This is an improvement to the current compressor which I have added
to my own Sansa Fuze V2 build. I am submitting here in case others
find it interesting.
Features added to the existing compressor:
Attack, Look-ahead, Sidechain Filtering.
Exponential attack and release characteristic response.
Benefits from adding missing features:
Attack:
Preserve perceived "brightness" of tone by letting onset transients
come through at a higher level than the rest of the compressed program
material.
Look-ahead:
With Attack comes clipping on the leading several cycles of a transient
onset. With look-ahead function, this can be pre-emptively mitigated with
a slower gain change (less distortion). Look-ahead limiting is implemented
to prevent clipping while keeping gain change ramp to an interval near 3ms
instead of instant attack.
The existing compressor implementation distorts the leading edge of a
transient by causing instant gain change, resulting in log() distortion.
This sounds "woofy" to me.
Exponential Attack/Release:
eMore natural sounding. On attack, this is a true straight line of 10dB per
attack interval. Release is a little different, however, sounds natural as
an analog compressor.
Sidechain Filtering:
Mild high-pass filter reduces response to low frequency onsets. For example,
a hard kick drum is less likely to make the whole of the program material
appear to fade in and out. Combined with a moderate attack time, such a
transient will ride through with minimal audible artifact.
Overall these changes make dynamic music sound more "open", more natural. The
goal of a compressor is to make dyanamic music sound louder without necessarily
sounding as though it has been compressed. I believe these changes come closer to this goal.
Enjoy. If not, I am enjoying it
Change-Id: I664eace546c364b815b4dc9ed4a72849231a0eb2
Reviewed-on: http://gerrit.rockbox.org/626
Tested: Purling Nayuki <cyq.yzfl@gmail.com>
Reviewed-by: Michael Giacomelli <giac2000@hotmail.com>
Much of the scrolling work is moved from lcd-bitmap-common to lcd-scroll.c,
a small scroll callback routine remains. This callback can potentially be
overridden by more extensive scrollers.
The callback also gets fed with pixel-based scrolling information, which
finally removes the strict line-based nature of the scroll engine. Along with
this is the change from scroll_stop_viewport_line() to scroll_stop_viewport_rect()
which works on a pixel-based rectangle instead of lines.
The ultimate goal is to move most of the scroll work to apps, which can
much better decide which line decorations to apply etc. This work is laying
the ground work.
Change-Id: I3b2885cf7d8696ddd9253d5a9a73318d3d42831a
This allows to draw lines without destroying styles that were drawn manually
(e.g. from apps/) beforehand.
Change-Id: I0de290c9343061efb115e1b76da5b76395c2b2af
Uses a similar technique as lcd_*.c files of #including a common .c file, so
that a unified implementation can be reused for both displays.
Change-Id: I21f6de76df757b093e1a1dff0a4caf96a44fe77e
This test program. I add it mainly to document somehow my work:
1) atj213x.h lists registers addresses
2) crt0.S exploits self relocation of the binary
3) test_bl.c documents how to control backlight on e150
Change-Id: I055e0fe065d926a5c3805b73cea3f537cb64bf52
Some targets like Sony NWZ use a watchdog, so we must disable it to prevent
spurious reboot when we take over
Change-Id: I138a8d7f9a1b089acb2d08d7f6c4a58e8b088b3a
Conditional no longer needed since ctr0.S is private to target, also setup
stack just before jumping to C code only
Change-Id: I74116239be9e87bbe53e8fa814c45f04f242f1c1
New section Touchpad added to the manual. Gigabeatfx and
SansaFuze+ entries added for touchpad sensitivity setting.
Change-Id: I0c5a173d6ad479c4e6995cf5045d90da6cc216ab
Reviewed-on: http://gerrit.rockbox.org/689
Reviewed-by: Benjamin Brown <foolshperson@gmail.com>
Tested: Benjamin Brown <foolshperson@gmail.com>
Reviewed-by: Michael Giacomelli <giac2000@hotmail.com>
The port uses the imx233 soc, it's a STMP3650 based Samsung player
Change-Id: I50b6d7e77fd292fab5ed26de87853cd5aaf9eaa4
Reviewed-on: http://gerrit.rockbox.org/490
Reviewed-by: Amaury Pouly <amaury.pouly@gmail.com>
This reverts commit 462adf2a0f.
Leaving the card in TRAN results in a huge power consumption because some cards
and internal bridges do not automatically enter power saving mode in TRAN state.
Change-Id: If79efe8cf99b24174889b3a5ebbcb51b07085f58
The ZEN/ZEN-XFi seem to be very picky about the lcd. And they do not like
standby mode so I'm going to drop it, the OF doesn't use it anyway. I still
don't know what this "power" pin is about, obviously it's not real power but
the OF toggle it. Let's hope the lcd will finally become more stable with
fix: the driver now does full power on/off on enable/disable.
Change-Id: I1c465ee4f2462bc3d9507e5f575f0a181af60214
