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HD Audio: to FLAC or not to FLAC

5K views 46 replies 21 participants last post by  T-Bone 
#1 ·
Using Another Eac3to GUI-Plus I am able to convert my Blu-Ray ISOs to MKVs. The option I select for audio is to extract HD-Audio and core tracks. My ATI 5XXX picks up those audio streams, performs the decoding, and everything is gravy.


My question is Does it make sense for me to convert the HD Audio to FLAC as I convert the ISOs to MKVs? I understand that the conversion will be lossless, but how do I verify that my HD Audio has indeed been converted into lossless FLAC? Also, is there an advantage to having the audio as FLAC in the MKV container vs. the regular HD-Audio streams?


Thanks in advance!
 
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#3 ·

Quote:
Originally Posted by harmann /forum/post/18732868


As far as I know, there's no free decoder for DTS-MA yet, only Dolby TrueHD. So if you want to play DTS-MA on PC you have to convert to flac. That's what I do anyway.

What free decoder do you use to convert your DTSHDMA tracks? Last time I looked (a bit ago admittedly) there were no free codecs for ocnverting DTSHDMA losslessly.


-Suntan
 
#4 ·
This post confuses me a bit... wouldn't it be better to just leave the HD audio untouched and have it bitstreamed to your receiver to decode, which negates the need to convert anything and gives you 100% untouched HD audio? I extract the HD audio untouched in my MKV files and they play through mediaportal bitstreamed to my receiver and I get the blue DTS-MA/TrueHD light and everything.
 
#5 ·
I don`t understand too. What do you mean by "the 5xxx series card performs the decoding" ? The 5xxx series cards perform no decoding, they bitstream audio to your receiver which does the decoding.


What receiver do you have?
 
#6 ·
ArcSoft Audio Decoder (from the trial version of TMT; a kind of free) decodes DTS-HD with full resolution. That's the method suggested in BLU - RAY/HD-DVD to mkv .....the options are endless!!!!


Converting to FLAC vs keeping the original HD audio format is just a matter of taste. Those who own a HD 5xxx/Clarkdale and a HDMI 1.3 receiver perhaps prefer the latter...
 
#7 ·

Quote:
Originally Posted by renethx /forum/post/18733938



Converting to FLAC vs keeping the original HD audio format is just a matter of taste. Those who own a HD 5xxx/Clarkdale and a HDMI 1.3 receiver perhaps prefer the latter...

Question, with the 5xxx do you still need TMT or PDVD or can you bitstream natively out of Media Center.


I use FLAC simply because I refuse to use either TMT or PDVD, and it's the only way I can get lossless audio. Currently I just use the on board audio on my G45 MB (which I know won't bitstream)
 
#8 ·
ffdshow is used for bitstreaming from mkv files, if that`s what you mean.
 
#9 ·
Yup.


1. Ripping BD movies into MKV with the original video/audio format intact.

2. Playing MKV with HD 5xxx/Clarkdale, an appropriate video decoder (such as MPC Video Decoder) and ffdshow Audio Decoder (thus TrueHD/DTS-HD are bitstreamed to an AVR)


is a preferred method of many people in this forum. The player is immaterial; you can use any customizable DirectShow media player including the 7MC internal player. (But for various reasons, people often prefer MPC HomeCinema [can be launched as an external player from inside 7MC].)
 
#10 ·
My apologies, I was not very clear. The ATI 5XXX does not do any decoding it just bitstreams the untouched HD Audio to my receiver, which does the decoding. The methodology I follow is precisely as Renethx stated.


I am just wondering if there is some kind of advantage for me to convert the HD Audio to FLAC. I plan to keep my Blu-Ray rips indefinitely, and would hate to re-rip movies down the line because something is not compatible with HD Audio. As an example, lets say I wanted to stream the movies to an iPad (don't have this yet) can I do it with MKVs with HD Audio? What about extenders, do they work with MKVs with HD Audio?


Thanks!


Quote:
Originally Posted by renethx /forum/post/18734016


Yup.


1. Ripping BD movies into MKV with the original video/audio format intact.

2. Playing MKV with HD 5xxx/Clarkdale, an appropriate video decoder (such as MPC Video Decoder) and ffdshow Audio Decoder (thus TrueHD/DTS-HD are bitstreamed to an AVR)


is a preferred method of many people in this forum. The player is immaterial; you can use any customizable DirectShow media player including the 7MC internal player. (But for various reasons, people often prefer MPC HomeCinema [can be launched as an external player from inside 7MC].)
 
#11 ·
The Ipad doesn`t support H.264 High Profile nor 1080p resolutions nor FLAC or DTS-HD MA or True HD. You have to re-encode the entire movie (both audio and video) to do that. Or buy a netbook with a ION GPU .
 
#13 ·

Quote:
Originally Posted by jrwalte /forum/post/18734401


I'm also curious about HD audio and extenders. Has anyone tried this to see if the transcoding extracts the core DD/DTS from the HD audio or does the transcoding software not recognize HD audio?

Depends what you mean by Extender. My Popcorn Hour C200 happily bitstreams DTS HD and True HD over HDMI to my amp for it to decode - though this is from BD ISOs. AIUI they are producing new firmware from a new Sigma SDK to cope with HD audio in other situations (MKV etc.)
 
#15 ·

Quote:
Originally Posted by aprikh1 /forum/post/18734336


...


I am just wondering if there is some kind of advantage for me to convert the HD Audio to FLAC. ...


Thanks!

Basically just a little more compatibility at the expense of more work and more storage space.


