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After the division routines the entropy decoder was the largest part of Monkey's Audio at the fast levels, with two things to gain. All of its state, the range coder's and the Rice parameters, was in statics, so each use was a load and each update a store: about half of the function's time on ARM7TDMI, where a load is 3 cycles. Copy it to locals for the length of a block and write it back after. The functions that take a pointer to it have to be inlined for that to work, and on ARMv4 gcc left the per-sample one out of line, so force them. The symbol was found by dividing low by help and searching the count table for the quotient. counts[n] <= low / help is the same as counts[n] * help <= low, so search with the multiply instead: the first symbols are by far the likeliest. That leaves two divisions a sample from three. MHz for real time in perfsim's models, -c1000, -c2000 and -c3000: Clip+ (ARMv5) 37.9, 53.8, 81.8 to 32.5, 48.4, 76.4 e200 (ARMv4) 45.3, 68.6, 111.4 to 35.2, 58.5, 101.3 A Clip+ measures 32.85 at -c1000 (61.4 before this and the division change), with test_codec's checksum, 1008ffab, the same as the old code's. The standalone decoder gives identical output for all four levels tested. The path for files older than 3.98 has the same change and was not tested, for want of a file. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Change-Id: Idf9002a5b5f3a423f44f70443936ea5ac427cd12 |
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| android | ||
| apps | ||
| backdrops | ||
| bootloader | ||
| docs | ||
| firmware | ||
| fonts | ||
| icons | ||
| lib | ||
| manual | ||
| packaging | ||
| tools | ||
| uisimulator | ||
| utils | ||
| wps | ||
| .gitattributes | ||
| .gitignore | ||
| .gitreview | ||
__________ __ ___.
Open \______ \ ____ ____ | | _\_ |__ _______ ___
Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
\/ \/ \/ \/ \/
Build Your Own Rockbox
1. Clone 'rockbox' from git (or extract a downloaded archive).
$ git clone git://git.rockbox.org/rockbox
or
$ tar xJf rockbox.tar.xz
2. Create a build directory, preferably in the same directory as the firmware/
and apps/ directories. This is where all generated files will be written.
$ cd rockbox
$ mkdir build
$ cd build
3. Make sure you have mips/m68k/arm-elf-gcc and siblings in the PATH. Make sure
that you have 'perl' in your PATH too. Your gcc cross compiler needs to be
a particular version depending on what player you are compiling for. These
can be generated using the rockboxdev.sh script in the /tools/ folder of the
source.
$ which arm-elf-eabi-gcc
$ which perl
4. In your build directory, run the 'tools/configure' script and enter what
target you want to build for and if you want a debug version or not (and a
few more questions). It'll prompt you. The debug version is for making a
gdb version out of it. It is only useful if you run gdb towards your target
Archos.
$ ../tools/configure
5. *ploink*. Now you have got a Makefile generated for you.
6. Run 'make' and soon the necessary pieces from the firmware and the apps
directories have been compiled, linked and scrambled for you.
$ make
$ make zip
7. unzip the rockbox.zip on your music player, reboot it and
*smile*.
If you want to build for more than one target, just create several build
directories and create a setup for each target:
$ mkdir build-fuzeplus
$ cd build-fuzeplus
$ ../tools/configure
$ mkdir build-xduoox3
$ cd build-xduoox3
$ ../tools/configure
Questions anyone? Ask on the mailing list or on IRC. We'll be happy to help you!