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View Full Version : Encoding DTS MA to FLAC to Save Space


StormMeows
15th July 2021, 18:53
Hey guys,

I typically want to keep the full lossless audio because we have really expensive home theater equipment. If I mux down the DTS-MA track to FLAC, is it going to be lesser quality? I see a lot of people do it for DTS MA 2.0 and DTS MA 1.0, along with PCM > FLAC as well. I just want to ensure I won't be losing any quality because a lot of times it appears that it is being muxed down to FLAC 16 bit, not 24 bit like the blu-ray source.

Thank you guys!

Boulder
15th July 2021, 20:18
It's lossless so there's no quality loss. The decoder sometimes notices that the original track does not contain 24-bit data so it will discard the padding (zeroes).

StormMeows
15th July 2021, 21:14
It's lossless so there's no quality loss. The decoder sometimes notices that the original track does not contain 24-bit data so it will discard the padding (zeroes).

Thank you so much Boulder. It seems like at least for DTS MA 2.0, DTS MA 1.0, and any PCM, FLAC conversion is the way to go so I can save some extra space and still have lossless audio. :) Agree? Thanks

Boulder
16th July 2021, 08:39
FLAC is more efficient than DTS-HD MA or TrueHD so you'll save space a bit that way. I have a habit of reducing bitdepth to 16 bits since I cannot tell a difference between the two.

SeeMoreDigital
16th July 2021, 10:30
If I mux down the DTS-MA track to FLAC, is it going to be lesser quality? I see a lot of people do it for DTS MA 2.0 and DTS MA 1.0, along with PCM > FLAC as well.I've converted a few Blu-ray audio discs encoded with 2 and 5.1-channel DTS-HD MA and Dolby TrueHD audio bit-streams to Flac. And when compared to the original, some offer much smaller file sizes than others.

When you say you have "really expensive home theater equipment", what device are you using to play these Flac files? During playback, Flac audio streams are transcoded to PCM and might be output a different audio level than the bit-streamed original.


Cheers

jpsdr
16th July 2021, 18:26
It's just that DTSHD and TrueHD can be send in pathrough via HDMI to audio receiver (for it to decode) if you have home theater equipment, leaving only the video to decode to the player, but FLAC can't.

microchip8
16th July 2021, 18:49
It's just that DTSHD and TrueHD can be send in pathrough via HDMI to audio receiver (for it to decode) if you have home theater equipment, leaving only the video to decode to the player, but FLAC can't.

If the AVR converts FLAC to PCM, it doesn't matter. Sound quality is the same since PCM is lossless too

jpsdr
18th July 2021, 10:00
Yes, the player can decode and send to PCM, but it's also true for DTSHD or TrueHD. One interest of sending audio HDMI pathrough it's to avoid the player to decode, and leave the video only to it to decode, to (eventualy) reduce the load/charge/CPU of the player. It's just that with FLAC, you can't.

SeeMoreDigital
18th July 2021, 10:23
Until it's been confirmed what gear the OP is using, it's pointless making any suggestions!

We don't even know if the OP is intending to play 'audio only' content or 'audio/video' content...

StormMeows
18th July 2021, 17:15
Until it's been confirmed what gear the OP is using, it's pointless making any suggestions!

We don't even know if the OP is intending to play 'audio only' content or 'audio/video' content...

Hey sorry for the late response. My "high end" home theater consists of a Marrantz processor, connected to amps and speakers. I use this room to watch blu-ray movies (audio and video). From what it sounds like, it is easier for my supported DTS-MA receiver to decode the audio versus doing the FLAC > PCM conversion through it?

Thank you guys!! You have been very helpful!! I just want to make sure I don't convert all of my audio to FLAC and create more headaches. Also, I set my Oppo Player to Bitstream the audio so I get the full lossless benefits.

StormMeows
20th July 2021, 20:21
Am I good to convert the PCM tracks found on blu-rays to FLAC and also, what about the DTS-MA 2.0? Since I have a high end home theater, I don't to lose quality, but if I can save space, that would be great as well. Let me know please. Thanks guys!

SeeMoreDigital
20th July 2021, 20:31
Am I good to convert the PCM tracks found on blu-rays to FLAC and also, what about the DTS-MA 2.0? Since I have a high end home theater, I don't to lose quality, but if I can save space, that would be great as well. Let me know please. Thanks guys!So ultimately... Is it your intension to back-up your Blu-ray discs to say, .mkv files and store them on HDD's?

