CD audio tracks support

[Former user]

Original issue 250 created by zglope on 2012-07-11T01:30:20.000Z:

not have the mega cd audio please deploy

[Former user]

Comment # 1 originally posted by ekeeke31 on 2012-07-11T09:00:47.000Z:

I guess i will leave at least one open with hope that if people never read the documentation coming with emulators, they will see it and give up flooding the issue reports with the same known stuff again and again :-)

[Former user]

Comment # 2 originally posted by ekeeke31 on 2012-07-11T09:38:18.000Z:

issue \#246 has been merged into this issue.

[Former user]

Comment # 3 originally posted by ekeeke31 on 2012-07-12T18:00:24.000Z:

issue \#246 has been merged into this issue.

[Former user]

Comment # 4 originally posted by ekeeke31 on 2012-07-12T18:03:23.000Z:

About the subject:

i would suggest converting original audio files to the wii samplerate, i.e from 44100 to 48000 Hz as it would save a lot of the wii CPU processing time and can easily be done externally by computer applications. This apply to wav and ogg files.

Another solution could be to have the emulator decode (when using ogg files) and resample audio files automatically when loading a new cd game, into temporary raw audio files that would be used dufor real-time emulation. Again, this could greatly speedup emulation of cd tracks since it would save up decoding and resampling processing time, with the downside of requiring extra size (max.600 mb) on sd/usb and extra initial loading time for writing the temporary files.

[Former user]

Comment # 5 originally posted by gora.patrick on 2012-07-12T18:54:44.000Z:

will it be possible to use a "raw" iso (bin/cue) or will the audiotracks have to be converted to at least wav?

[Former user]

Comment # 6 originally posted by ekeeke31 on 2012-07-12T19:00:38.000Z:

It should be supported but might be slower than separated iso + audio files.

[Former user]

Comment # 9 originally posted by tegskywalker on 2012-07-12T19:24:31.000Z:

This is in response to comment comment 4\.:

Is there a way you can offer both as a user selectable option in the emulator settings? The reason I ask is because with method comment 2\., some of us may not have 600 MB extra space on our SD cards and it can create issues if the emulator chooses to do this method automatically. Maybe have option comment 1\. as default and the more careful users can select method comment 2\. by choice.

[Former user]

Comment # 10 originally posted by ekeeke31 on 2012-07-12T19:26:23.000Z:

It's only theoretical right now, i don't even know if it is realistic. I obviously won't force such behavior if it is too much annoying to use.

[Former user]

Comment # 11 originally posted by sappharad on 2012-07-19T01:09:38.000Z:

I don't know if this is even worth considering, but if you're going to support .ISO + WAV, it would be fairly easy to support .ISO + ADPCM to help with the space problem. That wouldn't be too much larger than high quality MP3's, and still be quick to load and decode. I believe the GC/Wii DSP can decode ADPCM in hardware anyway, but since there are Genesis romhacks that actually use ADPCM for digital audio, it's light enough that you could decode it in software with minimal impact.

[Former user]

Comment # 12 originally posted by ekeeke31 on 2012-07-19T15:59:55.000Z:

This is an interesting idea indeed although i think that ADPCM decoding still need to be done in software by the DSP and require nintendo's proprietary library to be loaded. I am not sure if libogc DSP module (included with ASND or AESND libraries) supports this, i need to check but don't think it is the case. And even if it was, it would require to completely change the way whole audio is processed by the emulator since those libs need to handle audio DMA in their own way, so it might end up being more complicated than it seemed in the first place.

Regarding mp3, i have identified Helix MP3 decoder from Real Networks which is also used in Picodrive and which license seems to be compatible with our license. Need to check further if it is worth implementing when ogg decoding is already there with libtremor...

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Comment # 16 originally posted by johnkenney02 on 2012-07-21T02:39:38.000Z:

You can use cue/iso/wav. The audio tracks in a cue file can be named as separate files & whatever audio format you prefer, data can be an iso.

