BTW, does it occur randomly?
I only use the internal storage on my R0 so I don't have this issue.
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  #1149  
Old 11-12-2013, 10:53 AM
cyclist cyclist is offline
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Quote:
Originally Posted by lebellium View Post
Theoretically the bug should be present in both the OF and Rockbox since the same audio driver is used.

The only solution would be to look into the audio driver code, try to find out the bug and then fix it. I assume that would be quite difficult (if ever possible) and take some time. And obviously Lorenzo has no time these days

BTW, does it occur randomly?
I only use the internal storage on my R0 so I don't have this issue.
after analyze it for a while, i found that this bugs has some pattern. when i listened to MP3 Van Halen - Panama (320 kbps), when the bugs happens, it always happens only before the refrain begins.

well, if you suggest me to use only the internal storage, 8 gigs is too small for me.
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  #1150  
Old 11-12-2013, 03:47 PM
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On my player it happens not with all files, but I've got one album where the channels swap exactly 65 seconds after booting the device and starting playback. All these files are 192 kbps.

The strange thing is, when I copy one of these files to another folder and play it from there, the channels do not swap (or at least not within the first few minutes).
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  #1151  
Old 11-17-2013, 02:05 PM
Lorenz092 Lorenz092 is offline
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Ok guys, indeed it is an annoying problem.
unfortunately this is not related to rockbox at all, but don't worry we might solve it sooner or later (later is the right option )
but I did some quick digging into the driver. I'm quite sure this only happens at 200 mhz cpu clock, and that's why i think it is related to the transfer frequency between the CPU and the DAC.
There are two different values for 44.1k and 48k frequencies: can someone test a problematic song, also converting it to 48k (or 41k if originally was 48)?
So that we can start verifying some clues ...


EDIT: wait before doing this test, I'm not actually sure about 44.1K vs 48K but other sample rates, for which rockbox does software conversion, so nothing could change anyways
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Last edited by Lorenz092; 11-17-2013 at 02:16 PM.
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  #1152  
Old 12-08-2013, 09:40 AM
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Hey guys, we still got a complain from a French user today so I guess it's time to give you a first dirty fix for the channel swap bug.

I don't use a microSD card on my 16GB R0 and I already spent the whole afternoon on this thing thanks to Lorenzo's Alzheimer's disease () while it could have worked in 5 minutes... so I'm a bit tired now and I'm not gonna try with a SD card and can't say if it really fixes the bug. Please check yourself and report

Actually we think that the problem is due to a bug in the Linux kernel when the CPU is running at 200MHz. It's not Rockbox's fault. But the thing is that the OF only runs at full speed 532MHz while in Rockbox we use a 'on-demand' governor to run either at 200MHz or 532MHz depending on how much is needed for the current task. The purpose is to improve the battery life of course.

The dirty fix is to set the CPU frequency at 532MHz only as in OF. That will probably decrease a bit the battery life but hopefully the channel swap bug will be gone too. As you understood, that doesn't fix the bug in the kernel, it's just a dirty workaround, as dirty as Samsung's usual job

So here are the steps:
1) Connect your R0 to the computer in Safe Mode
2) Go to media1 (aka "Neo-Ghost") and open the rockbox.sh file with a text editor.
3) At line #60, replace
Code:
echo "1" > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/ignore_nice_load
by
Code:
echo "userspace" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "532000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
.

4) Save the file, disconnect the R0 from the computer and reboot it.
5) In Rockbox, go to System>Debug>View CPU stats and make sure you see CPU0: Cur/Scal freq: 532/532 MHz
6) Check if the channel swap bug is still present and let us know here
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Last edited by lebellium; 12-08-2013 at 09:54 AM.
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  #1153  
Old 12-08-2013, 03:31 PM
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Thanks, lebellium, it seems to help: I'm listening for 10 minutes now without any channel swap! Time will tell if it will continue working, and which effect on the battery life it will have. However, it shouldn't be worse than the OF with DNSe (which I had activated all the time when I was using the OF).

Some notes for the LightROM:
  • The file name is "rockbox_loader.sh", not "rockbox.sh".
  • The line to replace is:
    Code:
    echo "350000" > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/sampling_rate
    (Obviously 350 MHz is still too slow for the Linux kernel...)
  • The System menu doesn't show CPU frequencies.

Last edited by stbi; 12-09-2013 at 05:21 PM.
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  #1154  
Old 12-09-2013, 05:17 PM
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I did some experiments:

Code:
echo "powersave" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
Result: Channel swap after ~1 minute.

Code:
echo "userspace" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "200000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
Result: Channel swap after ~1 minute.

