AUDIO Patch supporting FLAC, Opus, and MP3 audio tracks

by **krcroft** » 2018-9-02 @ 05:34

This patch adds decoding of Opus, FLAC, and MP3 CDDA audio tracks to the current development branch of DOSBox.

This first-post tracks the latest of the following:

Patch for SVN DOSBox
Encoders and suggested compression settings
Example CUE files
Technical discussion of runtime and source improvements

What value does this patch add over the baseline? or Ogg Vorbis ought to be enough

for lossy compression, Opus supersedes Vorbis, which has been deprecated
for lossless compression, FLAC supersedes WAV by offering 2:1 or more compression with binary-identical output
CPU usage and decode latency are improved versus Vorbis (no change between FLAC and WAV), so this is win-win

When it comes to preserving audio content from the golden-era of PC gaming, these games deserve the best we can offer.

I've ripped my CDCOM and have WAV files ready to compress - where can I get the latest encoders?

Opus 1.3.1:

Windows: https://archive.mozilla.org/pub/opus/win32/opus-tools-0.2-opus-1.3.1.zip
macOSX: brew install opus-tools (if you don't have brew, see: http://macappstore.org/opus-tools/)
Linux: apt/zypper/yum install opus-tools (or build from source: ogg, opus, libopusfile, and opus-tools)

FLAC 1.3.2:

Windows: https://ftp.osuosl.org/pub/xiph/releases/flac/flac-1.3.2-win.zip
macOSX: brew install flac (if you don't have brew, see: http://macappstore.org/flac/)
Linux: apt/zypper/yum install flac (or build from source, http://www.linuxfromscratch.org/blfs/view/svn/multimedia/flac.html)

Vorbis:

Windows: Oggenc2.88 using aoTuVb6.03 (Lancer Builds) here
macOSX: Vorbis-Tools for MacOS X using aoTuVb5.5 here
Linux: oggenc 1.4.0 SVN + aoTuV Beta6.03 with libogg 1.2.0, FLAC 1.2.1 and Kate 0.3.8 (Static GCC 4 compile) here

LAME 3.100:

Windows: http://www.rarewares.org/mp3-lame-bundle.php
macOSX: brew install lame (if you don't have brew, see: http://macappstore.org/lame/)
Linux: apt/zypper/yum install lame (or build from source, http://www.linuxfromscratch.org/blfs/vi ... /lame.html)

What are some recommended encoding parameters I can try?

FLAC (all files):

flac -8 --output-name="outfile" "wavfile", followed by
metaflac --add-seekpoint=1s "flacfile"

Opus, for mono voice-only tracks:

opusenc --speech --bitrate 24 --downmix-mono "wavfile" "outfile"
Alone in the Dark 2, tracks 23 to 63
Alone in the Dark 3, tracks 24 to 61
Battle Chess Enhanced, track 22
Big Red Racing, tracks 12 to 29, and 33 to 39
Jones in the Fast Lane: all tracks
Shadowcaster: all tracks

Opus, for stereo voice-only tracks:

opusenc --speech --bitrate 36 "wavfile" "outfile"
Action Soccer, tracks 2 to 13
AD&D Dark Sun II Wake of the Ravager, tracks 38 and 39
Loom: all tracks

Opus for mono non-voice tracks:

opusenc --bitrate 54 --downmix-mono "wavfile" "outfile"
Destruction Derby, tracks 2, and 4 to 9
Stellar 7, tracks 4 and 5
Zyclunt, all tracks

Opus for stereo non-voice tracks:

opusenc --bitrate 84 "wavfile" "outfile"

How should my CUE files look?

Here's a CUE with examples for each codec:

Code: Select all: FILE "data.iso" BINARY TRACK 01 MODE1/2048 INDEX 01 00:00:00 FILE "track02.opus" OPUS TRACK 02 AUDIO PREGAP 00:02:00 INDEX 01 00:00:00 FILE "track03.flac" FLAC TRACK 03 AUDIO INDEX 01 00:00:00 FILE "track04.ogg" OGG TRACK 04 AUDIO INDEX 01 00:00:00 FILE "track05.mp3" MP3 TRACK 05 AUDIO INDEX 01 00:00:00

What runtime improvements have been made?

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)
Adds handling for exact track positions via MSF values if specified in the cue file (https://sourceforge.net/p/dosbox/bugs/489/)
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-SVN.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

What source-level maintenance improvements have been made?

