Sound again: got me much better quality

[Renaud Dartus]

On Mon, Mar 19, 2001, Gunther Hermann wrote:
> Actually, the vlc ac3 decoder is
> based on his code.

Yes, in many parts. But vlc was based on an old version of ac3dec and I
currently port the new ac3dec features to vlc (such as mxx support).

> To (1):
> you can check right away that the sample rate on the output device
> (/dev/dsp in my case) is set before any ac3 frame has been decoded,
> to a default value of 41100. This has considerable impact on the
> quality of (the many) 48k streams, but of course is easily fixed being a
> simple thread synchronization problem.

Ok, I check this. Actually ac3_decoder and audio_output are two
differents threads and they not communicate. I'll correct this problem.
Thanks for reporting, I haven't take this in consideration. For the
moment, you can modify include/config.h nd config.h.in line 254 :
#define AOUT_RATE_DEFAULT 48000

> To (2):

ac3dec imct seems to be very strange. I'm currently porting it to vlc. I
hope this corrects sound problems.

> These points apply to vlc 0.2.62 as well as 0.2.63, but I actually
> tried on 62 (because 63 is bad).

0.2.62 have an major downmix problem which is corrected in 0.2.63. But
there is no over ac3dec modification between 0.2.62 and 0.2.63. Could
you explain to me that is bad in 0.2.63, it is possibly an existing bug
we can't heard in 0.2.62.

> Clearly, if the ac3 decoder were buggy, it would be a pain to fix it,
> so I know what I'm saying here. But I believe the decoder is no good
> and I think I could convince me of this.

I'll spend my week on ac3dec and try to correct the main bugs (sound
quality in particular). (But it'll be easier if I could dispose of
streams in with audio is buggy because this problems seems to appear
only with somes dvd.)


Thanks for reporting.
-- 
Reno