How to convert to 2 channel DTS file 1536kbps?

[nick1977]

Hi all

I won't go into massive detail as to why I need this (unless I need to!) but basically, I need to create a 2 channel stereo DTS file from a stereo wav.
I have used eac3to and even tried the -downstereo command (not that I should need it) but the output dts always shows as 3/2 channel.
Now I know it's pretty much definitely only 2 channel but I need the file header to read correctly so I can join it to an existing audio file (in an mkv) which is stereo 2 channel DTS 1536kbps.

Any ideas how I can do this, ideally with a command line in eac3to, or alternatively some other way of converting (or editing the header if that is the sole issue).

Any help greatfully appreciated!

Nick

[El Heggunte]

eac3to uses Surcode DTS Encoder, which is a VERY limited and outdated application.
Its goal was create compliant DCA streams for DVD-Video.
Which means, it will always output multichannel streams, even if they contain 1, 2, 3, 4 or 5 silent channels,
and even though the DVD-Video specs do allow true stereo (2.0) DTS, encoded at lower bitrates (377.25kbps and 503.25kbps).

Therefore, you'll have to use a more-flexible DTS compressor. The freeware choice is ffdcaenc (OR ffmpeg).
The payware choice is the Master Audio Suite.
If you choose ffdcaenc, make sure you set the correct value for the bitrate, i.e., 1509.75kbps.
1536kbps is the target bitrate, which normally is different from the ACTUAL bitrate.
Blame it on DTS Inc. themselves, who created the stupid audio format.
But if you choose the Master Audio Suite, just read the manual

NOTICE: Using DTS compression at 1509.75kbps for 2-channel audio is a waste of bitrate
1536kbps is the bitrate of uncompressed stereo @ 16 bits @ 48kHz.

[nick1977]

Many thanks for the detailed response.
I will investigate the options over the next few days.
I completely understand that dts stereo at 1536 is pretty pointless. Unfortunately the file I need to join to (from a BluRay) is in that format.
Without wanting to digress from the topic too much, what would be the best format to use when archiving these files? I want to retain as much compatibility and "quality" as possible, so was thinking to remain as is, or should I convert to aac or ac3?

Thanks

[El Heggunte]

I completely understand that dts stereo at 1536 is pretty pointless. Unfortunately the file I need to join to (from a BluRay) is in that format.
Without wanting to digress from the topic too much, what would be the best format to use when archiving these files? I want to retain as much compatibility and "quality" as possible, so was thinking to remain as is, or should I convert to aac or ac3?

If I were you, I would convert the already-existent DTS stream to uncompressed PCM, since the final filesize will be nearly the same.

[nick1977]

I completely understand that dts stereo at 1536 is pretty pointless. Unfortunately the file I need to join to (from a BluRay) is in that format.
Without wanting to digress from the topic too much, what would be the best format to use when archiving these files? I want to retain as much compatibility and "quality" as possible, so was thinking to remain as is, or should I convert to aac or ac3?

If I were you, I would convert the already-existent DTS stream to uncompressed PCM, since the final filesize will be nearly the same.

Hmmm OK thanks for the suggestion. Could I ask what tee benefit of that would be? Better compatibility with players maybe?
I was considering an option of something like a high bitrate ac3 or aac (something like 640kbps) as the material doesn't have much dynamic range and the quantity I'm doing (around 90x 45 minute episodes) means I'll gain some hdd space.
Is there any bitrate that either format is considered to be virtually indistinguishable from the source?

Nick

[netmask56]

Uncompressed PCM is the best IMO - why compress when you don't need to from a file size point of view. Check on other forums for opinions as well. For example a comment from High Definition Forum

Technically PCM is the superior format since it's uncompressed and in the case of The Fifth Element it basically is the studio master slapped on the BD. The TrueHD on this disc matches the 16-bit PCM track, but it's in a 20-bit stream. But, either way, they're sourced from the same master so in the end they're theoretically sonically identical.

[nick1977]

Used ffdaenc and it works fine, many thanks

Nick