Eliminated external dependence on SDL_Sound and its outdated of external library dependencies -- thank you Dominus and DosFreak for recommending this approach.
SDL_Sound, Vorbis, FLAC, Opus, and Ogg libraries are not needed on your system nor do you need to build or provide pointers to these in CFLAGS/LIBS/etc..
All codec handling is 100% internal DOSBox's to source and "always on"
It strips all references to SDL_Sound from configure.ac
It strips all pre-processor #ifdef branching for SDL_Sound from the code
For Vorbis decoding, this patch employs the single-header stb_vorbis.h instead of of libogg, libvorbis, and libvorbisfile
For MP3 decoding, this patch employs the single-header dr_mp3.h
For FLAC decoding, this patch employs the single-header dr_flac.h
It adds src/libs/decoders, which holds the top-level opus, flac, vorbis, and wav decoders
It adds src/libs/decoders/internal, where the master-stable branch of opus is fetched, built, and statically linked along side DOSBox's internal libraries
Fixes all codec compiler warnings; 100% clean builds tested with gcc 4.x through 9.x
Built and tested on Linux, MacOSX (xcode), and Windows (MinGW msys 1.0)

The Makefile in src/libs/decoders/internal fetches Opus's dependencies using curl, so that should be in your PATH.

If you're on MinGW MSYS 1.0, I would suggest installing Git For Windows and allowing it to add itself to your PATH, which gives you a modern curl build
If you're on MinGW-32/64 or MSYS 2.0, then you might already have curl or can use their package manager to install it
macOS and Linux come with curl, so no action needed

What about SDL_Sound 1.0.3, can't we sit back and wait for the SDL Developers to add Opus and fix its broken MP3 and FLAC decoding?

SDL Sound 1.0.3 hasn't been touched in over a decade and has many bugs and autotool issues within modern environments. The developers are unyielding on going back and fixing SDL1 libraries to accommodate issues cropping up in modern environments. For them, it's SDL2 or the highway. Example: https://forums.libsdl.org/viewtopic.php?p=45264 (that was 4 years ago, and we're still at SDL 1.2.15)

Ryan Gordon informed me he will use my Opus decoder to add Opus handling to this new SDL2-based sound libraries, however DOSBox would have to move to SDL2 to get it.

This patch brings audio-codec handling under our own control, strips it down to the bare minimum, and corrects all deficiencies.

If and when DOSBox decides to move to SDL2, we can decide then if we want to move back to dependence on SDL2_Sound.

by **Qbix** » 2018-9-06 @ 12:20

would there be an easy way to remove all formatting changes that you did ? (familiar with git commits/patches)
As those don't belong in this patch.

I have to test the frame sized decoding, as the current ogg decoding can give a lot of stuttering I noticed..

by **krcroft** » 2018-9-06 @ 13:51

Qbix wrote:would there be an easy way to remove all formatting changes that you did ? (familiar with git commits/patches)
As those don't belong in this patch.

I have to test the frame sized decoding, as the current ogg decoding can give a lot of stuttering I noticed..

Yes, I will tidy up the diff today!

by **krcroft** » 2018-9-08 @ 22:45

Qbix,

Here's a non-SDL2, non-SDL_Mixer-X patch that focuses just on the core cdrom_image.cpp changes, so you can test on your side:

16KB circular buffer used to feed the callbacks
4KB chunked reads from SDL_Sound (recommended by the vorbis project)
SDL audio locking and unlocking has been eliminated
SDL_Sound's buffer-size is now set once and never resized (to avoid repeated re-malloc'ing in the library)
Only one seek is performed per-playback sequence; all remaining calls to SDL sound are sequential decodes (similar to a physical CDROM)
The DOSBox mixer channel is now only active during playback sequences, and is no longer left active and fed with silence (to reduce call overhead and audio latency in the mixer)

Highlighted diff is here: https://gitlab.com/krcroft/dosbox_audio ... expanded=1

by **krcroft** » 2018-9-08 @ 22:54

If you comment-in the three 'printStatus' calls in the callback, it will show the behavior of the buffer.

If the 16KB circular buffer doesn't have enough data to satisfy the callback, it attempts to fill itself using chunked-reads from SDL_Sound.

We see four of these reads initially here, followed by lots tiny callbacks that slowly deplete the buffer.