StormMeows
20th July 2021, 22:58
So ultimately... Is it your intension to back-up your Blu-ray discs to say, .mkv files and store them on HDD's?

That's right. We are mainly doing this so we can watch them digitally. We aren't too fond of the quality, especially the audio on streaming services. So if it is available on blu-ray, we prefer to have the good audio and video. So far what I am doing is converting LPCM to FLAC and leaving the True HD, ATMOS, and DTS-MA all untouched. Please let me know if that sounds feasible or if I should also be doing stuff like DTS-MA 1.0/2.0. I know I want to leave the DTS MA 5.1/7.1/ATMOS all untouched, but just trying to figure out the rest. Thanks

jpsdr
21st July 2021, 17:25
For me, your first intend is good : leave THD & DTSHD untouched, and convert PCM to FLAC to reduce size.

StormMeows
22nd July 2021, 03:13
For me, your first intend is good : leave THD & DTSHD untouched, and convert PCM to FLAC to reduce size.

Thank you, this seems like a solid way to go then! I'll leave all of the True HD & DTS-MA untouched and just convert PCM to FLAC :D Thanks!

SeeMoreDigital
23rd July 2021, 17:40
I don't remember having any Blu-ray movie disc's encoded with 1-channel or 2-channel Dolby TrueHD or DTS-HD MA audio. But I think I'd be inclined to encode such audio bit-streams to Flac too...

Personally, I keep all of the disc's multi-channel audio streams in their original format.

jpsdr
23rd July 2021, 17:59
For sending audio pathrought HDMI/SPIF to audio receiver, TrueHD or DTS-HDMA, no FLAC. So if audio is already TrueHD or DTS-HDMA, for this case, better to untouch it. I think i have seen 2 channels DTS-HDMA Discs, on old movies where the audio from was kept as when film was released, and no intend to "update" the original audio to 5.1 (or more).
Now, if you don't use an audio receiver and don't intend to send audio pathrougth HDMI/SPIF, converting to FLAC may reduce a little the size, it would be (eventualy) the only benefit.

tebasuna51
24th July 2021, 00:07
Just for clarify

1) By SPDIF (optical or coaxial) we can send AC3 (or the embebed AC3 from TrueHD BD's tracks), EAC3, DTS (standard or the 'core' from DTS-HD) or PCM 2.0 (from any format decoded by the player, maybe FLAC).
Can't be send TrueHD, DTS-HD, FLAC or any other format.

2) By HDMI can be send TrueHD, DTS-HD, AC3, EAC3, DTS or PCM 7.1.
A PC with free players (VLC, MPC-HC, etc.) and many standalone players can decode many formats (FLAC, AAC, OPUS, ...) and send PCM by HDMI without limits.

Each user must know the limits of their chain player and select the desired format.
Also without high quality AVR, speakers and ears a lossy format can be selected without change in perceived quality.

For instance my AVR support all formats and connected by HDMI to my PC I can use any format, but if I want use the TV player connected by SPDIF to the same AVR there are limits:
TrueHD, DTS-HD, DTS and FLAC unsupported at all, AC3 and EAC3 passed by SPDIF to AVR, even AAC 5.1 is recoded on the fly to AC3.
If I want use always my TV player only the best option is recode all to EAC3.

I see old movies with DTS-MA 2.0 with the same bitrate than uncompressed PCM 2.0 and does not make sense.
An AAC/EAC3 with high bitrate sound the same.

SeeMoreDigital
24th July 2021, 10:08
Just for clarify

1) By SPDIF (optical or coaxial) we can send AC3 (or the embebed AC3 from TrueHD BD's tracks), EAC3, DTS (standard or the 'core' from DTS-HD) or PCM 2.0 (from any format decoded by the player, maybe FLAC).
Can't be send TrueHD, DTS-HD, FLAC or any other format.

I can confirm that all my hardware SoC playback devices are able to play 2-channel Flac audio. And are also able to transcode it to 2-channel PCM and pass it via SPDIF (and HDMI).

That being said, my 2016 LG televisions are only able to play 2-channel Flac when encoded at 48.00KHz/16-bit max and muxed with video and placed within the .mkv container.... They can't play elementary Flac audio streams :(