Dts to AC3 help

[messi magician]

I've just ripped a few blu rays and i've noticed on playing back the films using Arcsoft Total Media that the AC3 tracks show odd kbps when viewing the information. for example, The Hunger Games says DOLBY_AC3 31kbps

When i rip my movies using clown bd i always select AC3 640kbps, when i check the file with mediainfo, it shows the track as English 48.0 KHz, 16bits, 6 channels, AC-3 which is correct

I just wondered if anyone knew why some films have these strange kbps showing in Arcsoft when playing the film and some just show DOLBY_AC3

I've also tried extracting the core from the dts-hd master and converting to ac3 but it still doesn't make any difference

[Baldrick]

But does it sound okey?
Have you checked the videofile with mediainfo?

It could just be arcsoft total media that reports wrong.

[messi magician]

Well it seems to sound alright through the TV and laptop, I just don't have a surround sound system to check if all the channels sound okay.

Mediainfo says the audio is 640kbps when checking the film and also the blu ray player reports the same when viewing the information.

I just don't understand why it only happens on certain films, I've read that some films have weird audio channels like 7.1 and 6.1 which is screwing eac3to over when it comes to encoding, I'm using the arcsoft decoder at the minute

[fritzi93]

Yeah, eac3to will remix extra channels, and will use the Arcsoft DTS decoder if it's available. I think Baldrick gave you your answer.

[yoda313]

Not necessarily. I don't own that movie to test but by chance were you looking at a commentary track?

I don't know how low studio produced commentary tracks go on bluray discs these days. However for just an audio discussion of how a movie was made there is no need to go very high on a track like that.

Though 31kpbs does seem quite a bit anemic for a studio produced disc. I could see 128kpbs or even 64kpbs for a dialogue only/stereo only commentary track.

I guess my main point is that it could be really low just not that low if its a commentary track.

[messi magician]

No the audio tracks i rip are the main film tracks (DTS-HD Master), i dont rip any other audio tracks, its not just Hunger Games ive noticed it on, this has happend on films such as Ted which said it was 156kbps and Saw The final chapter. I dont know how many more films have these odd kbps showing in Arcsoft TM until i remux some more of my mkv movies

Iv'e checked the films with Medainfo and they all say they are encoded to 640kbps


Strange enough i just ripped The Grey blu ray which as DTS-HD 5.1, When i ripped the core with eac3to it said it was patching the audio from 16bit to 24bit. Since i convert all my films audio to AC3 would this cause more loss having to encode back to 16bit ?
Should i just rip the DTS-HD instead of the core so it doesn't get patched and then convert to AC3 ?

[hello_hello]

Strange enough i just ripped The Grey blu ray which as DTS-HD 5.1, When i ripped the core with eac3to it said it was patching the audio from 16bit to 24bit. Since i convert all my films audio to AC3 would this cause more loss having to encode back to 16bit ?

I don't use eac3to much but if it was patching the audio from 16bit to 24 bit (and to be honest I'm not really sure I know what that means) then I'd assume you're extracting to a lossless format first such as wave?

It's just that lossy formats don't have a bitdepth as such.... they just compress the audio the way they compress it..... so in theory if you're converting from one lossy format to another it's probably better to convert "directly". In theory, if you convert to a lossless format format first then you're likely to introduce more "inaccuracies", although the greater the bit depth the less of a problem it'll be, but that's why dithering is often applied when converting from a lossy format to a lossless one, or when converting from one bit depth to another. http://en.wikipedia.org/wiki/Dither
Mind you, you'd probably need magic ears to hear differences.

So anyway, you're not converting back to 16bit by converting to AC3 as it's lossy and has no bitdepth as such, however you'll probably need to wait for an eac3to expert to find out what patching the audio from 16bit to 24 bit might mean in eac3to-land.

[Island_Dweller]

If you're using Eac3to, why do you extract the core and then transcode the core to ac3 640? Why not convert the DTS-HD directly to ac3? Unless I'm missing something here, extracting the core is unnecessary here and your final ac3 will be of lesser quality.