Code: Select all: 25% [||||||||||||||| ] - fill 50% [|||||||||||||||||||||||||||||| ] - fill 74% [|||||||||||||||||||||||||||||||||||||||||||| ] - fill 99% [||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - fill 98% [||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 97% [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 96% [||||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 95% [||||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 94% [|||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 93% [||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 92% [||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 91% [|||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 90% [|||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 89% [||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 87% [|||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 86% [|||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 85% [||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 84% [|||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 83% [|||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 82% [||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 81% [|||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 80% [|||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 79% [||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 78% [||||||||||||||||||||||||||||||||||||||||||||||| ] - consume 77% [|||||||||||||||||||||||||||||||||||||||||||||| ] - consume 76% [||||||||||||||||||||||||||||||||||||||||||||| ] - consume 75% [||||||||||||||||||||||||||||||||||||||||||||| ] - consume 74% [|||||||||||||||||||||||||||||||||||||||||||| ] - consume 73% [||||||||||||||||||||||||||||||||||||||||||| ] - consume 71% [||||||||||||||||||||||||||||||||||||||||||| ] - consume 70% [|||||||||||||||||||||||||||||||||||||||||| ] - consume 69% [||||||||||||||||||||||||||||||||||||||||| ] - consume 68% [||||||||||||||||||||||||||||||||||||||||| ] - consume 67% [|||||||||||||||||||||||||||||||||||||||| ] - consume 66% [||||||||||||||||||||||||||||||||||||||| ] - consume 65% [||||||||||||||||||||||||||||||||||||||| ] - consume 64% [|||||||||||||||||||||||||||||||||||||| ] - consume 63% [|||||||||||||||||||||||||||||||||||||| ] - consume 62% [||||||||||||||||||||||||||||||||||||| ] - consume 61% [|||||||||||||||||||||||||||||||||||| ] - consume 60% [|||||||||||||||||||||||||||||||||||| ] - consume 59% [||||||||||||||||||||||||||||||||||| ] - consume 58% [|||||||||||||||||||||||||||||||||| ] - consume 56% [|||||||||||||||||||||||||||||||||| ] - consume 55% [||||||||||||||||||||||||||||||||| ] - consume 54% [|||||||||||||||||||||||||||||||| ] - consume 53% [|||||||||||||||||||||||||||||||| ] - consume 52% [||||||||||||||||||||||||||||||| ] - consume 51% [|||||||||||||||||||||||||||||| ] - consume 50% [|||||||||||||||||||||||||||||| ] - consume 49% [||||||||||||||||||||||||||||| ] - consume 48% [||||||||||||||||||||||||||||| ] - consume 47% [|||||||||||||||||||||||||||| ] - consume 46% [||||||||||||||||||||||||||| ] - consume 45% [||||||||||||||||||||||||||| ] - consume 44% [|||||||||||||||||||||||||| ] - consume 42% [||||||||||||||||||||||||| ] - consume 41% [||||||||||||||||||||||||| ] - consume 40% [|||||||||||||||||||||||| ] - consume 39% [||||||||||||||||||||||| ] - consume 38% [||||||||||||||||||||||| ] - consume 37% [|||||||||||||||||||||| ] - consume 36% [||||||||||||||||||||| ] - consume 35% [||||||||||||||||||||| ] - consume 34% [|||||||||||||||||||| ] - consume 33% [||||||||||||||||||| ] - consume 32% [||||||||||||||||||| ] - consume 31% [|||||||||||||||||| ] - consume 30% [|||||||||||||||||| ] - consume 28% [||||||||||||||||| ] - consume 27% [|||||||||||||||| ] - consume 26% [|||||||||||||||| ] - consume 25% [||||||||||||||| ] - consume 24% [|||||||||||||| ] - consume 23% [|||||||||||||| ] - consume 22% [||||||||||||| ] - consume 21% [|||||||||||| ] - consume 20% [|||||||||||| ] - consume 19% [||||||||||| ] - consume 18% [|||||||||| ] - consume 17% [|||||||||| ] - consume 16% [||||||||| ] - consume 15% [||||||||| ] - consume 14% [|||||||| ] - consume 12% [||||||| ] - consume 11% [||||||| ] - consume 10% [|||||| ] - consume 9% [||||| ] - consume 8% [||||| ] - consume 7% [|||| ] - consume 6% [||| ] - consume 5% [||| ] - consume 4% [|| ] - consume 3% [|| ] - consume 2% [| ] - consume 1% [ ] - consume 0% [ ] - consume 0% [ ] - wrap 24% [|||||||||||||| ] - fill 49% [||||||||||||||||||||||||||||| ] - fill 48% [||||||||||||||||||||||||||||| ] - consume 47% [|||||||||||||||||||||||||||| ] - consume 46% [||||||||||||||||||||||||||| ] - consume 45% [||||||||||||||||||||||||||| ] - consume 44% [|||||||||||||||||||||||||| ] - consume 43% [|||||||||||||||||||||||||| ] - consume 42% [||||||||||||||||||||||||| ] - consume 41% [|||||||||||||||||||||||| ] - consume 40% [|||||||||||||||||||||||| ] - consume 39% [||||||||||||||||||||||| ] - consume 38% [|||||||||||||||||||||| ] - consume 36% [|||||||||||||||||||||| ] - consume 35% [||||||||||||||||||||| ] - consume 34% [|||||||||||||||||||| ] - consume 33% [|||||||||||||||||||| ] - consume 32% [||||||||||||||||||| ] - consume 31% [|||||||||||||||||| ] - consume 30% [|||||||||||||||||| ] - consume 29% [||||||||||||||||| ] - consume 28% [||||||||||||||||| ] - consume 27% [|||||||||||||||| ] - consume 26% [||||||||||||||| ] - consume 25% [||||||||||||||| ] - consume 24% [|||||||||||||| ] - consume 23% [||||||||||||| ] - consume 21% [||||||||||||| ] - consume 20% [|||||||||||| ] - consume 19% [||||||||||| ] - consume 18% [||||||||||| ] - consume 18% [|||||||||| ] - consume 18% [|||||||||| ] - stop StopAudio -- CDROM audio channel disabled CDROM audio channel freed

