[FFmpeg-devel] [PATCH] Include field_mode information in NUT stream info

[Michael Niedermayer]

Hi

On Mon, Mar 10, 2025 at 05:44:22PM +0100, Anders Rein wrote:
> This will make it possible to transmit raw video over NUT without losing
> the field order information.

[...]

> diff --git a/libavformat/nutenc.c b/libavformat/nutenc.c
> index 55efb114c3..abe4e3fb98 100644
> --- a/libavformat/nutenc.c
> +++ b/libavformat/nutenc.c
> @@ -21,6 +21,7 @@
>  
>  #include <stdint.h>
>  
> +#include "libavcodec/defs.h"
>  #include "libavutil/intreadwrite.h"
>  #include "libavutil/mathematics.h"
>  #include "libavutil/mem.h"
> @@ -560,12 +561,22 @@ static int write_streaminfo(NUTContext *nut, AVIOContext *bc, int stream_id) {
>              count += add_info(dyn_bc, "Disposition", ff_nut_dispositions[i].str);
>      }
>      if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
> +        const char* field_order;
>          uint8_t buf[256];
>          if (st->r_frame_rate.num>0 && st->r_frame_rate.den>0)
>              snprintf(buf, sizeof(buf), "%d/%d", st->r_frame_rate.num, st->r_frame_rate.den);
>          else
>              snprintf(buf, sizeof(buf), "%d/%d", st->avg_frame_rate.num, st->avg_frame_rate.den);
>          count += add_info(dyn_bc, "r_frame_rate", buf);
> +
> +        // Since the NUT specifications (nut.txt) do not support field order information,
> +        // the stream_info side channel is used as a means to transfer this information.
> +        // This is strictly not a part of the NUT specifications and should not be required.
> +        field_order = ff_nut_serialized_field_order_value_or_null(st->codecpar->field_order);
> +        if (field_order != NULL) {
> +            count += add_info(dyn_bc, "field_order", field_order);
> +        }

either send a patch to nut.txt or it should be "X-field_order" for non
standard fields

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Freedom in capitalist society always remains about the same as it was in
ancient Greek republics: Freedom for slave owners. -- Vladimir Lenin
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