[FFmpeg-devel] [PATCH] avcodec/av1dec: Adjust incorrect error output

[Soft Works]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> Ronald S. Bultje
> Sent: Tuesday, 24 August 2021 04:34
> To: FFmpeg development discussions and patches <ffmpeg-
> devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH] avcodec/av1dec: Adjust incorrect
> error output
> 
> Hi,
> 
> On Mon, Aug 23, 2021 at 9:39 PM Soft Works <softworkz at hotmail.com>
> wrote:
> 
> > The current message "Your platform doesn't suppport
> > hardware accelerated AV1 decoding." is inaccurate and
> > misleading. When a user doesn't specify a hwcaccel,
> > this doesn't tell anything about what is actually
> > supported on that platform.
> >
> > Signed-off-by: softworkz <softworkz at hotmail.com>
> > ---
> >  libavcodec/av1dec.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/libavcodec/av1dec.c b/libavcodec/av1dec.c
> > index a75d6744d3..8dfcd26cb6 100644
> > --- a/libavcodec/av1dec.c
> > +++ b/libavcodec/av1dec.c
> > @@ -462,8 +462,8 @@ static int get_pixel_format(AVCodecContext
> *avctx)
> >       * implemented in the future, need remove this check.
> >       */
> >      if (!avctx->hwaccel) {
> > -        av_log(avctx, AV_LOG_ERROR, "Your platform doesn't
> suppport"
> > -               " hardware accelerated AV1 decoding.\n");
> > +        av_log(avctx, AV_LOG_ERROR, "AV1 decoding requires a hw
> > acceleration"
> > +               " to be specified.\n");
> >
> 
> This is misleading.
> 
> This error message (for me) happens when I accidentally compile
> FFmpeg
> without aom/dav1d support, and try to play AV1 content.

It also happens to me when I specify:

ffmpeg -c:v av1 -i INPUT OUTPUT

(e.g. like when I'd have forgotten to specify the hwaccel)

> AV1 decoding
> does
> not require hw decoding - it simply requires an external library.
> 
> Will the hwaccel be autodetected when AV1 hw decoding is supported by
> the
> platform?

No.

How about this: "The AV1 decoder requires a hw acceleration to be
specified." ?

softworkz