[FFmpeg-devel] [PATCH] QOA decoding support

[Paul B Mahol]

On Wed, Sep 27, 2023 at 2:51 PM Andreas Rheinhardt <
andreas.rheinhardt at outlook.com> wrote:

> Paul B Mahol:
> > On Sun, Sep 24, 2023 at 2:04 AM Andreas Rheinhardt <
> > andreas.rheinhardt at outlook.com> wrote:
> >
> >> Paul B Mahol:
> >>>
> >>> +        if (!qoa->frame_size) {
> >>> +            for (; i < buf_size; i++) {
> >>> +                state = (state << 8) | buf[i];
> >>> +                if (((state & 0xFFFF) > 0 && (state >> 56))) {
> >>> +                    qoa->frame_size = state & 0xFFFF;
> >>> +                    qoa->duration = (state >> 16) & 0xFFFF;
> >>> +                    break;
> >>> +                }
> >>> +            }
> >>> +        }
> >>
> >> So this codec uses a length field. In this case it is quite simple to
> >> avoid the parser (and its implicit memcpy) altogether and just make the
> >> demuxer directly output packets of the correct size. This is quite
> >> natural given that this format does not seem to provide any features
> >> like resyncing support (or at least the parser does not implement them).
> >>
> >
> > But channels/sample rate may differ between packets.
>
> And?
>
> > Also it may be in other formats, like wav. So I picked parser as more
> > valuable implementation.
> >
>
> Then you could simply reuse the code inside libavformat.
>

What code?
I think that having parser is much more useful.


>
> - Andreas
>
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