[vlc-devel] [PATCH] Added libvlc_video_take_snapshot_addr to libvlc and related functions to libvlccore

[Rémi Denis-Courmont]

On Wed, 30 Nov 2011 22:43:34 +0100, PaulK <gci at paulk.fr> wrote:
> diff --git a/include/vlc/libvlc_media_player.h
> b/include/vlc/libvlc_media_player.h
> index a2b5748..b2a5c54 100644
> --- a/include/vlc/libvlc_media_player.h
> +++ b/include/vlc/libvlc_media_player.h
> @@ -35,6 +35,7 @@
>  extern "C" {
>  # else
>  #  include <stdbool.h>
> +#  include <stdlib.h>
>  # endif
>  
> 
/*****************************************************************************
> @@ -1151,6 +1152,25 @@ int
> libvlc_video_take_snapshot( libvlc_media_player_t *p_mi, unsigned num,
>                                  unsigned int i_height );
>  
>  /**
> + * Take a snapshot of the current video window and return the snapshot
> address.
> + *
> + * If i_width AND i_height is 0, original size is used.
> + * If i_width XOR i_height is 0, original aspect-ratio is preserved.
> + *
> + * \param p_mi media player instance
> + * \param num number of video output (typically 0 for the first/only
> one)
> + * \param psz_addr place to return the snapshot address (you MUST free
> it after use)
> + * \param i_width the snapshot's width
> + * \param i_height the snapshot's height
> + * \return the snapshot memory area size on success, -1 if there was a
> problem
> + */
> +LIBVLC_API
> +ssize_t
> +libvlc_video_snapshot_get_data( libvlc_media_player_t *p_mi, unsigned
> num,
> +                                 void **psz_addr, unsigned int
> i_width, 
> +                                 unsigned int i_height );
> +
> +/**
>   * Enable or disable deinterlace filter
>   *
>   * \param p_mi libvlc media player
> diff --git a/lib/libvlc.sym b/lib/libvlc.sym
> index 6582a96..099cbb8 100644
> --- a/lib/libvlc.sym
> +++ b/lib/libvlc.sym
> @@ -215,6 +215,7 @@ libvlc_video_set_spu
>  libvlc_video_set_subtitle_file
>  libvlc_video_set_teletext
>  libvlc_video_set_track
> +libvlc_video_snapshot_get_data
>  libvlc_video_take_snapshot
>  libvlc_vlm_add_broadcast
>  libvlc_vlm_add_vod
> diff --git a/lib/video.c b/lib/video.c
> index 6e1ea06..3071646 100644
> --- a/lib/video.c
> +++ b/lib/video.c
> @@ -34,6 +34,7 @@
>  #include <vlc/libvlc_media_player.h>
>  
>  #include <vlc_common.h>
> +#include <vlc_block.h>
>  #include <vlc_input.h>
>  #include <vlc_vout.h>
>  
> @@ -158,6 +159,63 @@ libvlc_video_take_snapshot( libvlc_media_player_t
> *p_mi, unsigned num,
>      return 0;
>  }
>  
> +ssize_t
> +libvlc_video_snapshot_get_data( libvlc_media_player_t *p_mi, unsigned
> num,
> +                                 void **psz_addr, unsigned int
> i_width, 
> +                                 unsigned int i_height )
> +{
> +    block_t *block_buffer;
> +    size_t buffer_len = 0;
> +    char *buffer = NULL;
> +    ssize_t ret_len;
> +    video_format_t fmt;
> +
> +    vout_thread_t *p_vout = GetVout( p_mi, num );
> +    if (p_vout == NULL)
> +    {
> +        libvlc_printerr ("No usable vout");
> +        return -1;
> +    }
> +
> +    var_SetInteger( p_vout, "snapshot-width", i_width);
> +    var_SetInteger( p_vout, "snapshot-height", i_height );

Not thread-safe.

> +
> +    if( vout_GetSnapshot( p_vout, &block_buffer, NULL, &fmt, "png",
> 500*1000 ) )
> +    {
> +        libvlc_printerr ("Can't get the snapshot");
> +        ret_len = -1;
> +        goto exit;
> +    }
> +
> +
> +    buffer_len = block_buffer->i_buffer;
> +    if( buffer_len <= 0 )
> +    {
> +        libvlc_printerr ("Snapshot buffer length is negative or zero");
> +        ret_len = -1;
> +        goto exit;
> +    }
> +
> +    buffer = malloc( buffer_len );
> +    if( buffer == NULL )
> +    {
> +        libvlc_printerr ("buffer memory allocation failed");
> +        ret_len = -1;
> +        goto exit;
> +    }
> +
> +    psz_addr[0] = buffer;
> +    memcpy( buffer, block_buffer->p_buffer, buffer_len );

For the second time, please don't do this. We have buffer management.

> +
> +    ret_len = buffer_len;
> +
> +exit:
> +    if( block_buffer != NULL )
> +        block_Release( block_buffer );
> +
> +    return ret_len;
> +}
> +
>  int libvlc_video_get_size( libvlc_media_player_t *p_mi, unsigned num,
>                             unsigned *restrict px, unsigned *restrict py
> )
>  {
> 
> 
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-- 
Rémi Denis-Courmont
http://www.remlab.net/