Since 0.84a no/bad sound with AC3/DTS on SPDIF using ALSA on Linux 2.6.x.

Do you happen to have an exact version number that was working from debian builds? I am also encountering this in 0.8.6 Ubuntu builds, and tried to roll back to an older 0.8.4 based one but only had worse problems:

[00000331] alsa audio output error: internal: can't find audio-device (10) [00000331] oss audio output error: cannot reset OSS audio device

I'm using "vlc (0.8.4-svn20050920-1) unstable; urgency=low" aka vlc-0.8.4a.

Path to fix the problemen (reverted changes in alsa.c)

Index: alsa.c

--- alsa.c (revision 20927) +++ alsa.c (working copy) @@ -827,16 +827,18 @@ } else #endif

```
       {
```

           /* With screwed ALSA drivers the timestamp is always zero;

            * use another method then */

+{

          int i_bytes;
           snd_pcm_sframes_t delay = 0;

           if( !snd_pcm_delay( p_sys->p_snd_pcm, &delay ) )

```
           {
```

                  i_bytes = snd_pcm_frames_to_bytes(p_sys->p_snd_pcm, delay);

```
           }
```

           next_date = mdate() + (mtime_t)i_bytes * 1000000

                  / p_aout->output.output.i_bytes_per_frame

                  / p_aout->output.output.i_rate;

+}

           snd_pcm_delay( p_sys->p_snd_pcm, &delay );

           next_date = mdate() + (mtime_t)(delay) * 1000000 /

                     p_aout->output.output.i_rate

                   * p_aout->output.output.i_frame_length;

       }
   }

   p_buffer = aout_OutputNextBuffer( p_aout, next_date,

Pach for AC3 / Alsa problem (reverted changes)

Added attachment:

alsafix1.diff

what's the state of current trunk ?

changed milestone to %0.9.0 bugs

Using vlc-trunk of today (20071027) there is still no sound with DTS/AC3 using the spdif pass-through.

VLC media player 0.9.0-svn Grishenko [00000001] main libvlc debug: VLC media player - version 0.9.0-svn Grishenko - (c) 1996-2007 the VideoLAN team [00000001] main libvlc debug: libvlc was configured with ../configure '--prefix=/home/insecure/vlc/local' '--disable-zvbi' [00000001] main libvlc debug: translation test: code is "C" VLC version 0.9.0-svn Grishenko Compiler: gcc version 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2) Based upon svn changeset [22864] This program comes with NO WARRANTY, to the extent permitted by law. You may redistribute it under the terms of the GNU General Public License; see the file named COPYING for details. Written by the VideoLAN team; see the AUTHORS file.

Using the same fix i get the sound working again.

Index: alsa.c

--- alsa.c (revision 22864) +++ alsa.c (working copy) @@ -852,11 +852,27 @@ /* With screwed ALSA drivers the timestamp is always zero; * use another method then */ snd_pcm_sframes_t delay = 0;

```
                                   //
```
```
                                   //
```
```
           long int i_bytes;
```

            if( !snd_pcm_delay( p_sys->p_snd_pcm, &delay ) )

```
            {
```

                  i_bytes = snd_pcm_frames_to_bytes(p_sys->p_snd_pcm, delay);

```
            }
```

            next_date = mdate() + (mtime_t)i_bytes * 1000000

                  / p_aout->output.output.i_bytes_per_frame

                  / p_aout->output.output.i_rate;

```
                                   //
```

+/* snd_pcm_delay( p_sys->p_snd_pcm, &delay ); next_date = mdate() + (mtime_t)(delay) * 1000000 / p_aout->output.output.i_rate * p_aout->output.output.i_frame_length; +*/ } }

Hello,

the change reverted by this patch was for this ticket https://trac.videolan.org/vlc/ticket/461

Before reverting it, we must check what this has no side effects, especially about this ticket.

Unfortunately I've no knowledge about alsa :(

We are totally not going to revert this at this point in the release schedule. We know it's going to screw many many users if we do so. At least AC97 was badly broken before this change. Given the commonality of the device, no way we revert unless we get warranty from ALSA developpers that this won't bring back the heavy stuttering problems.

Sorry for reopening an old ticket but my agenda is to try to make a fix for both problems.

a better patch

Added attachment:

alsa.diff

patch for 0.8.6 version

Added attachment:

alsa-0.8.6.diff

(In [23022]) alsa: use the pcm status to compute the delay. fix #894 (closed) (spdif passthrough) Please report loudly any regression, using spdif or not.

added Status::fixed label

closed

Since 0.84a no/bad sound with AC3/DTS on SPDIF using ALSA on Linux 2.6.x.

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Index: alsa.c

Index: alsa.c