[Spice-devel] [spice v2] gstreamer-encoder: Return the average frame size as a 32 bit int

[Frediano Ziglio]

> 
> It makes no sense to expect average frame sizes anywhere close to 2GB.
> But then make sure to avoid arithmetic overflows.
> 
> Signed-off-by: Francois Gouget <fgouget at codeweavers.com>

Acked-by: Frediano Ziglio <fziglio at redhat.com>

> ---
> 
> In get_min_playback_delay() I opted for the cast approach as this makes
> what happens clearer. I deemed the assignment (uint32_t) unnecessary
> though.
> 
>  server/gstreamer-encoder.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/server/gstreamer-encoder.c b/server/gstreamer-encoder.c
> index 0ff1201a9..0101b36fa 100644
> --- a/server/gstreamer-encoder.c
> +++ b/server/gstreamer-encoder.c
> @@ -396,7 +396,7 @@ static uint64_t get_average_encoding_time(SpiceGstEncoder
> *encoder)
>      return encoder->stat_duration_sum / count;
>  }
>  
> -static uint64_t get_average_frame_size(SpiceGstEncoder *encoder)
> +static uint32_t get_average_frame_size(SpiceGstEncoder *encoder)
>  {
>      uint32_t count = encoder->history_last +
>          (encoder->history_last < encoder->stat_first ?
>          SPICE_GST_HISTORY_SIZE : 0) -
> @@ -520,8 +520,8 @@ static uint32_t get_min_playback_delay(SpiceGstEncoder
> *encoder)
>       * an I frame) and an average frame. This also takes into account the
>       * frames dropped by the encoder bit rate control.
>       */
> -    uint64_t size = get_maximum_frame_size(encoder) +
> get_average_frame_size(encoder);
> -    uint32_t send_time = MSEC_PER_SEC * size * 8 / encoder->bit_rate;
> +    uint32_t size = get_maximum_frame_size(encoder) +
> get_average_frame_size(encoder);
> +    uint32_t send_time = ((uint64_t)MSEC_PER_SEC * 8) * size /
> encoder->bit_rate;
>  
>      /* Also factor in the network latency with a margin for jitter. */
>      uint32_t net_latency = get_network_latency(encoder) * (1.0 +
>      SPICE_GST_LATENCY_MARGIN);