[vlc-devel] [RFC PATCH 8/9] decoder: reload module if aout device changes

[Rémi Denis-Courmont]

Hell no, obviously.

On lauantaina 9. heinäkuuta 2016 12.20.16 EEST Thomas Guillem wrote:
> In order to be able to change from PCM to SPDIF and from SPDIF to PCM.
> 
> There is a Time of check to time of use issue here. DecoderPlayAudio() can
> still be called when the decoder is configured with a wrong audio device.
> This will result in a loss of few audio blocks. This is hard to avoid when
> the user choose to change audio devices.
> ---
>  src/input/decoder.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/src/input/decoder.c b/src/input/decoder.c
> index de03dd6..a437930 100644
> --- a/src/input/decoder.c
> +++ b/src/input/decoder.c
> @@ -82,6 +82,7 @@ struct decoder_owner_sys_t
>      /* */
>      bool           b_fmt_description;
>      vlc_meta_t     *p_description;
> +    atomic_bool    aout_device_changed;
> 
>      /* fifo */
>      block_fifo_t *p_fifo;
> @@ -270,6 +271,20 @@ static vout_thread_t *aout_request_vout( void
> *p_private, return p_vout;
>  }
> 
> +static int aout_device_changed( vlc_object_t *p_obj, const char *p_var,
> +                                vlc_value_t prev, vlc_value_t cur, void
> *p_data) +{
> +    (void) p_obj; (void) p_var;
> +    decoder_t *p_dec = p_data;
> +    decoder_owner_sys_t *p_owner = p_dec->p_owner;
> +
> +    if( prev.psz_string == NULL || cur.psz_string == NULL
> +     || strcmp( prev.psz_string, cur.psz_string ) != 0 )
> +        atomic_store( &p_owner->aout_device_changed, true );
> +
> +    return VLC_SUCCESS;
> +}
> +
>  static int aout_update_format( decoder_t *p_dec )
>  {
>      decoder_owner_sys_t *p_owner = p_dec->p_owner;
> @@ -283,6 +298,7 @@ static int aout_update_format( decoder_t *p_dec )
>          vlc_mutex_lock( &p_owner->lock );
>          p_owner->p_aout = NULL;
>          vlc_mutex_unlock( &p_owner->lock );
> +        var_DelCallback( p_aout, "device", aout_device_changed, p_dec );
>          aout_DecDelete( p_aout );
> 
>          input_resource_PutAout( p_owner->p_resource, p_aout );
> @@ -328,6 +344,8 @@ static int aout_update_format( decoder_t *p_dec )
>                  input_resource_PutAout( p_owner->p_resource, p_aout );
>                  p_aout = NULL;
>              }
> +            else
> +                var_AddCallback( p_aout, "device", aout_device_changed,
> p_dec ); }
> 
>          vlc_mutex_lock( &p_owner->lock );
> @@ -1418,6 +1436,14 @@ static void DecoderProcess( decoder_t *p_dec, block_t
> *p_block ) if( p_dec->b_error )
>          goto error;
> 
> +    if( atomic_exchange( &p_owner->aout_device_changed, false ) )
> +    {
> +        msg_Warn( p_dec, "Restarting decoder since the audio device
> changed" ); +
> +        if( ReloadDecoder( p_dec, NULL, &p_dec->fmt_in ) != VLC_SUCCESS )
> +            goto error;
> +    }
> +
>      if( p_block )
>      {
>          if( p_block->i_buffer <= 0 )
> @@ -1668,6 +1694,7 @@ static decoder_t * CreateDecoder( vlc_object_t
> *p_parent, p_owner->flushing = false;
>      p_owner->b_draining = false;
>      atomic_init( &p_owner->drained, false );
> +    atomic_init( &p_owner->aout_device_changed, false );
>      p_owner->b_idle = false;
> 
>      es_format_Init( &p_owner->fmt, UNKNOWN_ES, 0 );


-- 
Rémi Denis-Courmont
http://www.remlab.net/