mirror of
https://github.com/Rockbox/rockbox.git
synced 2026-10-10 08:03:04 -04:00
374f7c0334
Replaces flac_lpc_32_c, the wide predictor path every 24-bit stream takes, and 16-bit streams encoded at high coefficient precision. The coefficients are invariant for the whole call, but the C loop reloaded all of them for every output sample and spilled its loop bound to the stack on top of that. Orders 1-8 now keep every coefficient in a register; orders 10 and 12, which is what -8 emits, get their own unrolled loops instead of the generic chunked one. An ARMv5E kernel using the packed 16-bit multiplies is included behind FLAC_LPC32_NARROW_ASM, off by default: it needs bps <= 16, and only about half the subframes of such a stream can use it. Measured with test_codec on 24-bit/96kHz streams. At predictor order 12: 36.24 MHz on e200 (ARMv4) against 62.29 MHz before. The same file improves from 37.65 MHz to 27.3 MHz on Clip+ (ARMv5). Bit-exact against flac -d over four complete streams on both targets, with and without the assembly, and the kernels are checked against an int64_t reference across every order 1-32, qlevel 0-15 and coefficient precision 1-15. The rarely-executed orders stay in DRAM: the codec's IRAM window on PP502x is nearly full and demoting them measured no cost, leaving 96 bytes free. FLAC_LPC32_NO_IRAM demotes the whole filter. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Change-Id: Icd8bd298973b9f5c26c103af8adf47b03489d69f |
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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!