During that second round of fills (which only partially filled the buffer), it only needed two chunks to satisfy the remaining playback duration.

by **krcroft** » 2018-9-13 @ 04:41

Windows binaries attached in top-post, including latest version of the audio encoders:
- DOSBox r4160 (latest) with ability to play FLAC and Opus audio tracks (in addition to improved Vorbis decoding) from BIN/CUE files.
- FLAC 1.3.2 encoder
- Opus 1.3-rc and encoding tools 0.1.10-2
- Vorbis 1.3.6 + aoTuV b6.03 + Lancer encoder

in your CUE files, you can now include opus and flac files, with the following example format:

Code: Select all: FILE "data.iso" BINARY TRACK 01 MODE1/2048 INDEX 01 00:00:00 FILE "audio02.ogg" OGG TRACK 02 AUDIO PREGAP 00:02:00 INDEX 01 00:00:00 FILE "track03.opus" OPUS TRACK 03 AUDIO PREGAP 00:02:00 INDEX 01 00:00:00 FILE "track04.flac" FLAC TRACK 04 AUDIO PREGAP 00:02:00 INDEX 01 00:00:00

Attached are the two patches used to create this:
- dosbox-r4160-audio_updates.patch
- sdl_sound-1.0.3-opus_flac_stb_vorbis.patch

The DOSBox patch applies to r4160 (-p1), and includes:
- Lock-free chunked reads from SDL_Audio
- Direct pass-through of the audio-track's channels and sampling rate to the mixer
This allows for interpolation-free playback if your files match your mixer sampling rate.
The channel is adjusted at playback, so it's fine to have a cue sheet with mono and stereo files, as well as different sampling rates.
- Fix for the double-loading of CD image's

The SDL_Sound patch applies to SDL_Sound-1.0.3 (-p1), and includes:
- Ogg Opus decoder routines (new)
- Improved Dr.FLAC decoder routines (ported from upstream)
- Improved STB Vorbis decoder routines (ported from upstream)

Meanwhile, SDL_Sound upstream is being renovated (SDL2.0 exclusive, autotools ripped out and replaced w/ cmake, decoders are being replaced and deprecated).

Changelog:
- rev2: fixed raw BIN audio playback (which doesn't involve audio files).

by **Qbix** » 2018-9-13 @ 06:55

let me move it to the patches forum.
I have to check the changes in more detail when I finally find that dynrec bug that has been haunting me.

by **krcroft** » 2018-9-14 @ 04:00

Qbix wrote:let me move it to the patches forum.
I have to check the changes in more detail when I finally find that dynrec bug that has been haunting me.

