Support Cuesheet for imgmount

[rwv]

https://github.com/js-dos/emulators/blob/3f4d6b44c0969328c8e5ded834e7b33331bdfe15/native/dosbox/config.h#L98

#define C_SDL_SOUND 1 to enable dosbox cuesheet support

See also https://www.dosbox.com/wiki/Cuesheet

[rwv]

Maybe need other work to do instead of just simply set SDL_SOUND to 1.

[caiiiycuk]

Can't use SDL_SOUND=1 cause js-dos build didn't use sdl at all. So need to look how to add cue support without SDL

[rwv]

SDL_SOUND is only used in https://github.com/js-dos/emulators/blob/c06afe5682fcec1c409cf3725520970aba6310fb/native/dosbox/src/dos/cdrom.h and have nothing to do with display.

Could we just import SDL_SOUND without importing SDL?

From dosbox INSTALL file: SDL_Sound (optional) For compressed audio on diskimages (cue sheets) support. This is for cue/bin cdrom images with compressed (mp3/ogg) audio tracks. Get it from http://icculus.org/SDL_sound Licence: LGPLv2+

It seems that SDL_sound and SDL are two different libs with similar name.

[caiiiycuk]

Yeah looks so, if SDL_sound is not hardcoupled with SDL maybe we can add it by simply defining SDL_SOUND 1 as you say. Will check this later, or you can chek by yourself

[rwv]

SDL_sound depends on SDL. We need to implement class AudioFile without SDL.

P.S. Can we just import SDL but treat it just a dep of SDL_sound? (not a display backend)

[rwv]

More specific, this part.

#if defined(C_SDL_SOUND)
CDROM_Interface_Image::AudioFile::AudioFile(const char *filename, bool &error)
{
	Sound_AudioInfo desired = {AUDIO_S16, 2, 44100};
	sample = Sound_NewSampleFromFile(filename, &desired, RAW_SECTOR_SIZE);
	lastCount = RAW_SECTOR_SIZE;
	lastSeek = 0;
	error = (sample == NULL);
}

CDROM_Interface_Image::AudioFile::~AudioFile()
{
	Sound_FreeSample(sample);
}

bool CDROM_Interface_Image::AudioFile::read(Bit8u *buffer, int seek, int count)
{
	if (lastCount != count) {
		int success = Sound_SetBufferSize(sample, count);
		if (!success) return false;
	}
	if (lastSeek != (seek - count)) {
		int success = Sound_Seek(sample, (int)((double)(seek) / 176.4f));
		if (!success) return false;
	}
	lastSeek = seek;
	int bytes = Sound_Decode(sample);
	if (bytes < count) {
		memcpy(buffer, sample->buffer, bytes);
		memset(buffer + bytes, 0, count - bytes);
	} else {
		memcpy(buffer, sample->buffer, count);
	}
	
	return !(sample->flags & SOUND_SAMPLEFLAG_ERROR);
}

int CDROM_Interface_Image::AudioFile::getLength()
{
	int time = 1;
	int shift = 0;
	if (!(sample->flags & SOUND_SAMPLEFLAG_CANSEEK)) return -1;
	
	while (true) {
		int success = Sound_Seek(sample, (unsigned int)(shift + time));
		if (!success) {
			if (time == 1) return lround((double)shift * 176.4f);
			shift += time >> 1;
			time = 1;
		} else {
			if (time > ((numeric_limits<int>::max() - shift) / 2)) return -1;
			time = time << 1;
		}
	}
}
#endif

Data Structures

• Sound_AudioInfo
• SDL_AudioSpec.format

Enumerations

• Sound_SampleFlags

Functions

• Sound_NewSampleFromFile
• Sound_FreeSample
• Sound_SetBufferSize
• Sound_Seek
• Sound_Decode

[caiiiycuk]

Wow, thanks for this investigation! I am on vacations until 11th of January, so I can look after that

[rwv]

Anything I can help with?

