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..

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!

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_updat … ffer?expanded=1

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.

1 25% [|||||||||||||||                                             ] - fill
2 50% [||||||||||||||||||||||||||||||                              ] - fill
3 74% [||||||||||||||||||||||||||||||||||||||||||||                ] - fill
4 99% [||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - fill
5 98% [||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| ] - consume
6 97% [||||||||||||||||||||||||||||||||||||||||||||||||||||||||||  ] - consume
7 96% [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||   ] - consume
8 95% [|||||||||||||||||||||||||||||||||||||||||||||||||||||||||   ] - consume
9 94% [||||||||||||||||||||||||||||||||||||||||||||||||||||||||    ] - consume
10 93% [|||||||||||||||||||||||||||||||||||||||||||||||||||||||     ] - consume
11 92% [|||||||||||||||||||||||||||||||||||||||||||||||||||||||     ] - consume
12 91% [||||||||||||||||||||||||||||||||||||||||||||||||||||||      ] - consume
13 90% [||||||||||||||||||||||||||||||||||||||||||||||||||||||      ] - consume
14 89% [|||||||||||||||||||||||||||||||||||||||||||||||||||||       ] - consume
15 87% [||||||||||||||||||||||||||||||||||||||||||||||||||||        ] - consume
16 86% [||||||||||||||||||||||||||||||||||||||||||||||||||||        ] - consume
17 85% [|||||||||||||||||||||||||||||||||||||||||||||||||||         ] - consume
18 84% [||||||||||||||||||||||||||||||||||||||||||||||||||          ] - consume
19 83% [||||||||||||||||||||||||||||||||||||||||||||||||||          ] - consume
20 82% [|||||||||||||||||||||||||||||||||||||||||||||||||           ] - consume
21 81% [||||||||||||||||||||||||||||||||||||||||||||||||            ] - consume
22 80% [||||||||||||||||||||||||||||||||||||||||||||||||            ] - consume
23 79% [|||||||||||||||||||||||||||||||||||||||||||||||             ] - consume
24 78% [|||||||||||||||||||||||||||||||||||||||||||||||             ] - consume
25 77% [||||||||||||||||||||||||||||||||||||||||||||||              ] - consume
26 76% [|||||||||||||||||||||||||||||||||||||||||||||               ] - consume
27 75% [|||||||||||||||||||||||||||||||||||||||||||||               ] - consume
28 74% [||||||||||||||||||||||||||||||||||||||||||||                ] - consume
29 73% [|||||||||||||||||||||||||||||||||||||||||||                 ] - consume
30 71% [|||||||||||||||||||||||||||||||||||||||||||                 ] - consume
31 70% [||||||||||||||||||||||||||||||||||||||||||                  ] - consume
32 69% [|||||||||||||||||||||||||||||||||||||||||                   ] - consume
33 68% [|||||||||||||||||||||||||||||||||||||||||                   ] - consume
34 67% [||||||||||||||||||||||||||||||||||||||||                    ] - consume
35 66% [|||||||||||||||||||||||||||||||||||||||                     ] - consume
36 65% [|||||||||||||||||||||||||||||||||||||||                     ] - consume
37 64% [||||||||||||||||||||||||||||||||||||||                      ] - consume
38 63% [||||||||||||||||||||||||||||||||||||||                      ] - consume
39 62% [|||||||||||||||||||||||||||||||||||||                       ] - consume
40 61% [||||||||||||||||||||||||||||||||||||                        ] - consume
41 60% [||||||||||||||||||||||||||||||||||||                        ] - consume
42 59% [|||||||||||||||||||||||||||||||||||                         ] - consume
43 58% [||||||||||||||||||||||||||||||||||                          ] - consume
44 56% [||||||||||||||||||||||||||||||||||                          ] - consume
45 55% [|||||||||||||||||||||||||||||||||                           ] - consume
46 54% [||||||||||||||||||||||||||||||||                            ] - consume
47 53% [||||||||||||||||||||||||||||||||                            ] - consume
48 52% [|||||||||||||||||||||||||||||||                             ] - consume
49 51% [||||||||||||||||||||||||||||||                              ] - consume
50 50% [||||||||||||||||||||||||||||||                              ] - consume
51 49% [|||||||||||||||||||||||||||||                               ] - consume
52 48% [|||||||||||||||||||||||||||||                               ] - consume
53 47% [||||||||||||||||||||||||||||                                ] - consume
54 46% [|||||||||||||||||||||||||||                                 ] - consume
55 45% [|||||||||||||||||||||||||||                                 ] - consume
56 44% [||||||||||||||||||||||||||                                  ] - consume
57 42% [|||||||||||||||||||||||||                                   ] - consume
58 41% [|||||||||||||||||||||||||                                   ] - consume
59 40% [||||||||||||||||||||||||                                    ] - consume
60 39% [|||||||||||||||||||||||                                     ] - consume

