[Cin] Procedure for making LPCM DVD

Andrew Randrianasulu randrianasulu at gmail.com
Tue Jan 23 23:49:09 CET 2024

On Tue, Jan 23, 2024 at 11:58 PM Phyllis Smith <phylsmith2017 at gmail.com> wrote:
> For inclusion in the Manual based on Andrew's work is the text below.  Let me know if it needs changes.
> Note, that I did not find the following exception.  I tested audio at 8K and 80K with no problem.
>> ALSO, IMPORTANT! Audio must be 48Khz or 96Khz, nothing else is
>> supported, even by ffmpeg's dvd pcm encoder.
> DVD with LPCM audio (new small section)
> By default, the audio when creating a DVD is always AC3 (Arc Consistency Algorithm 3).
> However you can switch to PCM, Pulse Code Modulator, with just a few additional steps
> as outlined below.
> 0) Start CinGG from a terminal window so you will be able to see what is happening.
> 1) Make sure you have your video with audio loaded and edited in CinGG to your satisfaction.
> 2) Use the File pulldown and select the "DVD Render" option.
> 3) In the Create DVD window, accept the defaults or select different values and then click OK.
> 4) When the Batch Render window pops up, in the big box towards the bottom will be 2 lines
> with the first line for Video already highlighted.  Instead, click on the second line so that
> it is highlighted.
> 5) On the top left, you will see the "File Format" set as AC3.  Use the down arrow next to
> the box and change it to "Raw PCM" by clicking on it.
> 6) When you switch to Raw PCM, you see the extension in the "Output path" change to "pcm"
> instead of "ac3".  Now just reset the extension from "pcm" to "lpcm" as that is required.
> In most cases if you click on the Audio wrench to see the settings, you will find that the
> standard settings of 16 bit Linear / Hi Lo work.  If not, experiment for alternatives.
> 7) Now click on the "Start" box in the bottom left hand corner and CinGG will process what
> it can of the job and put you back at your terminal startup window.
> 8) You will see a few lines of output, some of which are shown below, and the ERROR:
> running /dev/shm//dvd_20240116-182336/dvd.sh
>    INFO: [mplex] mplex version 2.1.0 (2.2.7 $Date: 2012/11/17 01:55:16 $)
> **ERROR: [mplex] Unable to open file
> /dev/shm/dvd_20240116-182336/dvd.ac3 for reading.
> 8) Change directory to the location as shown on the terminal window of dvd.sh.
> 9) Using an editor, modify the line in dvd.sh to change "dvd.ac3" to "dvd.lpcm"
> and change the mplex parameter to include:
>  -L  48000:2:16
> The full line will look like this:
>  mplex -f 8 -L 48000:2:16 -o $dir/dvd.mpg $dir/dvd.m2v $dir/dvd.lpcm
> 10) Now the script is ready to run in the same manner it would have had it been ac3.
> That is just run via:  ./dvd.sh
> 11) Check to make sure there are no errors in the output shown on the window and proceed
> as usual.

I think it also important to remember only 48Khz/16 bit/2 ch will
relatively omfortably sit with our default video bitrate.
For anything bigger you need to lower video bitrate, as complete
stream rate fixed at max 9.8Mbit/s from memory ...

Also, how was audio level?

You also can change dvdauthor xml part as exist in dvd.sh so it says
"pcm" instead of "ac3" - mostly
cosmetical due to dvdauthor ignoring empty channel and adding our
audio as next stream (1 vs 0)

>> ALSO, IMPORTANT! Audio must be 48Khz or 96Khz, nothing else is
>> supported, even by ffmpeg's dvd pcm encoder.

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