[vlc-devel] [PATCH 09/31] decoder: split the decoder format update in 2 parts

[Rémi Denis-Courmont]

Le maanantaina 23. syyskuuta 2019, 18.01.14 EEST Steve Lhomme a écrit :
> The first part is to create the decoder device.
> The second part is to create the display module (or other depending on the
> decoder owner).
> 
> Turn decoder_UpdateVideoFormat() is calling the two new functions.
> ---
>  include/vlc_codec.h         | 38 +++++++++++++++++++++++++++++++++++++
>  src/input/decoder_helpers.c | 20 +++++++++++++++++++
>  src/libvlccore.sym          |  2 ++
>  3 files changed, 60 insertions(+)
> 
> diff --git a/include/vlc_codec.h b/include/vlc_codec.h
> index 28a65846d9e..8d2680f1965 100644
> --- a/include/vlc_codec.h
> +++ b/include/vlc_codec.h
> @@ -49,6 +49,7 @@ struct decoder_owner_callbacks
>      {
>          struct
>          {
> +            int         (*hold_device)( decoder_t *, vlc_decoder_device **
> );

Uh, that's very unconventional naming. Hold normally increase the reference 
count on an object that you already have. Get returns a reference to an object 
that you do not have. Ditto earlier.

> int         (*format_update)( decoder_t * );
>              /* cf. decoder_NewPicture, can be called from any decoder
> thread */ @@ -253,6 +254,43 @@ struct encoder_t
>   * @{
>   */
> 
> +/**
> + * Creates/Updates the output decoder device.
> + *
> + * This function notifies the video output pipeline of a new video output
> + * format (fmt_out.video). If there was no decoder device so far or a new
> + * decoder device is required, a new decoder device will be set up.
> + * decoder_UpdateVideoOutput() can then be used.
> + *
> + * If the format is unchanged, this function has no effects and returns
> zero. + *
> + * \param dec the decoder object
> + * \param pp_dec_dev the received of the held decoder device, NULL not to
> get one + *
> + * \note
> + * This function is not reentrant.
> + *
> + * @return 0 if the video output was set up successfully, -1 otherwise.
> + */
> +VLC_API int decoder_HoldDecoderDevice( decoder_t *dec, vlc_decoder_device
> **pp_dec_dev ); +
> +/**
> + * Creates/Updates the rest of the video output pipeline.
> + *
> + * After a call to decoder_HoldDecoderDevice() this function notifies the
> + * video output pipeline of a new video output format (fmt_out.video). If
> there + * was no video output from the decoder so far, a new decoder video
> output will + * be set up. decoder_NewPicture() can then be used to
> allocate picture buffers. + *
> + * If the format is unchanged, this function has no effects and returns
> zero. + *
> + * \note
> + * This function is not reentrant.
> + *
> + * @return 0 if the video output was set up successfully, -1 otherwise.
> + */
> +VLC_API int decoder_UpdateVideoOutput( decoder_t *dec );
> +
>  /**
>   * Updates the video output format.
>   *
> diff --git a/src/input/decoder_helpers.c b/src/input/decoder_helpers.c
> index 6d5b0050ed7..51e097961b9 100644
> --- a/src/input/decoder_helpers.c
> +++ b/src/input/decoder_helpers.c
> @@ -76,6 +76,26 @@ void decoder_Destroy( decoder_t *p_dec )
>  }
> 
>  int decoder_UpdateVideoFormat( decoder_t *dec )
> +{
> +    int res = decoder_HoldDecoderDevice( dec, NULL );
> +    if (res == 0)
> +        res = decoder_UpdateVideoOutput( dec );
> +    return res;
> +}
> +
> +int decoder_HoldDecoderDevice( decoder_t *dec, vlc_decoder_device
> **pp_dec_dev ) +{
> +    vlc_assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
> +    if ( unlikely(dec->fmt_in.i_cat != VIDEO_ES || dec->cbs == NULL ) )
> +        return -1;
> +
> +    if ( dec->cbs->video.hold_device == NULL )
> +        return 0; /* TODO make it mandatory for all decoder owners */
> +
> +    return dec->cbs->video.hold_device( dec, pp_dec_dev );
> +}
> +
> +int decoder_UpdateVideoOutput( decoder_t *dec )
>  {
>      vlc_assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
>      if ( unlikely(dec->fmt_in.i_cat != VIDEO_ES || dec->cbs == NULL ||
> diff --git a/src/libvlccore.sym b/src/libvlccore.sym
> index e5241c411d0..fb2952ee5ef 100644
> --- a/src/libvlccore.sym
> +++ b/src/libvlccore.sym
> @@ -82,6 +82,8 @@ decoder_Destroy
>  decoder_AbortPictures
>  decoder_NewAudioBuffer
>  decoder_UpdateVideoFormat
> +decoder_HoldDecoderDevice
> +decoder_UpdateVideoOutput
>  vlc_decoder_device_Hold
>  vlc_decoder_device_Release
>  demux_PacketizerDestroy


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