Discussion in 'Functions Operation Guidance' started by Rita, May 14, 2018.
the egreat music player can't play 5.1 LPCM but the himedia music player can ?
maybe because of BETA ? or android 7 ? dunno....
More bugs found in the music player:
If we press the pause button on both the remote control and the interface, when you give to play, go to the next song, instead of continuing from where we stopped it.
There is also no way to go back to the "now playing" interface when browsing through folders or music files.
They are inexplicable errors in such basic functions, after so much time waiting for the new music player. I hope that they solve the faults, added to those that I already explained before.
Here is my advice for SACD support. It’s actually really hard to properly implement SACD support because of the complexity of the format.
First, you have four official means of storing DSD on SACD:
DSDIFF – Supports 2, 5 [5.0], and 6 [5.1 surround] channel audio. Does not support tags.
DSDIFF Master – Same as DSDIFF with limited tagging support
DSDIFF with DST Compression – Many standalone players do not support this because it is extremely processor intensive to decode DST. Indeed, even many PCs cannot do it in real time. Generally used on SACD with surround sound tracks.
DSF – Unlike DSDIFF, DSF allows you to have tags. It also has a different set of possible channel configurations than DSDIFF: 1 [mono], 2 [stereo], 3 [three channel stereo], 4 [quadraphonic], 4 channels [3.1], 5 [5.0], 5.1. However, DSF does not support DSF compression so a 5 minute song tends to be around 600mb.
And one unofficial method of compressing DSD information to reduce the file size: wavpack 5.0
The benefit to wavpack is that it is open source, supports tags, and provides quite excellent reduction of file sizes. It would be amazing to have wavpack 5 support. Please, please, implement it.
Second, not all receivers support DSD so the player needs to support conversion of DSD to PCM in the settings menu.
In the setting menu, there needs to be the following options
DSD Output Format: Bitstream – Outputs raw DSD over HDMI
PCM – Converts DSD to PCM
PCM Conversion Method: (Greyed out unless DSD Output Format is set to PCM)
There should be a variety of options. I suggest taking a look at Super Audio CD Decoder Project on Sourceforge for inspiration and explanations. Leave the best one that the player can support as the default. You can choose to implement only the multistage, but you should give the option to apply a 30khz low pass cutoff filter to protect older equipment.
PCM Bitdepth: (Greyed out unless DSD Output Format is set to PCM)
24bit – Default; 16bit – Selectable; 32bit – only if you can support it.
Reason: SACD is around 20bit, but no player supports that so it should be 24bit.
PCM Samplerate: (Greyed out unless DSD Output Format is set to PCM)
176.4khz – Default; 88.2khz – Selectable; 44.1khz – selectable; 358.2khz – only if you can support it
Reason: DSD is always multiples of the CD standard sample rate of 88.2khz. 176.4khz is supposed to mathematically capture all of the DSD information at 24bit.
Pad PCM: (Greyed out unless DSD Output Format is set to PCM)
Yes; No – Default
Reason: Some receivers do not support sample rates of 88.2khz, 176.4khz, or 358.2khz, but will support sample rates of 96khz, 192khz or 384khz. If “Pad PCM” is set to yes, then the player should add silence to increase the sample rate to a compatible one. [88.1khz -> 96khz, 176.4khz -> 192khz; 358.2 -> 384khz]
Third, for SACD iso, you need a fast way to switch between stereo and multichannel track. I suggest using the red button for stereo and the blue button for multichannel. The audio button should also bring up the available formats.
I can give further suggestions for the Music player, if you would like.
a) What would be great is a link to a test set where all DSF/DSD derived formats you mentioned are available? Frankly I have seen in practice a decent collection of SACD in Stereo, some in 5.1 MCH and a very few in 5.0 MCH formats. So there may be many formats possible according the SACD standards but most MCH variants are never or hardly ever used. Thus far never ran into an SACD.ISO or DSF not playing Stereo. My Pioneer SACD HW player plays all SACD I have also in MCH (needed a firmware update).
b) I own an Android based Media Player supporting DSF, SACD-ISO playback with realtime Stereo decoding to PCM 16-bit 48 Khz (default Android) and PCM 24-bit 176.4 Khz (selectable option). For me that really is good enough regarding PCM decoding. Only RAW DSD64 output and MCH support are still missing but it does play MCH DVD-CD and FLAC up-to 192Khz also includes support for CUE sheets.
c) Suggestions are always welcome.
