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Old 11th May 2010, 17:33   #9981  |  Link
Midzuki
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Quote:
Originally Posted by Moondust View Post
I have the same problem with crackling sound when converting a DTS-HD 7.1 file into a FLAC 7.1 file using the Arcsoft decoder. Only 7.1 goes wrong, 5.1 works like a charm.
To me, it seems a problem in the ArcSoft DTS decoder.
I have tested DtsDec.dll 1.0.2.2 + DTSdecoderDLL.dll 1.1.0.0, and these do NOT decode stereo DTSHD Master Audio correctly (not on my computer, at least).

Last edited by Midzuki; 11th May 2010 at 17:35. Reason: typo
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Old 11th May 2010, 21:54   #9982  |  Link
Abradoks
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Originally Posted by ~Revolution~ View Post
Is there an updated version of the Libav / ffmpeg decoder that doesn't cause this problem?
You can get latest ffmpeg here.
Eac3to has too many unresolved issues to use it as decoder:
- Nero DRC bug
- DTS-HD 7.1 bug
- bug, when output is different for *.wav and *.wavs (at least with libav and ac3/dts)
- libav attenuates high frequencies of non-mono dolby-encoded ac3. Seems like a libavcodec bug because for some streams (5.1 encoded using dolby encoder) ffmpeg produces two times worse PSNR than eac3to.
- ...

Last edited by Abradoks; 12th May 2010 at 07:13.
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Old 12th May 2010, 04:05   #9983  |  Link
~Revolution~
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So anyone have a suggested solution to fix the two bugs?
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Old 12th May 2010, 22:55   #9984  |  Link
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Hey guys, I'm a little confused re DTS HD master 7.1 Blu-ray tracks.

If the player or receiver is only capable of 5.1, will it revert to the 5.1 core and you lose the advantage of lossless, or will it/they downmix the 7.1 to 5.1 and you'll still have the lossless track.

Using eac3to to decode the MA 7.1 track to wavs, will those wavs be lossless, or will they be decoded from the core ?
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Old 12th May 2010, 23:13   #9985  |  Link
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Quote:
If the player or receiver is only capable of 5.1, will it revert to the 5.1 core
yes it will play the core...all the ancient 5.1 receivers have to play something!...clever design to have backwards compatibility!

Quote:
Using eac3to to decode the MA 7.1 track to wavs, will those wavs be lossless, or will they be decoded from the core ?
if you have ArcSoft DTS decoder installed you will get 8 lossless wavs...if not then libav will be used and you get 6 core wavs...
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Old 13th May 2010, 00:55   #9986  |  Link
rapscallion
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Originally Posted by b66pak View Post
yes it will play the core...all the ancient 5.1 receivers have to play something!...clever design to have backwards compatibility!
Thanks for the response, however are you saying that a receiver capable of playing/decoding only 5.1 MA (not 7.1) will also revert to the core, if it's presented with 7.1 MA ?

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if you have ArcSoft DTS decoder installed you will get 8 lossless wavs...if not then libav will be used and you get 6 core wavs...
Well, that's good news, if the above is true. Because (yes, I have Arcsoft) I can decode to the lossless wavs and then re encode to DTS MA 5.1, using DTS MA Suite. Just ignore the 2 side channels, no need to downmix, correct ?
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Old 13th May 2010, 03:02   #9987  |  Link
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Originally Posted by rapscallion View Post
Just ignore the 2 side channels, no need to downmix, correct ?
Correct
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Old 13th May 2010, 07:57   #9988  |  Link
Snowknight26
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Any plans to add -check capabilities to MKVs?
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Old 14th May 2010, 17:15   #9989  |  Link
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For a particular HD-DVD, eac3to detects no subtitle track. Same thing when I open the main EVO files in MediaInfo.
But when I play the disc in my HD-DVD player, I have the possibility to switch between french audio / no subtitle and english audio / french subtitle.
eac3to detects only one video track, so I don't think there are two video tracks, one with subtitles and one without subtitles.
Can you explain where are (hidden) the subtitles please ?
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Old 14th May 2010, 18:19   #9990  |  Link
Thunderbolt8
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got a 5.1 dtsma track, which only has data for the 2.0 channels, the rest is empty. so instead of keeping it as 5.1 with 4 empty channels, I'd rather turn in into a 2.0 dtsma & flac track. how do I do this? 5.1 -> wavs? and then afterwards?
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Old 14th May 2010, 19:23   #9991  |  Link
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Do you know what is the current status of the libav decoder and support of spectral extension for E-AC3 audio tracks ?
If eac3to could support audio tracks from our french HD DVB-T standard, that would be really cool.
It looks like ffdshow is able to decode these tracks, and ffdshow is using libav decoder, isn't it ? So why not using this version of the libav decoder in eac3to ?
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Old 14th May 2010, 20:38   #9992  |  Link
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Quote:
Originally Posted by Laurent View Post
Do you know what is the current status of the libav decoder and support of spectral extension for E-AC3 audio tracks ?
this has been officially introduced few weeks ago in the FFmpeg trunk...
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Old 15th May 2010, 01:08   #9993  |  Link
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this has been officially introduced few weeks ago in the FFmpeg trunk...
That's a good news.
I hope it means that lots of tools, and especially eac3to, could very soon support this E-AC3 extension ?
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Old 15th May 2010, 16:07   #9994  |  Link
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Originally Posted by Abradoks View Post
- libav attenuates high frequencies of non-mono dolby-encoded ac3. Seems like a libavcodec bug because for some streams (5.1 encoded using dolby encoder) ffmpeg produces two times worse PSNR than eac3to.
I haven't ever seen anything like this reported before. Do you have a sample? And I'm assuming you mean using eac3to with Nero rather than libavcodec for AC-3 decoding...

