[Cin] Procedure for making LPCM DVD

Andrew Randrianasulu randrianasulu at gmail.com
Wed Jan 31 00:34:21 CET 2024


ср, 31 янв. 2024 г., 02:19 Phyllis Smith <phylsmith2017 at gmail.com>:

> Strange but "mplex" requires an extension of "lpcm" or else you get the
> following error:
>
>> **ERROR: [mplex] File /tmp/dvd_20240130-160930/dvd.pcm unrecogniseable!
>>
> bash: **ERROR:: command not found...
>
> But, "dvdauthor" only creates the iso files if <audio format="pcm"
> lang="en"/> without the "l" on "pcm".
>

yeah, little inconsistence .....


> However, my LG connected to the TV does report the audio as "PCM" even
> when I did not change the second "ac3" in dvd.sh.
>

I think it just plays audo stream 1 instead of audio stream 0. Pay
attention to dvdauthor output in both cases.

Not a big problem as long as you do not include other streams manually :)

And it has always reported "AC3" when I just took the defaults and then
> when used Mpeg Audio of Layer II or III, it reported it as just MPEG.
>


A bit unfortunate! We hoped for more info :)

I tried encode2mpeg script, it semi-works, I needed to manually create 44.1
khz   6 ch aiff from wav extracted  by ffmpeg ... but it mux 384khz mp2
stream.

Sadly, xine/mplayer all only can decode stereo, and even wine + PowerDVD
7.0 report only stereo (powerdvd hints at absense of extension mpeg2 audio
bitstream. I found pdf describing it in more details, but still not sure
how it all framed/muxed ....)

As noticed by some old forum posts some c-cube based DVD players (ZiVA 3,
4.1, 5) had mpeg2 audio surround support, but not sure if it survived in
much newer players!

also, 44.1khz pcm audio was supported by same gen. of players, one can hope
support was not quietly axed!



> According to the web, the difference between PCM and LPCM is:
>
>> In a PCM, the amplitude of the analog signal is sampled at uniform
>> intervals. Also, every sample is quantized to the nearest value of digital
>> steps. On the other hand, in Linear pulse-code modulation (LPCM), every
>> sample is quantized uniformly and offers lossless transmission of audio
>> signals
>>
>
> OK, more testing.  You can change it to just "pcm" and that will create
>> the iso.  "lpcm" does not work and I have not determined what the "l"
>> stands for.  I will experiment using just "pcm" and fix the Manual document.
>>
>>
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