Bottom line it is proven SACD support under Android is possible on media players. I expect that Music Player 2.0 will be updated further to fully support SACD and other High Definition formats also.
a) I do not have a test set. As you, I have mostly seen 2.0 and 5.1 SACD disk. I intended to point out that DSDIFF and DSF have subtle differences with tag support, channel support, and DSF support being the main differences. I believe that a player should properly support the entire specification for a format.
2) If I understand correctly, your question is why support DSD bitstreaming? There are several reasons. First, DSD came into existence to eliminate unnecessary conversion back and forth from PCM. In one production chain, it goes Analog Source -> DSD -> PCM and then on the playback device PCM -> DSD -> speakers. Sony and Phillips intended DSD to eliminate the back and forth conversion from DSD to PCM. Second, if a player says that it supports SACD playback, it should support DSD bitstreaming because that is the definition of SACD playback. Otherwise, the consumer may feel cheated. Third, DSD -> PCM is not a lossless process. Therefore, you lose some information. At higher bit depths and sample rates, this loss becomes invisible for practical purposes. Yet not all players support such high rates.
Overall, my intention is to give egreat my advice based on my experiences and frustrations. If egreat doesn't want it, then that's ok.
This music media player is a new equipment or an application? if it is an application, where can it be find?
I have a large music collection (more than 7.500 albums) stored on a NAS. File formats are: FLAC, WAV, DSD.
Music Player 2.0 is a new APP included with the most recent beta.
I’d like to continue my suggestions by discussing which file format’s I would like egreat to support.
ISO: SACD, DVD-Audio, High Fidelity Pure Audio
DVD-Audio support would require support for the proprietary formats Meridian Lossless packaging, DTS, and AC-3. I don’t know if egreat could use one of the open source MLP decoders or if it would have to pay royalty.
High Fidelity Pure Audio is an audio only Blu-ray that has DTS-MA, DTS-HD, and LPCM. There are special mapping of the standard color buttons that control the audio selection. This should be an easy format to support.
AIFF used in several places including HD Tracks.
Wav (LPCM) – standard workhorse.
FLAC – This is the lossless compression that has emerged as standard. However, it does have a few minor drawbacks like not supporting floating-point. BSD license.
Monkey Audio – Offers better compression than flac but more decoder intensive. It’s probably the second most popular lossless compression format. Monkey Audio license.
Apple Lossless Audio Codec (ALAC) – Apple’s proprietary format. Some audio is sold in this format. I’m personally not a fan of any proprietary formats but it’s semi-popular due to Apple’s market dominance. Apache License 2
Wavpack – Probably the fourth most popular lossless compression format. The only one to support DSD encoding which makes it extremely important. It can reduce the size of a multi-channel DSD file by around 50% -60%. Also, supports floating point. BSD license
Lossless Audio support should include support for embedded cuesheets. If the format supports an embedded cuesheet, then the music player should check and read it before it load the files for playback or adds it to the library. Lack of embedded cuesheet support is a major weakness of many media players.
Full disclosure, I don’t have as much experience with this.
Open Source: Ogg Vorbis, Opus
Proprietary: MP3, AAC, WMA, DTS [Found on DVD-Audio], AC3 [Found on DVD-Audio], ATRAC [SONY format with support in the ffmpeg library used on minidisks and the Sony store].
M4A, MKV, MKA
Edit: 26 August 2018 Added AIFF.
@keytotime May I suggest you try these formats before commenting? A lot in fact just work. BD Pure Audio e.g. works just fine as an example since BD Menu support was included. Some proprietary formats like ALAC/ATRAC are not very relevant as they should be converted to public/common formats.
I know that egreat supports some of them. I just wanted to make a list of all the formats that egreat should support. You ask why egreat should support proprietary formats? The simple answer is that they are popular ones. ATRAC is the encoding on used on minidiscs and the Sony store. Also, supporting ATRAC will also give egreat a feature that the Dune HD does not. Furthermore, ATRAC is a lossy format so it can't be converted without quality loss. ALAC is used on the iTunes store. The more extensive answer is that I believe that there is a market for a high quality hard disk based music player. The Sony hap-z1es is a 1tb HDD media player that sells for $2,000 USD. Egreat can compete with that if it supports all the formats. Yes, the hap-z1es has an inbuilt DAC but most people don't need that. I know quite a few people who want a hi-fi component in the AV system that they can use to play music that isn't their PC. If egreat supports all the major formats that it can tap into quite a profitable market.
Properly supporting formats is the first step. The next and probably the important part from the user side is designing a good interface/library system. I intend to post about that later.
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