61 38% [|||||||||||||||||||||||                                     ] - consume
62 37% [||||||||||||||||||||||                                      ] - consume
63 36% [|||||||||||||||||||||                                       ] - consume
64 35% [|||||||||||||||||||||                                       ] - consume
65 34% [||||||||||||||||||||                                        ] - consume
66 33% [|||||||||||||||||||                                         ] - consume
67 32% [|||||||||||||||||||                                         ] - consume
68 31% [||||||||||||||||||                                          ] - consume
69 30% [||||||||||||||||||                                          ] - consume
70 28% [|||||||||||||||||                                           ] - consume
71 27% [||||||||||||||||                                            ] - consume
72 26% [||||||||||||||||                                            ] - consume
73 25% [|||||||||||||||                                             ] - consume
74 24% [||||||||||||||                                              ] - consume
75 23% [||||||||||||||                                              ] - consume
76 22% [|||||||||||||                                               ] - consume
77 21% [||||||||||||                                                ] - consume
78 20% [||||||||||||                                                ] - consume
79 19% [|||||||||||                                                 ] - consume
80 18% [||||||||||                                                  ] - consume
81 17% [||||||||||                                                  ] - consume
82 16% [|||||||||                                                   ] - consume
83 15% [|||||||||                                                   ] - consume
84 14% [||||||||                                                    ] - consume
85 12% [|||||||                                                     ] - consume
86 11% [|||||||                                                     ] - consume
87 10% [||||||                                                      ] - consume
88  9% [|||||                                                       ] - consume
89  8% [|||||                                                       ] - consume
90  7% [||||                                                        ] - consume
91  6% [|||                                                         ] - consume
92  5% [|||                                                         ] - consume
93  4% [||                                                          ] - consume
94  3% [||                                                          ] - consume
95  2% [|                                                           ] - consume
96  1% [                                                            ] - consume
97  0% [                                                            ] - consume
98  0% [                                                            ] - wrap
99 24% [||||||||||||||                                              ] - fill
100 49% [|||||||||||||||||||||||||||||                               ] - fill
101 48% [|||||||||||||||||||||||||||||                               ] - consume
102 47% [||||||||||||||||||||||||||||                                ] - consume
103 46% [|||||||||||||||||||||||||||                                 ] - consume
104 45% [|||||||||||||||||||||||||||                                 ] - consume
105 44% [||||||||||||||||||||||||||                                  ] - consume
106 43% [||||||||||||||||||||||||||                                  ] - consume
107 42% [|||||||||||||||||||||||||                                   ] - consume
108 41% [||||||||||||||||||||||||                                    ] - consume
109 40% [||||||||||||||||||||||||                                    ] - consume
110 39% [|||||||||||||||||||||||                                     ] - consume
111 38% [||||||||||||||||||||||                                      ] - consume
112 36% [||||||||||||||||||||||                                      ] - consume
113 35% [|||||||||||||||||||||                                       ] - consume
114 34% [||||||||||||||||||||                                        ] - consume
115 33% [||||||||||||||||||||                                        ] - consume
116 32% [|||||||||||||||||||                                         ] - consume
117 31% [||||||||||||||||||                                          ] - consume
118 30% [||||||||||||||||||                                          ] - consume
119 29% [|||||||||||||||||                                           ] - consume
120 28% [|||||||||||||||||                                           ] - consume
121 27% [||||||||||||||||                                            ] - consume
122 26% [|||||||||||||||                                             ] - consume
123 25% [|||||||||||||||                                             ] - consume
124 24% [||||||||||||||                                              ] - consume
125 23% [|||||||||||||                                               ] - consume
126 21% [|||||||||||||                                               ] - consume
127 20% [||||||||||||                                                ] - consume
128 19% [|||||||||||                                                 ] - consume
129 18% [|||||||||||                                                 ] - consume
130 18% [||||||||||                                                  ] - consume
131 18% [||||||||||                                                  ] - stop
132StopAudio -- CDROM audio channel disabled
133CDROM 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.

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:

1FILE "data.iso" BINARY
2  TRACK 01 MODE1/2048
3    INDEX 01 00:00:00
4
5FILE "audio02.ogg" OGG
6  TRACK 02 AUDIO
7    PREGAP 00:02:00
8    INDEX 01 00:00:00
9
10FILE "track03.opus" OPUS
11  TRACK 03 AUDIO
12    PREGAP 00:02:00
13    INDEX 01 00:00:00
14
15FILE "track04.flac" FLAC
16  TRACK 04 AUDIO
17    PREGAP 00:02:00
18    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).

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 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.

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.

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/blob/mas … decoders/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.

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,116618 … .html#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:

1FILE "data.iso" BINARY
2  TRACK 01 MODE1/2048
3    INDEX 01 00:00:00
4FILE "track02.opus" OPUS
5  TRACK 02 AUDIO
6    PREGAP 00:02:00
7    INDEX 01 00:00:00

Enjoy!

To use FLAC:

1FILE "data.iso" BINARY
2  TRACK 01 MODE1/2048
3    INDEX 01 00:00:00
4FILE "track02.flac" FLAC
5  TRACK 02 AUDIO
6    PREGAP 00:02:00
7    INDEX 01 00:00:00

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)

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).

Many thanks for clarifying. Very impressive work. Very

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!

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/1G13rk … VZfop3aMO8U9mvV

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.

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.

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):

1patch -p1 < ~/dosbox-r4168-internal_decoders.patch 
2patching file configure.ac
3patching file Makefile.am
4patching file src/dos/cdrom.h
5patching file src/dos/cdrom_image.cpp
6patching file src/dos/dos_mscdex.cpp
7patching file src/dos/drive_iso.cpp
8patching file src/libs/decoders/audio_convert.c
9patching file src/libs/decoders/docs/copying.txt
10patching file src/libs/decoders/docs/credits.txt
11patching file src/libs/decoders/docs/license.txt
12patching file src/libs/decoders/dr_flac.h
13patching file src/libs/decoders/extra_rwops.c
14patching file src/libs/decoders/extra_rwops.h
15patching file src/libs/decoders/flac.c
16patching file src/libs/decoders/internal/Makefile
17patching file src/libs/decoders/Makefile.am
18patching file src/libs/decoders/opus.c
19patching file src/libs/decoders/SDL_sound.c
20patching file src/libs/decoders/SDL_sound.h
21patching file src/libs/decoders/SDL_sound_internal.h
22patching file src/libs/decoders/stb_vorbis.h
23patching file src/libs/decoders/vorbis.c
24patching file src/libs/decoders/wav.c
25patching file src/libs/Makefile.am
26patching file src/Makefile.am

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!!!!