Qbix, please disregard that first DOSBox patch; it broken BIN-audio playback (not involving audio files).
I've attached "dosbox-r4160-audio_updates-rev2.patch" above which corrects it using TrackFile polymorphism (included in patch in top-post).
All of the improvements made in on the AudioFile playback side now similarly apply when playing audio from a BinaryFile.

by **leileilol** » 2018-10-12 @ 01:47

A big problem with Opus for this is the fact it only supports 48khz, which really isn't tbe most desirable (or "recommended") way dealing with 44.1khz CD audio.

FLAC support's way more realistic however.

by **krcroft** » 2018-10-12 @ 05:00

When it comes to lossy audio, you can't do better than Opus - it beats AAC, High-Efficiency-AAC, Ogg Vorbis, and MP3 across multiple ABX-based listening tests. The quality-gap keeps widening as new versions are released (we're only months away from Opus 1.3 being released).

There are no drawbacks to encoding your 44.1 kHz DOS audio tracks to Opus; assuming you use this patch. Yes, Opus up-samples all inputs internally to 48 kHz using the SpeexDSP resampler, which introduces a mathematically measurable difference of -90dB, which is beneath the noise floor of a CDROM. So this is a non-issue.

Besides getting the best quality-for-your-bytes, there are other minor technical advantages with this patch, too:

The patch makes DOSBox read compressed audio in large chunks into a 16KB circular buffer; likewise the Opus decoder for SDL1 Sound (https://gitlab.com/krcroft/sdl_sound/bl ... ers/opus.c) reads data in exact Opus-framed chunks (also into a circular buffer); both efficiency improvements combine to result in roughly an order-of-magnitude fewer function calls per second and a modest reduction in CPU usage when I've profile it against the existing DOSBox + Vorbis code.

My Opus decoder is also the only SDL decoder that will seek within its buffer (if possible) before actually moving the file pointer and re-running the decode sequence to get a different chunk of data.

Compare that to the existing SDL1 Ogg Vorbis decoder: it doesn't use a circular buffer and will make repeated read calls inefficiently across Vorbis frame boundaries to fill the requested buffer. Likewise, the existing DOSBox code reads compressed audio in unnecessarily small CDROM Redbook 2352-byte chunks, which does not translate to any compressed stream frame-size (FLAC for example uses 8KB frames).

Another minor advantage is the fact that almost every consumer hardware audio DACs' native sampling rate is 48 kHz: this includes the your audio card chipset, USB headphones, A/V digital receiver, and your HDMI TV input.
- By setting DOSBox's mixer to 48 kHz and using Opus audio tracks, those samples pass-through the entire software and hardware chain as-is.
- However, by using 44.1 kHz audio tracks, you guarantee your audio is going to be re-sampled one or more times, possibly by DOSBox and/or again by your audio hardware.
- But using 48 kHz straight-through, it removes cheap hardware DACs and DOSBox from the resampling equation.

by **krcroft** » 2018-10-12 @ 05:13

Attached are ready-to-run builds tracking DOSBox's SVN r1468 source (see top-post)

To compress your WAV tracks, grab the latest Opus encoder here: https://hydrogenaud.io/index.php/topic, ... #msg963060

To see the power of Opus in DOSBox:

Encode the Jones in the Fast Lane 373 MB audio track to Opus:

opusenc --speech --bitrate 24 --downmix-mono track02.wav track02.opus

This will produce a 6.4 MB track with little to no discernible audio fidelity difference versus the original.

Set DOSBox's mixer rate to 48000 (although this isn't necessary), and use a CUE file like:

Code: Select all: FILE "data.iso" BINARY TRACK 01 MODE1/2048 INDEX 01 00:00:00 FILE "track02.opus" OPUS TRACK 02 AUDIO PREGAP 00:02:00 INDEX 01 00:00:00

Enjoy!

by **krcroft** » 2018-10-12 @ 05:28

To use FLAC:

