Re: [PATCH v3 4/9] h264: search for available h264 encoder

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, Apr 18, 2025 at 01:29:48PM +0200, Dietmar Maurer wrote:
> The search list is currently hardcoded to: ["x264enc", "openh264enc"]
> 
> x264enc: is probably the best available software encoder
> openh264enc: lower quality, but available on more systems.
> 
> We restrict encoders to a known list because each encoder requires
> fine tuning to get reasonable/usable results.
> 
> Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>
> ---
>  ui/vnc-enc-h264.c | 89 +++++++++++++++++++++++++++++++++++++++--------
>  ui/vnc.h          |  1 +
>  2 files changed, 75 insertions(+), 15 deletions(-)
> 
> diff --git a/ui/vnc-enc-h264.c b/ui/vnc-enc-h264.c
> index 3abe6a1528..047f4a3128 100644
> --- a/ui/vnc-enc-h264.c
> +++ b/ui/vnc-enc-h264.c
> @@ -27,6 +27,68 @@
>  
>  #include <gst/gst.h>
>  
> +const char *encoder_list[] = { "x264enc", "openh264enc", NULL };
> +
> +static const char *get_available_encoder(void)
> +{
> +    int i = 0;
> +    do {
> +        const char *encoder_name = encoder_list[i];
> +        if (encoder_name == NULL) {
> +            break;
> +        }
> +        GstElement *element = gst_element_factory_make(
> +            encoder_name, "video-encoder");
> +        if (element != NULL) {
> +            gst_object_unref(element);
> +            return encoder_name;
> +        }
> +        i = i + 1;
> +    } while (true);

This while loop is incredibly verbose as written.

   for (int i = 0; i < G_N_ELEMENTS(encoder_list); i++) {
         GstElement *element = gst_element_factory_make(
             encoder_list[i], "video-encoder");
         if (element != NULL) {
             gst_object_unref(element);
             return encoder_list[i];
         }
  }

and get rid of the trailing "NULL" in encoder_list as it
isn't required

> +
> +    return NULL;
> +}
> +

With regards,
Daniel
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