[Former user]

Comment # 17 originally posted by sonocolourful on 2012-07-21T22:00:04.000Z:

I'm not the world's greatest DSP programmer but wouldn't upsampling from 44100 to 48khz in realtime be reasonably light? My understanding is you don't need a high quality algorithm, or filtering, when going up in sample rate because it doesn't really create aliasing problems. If you took it and mixed it in with the Genesis output, you could just enable the lowpass filter by default and set it to a lenient value (98, 99%?) to filter the whole output. If it's too much for the Wii to handle or causes slowdowns, how about an option to automatically enable lower quality FM when playing Mega CD? Lots of Mega CD games don't use FM for much other than sound effects anyway. Forgive me if I'm making big assumptions here, I'm not familiar with exactly how the emulator is put together internally.

Dustin

[Former user]

Comment # 18 originally posted by [e-mail] on 2012-07-22T01:09:27.000Z:

The automatically enable lower quality for Mega/Sega CD Games sounds perfect to me.

[Former user]

Comment # 19 originally posted by ekeeke31 on 2012-07-22T08:39:01.000Z:

You can always disable HQ FM if you want, but it's bad design to do it automatically under some situation.

Linear interpolation from 44.1 to 48 khz should \*in theory\* be fine for CD audio tracks and not too much CPU time consuming but in practice, proper resampling might be needeed to avoid clicks or noise: i think that when the original signal has lot of harmonics close (or above ?) to the max frequency (i.e 22.05 khz), interpolation does not give very good result. Well, we will see, i know gens/picodrive are doing basic interpolation (not even linear) to resample 32khz PCM to 44.1hz output.

As for filtering, it must be specific and applied during the resampling, low-pass filter applied on the output probably won't be efficient enough.

Anyway, my idea was that for external compressed audio files (obviously for bin image the raw audio will need to be resampled), it could be better to have them already resampled by an external program because 1) it would be better quality resampling 2) it will still save CPU time for other tasks, like decompressing for example. Seems quite logical to me and honestly i don't really care if people complains about having to resample their iso "collection" if this makes emulation better and faster.. In most cases, you will already have to convert mp3 to ogg so why not resampling them as well ?

[Former user]

Comment # 20 originally posted by sonocolourful on 2012-07-22T13:30:14.000Z:

If that's the direction you think is best, how about the pre-processing resampling idea, but doing it on the Wii side? For example, the first time you launch a bin/cue, inform the user that it has to be preprocessed once before running. Have genplus extract the tracks from the bin, resample them and encode them to ogg. Extract the data track to iso (or even better, if not too hard to implement, CSO, like picodrive). Once complete give the option of deleting the bin/cue.

If this solution got used, it would be best if the "converted" game could be added to, say, an xml list that includes the iso and the audio tracks it uses, so that so it could be easily selected and have a "clean" entry in the file selector. You could even store the TOC in there for games like Snatcher.

Personally, it wouldn't really bother me to have to do the conversion on my PC, but it would be nice to have the functionality built right into genplus.

[Former user]

Comment # 21 originally posted by ekeeke31 on 2012-07-22T14:20:37.000Z:

Yes, that's what I suggested on comment comment 4\. although I'm not a big fan of converting accurate bin+cue dump to something less accurate. If post-processing is done, then better uncompress everything and use RAW or WAV audio file converted to 48khz so the emulator only has to read files and write data back to audio buffers, without any additional processing. Compressed ISO will not be supported as it will only add more processing to decompress the iso data in real time, it's not really a matter of how "hard" it would be to implement than how "useful" it is beside leaving more rooms on storage device.

Again, if it was not clear enough, my goal is not to make it easier to store as many games as possible on USB stick or small SD cards, it's to make it so that emulation remains accurate while still being running full-speed and without any frame-skipping. If that's only possible by using fully uncompressed CD images with audio files resampled to 48khz RAW data and leaded to 1GB by game file, I would still do it. Hopefully, the Wii is powerful enough to decompress OGG file or interpolate CD audio to 48khz while handling the existing hardware emulation process.

[Former user]

Comment # 22 originally posted by ekeeke31 on 2012-07-22T14:43:55.000Z:

Off topic, I have come across some BIN/CUE images that were actually holding WAVE files inside the BIN file. Is that something normal and allowed by the CUE/BIN format ? The CUE file mentions the start of raw audio track inside the .bin file but it points to a "RIFF WAVE" header before actual raw data. Or maybe that's a badly reconstructed CD image that was done using external WAV files ?