[caiiiycuk]

Unfortunately IPX feature takes all my time. Hope to finish it soon, and then I will take some other task, maybe this one. You can only try to do it :)

[caiiiycuk]

I think we can easily add support for OGG track using minivorbis instead of SDL_sound

[rwv]

I think we can easily add support for OGG track using minivorbis instead of SDL_sound

minivorbis only supports Vorbis codec. However, Cuesheet support multi codec including MP3 See https://www.dosbox.com/wiki/Cuesheet#Compressed_audio_tracks

[caiiiycuk]

Yes, but i think it's not a big deal to convert mp3 to ogg. I think because we have full control over bundle creation we can create cue with ogg. At least it will be a good start.

[rwv]

Yes. It is a good start. But I think nearly full compatibility with DosBox is also important since DOS.Zone Studio is provided for user and reconvert audio is very confusing and frustrating for user.

P.S. OGG is a container format and may contain different codec. Convert MP3 to Vorbis is a more accurate term.

[caiiiycuk]

Okay, not sure that we can add mp3 decoder, is it free?

[rwv]

The MP3 technology became patent-free in the United States on 16 April 2017 when U.S. Patent 6,009,399, held by and administered by Technicolor, expired.

SDL_sound is licensed zlib license. They use of LGPL'd code from mpg123 to decode MP3.

mackron/dr_libs claims mp3 decode in public domain.

[caiiiycuk]

How to build with cue support: 1. Get SDL_sound 2 from https://github.com/icculus/SDL_sound (use latest git version) Extract to native\dosbox\3rdparty\SDL_sound

2. Edit native\dosbox\3rdparty\SDL_sound\src\SDL_sound.h Change #include "SDL.h" to #include <SDL2/SDL.h>

3. Edit native\dosbox\3rdparty\SDL_sound\src\SDL_sound_internal.h leave support for vorbis only(or other formats)

4. Edit native\dosbox\src\dos\dos_programs.cpp Line: 1501 Comment out MSCDEX_SetCDInterface(CDROM_USE_SDL, -1);

5. Edit DOSBOX config.h Add #define C_SDL_SOUND 1

6. Edit native\dosbox-jsdos\dosbox-jsdos.cmake Add "${CMAKE_CURRENT_LIST_DIR}/../dosbox/3rdparty/SDL_sound/src" to include_directories

7. Edit native\dosbox-jsdos\dosbox-jsdos.cmake Add following lines(or other c files depand on formats you want):

set(SOURCES_JSDOS_SDL_SOUND
        ${CMAKE_CURRENT_LIST_DIR}/../dosbox/3rdparty/SDL_sound/src/SDL_sound.c
        ${CMAKE_CURRENT_LIST_DIR}/../dosbox/3rdparty/SDL_sound/src/SDL_sound_vorbis.c
)

Modify SOURCES_SERVER_CORE to add SDL_sound files:

set(SOURCES_SERVER_CORE  ${SOURCES_JSDOS_SDL_SOUND} ${SOURCES_CORE_CXX11} ${SOURCES_CORE_CXX03})

8. Edit src\dos\dosbox\dosbox.cmake add -sUSE_SDL=2 for SDL2 support:

set_target_properties(wdosbox PROPERTIES LINK_FLAGS "${WORKER_LINK_FLAGS} -sUSE_SDL=2 -s WASM=1 -s ASYNCIFY=1 -s 'ASYNCIFY_IMPORTS=[\"syncSleep\"]' -s ASYNCIFY_WHITELIST=@${CMAKE_CURRENT_LIST_DIR}/../../../native/dosbox-jsdos/asyncify.txt -s EXPORT_NAME='WDOSBOX'")
set_target_properties(wdosbox.shared PROPERTIES LINK_FLAGS "${WORKER_LINK_FLAGS} -sSHARED_MEMORY=1 -sUSE_SDL=2 -Wl,--shared-memory,--no-check-features -sUSE_PTHREADS=1 -s WASM=1 -s ASYNCIFY=1 -s 'ASYNCIFY_IMPORTS=[\"syncSleep\"]' -s ASYNCIFY_WHITELIST=@${CMAKE_CURRENT_LIST_DIR}/../../../native/dosbox-jsdos/asyncify.txt -s EXPORT_NAME='WDOSBOX'")