So, for example, if you want to go over a buddies house and he doesn't have bitstreaming capabilities you at least have a chance of getting flac decoding working.


Or if you buy new hardware and end up not being able to get the bitstreaming working (like a bunch of people around here) then you're not screwed.


But in both those cases there's not a big incentive to transcode everything right now since you can always wait until you actually need it.


I have heard of some people who transcode everything to FLAC so that everything is the same so that they don't have to constantly tweek settings when switching from one format to the other (this can also improve the WAF since it means fewer variables that can trip up the casual user).
 
#16 ·
Please enlighted us what settings i/we should be "tweaking" when switching from one one format to another....
 
#17 ·
Well, I spent this afternoon listening to Star Trek 2009 with FLAC and with HD Audio. Both of the rips were in MKV format played back by MPC HC. The HD Audio MKV seemed more lifelike and a tad bit louder. I know that FLAC is supposed to be lossless, so I am not sure why HD Audio sounded better. It could be just my perception.


When I look at my eac3to log I see this


eac3to v3.17

command line: "C:\\eac3to\\eac3to.exe" 1) -log="C:\\Program Files (x86)\\ACD\\Another EAC3to GUI\\log.txt"

------------------------------------------------------------------------------

M2TS, 1 video track, 4 audio tracks, 7 subtitle tracks, 2:06:50, 24p /1.001

1: Chapters, 15 chapters

2: h264/AVC, 1080p24 /1.001 (16:9)

3: TrueHD/AC3, English, 5.1 channels, 48khz, dialnorm: -27dB

(embedded: AC3, 5.1 channels, 640kbps, 48khz, dialnorm: -27dB)

4: AC3, French, 5.1 channels, 640kbps, 48khz, dialnorm: -27dB

5: AC3, Spanish, 5.1 channels, 640kbps, 48khz, dialnorm: -27dB

6: AC3, English, 2.0 channels, 224kbps, 48khz, dialnorm: -27dB

7: Subtitle (PGS), English

8: Subtitle (PGS), English

9: Subtitle (PGS), French

10: Subtitle (PGS), Spanish

11: Subtitle (PGS), Portuguese

12: Subtitle (PGS), French

13: Subtitle (PGS), Spanish



So which audio stream was encoded into FLAC? TrueHD or AC3? How do I know?
 
#19 ·

Quote:
Originally Posted by aprikh1 /forum/post/18735252


Well, I spent this afternoon listening to Star Trek 2009 with FLAC and with HD Audio. Both of the rips were in MKV format played back by MPC HC. The HD Audio MKV seemed more lifelike and a tad bit louder. I know that FLAC is supposed to be lossless, so I am not sure why HD Audio sounded better. It could be just my perception.

Have you tried WASAPI exclusive mode to play FLAC? Otherwise you won't get sounds faithful to the original. (Another advantage of bitstreaming.)
 
#20 ·
In my view, there are three advantages to using FLAC:


- Hardware compatibility: No HD audio bitstreaming capable hardware required. This problem will go away over time, but right now it's limiting hardware choices somewhat.

- Software compatibility: Last I checked the available non-commercial solution (ffdshow) and also the drivers were still a bit immature and had issues like incorrect EDID readout etc. Might be better now though.

- Space: FLAC encodings are usually significantly smaller than DTS-HD MA due to better coding efficiency. On a 2hr feature film, it often saves a GB or more. This is not so much the case for TrueHD though.


But if you are sure that your software and hardware is compatible, keeping the original encodings should be fine too.
 
#21 ·
Since all the HTPCs in my house are bitstream capable I just stick with the original HD Audio track as I see no need for FLAC. Any media players that don't support HD Audio can at least downmix it to stereo (and some of those players don't support multi channel FLAC), so the original HD Audio tracks works best for me. Really nothing more then a matter of preference. Bitstreaming HD Audio (FFDShow + MPC HC) has been very stable for me on both the core i5 and ATI 5670 and seems to be getting better support amongst various front ends (I have bitstreaming working with XBMC and almost there with SageTV). And of course there are some of us that just like to see the HD Audio lights light up on the AVR



I can't recall off the top of my head, but is Reclock only for x32 systems?
 
#22 ·

Quote:
Originally Posted by sneals2000 /forum/post/18734520


Depends what you mean by Extender. My Popcorn Hour C200 happily bitstreams DTS HD and True HD over HDMI to my amp for it to decode - though this is from BD ISOs. AIUI they are producing new firmware from a new Sigma SDK to cope with HD audio in other situations (MKV etc.)

Correct, the latest beta FW for the C200 allows for bitstreaming of HD audio from standalone mkv/m2ts:

http://www.mediasmartserver.net/2010...beta-firmware/
 
#23 ·
On the topic of MPC-HC and FFDShow working with bitstreaming, does anyone have a link to a guide of setting this up and how to properly extract the HD audio into a MKV? I've been having a hard time finding it, as most searches result in threads with 100s of posts.
 
#24 ·

Quote:
Originally Posted by jrwalte /forum/post/18738645


On the topic of MPC-HC and FFDShow working with bitstreaming, does anyone have a link to a guide of setting this up and how to properly extract the HD audio into a MKV? I've been having a hard time finding it, as most searches result in threads with 100s of posts.

Here is my guide on setting up MPC + FFDSHow:

http://www.mediasmartserver.net/2010...7-htpc-part-i/


Here are some of my guides on mkv creation:

http://www.mediasmartserver.net/tag/mkv/


Another EAC3To GUI is probably the easiest method or some version of EAC3To (like Clown_BD) + MKVMerge
 
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