Runtime improvements:
- Replaces the existing audio callback routine with an efficient chunked
circular-buffer audio reader
- Replaces assumptions that all audio tracks are 44.1 kHz & stereo.
The mixer is now fed data at the actual compressed track's rate and
channel count
- Eliminates all SDL locks in the audio code in favour of mixer state
control
- Queries the codec for track-length instead of using hundreds of
iterative decimating seeks to determine track length (loading
a 99-track CUE now takes 0.1 user-seconds versus 3+ seconds
previously)
- Seeks are performed within the already-decoded buffer (for all
codecs) instead of discarding and re-running the decode sequence
- SDL_Sound's buffer-size is now set once and never resized, which
eliminates repeated re-malloc'ing in the library
- Only one seek is performed per-playback sequence followed by
sequential decodes, similar to a physical CDROM (The baseline dosbox
performs a seek for every 2352-bytes of uncompressed audio)
- The DOSBox mixer is now only active during playback sequences and
fully dormant otherwise (baseline dosbox instead performs hundreds of
calls/second with empty data)
- When using Opus audio tracks, and if your dosbox.conf [mixer]
rate=48000, then you will (very likely) achieve sample-exact
unadulterated pass-through along your entire audio chain from the
decoder, to DOSBox, to your operating system's software mixer,
to your sound card driver, to your sound card, to your speakers,
or to your digital receiver / USB speakers/headphones / or HDMI
TV/screen. This is because almost all modern hardware DACs use
a native sample rate of 48000
Source-level maintenance improvements:
- It strips all pre-processor #ifdef branching for SDL_Sound from
the code
- Fixes all codec compiler warnings (in the modified files); builds
have been tested with GCC 4 to 10, Clang 6 to 10, and MSVC 14
- Tested on Linux, macOS (Xcode), and Windows (MinGW MSYS 1.0)
operating systems
- Tested on i386, x86_64, ARM, and PowerPC (big-endian) architectures
So far, a splash screen exists only in raster format, encoded with RLE
for easy inclusion in .cpp files (src/gui/dosbox_splash.h).
Vector format is easier to modify and can be used as basis for more
artwork, to provide splash screen in better resolutions, etc.
This vector was obtained by resizing raster image to high resolution,
using a set of Gimp filters to sharpen it, then converted in Inkscape
using Path Bitmap functionality and finally optimized by hand to e.g.
remove excessive path nodes.
To convert it to a format easily usable from C/C++: open the file in
Gimp, edit to fit your requirements and export as C header.
This null-check resolves a potential issue detected by static analysis.
It might be the case, that crash never happens due to the way this
static function is used at the moment, and because DYNFLG_CHANGED is being
cleared in dnew->genreg->Clear() few lines before, but the crash might
still happen if initial state of flags is inconsistent or surrounding
code will be changed even a little bit.
This nullcheck makes the code more robust at no performance penalty.
Macros FRAMES_TO_MSF and MSF_TO_FRAMES come from SDL_cdrom library.
SDL_cdrom was removed from SDL2 and these macros are used also in code
not directly related to SDL_cdrom library, so a replacement is needed.
Turns out output pointer type is different on Windows (int*) than it is on
Linux (unsigned char*); given choice between using void* for parameters and
a template function, I prefer template.
- Removes extraneous (and unused) includes
- Cleans up many compiler warnings
- Fixes SDL include statements (using proper `#include <file.h>` directives
given the prior `#include "file.h"` directives should only be used when
including a projects' own header files instead of -Ipath-provided system
headers)
- Eliminates extraneous codecs
Many of these were made after building SDL_Sound under various compilers
and operating systems and hitting various issues. It currently builds
clean without errors or warnings on all our workflow compilers and
versions.
Should fix that directories with the same length as a deleted directory had some small issues.
Also blocks the creation of files in directories marked as deleted.
Small speed up to MakeDir, so it doesn't rely on mkdir when a directory is created inside a deleted directory.
Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@4268
