[Libav-user] AC3 -> LPCM -> MPEG2 PES

Pavel Sokolov pavel at sokolov.me
Tue Feb 28 10:48:42 CET 2012


28.02.2012 13:12, Pavel Sokolov пишет:
> 27.02.2012 22:11, Andrey Utkin пишет:
>> 2012/2/27 Pavel Sokolov<pavel at sokolov.me>:
>>> How I can convert this data to LPCM?
>> Isn't _that_ called LPCM?
>>
> My hardware decoder in the embedded device can play sound in the 
> LpcmDvd, LpcmHdDvd or LpcmBluRay formats.
>
> I have found function "pcm_bluray_parse_header" in file "pcm-mpeg.c"
> Comment on this function is "Parse the header of a LPCM frame read 
> from a MPEG-TS stream"
> So, I think, that LPCM must have some specific header...
>
I found LPCM header format, but I'm not sure, that it is correct: 
http://lists.mplayerhq.hu/pipermail/mplayer-dvb/2001-December/000224.html

    id                                                     8 bit
    number of frames                                       8 bit
    first acces unit pointer, i.e. start of audio frame   16 bit
    audio emphasis on-off                                  1 bit
    audio mute on-off                                      1 bit
    reserved                                               1 bit
    audio frame number                                     5 bit
    quantization word length                               2 bit
    audio sampling frequency (48khz = 0, 96khz = 1)        2 bit
    reserved                                               1 bit
    number of audio channels - 1 (e.g. stereo = 1)         3 bit
    dynamic range control (0x80 if off)                    8 bit


-- 

With best regards, Pavel A. Sokolov
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skype: pavel_a_sokolov



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