[vlc] Re: AAC and TS transport stream playback problem

[psme]

Wow! Thanks for all the help!

First of all, vlc DOES decode AAC!

I tried demux the TS into .m2v and .aac using TSDemux
http://arbor.ee.ntu.edu.tw/~jackei/projectbsd/TSDemux018.zip and play the
.aac in vlc. vlc decodes the AAC audio correctly (with some minor issue, see
below) and sounds good.

So it's a simple issue to locate the correct PID for the AAC track in the
TS.

There are around 8 channels on the Japanese BS HDTV system. I have a table
with what video/audio PID each channel uses.

channel/videoPID/audioPID
NHK BS1/0x0100/0x0110
NHK BS2/0x0200/0x0210
NHK BShi/0x0100/0x0110
BS day call/0x0140/0x0141
BS morning sun/0x0140/0x0141
BS-i/0x0111/0x0112
BS Japan/0x0140/0x0141
BS FUJI/0x0111/0x0112
WOWOW/0x0140/0x0141

I'll try to upload a 10secs sample for each station. Since it's a HDTV
baordcast at around 22Mbps, each file will be around 25MB. I hope that's ok
for the vlc ftp server.

The AAC decoding issue I mentioned above is due to AAC multi-channel. For
the most ususal AAC2.0, I think vlc decodes the sound perfectly fine. But
there is also AAC 3/1.0 and AAC 3/2.1 (5.1).

For these multiple channel AAC tracks, if I use aacDECdrop from
http://rarewares.hydrogenaudio.org/aac.html to decode into a WAV file and
load the WAV file in a WAV editor, I see the CENTER channel is listed as the
first channel, followed by LEFT, RIGHT, LEFT REAR, RIGHT REAR (or just a
single REAR channel in AAC 3/1 format) then finally the LFE channel.

When I play those AAC 3/1.0 format in vlc, the LEFT channel has the vocal
only. It seems vlc takes the LEFT channel as the first channel which in fact
is the CENTER.

Or maybe it's a demux problem in TSDemux, though I doubt it.

Anyway, you should find out with the sample. I will upload some sample with
AAC2.0, AAC3/1.0 and AAC3/2.1.

Finally, AC3 audio has a option to pass-through the bitstream (SPDIF mode)
for external decoding. It would be nice if such option can be also avaible
for AAC. Though I don't have a external AAC decoder yet but I may have one
in the future.

Ok, now go get each sample and upload! It may take a day or 2.

Thanks, a BIG thanks! :)

regards,

Li On

>  VLC should support it but I have never tested because I haven't any
sample
> and I have failed to find one.
>
>  So, please provide some samples. You could upload them at
> ftp://ftp.videolan.org/incomming
>
>  I will look at it and will try to provide support for the next release.
>
> -- 
> fenrir
>
> -- 
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