[vlc-devel] [PATCH 10/11] decoder: add the possibility to have a custom fmt_out setup to load a decoder

[Rémi Denis-Courmont]

On jeudi 13 juillet 2017 15:44:43 EEST Steve Lhomme wrote:
> By default it is a blank fmt_out with just the category set.
> ---
>  include/vlc_codec.h |  7 ++++++-
>  src/input/decoder.c | 21 +++++++++++++++++----
>  src/misc/image.c    |  3 +--
>  3 files changed, 24 insertions(+), 7 deletions(-)
> 
> diff --git a/include/vlc_codec.h b/include/vlc_codec.h
> index 76a86767f1..eacb57f5e0 100644
> --- a/include/vlc_codec.h
> +++ b/include/vlc_codec.h
> @@ -30,6 +30,7 @@
>  #include <vlc_es.h>
>  #include <vlc_picture.h>
>  #include <vlc_subpicture.h>
> +#include <vlc_modules.h>
> 
>  /**
>   * \defgroup codec Codec
> @@ -411,8 +412,12 @@ VLC_API int decoder_GetDisplayRate( decoder_t * )
> VLC_USED;
> 
>  /**
>   * This function loads a decoder module matching the fmt_in of the decoder
> object. + *
> + * The probe is responsible for setting up the decoder fmt_out before/after
> + * loading a module. By default it initializes a blank fmt_out with just +
> * the category and cleans it up on module loading error.
>   */
> -VLC_API module_t *decoder_LoadModule( decoder_t * ) VLC_USED;
> +VLC_API module_t *decoder_LoadModule( decoder_t *, vlc_activate_t probe )
> VLC_USED;
> 
>  /** @} */
>  /** @} */
> diff --git a/src/input/decoder.c b/src/input/decoder.c
> index f2bb533a23..5d751157b6 100644
> --- a/src/input/decoder.c
> +++ b/src/input/decoder.c
> @@ -151,7 +151,18 @@ struct decoder_owner_sys_t
>  #define DECODER_SPU_VOUT_WAIT_DURATION ((int)(0.200*CLOCK_FREQ))
>  #define BLOCK_FLAG_CORE_PRIVATE_RELOADED (1 <<
> BLOCK_FLAG_CORE_PRIVATE_SHIFT)
> 
> -module_t *decoder_LoadModule( decoder_t *p_dec )
> +static int DecoderStart(void *func, va_list ap)
> +{
> +    decoder_t *p_dec = va_arg(ap, decoder_t *);
> +    int (*activate)(vlc_object_t *) = func;
> +
> +    int res = activate( VLC_OBJECT(p_dec) );
> +    if ( res != VLC_SUCCESS )
> +        es_format_Change( &p_dec->fmt_out, p_dec->fmt_out.i_cat, 0 );

IMO, it's far more logical and straightforward to init before activate() and 
clean after failed activate.

> +    return res;
> +}
> +
> +module_t *decoder_LoadModule( decoder_t *p_dec, vlc_activate_t probe )
>  {
>      const char caps[ES_CATEGORY_COUNT][16] = {
>          [VIDEO_ES] = "video decoder",
> @@ -169,7 +180,10 @@ module_t *decoder_LoadModule( decoder_t *p_dec )
>          return NULL; /* no decoder for this type */
>      }
> 
> -    return module_need( p_dec, caps[p_dec->fmt_in.i_cat], "$codec", false
> ); +    if ( probe == NULL )
> +        es_format_Init( &p_dec->fmt_out, p_dec->fmt_in.i_cat, 0 );
> +    return vlc_module_load( p_dec, caps[p_dec->fmt_in.i_cat], "$codec",
> +                     false, probe ? probe : DecoderStart, p_dec );
>  }
> 
>  /**
> @@ -191,8 +205,7 @@ static int LoadDecoder( decoder_t *p_dec, bool
> b_packetizer, /* Find a suitable decoder/packetizer module */
>      if( !b_packetizer )
>      {
> -        es_format_Init( &p_dec->fmt_out, p_fmt->i_cat, 0 );
> -        p_dec->p_module = decoder_LoadModule( p_dec );
> +        p_dec->p_module = decoder_LoadModule( p_dec, NULL );
>      }
>      else
>      {
> diff --git a/src/misc/image.c b/src/misc/image.c
> index 19aa95cfe2..f2dbde3d2d 100644
> --- a/src/misc/image.c
> +++ b/src/misc/image.c
> @@ -647,14 +647,13 @@ static decoder_t *CreateDecoder( vlc_object_t *p_this,
> const video_format_t *fmt
> 
>      p_dec->p_module = NULL;
>      es_format_InitFromVideo( &p_dec->fmt_in, fmt );
> -    es_format_Init( &p_dec->fmt_out, VIDEO_ES, 0 );
>      p_dec->b_frame_drop_allowed = false;
> 
>      p_dec->pf_vout_format_update = video_update_format;
>      p_dec->pf_vout_buffer_new = video_new_buffer;
> 
>      /* Find a suitable decoder module */
> -    p_dec->p_module = decoder_LoadModule( p_dec );
> +    p_dec->p_module = decoder_LoadModule( p_dec, NULL );
>      if( !p_dec->p_module )
>      {
>          msg_Err( p_dec, "no suitable decoder module for fourcc `%4.4s'. "

-- 
Rémi Denis-Courmont