If you do have a sample, it would be great to have the original AC-3 snippet, along with the eac3to wav or flac output.
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Old 16th May 2010, 03:47   #9995  |  Link
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I haven't ever seen anything like this reported before. Do you have a sample? And I'm assuming you mean using eac3to with Nero rather than libavcodec for AC-3 decoding...

If you do have a sample, it would be great to have the original AC-3 snippet, along with the eac3to wav or flac output.
Hi, jruggle. It's nice to see you here. I thought I should better investigate the problem before reporting it to ffmpeg, but was too lazy recently.
Here are some samples:
1) 5amctest.rar (mirror) : test.wav — mono source; test.ac3 — 2.0 ac3 produced from source (both channels are same) by Dolby encoder. Man who originally reported the problem has made this graph, where you can see attenuation in the high frequencies when using eac3to with libav. ffmpeg (SVN-r23056) has the same problem but attenuation starts on higher frequency. The funny thing is that a52dec hasn't such issue.
2) qs.7z (mirror) (14.5 MB) — two another samples and source file. 5.1, Dolby encoder. For 640.ac3 eac3to (with libav) shows 27.809 dB SNR, while ffmpeg 11.547 dB. liba52 (through foobar2000 plugin) gives 27.537 dB. When comparing average sound level graphs, it looks like eac3to and ffmpeg start to attenuate at ~16.8 kHZ. And ffmpeg is always ~2 dB quieter than eac3to. For 224.ac3 attenuation starts near 4.5 kHZ but only for eac3to. ffmpeg is just always ~2 dB quieter than source.
Also in all 3 samples ffmpeg has average sound level about -140 dB after frequency cutoff. Is it ok?
Graphs:

Last edited by Abradoks; 7th July 2010 at 12:48. Reason: links
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Old 16th May 2010, 20:05   #9996  |  Link
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Originally Posted by Abradoks View Post
Hi, jruggle. It's nice to see you here. I thought I should better investigate the problem before reporting it to ffmpeg, but was too lazy recently.
Here are some samples:
There could be a few things going on. First, with FFmpeg did you use the -drc_scale 0 option? IIRC eac3to always disables DRC. Also, eac3to uses a patch to get floating-point output from the libavcodec AC-3 decoder, while FFmpeg always converts to 16-bit.
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Old 16th May 2010, 21:15   #9997  |  Link
Abradoks
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First, with FFmpeg did you use the -drc_scale 0 option?
No, I didn't. But those tracks haven't DRC, so with -drc_scale 0 ffmpeg produces identical files.
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Old 16th May 2010, 22:17   #9998  |  Link
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No, I didn't. But those tracks haven't DRC, so with -drc_scale 0 ffmpeg produces identical files.
Ok, then there are a few things left to investigate.

1) If FFmpeg is modified to give floating-point output will the results be closer to eac3to. I think this is likely. If not, what other libavcodec patches is Madshi using?

2) The first drop is probably at the rematrixing start point for the stereo sample and at the coupling start point for the 5.1 samples. First step is to verify this. If so, that gives a good starting point for investigation.

3) See what the Nero decoder does compared to liba52 and libavcodec.

What program did you use to make the graphs? I want to use it in my comparisons as well.
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Old 18th May 2010, 20:58   #9999  |  Link
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Hi everyone,
it's been several days I went on with this issue, so I decided to ask for help here.
I've recently bought Spiderman trilogy in bluray, and I successfully extracted all the audio tracks I needed from the 3 discs (in truehd format, .thd).
When I tried to convert the .thd files to mono wavs (or flac, or single wav) with eac3to & libav, no issue at all with audio from movie 1 and 3, but I experienced some problems, with the second movie's track decoding... Libav decoding in eac3to gave the repeated "Lossless check failed" warnings, even if the encoded wav files seemed to be good (seemed because I couldn't stay there on listening the entire two hours' track...).
Unsatisfied, I tried to use Nero Audio Decoder plugin in eac3to, but, even if the plugin correctly works for ac3, e-ac3 tracks, with TrueHD streams it stops immediately, giving the error "Nero Directshow decoder didn't accept the input stream" or something similar.
Is there any way to make the Nero plugin work for truehd tracks, or should I wait for madshi to release support for Arcsoft hd audio plugin?
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Old 18th May 2010, 23:09   #10000  |  Link
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Unless you're getting thousands of those warnings, ignore them.
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