Code: Select all: FILE "data.iso" BINARY TRACK 01 MODE1/2048 INDEX 01 00:00:00 FILE "track02.flac" FLAC TRACK 02 AUDIO PREGAP 00:02:00 INDEX 01 00:00:00

by **Dominus** » 2018-10-12 @ 07:07

Out of interest, is your patch now independent of SDL-mixer X (? - never heard about X before this thread) and SDL-Sound? And if not, what does it patch? The SDL satellite libs and DOSBox or only DOSBox?
I got confused by the posts

(A patch to directly work with mp3/ogg/opus/flac borrowing from the simple headers the new SDL-Sound uses would be perfect IMHO - I never liked either SDL-Sound or -Mixer - in Exult we long ago got rid of SDL-Mixer)

by **krcroft** » 2018-10-12 @ 21:12

Dominus wrote:Out of interest, is your patch now independent of SDL-mixer X (? - never heard about X before this thread) and SDL-Sound? And if not, what does it patch? The SDL satellite libs and DOSBox or only DOSBox?

Sorry for the confusion! Completely understandable given I started the thread talking about SDL2 and Mixer-X.

Yes, the patch is independent of SDL-Mixer-X and SDL2; I've since transitioned back to pure SDL1.

First patch is to SDL1_Sound 1.0.3:
- Updates auto-tools configs to current standards
- Fixes all compiler warnings; 100% clean builds now
- Renames all 'ogg' instances to Vorbis (which was a desired "TODO" item listed by the SDL team)
- Replaces the broken FLAC decoder with the header-only Dr. FLAC - eliminating the need for libFLAC
- Replaces the Vorbis decoder with the header-only STB Vorbis - eliminating the need for libvorbis and vorbisfile
- Adds my Opus decoder, which depends on libopusfile, libspeexdsp, libopus, and libogg
Ryan Gordon mentioned he's pulling my Opus decoder into the new SDL(2)_Sound which he plans to use until a BSD-licensed pure-header only-decoder is developed.
That said, the SDL team hasn't responded to my SDL-Sound mailing-list posts so it seems 1.0.3 is end-of-the-line, and Ryan Gordon is going 100% SDL2 now.

Second patch is to DOSBox:
- Replaces the existing audio callback routine with the the chunked circular-buffer audio reader
- Replaces assumptions that the audio track is 44.1 kHz - calculations now use whatever the rate the track actually is
- Eliminates all SDL locks in the audio code in favour of mixer state control
- Fixes the double-load bug (https://sourceforge.net/p/dosbox/bugs/488/)
- Adds a fast track-length call (determined by configure.ac if SDL_Sound supports "getDuration"), eliminating the need for iterative seeks to determine track length.
(loading a 99-track CUE now takes 0.1 user-seconds versus 3+ seconds previously)
- Adds handling for exact track positions via MSF values if specified in the cue file (https://sourceforge.net/p/dosbox/bugs/489/)

(A patch to directly work with mp3/ogg/opus/flac borrowing from the simple headers the new SDL-Sound uses would be perfect IMHO - I never liked either SDL-Sound or -Mixer - in Exult we long ago got rid of SDL-Mixer)

Completely agree.. it would be ideal to strip down this patched SDL_Sound to its essential Opus-FLAC-Vorbis source files, throw away everything else, and simply package it in with DOSBox and make it our own.
Every build would have Vorbis and FLAC out of the box - we wouldn't need a bunch of #IFDEF's riddling the code to check for SDL_Sound. This would retain compatibility with legacy GOG releases using Vorbis-encoded tracks, while distributions and expeditious users looking for the highest audio fidelity would take advantage of Opus-encoded tracks (or FLAC).

by **Dominus** » 2018-10-12 @ 21:17

Many thanks for clarifying. Very impressive work. Very

by **krcroft** » 2018-10-12 @ 21:27

Dominus wrote:Many thanks for clarifying. Very impressive work.

Thanks Dominus! Hey - it was your very helpful build-guilds that got me off the ground; thank you!

by **DosFreak** » 2018-10-12 @ 21:49

Anything that cleans up the SDL_Sound mess I'm all for. In my guides I encountered some oddities and it would simplify the guide alot, it's also a pain troubleshooting when SDL_Sound can't find the other libraries.