FILE "Earthworm Jim - Special Edition (Sega CD) (U).bin" BINARY TRACK 01 MODE1/2352 INDEX 01 00:00:00 TRACK 02 AUDIO INDEX 00 01:31:14 INDEX 01 01:33:14 ...

006daff0:00 00 00 00 00 00 00 00 00 00 00 00 52 49 46 46 ............RIFF 006db000:dc c1 0b 00 57 41 56 45 66 6d 74 20 10 00 00 00 ÜÁ..WAVEfmt .... 006db010:01 00 02 00 44 ac 00 00 10 b1 02 00 04 00 10 00 ....D¬...±...... 006db020:64 61 74 61 8c c1 0b 00 ef ff 1c 00 e9 ff 14 00 dataŒÁ..ïÿ..éÿ..

[Former user]

Comment # 23 originally posted by sonocolourful on 2012-07-22T15:11:13.000Z:

I've actually seen this before. Provided the bin/cue isn't badly dumped, or a bad CD image, it may be actually a mastering error. Most mixed mode CDs that have this problem have a little click before the audio starts playing, because of the header. I can't recall any Mega CD games that I know of with the problem but I've seen it on other discs.

In response to your comment 21, I'm in total agreement. I'm sure most people using genplus are running off of USB hard drives or large SD cards anyway. I would much rather be able to load & run unmodified bin/cue files myself. As far as audio tracks being stored as ogg files, that would probably eat up more CPU time than just resampling the raw audio in realtime, but I wasn't really giving it much thought. I peeked at the source--is the FIR resampler too "heavy" to apply to the CD audio?

By the way eke-eke thanks for the thoughtful replies, the fantastic emulator (it is the best emulator of any system on the wii), the Sega CD support and everything.

[Former user]

Comment # 24 originally posted by tegskywalker on 2012-07-22T19:15:16.000Z:

Here is my two cents about the audio situation and available SegaCD roms.

CoolRom (www.coolrom.com) - ROMs are in ISO format with MP3s Emuparadise (www.emuparadise.me) - ROMs are in BIN format with CUE

Say for example you try Final Fight CD or Sonic CD from Emuparadise with the BIN/CUE combination. I have looked at the CUE files that come with the BIN and there is no mention of a WAV extension. Say we were to rip that BIN file into an ISO with WAV or OGG files, will a new CUE file have to be created to specifically look for WAV/OGG ?

[Former user]

Comment # 26 originally posted by ekeeke31 on 2012-07-22T20:00:37.000Z:

ISO+wav or any type of separated audio files normally does not require cue file because the TOC can be guessed from the different files length/format. You can still use a cue file but the image format is obviously different from a plain .bin dump and each file must be explicitely mentionned. See online documentation if you have more question about cue files.

I am planning to support bin+cue anyway so you really should not bother about having to convert anything, i was only discussing the conversion of existing audio files to a suitable rate and format...

[Former user]

Comment # 27 originally posted by emukidid on 2012-07-25T04:19:05.000Z:

It's a real shame no one reads the user manual - you've got the best manual I've seen in a long time for an emulator and I often find myself looking at it just cause of all the nice detail and care put into it, keep up the good work :D

As for ADPCM route, I'd also advise against it if you want to get it done some time this lifetime ;) (you'd need to write your own copy of the proprietary ADPCM decoder or learn to use the Nintendo one and have it provided in some BIN format by the users.. too much fussing around..)

I would recommend using ASND/AESND (AESND utilizes more special DSP instructions to get higher performance on GameCube than ASND) and having the users provide the files in MP3 format or something else lossy and low bandwidth. Although I'm not sure how much CPU you have to spare on the GameCube to software decode the MP3. Another thing to consider is that on GameCube the SDGecko is going to do polled I/O reads so you want to minimize bandwidth to minimize CPU blocking from I/O.

When we did CDDA support in WiiSX, it considerably brought down the framerate using the raw data from the ISO, but we never got around to trying anything else or performing optimizations on the ugly PC driver we ported.

Just my thoughts - again, keep up the great work - I was amazed when I ran Sonic CD on my GameCube, amazing work :D

[Former user]

Comment # 28 originally posted by ekeeke31 on 2012-07-25T20:09:52.000Z:

Thanks for the input ;-) Yes, i expect some performance drop with audio track support but hope not so much (it's actually the same as continuously streaming data from usb/sd like fmv games are doing already, with additional resampling or decompression eventually). I already thought about using DSP through AESND (mainly for the resampling) but, unless i missed something, it finally seemed too much complicated since i need to keep control on audio DMA lengths (to prevent any audio/video desync) and it would probably means redesigning completely the way the emulator is outputing samples.

