[FFmpeg-devel] [PATCH 2/2] avformat/mxf: support MCA audio information

[Tomas Härdin]

tor 2021-09-23 klockan 00:02 +0200 skrev Marton Balint:


On Fri, 17 Sep 2021, Marc-Antoine Arnaud wrote:

> ---
> libavformat/mxf.h    |   1 +
> libavformat/mxfdec.c | 277
> ++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 272 insertions(+), 6 deletions(-)

I guess the questionable part of this patch is the internal reordering
of
audio channels. This might or might not be what the user expects.

Can we signal this and have the ffmpeg CLI automagically insert a
channel reordering filter? That way someone wanting to speed the
reordering up could write vectorized code for it
> 
> +static int mxf_read_mca_sub_descriptor(void *arg, AVIOContext *pb,
> int tag, int size, UID uid, int64_t klv_offset)
> +{
> +    MXFMCASubDescriptor *mca_sub_descriptor = arg;
> +
> +    if (IS_KLV_KEY(uid, mxf_mca_label_dictionnary_id)) {
> +        avio_read(pb, mca_sub_descriptor->mca_label_dictionnary_id,
> 16);
> +    }
> +    if (IS_KLV_KEY(uid, mxf_mca_link_id)) {
> +        avio_read(pb, mca_sub_descriptor->mca_link_id, 16);
> +    }
> +    if (IS_KLV_KEY(uid, mxf_soundfield_group_link_id)) {
> +        avio_read(pb, mca_sub_descriptor->mca_group_link_id, 16);
> +    }

You don't have to open braces for single-line blocks, ffmpeg tends to 
follow this style, so preferably you should too.

I actually prefer braces always. I've been bitten by lack of braces at
least once.

/Tomas