Anyone test to make sure it still compiles with Mingw w/ Msys 1? Had to manually update some of the tools in the Windows ver of Mingw since the Mingw site downloads old ver that have issues when compiling the various libraries DOSBox uses, no issue with Linux since the repos keep those tools up to date. I have an up to date Mingw/Msys 1 on my Google Drive so will give it a shot next week. https://drive.google.com/drive/folders/ ... 3aMO8U9mvV

Reminds me I need to contact the SDL_net devs about adding a def or ver check to remove a dependency added in the last ver of 1.2.8 that most people don't need.
"Added SDLNet_GetLocalAddresses() to query local interfaces"

Even if you use WSOCK instead of ws2_32 it still tries to use a dll it doesn't even need and if your program doesn't use that functionality (DOSBox) it still needs the dependency.

by **krcroft** » 2018-10-12 @ 22:35

mingw32-msys1.0-gcc.txt

DosFreak wrote:Anyone test to make sure it still compiles with Mingw w/ Msys 1?

Yup, the patched SDL_Sound builds clean under MinGW and Msys 1.0 (attached are my configure, make, and gcc -v logs).

Glad to hear more people want to do away SDL_Sound and all its dependency baggage - I'll start gutting what I have, and folding the remaining useful bits into DOSBox's source.

by **krcroft** » 2018-10-14 @ 18:24

This patch makes compressed-audio handing internal to DOSBox.
- It adds src/libs/decoders, which holds the top-level opus, flac, vorbis, and wav decoders
- It adds src/libs/decoders/internal, where the opus-dependencies are fetched and built
- It strips all references to SDL_Sound from configure.ac
- It strips all the #IFDEFs for SDL_Sound from the code
- SDL_Sound, Vorbis, FLAC, Opus, and Ogg libraries are not needed on your system nor do you need to build or provide pointers to these in CFLAGS/LIBS/etc..

The Makefile in src/libs/decoders/internal fetches Opus's dependencies using curl, so that should be in your PATH.
- If you're on MinGW MSYS 1.0, I would suggest installing Git For Windows and allowing it to add itself to your PATH, which gives you a modern curl build
- If you're on MinGW-32/64 or MSYS 2.0, then you might already have curl or can use their package manager to install it
- This isn't a requirement though: you can also simply download the gzip's and place them in src/libs/decoders/internal, which the Makefile will happily use

Dominus, DosFreak - thanks for the suggestion.

This is the right move to take an improved SDL_Sound internally given it's now whittled down to down to handful of files and the fact the public package has been unmaintained for over 10 years now. If and when DOSBox moves to SDL2 - then we can drop this.

The patch output gives a nice overview of its structure (see patch in top-post):

Code: Select all: patch -p1 < ~/dosbox-r4168-internal_decoders.patch patching file configure.ac patching file Makefile.am patching file src/dos/cdrom.h patching file src/dos/cdrom_image.cpp patching file src/dos/dos_mscdex.cpp patching file src/dos/drive_iso.cpp patching file src/libs/decoders/audio_convert.c patching file src/libs/decoders/docs/copying.txt patching file src/libs/decoders/docs/credits.txt patching file src/libs/decoders/docs/license.txt patching file src/libs/decoders/dr_flac.h patching file src/libs/decoders/extra_rwops.c patching file src/libs/decoders/extra_rwops.h patching file src/libs/decoders/flac.c patching file src/libs/decoders/internal/Makefile patching file src/libs/decoders/Makefile.am patching file src/libs/decoders/opus.c patching file src/libs/decoders/SDL_sound.c patching file src/libs/decoders/SDL_sound.h patching file src/libs/decoders/SDL_sound_internal.h patching file src/libs/decoders/stb_vorbis.h patching file src/libs/decoders/vorbis.c patching file src/libs/decoders/wav.c patching file src/libs/Makefile.am patching file src/Makefile.am

by **Dominus** » 2018-10-14 @ 18:32

Hey wow! That was fast!
What about mp3 decoding? This was working with SDL-Sound, I think.

Qbix: apart from not having tested this, I really agree that this is a good direction!!!!

AUDIO Patch supporting FLAC, Opus, and MP3 audio tracks

AUDIO Patch supporting FLAC, Opus, and MP3 audio tracks

Re: AUDIO Patch for FLAC and Ogg Opus support (SDL2)

Re: AUDIO Patch for FLAC and Ogg Opus support (SDL2)

Re: AUDIO Patch for FLAC and Ogg Opus support (SDL2)

Re: AUDIO Patch for FLAC and Ogg Opus support (SDL2)

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Re: AUDIO Patch for FLAC and Ogg Opus support

Who is online