Code:
echo "userspace" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "266000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
(266000 = half of 532000)

Result: No channel swap observed within 1 hour of listening.
Perhaps it's just luck - I will observe it further...
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  #1155  
Old 12-10-2013, 03:24 AM
Lorenz092 Lorenz092 is offline
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Quote:
Originally Posted by stbi View Post
I did some experiments:

Code:
echo "powersave" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
Result: Channel swap after ~1 minute.

Code:
echo "userspace" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "200000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
Result: Channel swap after ~1 minute.

Code:
echo "userspace" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "266000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
(266000 = half of 532000)

Result: No channel swap observed within 1 hour of listening.
Perhaps it's just luck - I will observe it further...
Call it luck or placebo effect, but there cannot be a "mid" setting
There are just 3 options available as far i know on this CPU
200,400,532 MHz
Nothing less, nothing more.
*Perhaps* the only reason behind this is that the on invalid settings, the kernel defaults to 400 or 532, i should have a closer look at the kernel
To prove this, just look at kernel's source code
Code:
/* does need to be in ascending order for calc_frequency_khz() below */
static struct cpufreq_frequency_table imx37_freq_table[] = {
    {0x01, CPU_FREQUENCY_200000_KHZ},
    {0x02, CPU_FREQUENCY_400000_KHZ},
    {0x03, CPU_FREQUENCY_532000_KHZ},
    {0, CPUFREQ_TABLE_END},
};
Let us know for other experiments ! Thanks in advance !
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  #1156  
Old 12-15-2013, 02:50 PM
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OK, then my "266000" value actually did nothing, and the CPU clock remained at 532 MHz. - No wonder that it worked...!

However, if only 200, 400 and 532 MHz are possible, then what does

Code:
echo "350000" > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/sampling_rate
in the rockbox_loader.sh of the LightROM do?

Anyway, I set my CPU to 400 MHz now: No channel swap so far.

Edit:
It seems that it's not possible to set CPU clock to 400 MHz:
Code:
echo "userspace" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "400000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed > /mnt/media0/scaling_setspeed.txt
In the file "scaling_setspeed.txt" the value "532000" is written.
Only the values "200000" and "532000" can be set.

Last edited by stbi; 12-15-2013 at 03:25 PM.
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  #1157  
Old 12-15-2013, 03:52 PM
Lorenz092 Lorenz092 is offline
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Quote:
Originally Posted by stbi View Post
OK, then my "266000" value actually did nothing, and the CPU clock remained at 532 MHz. - No wonder that it worked...!

However, if only 200, 400 and 532 MHz are possible, then what does

Code:
echo "350000" > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/sampling_rate
in the rockbox_loader.sh of the LightROM do?

Anyway, I set my CPU to 400 MHz now: No channel swap so far.

Edit:
It seems that it's not possible to set CPU clock to 400 MHz:
Code:
echo "userspace" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "400000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed > /mnt/media0/scaling_setspeed.txt
In the file "scaling_setspeed.txt" the value "532000" is written.
Only the values "200000" and "532000" can be set.
Carefully look at the file/parameter you are going to set with the first:
/cpufreq/ondemand/sampling_rate <- *sampling rate* not clock
This simply tells the system the "frequency" for sampling cpu load and act accordingly for the ondemand governor...

For the 400 MHz that is both interesting and strange, I should have a closer look at the kernel actually!

EDIT: could you please check if the same happens when backlight stays on? i.e. play music and set backlight always on
I think this could be due to a low power mode, but I might be wrong...In case we test!
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Last edited by Lorenz092; 12-15-2013 at 04:04 PM.
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  #1158  
Old 12-15-2013, 04:27 PM
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Quote:
Originally Posted by Lorenz092 View Post
EDIT: could you please check if the same happens when backlight stays on? i.e. play music and set backlight always on
What are you referring to - what should happen with backlight on? Channel swap at 200 MHz?
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  #1159  
Old 12-19-2013, 02:09 AM
wrm76 wrm76 is offline
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Default Thanks !!!

Thank you for this fine masterpiece ! i finally find a working mp3 player !!! i have tried many mp3 players and mobile phones , they all suck at sound ! with your firmware , my yp-ro sounds divine ! i am very exigent at the quality of sound , i make music . if the moderator find a better way to improve the sound quality of this samsung yo-ro , please email me ! from Romania with love - wrm76 ! keep up the good work !!!!
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  #1160  
Old 01-02-2014, 12:22 PM
VanniX VanniX is offline
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@stbi - lebellium - Lorenz092:
Fixing the cpu freq to 532mhz with userspace governor it's not a good solution for the channel swap issue..
Battery drain will increase dramatically. nice load and sampling rate are also required for a correct cpu frequency management. If it works by locking cpu frequency it's just a case of luck.. I think the problem is a bug in rockbox that hasn't be solved yet..


@wrm76: you can use audio and equalizer settings to improve audio quality (depending on your headphone)
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