It's nice that Mega CD games are running fine on Game Cube, i still have my original modded one from good old tehskeen time but it seems like my sd-gekko adapter got lost or trashed so i couldn't test it. I wasn't much optimistic about the framerate however.

[Former user]

Comment # 29 originally posted by emukidid on 2012-07-25T23:18:28.000Z:

Yes, that's the problem with AESND, it really does require a re-write of anything that wasn't designed to use it in the first place.

Good luck with it, I'm personally looking forward to seeing it (or listening to it rather):)

[Former user]

Comment # 30 originally posted by sappharad on 2012-07-29T19:19:18.000Z:

Linear interpolation can be done in a few lines of code, and I think it sounds fine. It shouldn't create much overhead at all, and you won't need to incorporate an external library for it. You can find an example of it at the very bottom of the attached file. (This is the code I used for the ADX playback in the Gamecube Disc Browser)

[Former user]

Comment # 31 originally posted by ekeeke31 on 2012-07-30T08:34:06.000Z:

Thank you for the code but i am planning to use blip\_buffer linear interpolation instead (it's very similar actually, just add a little bit of high-pass filtering). This way, better resampling using band-limited synthesis from blib buffer library could also later be used (i plan to add options for "high-quality" CD, PCM and even PSG this way).

[Former user]

Comment # 32 originally posted by superballena on 2012-07-31T21:06:53.000Z:

Speaking of formats for CD audio emulation, perhaps it would help checking out how the SCUMMVM team handled the CD tracks?

They currently support WAV, OGG and even FLAC without slowing down the games (although I'm pretty sure they aren't as CPU intensive since it's not emulation).

[Former user]

Comment # 33 originally posted by superballena on 2012-08-01T21:58:06.000Z:

Also, MESS and MAME have also implemented FLAC support lately. Here's a post Haze made a few months ago about it, for the record:

http://mamedev.emulab.it/haze/2012/01/18/taking-the-flac/

[Former user]

Comment # 34 originally posted by ekeeke31 on 2012-08-02T15:27:36.000Z:

Yes, FLAC is a nice lossless library although my goal isn't to support all possible audio formats because emdedding external libraries has signicant costs. The advantage of ogg is that libtremor is already there and being used. As for taking inspiration from other emu implementations, this isn't really useful or applicable because every apps are designed differently and have different requirements. Also, the use of decompressing libraries is pretty much standard, i doubt that scummvm or mess do something special beside using the existing documented API . From the discussion you linked, it's more about how to correctly and efficiently compress CD image existing sets to replace CHD format.

Anyway, don't worry, i already have a pretty clear idea about existing audio tracks formats and how i it's gonna be done, just missing time to really get my hands on it, especially with vacations finally coming on their ways. It's also very likely that compressed audio files support won't come immediately and that next release will first attempt to deal correctly with Cue+Bin and Iso+Wav images.

[Former user]

Comment # 35 originally posted by ekeeke31 on 2012-08-31T13:35:50.000Z:

issue \#273 has been merged into this issue.

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Comment # 36 originally posted by jlenoconel on 2012-08-31T19:12:59.000Z:

So is there no way to get music to play currently? I tried Final Fight (two different versions). One the game wouldn't play and the other the game would play but the music wouldn't.

[Former user]

Comment # 37 originally posted by superballena on 2012-09-02T18:28:19.000Z:

You got it.

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Comment # 38 originally posted by punkydudester on 2012-09-04T05:51:21.000Z:

Yes this Final Fight CD is an issue everyone is aware of. Many games play no music at all except for some in game music like in Sonic CD when you go to a hidden area & music plays. Ekeeke is working on stuff, just be patient.

[Former user]

Comment # 39 originally posted by ekeeke31 on 2012-09-30T17:42:17.000Z:

[Former user]

Comment # 40 originally posted by ekeeke31 on 2012-10-13T17:05:55.000Z:

Added in r715

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Comment # 41 originally posted by ekeeke31 on 2012-10-13T17:06:06.000Z: