Rockbox
4dd3c2b33e
Seeking doesn't work well in M4A files with very few chunks due to the seek method used (chunk based using the info in the 'stco' atom). According to libm4a/demux.c the expected seek resolution using this method is 1/4 to 1/2 seconds. However, ffmpeg generates files with a 1 megabyte chunk size, so the resolution is much worse than expected on some files: around 30-40 seconds at 256kbps. There was a bug with the seek position reported back to Rockbox: the codec pretended it could seek exactly to the requested sample, but it would only seek to the start of a chunk. This could leave the UI in a confusing state because the real playback position was different from what the elapsed time showed. Fix this by recalculating the reported sample position using the chunk start. To fix the low seek accuracy, use the table in the 'stsz' atom to skip individual packets within a chunk. This is very accurate, but it takes a lot of RAM to allocate the table. Currently the table is not allowed to use more than half of the codec RAM, which should suffice for short files on most targets. On files where the table is too large the codec will fall back to the less accurate chunk-based seek method. Change-Id: Ide38ea846c1cdd69691e9b1e1cd87eb0fa11cf78 |
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| android | ||
| apps | ||
| backdrops | ||
| bootloader | ||
| debian | ||
| docs | ||
| firmware | ||
| fonts | ||
| gdb | ||
| 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.bz2
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!