[Spice-devel] [PATCH spice-server 1/2] Fix GStreamer encoding if stride is not 4 bytes aligned

[Pavel Grunt]

Hi Frediano,

On Wed, 2017-03-22 at 10:18 +0000, Frediano Ziglio wrote:
> This is required by GStreamer.

Is it related to the gstreamer bug you have opened recently ?
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  server/gstreamer-encoder.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/server/gstreamer-encoder.c b/server/gstreamer-encoder.c
> index df54cad..e637b8a 100644
> --- a/server/gstreamer-encoder.c
> +++ b/server/gstreamer-encoder.c
> @@ -1260,7 +1260,7 @@ static inline int line_copy(SpiceGstEncoder
> *encoder, const SpiceBitmap *bitmap,
>  
>           /* Copy the line */
>           uint8_t *src = chunks->chunk[chunk_index].data +
> chunk_offset;
> -         memcpy(dst, src, stream_stride);
> +         memcpy(dst, src, MIN(stream_stride, bitmap->stride));
>           dst += stream_stride;
>           chunk_offset += bitmap->stride;
>       }
> @@ -1351,7 +1351,7 @@ static int push_raw_frame(SpiceGstEncoder
> *encoder,
>  {
>      uint32_t height = src->bottom - src->top;
>      uint32_t stream_stride = (src->right - src->left) * encoder-
> >format->bpp / 8;
> -    uint32_t len = stream_stride * height;
> +    uint32_t len;
>      GstBuffer *buffer = gst_buffer_new();
>      /* TODO Use GST_MAP_INFO_INIT once GStreamer 1.4.5 is no longer
> relevant */
>      GstMapInfo map = { .memory = NULL };
> @@ -1362,6 +1362,10 @@ static int push_raw_frame(SpiceGstEncoder
> *encoder,
>      uint32_t skip_lines = top_down ? src->top : bitmap->y - (src-
> >bottom - 0);
>      uint32_t chunk_offset = bitmap->stride * skip_lines;
>  
> +    // GStreamer require the stream to be 4 bytes aligned
> +    stream_stride = (stream_stride + 3) & -4;

(maybe it is just me but) imho is not easy to read binary operation
with negative numbers. Can you switch to ~3 

Thanks,
Pavel

> +    len = stream_stride * height;
> +
>      if (stream_stride != bitmap->stride) {
>          /* We have to do a line-by-line copy because for each we
> have to
>           * leave out pixels on the left or right.