[vlc-devel] [PATCH 1/1] packetizer: flac: reduce memory allocations

[Jean-Baptiste Kempf]

Do you see a CPU difference?

On 21 Nov, Tristan Matthews wrote :
> ---
>  modules/packetizer/flac.c | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/modules/packetizer/flac.c b/modules/packetizer/flac.c
> index ecf854f..25f1957 100644
> --- a/modules/packetizer/flac.c
> +++ b/modules/packetizer/flac.c
> @@ -90,6 +90,8 @@ struct decoder_sys_t
>      size_t i_frame_size;
>      uint16_t crc;
>      unsigned int i_rate, i_channels, i_bits_per_sample;
> +    size_t i_buf;
> +    uint8_t *p_buf;
>  };
>  
>  static const int pi_channels_maps[9] =
> @@ -603,19 +605,21 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
>      {
>          /* Calculate the initial CRC for the minimal frame size,
>           * We'll update it as we look for the next start code. */
> -        uint8_t *buf = malloc(p_sys->i_frame_size);
> -        if (!buf)
> -            return NULL;
> +        if (p_sys->i_buf < p_sys->i_frame_size)
> +        {
> +            p_sys->p_buf = realloc(p_sys->p_buf, p_sys->i_frame_size);
> +            if (!p_sys->p_buf)
> +                return NULL;
> +            p_sys->i_buf = p_sys->i_frame_size;
> +        }
>  
> -        if (block_PeekOffsetBytes(&p_sys->bytestream, 0, buf, p_sys->i_frame_size)) {
> -            free(buf);
> +        if (block_PeekOffsetBytes(&p_sys->bytestream, 0, p_sys->p_buf, p_sys->i_frame_size)) {
>              return NULL;
>          }
>  
>          uint16_t crc = 0;
>          for (unsigned i = 0; i < p_sys->i_frame_size; i++)
> -            crc = flac_crc16(crc, buf[i]);
> -        free(buf);
> +            crc = flac_crc16(crc, p_sys->p_buf[i]);
>          p_sys->crc = crc;
>  
>          /* Check if next expected frame contains the sync word */
> @@ -752,6 +756,8 @@ static int Open(vlc_object_t *p_this)
>      p_sys->i_state       = STATE_NOSYNC;
>      p_sys->b_stream_info = false;
>      p_sys->i_pts         = VLC_TS_INVALID;
> +    p_sys->i_buf         = 0;
> +    p_sys->p_buf         = NULL;
>      block_BytestreamInit(&p_sys->bytestream);
>  
>      /* */
> @@ -773,5 +779,6 @@ static void Close(vlc_object_t *p_this)
>  
>      es_format_Clean(&p_dec->fmt_out);
>      block_BytestreamRelease(&p_sys->bytestream);
> +    free(p_sys->p_buf);
>      free(p_sys);
>  }
> -- 
> 1.9.3
> 
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-- 
With my kindest regards,

-- 
Jean-Baptiste Kempf
http://www.jbkempf.com/ - +33 672 704 734
Sent from my Electronic Device