Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Oliverlim]

I have configured jriver to export the various file formats to AAC while exporting to my ipod classic. But for some reasons, DSD file are converted to AAC in a "bitrate"? that results in a music file playing very slowly on my ipod. Like 5 times slower then normal speed.  I am not sure what I am doing wrong but I do not see anything on the options to tell jriver to convert DSD to any format that will work on my ipod. What am I doing wrongly?

[ferday]

question:   do you mean ALAC or AAC with an external encoder? 

i tested with a .dsf and a .dff file to ALAC and mp3

both converted fine with normal bitrates and play ok on my classic.  i don't have an AAC encoder (other than the MC video AAC encoder which i haven't monkeyed with), perhaps it's an external encoder issue?

[Oliverlim]

question:   do you mean ALAC or AAC with an external encoder? 

i tested with a .dsf and a .dff file to ALAC and mp3

both converted fine with normal bitrates and play ok on my classic.  i don't have an AAC encoder (other than the MC video AAC encoder which i haven't monkeyed with), perhaps it's an external encoder issue?

I was using the recommended external AAC encoder.  I used it as it sounds pretty good or similar to 320kbps and smaller in size at 256kbps aac.  So I might need to encode .dsf and .dff files to mp3 instead. Is there a logic build into MC21 to use different encoders depending on the file type?

[glynor]

I'm wildly guessing here, but I'd bet you a beer I'm in the ballpark...

When MC converts a file using an internal encoder, it goes through the normal audio engine to the encoder, because MC knows exactly what formats it can handle and not handle.

When you convert with an external encoder, I bet it works similarly to bitstreaming: if the external encoder can handle the input (or maybe just "if it is already PCM") then it passes it through directly. Since DSD encoded data is packed in a PCM stream, and the encoder can take PCM, it passes it through. So, for this to work, the external encoder would need to be able to handle DSD input.

When MC actually bitstreams DSD, it has to look at the data inside the PCM stream and decide on the fly if it is DSD formatted or PCM audio. I'm thinking it doesn't do this detection here, so it shunts the PCM through (as it would with a WAV file or whatever).

Assuming this was done on purpose, it certainly doesn't help you in this case, but I can see how that would be a good "rule of thumb" for external encoders. Perhaps some user's entire point for using the external encoder is that it can handle a formatting that MC cannot, or something?

But I have no idea if this is on purpose. Might just be an oversight. 

[RD James]

I bet it's simpler than that.
It probably converts to a sample rate (not bitrate) which is too high for the iPod, and the iPod simply plays it back at the highest rate that it can handle.
So if it was exported at 352.8kHz (default rate for DSD to PCM conversion) and the iPod only supports 44.1kHz, it would be played at 1/8 speed.
 
I think you're confusing DSD and DoP, Glynor.
DSD is only packed in a PCM container with DoP. SACD/DSF/DFF all store native DSD data.
DoP shouldn't be used to store DSD in a file, only for playback, though I know that some people do convert DSD files to DoP for some reason.

[blgentry]

RD James is probably correct.  I've done a few experiments, but they weren't definitive.

You probably want to tell JRiver to convert to 44.1kHz first before encoding.  Luckily, this is easy to do.  On the convert dialog:

Options > Audio > Apply DSP Settings > (checked)
then:  DSP Settings....

Output format > (checked)
Output format > Sample Rate > 352,800 Hz > (44,100 Hz)

Try it with a file or two and see how it works.

Brian.

[glynor]

Good call, rd. That's certainly it (and, yes, I was confusing DoP).

[Oliverlim]

RD James is probably correct.  I've done a few experiments, but they weren't definitive.

You probably want to tell JRiver to convert to 44.1kHz first before encoding.  Luckily, this is easy to do.  On the convert dialog:

Options > Audio > Apply DSP Settings > (checked)
then:  DSP Settings....

Output format > (checked)
Output format > Sample Rate > 352,800 Hz > (44,100 Hz)

Try it with a file or two and see how it works.

Brian.

I did some further testing and I defintely have all above 44khz options output format changed to 44k as well.  This works well on flac high res files at 24/196 which plays well on my ipod. Only the dsd files ends up with this "super slow wrong speed" playback.  However, if I do use the internal AAC option, it plays back well on my ipod. Still not able to understand the reason why.

[blgentry]

Note I'm talking about the DSP setting that are INSIDE of the convert tool.  NOT the standard DSP settings.

It's also unclear what converter you are using.  You've said both internal and external and AAC and ALAC.

Brian.

[Oliverlim]

Note I'm talking about the DSP setting that are INSIDE of the convert tool.  NOT the standard DSP settings.

It's also unclear what converter you are using.  You've said both internal and external and AAC and ALAC.

Brian.

I did not know there was a seperate convert tool option. I see it in the tools, convert, is that the one you are referring to?  I do not use it that way. I usually just select the files and then right click and use the send to option to send to ipod that is connected.

I am using qaac.exe to convert my files into aac to transfer to my ipod.  Namely 256k aac

[RD James]

Do the files play correctly in JRiver?
I set up some test conversions and it seems that QAAC automatically converts DSD files to a 48kHz sample rate even if you don't use the --rate 44100 command, or you can set up JRiver to convert to 44.1kHz in the DSP options for the handheld device.
All the files play at the correct speed in JRiver for me. I don't have an iPod to test.

[blgentry]

I did not know there was a seperate convert tool option. I see it in the tools, convert, is that the one you are referring to? 

That's the one!

I do not use it that way. I usually just select the files and then right click and use the send to option to send to ipod that is connected.

I don't have any experience with that.  Is there a DSP option in the "send to ipod" function?

You might try doing a conversion using the Convert Audio tool explicitly, using it's DSP, and then syncning the resulting files to your ipod.  As a test.

Brian.

[Mark_Chat]

I did some further testing and I defintely have all above 44khz options output format changed to 44k as well.  This works well on flac high res files at 24/196 which plays well on my ipod. Only the dsd files ends up with this "super slow wrong speed" playback.  However, if I do use the internal AAC option, it plays back well on my ipod. Still not able to understand the reason why.

I would't think using 44.1kHz for everything is best practice, unless space is really a premium over quality.

Use 44.1kHz for 44.1, 88.2, 176.4, 352.8kHz files (including DSD)

Use 48kHz for 48, 96, 192, 383kHz files

The iPods and just about any DAP will play 44.1 and 48kHz seamlessly (maybe a faint click as the clock realligns on changing from one to the other)