[FFmpeg-devel] [PATCH 1/2] avcodec/libaom: Add HDR10+ metadata support

[James Zern]

On Fri, May 30, 2025 at 3:52 AM Maryla Ustarroz-Calonge via
ffmpeg-devel <ffmpeg-devel at ffmpeg.org> wrote:
>
> Signed-off-by: Maryla Ustarroz-Calonge <maryla at google.com>
> ---
>  libavcodec/libaomdec.c | 62 ++++++++++++++++++++++++++++++++++++++++++
>  libavcodec/libaomenc.c | 60 ++++++++++++++++++++++++++++++++++++++++
>  libavcodec/version.h   |  2 +-
>  3 files changed, 123 insertions(+), 1 deletion(-)
>
> diff --git a/libavcodec/libaomdec.c b/libavcodec/libaomdec.c
> index 69eec8b089..5995f0ab9b 100644
> --- a/libavcodec/libaomdec.c
> +++ b/libavcodec/libaomdec.c
> @@ -28,11 +28,15 @@
>
>  #include "libavutil/common.h"
>  #include "libavutil/cpu.h"
> +#include "libavutil/hdr_dynamic_metadata.h"
>  #include "libavutil/imgutils.h"
>
> +#include "libavcodec/bytestream.h"

This can be "bytestream.h" and added to the group below.

> +
>  #include "avcodec.h"
>  #include "codec_internal.h"
>  #include "decode.h"
> +#include "itut35.h"
>  #include "libaom.h"
>  #include "profiles.h"
>
> @@ -137,6 +141,59 @@ static int set_pix_fmt(AVCodecContext *avctx, struct aom_image *img)
>      }
>  }
>
> +static int decode_metadata_itu_t_t35(AVFrame *frame,
> +                                     const uint8_t *buffer, size_t buffer_size)
> +{
> +    if (buffer_size < 6)
> +        return AVERROR(EINVAL);
> +
> +    GetByteContext bc;
> +    bytestream2_init(&bc, buffer, buffer_size);
> +
> +    const int country_code = bytestream2_get_byteu(&bc);
> +    const int provider_code = bytestream2_get_be16u(&bc);
> +    const int provider_oriented_code = bytestream2_get_be16u(&bc);
> +    const int application_identifier = bytestream2_get_byteu(&bc);
> +
> +    if (country_code == ITU_T_T35_COUNTRY_CODE_US
> +        && provider_code == ITU_T_T35_PROVIDER_CODE_SMTPE
> +        && provider_oriented_code == 1
> +        && application_identifier == 4) {

Is there a spec or other source that can be referenced for these
values? The same goes for the setting of the values in libaomenc.c

> [...]
> diff --git a/libavcodec/libaomenc.c b/libavcodec/libaomenc.c
> index 9a384fcc39..4d899559d0 100644
> --- a/libavcodec/libaomenc.c
> +++ b/libavcodec/libaomenc.c
> @@ -33,12 +33,15 @@
>  #include "libavutil/base64.h"
>  #include "libavutil/common.h"
>  #include "libavutil/cpu.h"
> +#include "libavutil/hdr_dynamic_metadata.h"
>  #include "libavutil/imgutils.h"
>  #include "libavutil/mathematics.h"
>  #include "libavutil/mem.h"
>  #include "libavutil/opt.h"
>  #include "libavutil/pixdesc.h"
>
> +#include "libavcodec/bytestream.h"

This can be "bytestream.h" and added to the group below.

> +
>  #include "av1.h"
>  #include "avcodec.h"
>  #include "bsf.h"
> @@ -46,6 +49,7 @@
>  #include "dovi_rpu.h"
>  #include "encode.h"
>  #include "internal.h"
> +#include "itut35.h"
>  #include "libaom.h"
>  #include "packet_internal.h"
>  #include "profiles.h"
> @@ -326,6 +330,57 @@ static av_cold int codecctl_int(AVCodecContext *avctx,
>      return 0;
>  }
>
> +static int add_hdr_plus(AVCodecContext *avctx, struct aom_image *img, const AVFrame *frame)
> +{
> +    // Check for HDR10+
> +    AVFrameSideData *side_data =
> +        av_frame_get_side_data(frame, AV_FRAME_DATA_DYNAMIC_HDR_PLUS);
> +    if (!side_data)
> +        return 0;
> +
> +    size_t payload_size;
> +    AVDynamicHDRPlus *hdr_plus = (AVDynamicHDRPlus *)side_data->buf->data;
> +    int res = av_dynamic_hdr_plus_to_t35(hdr_plus, NULL, &payload_size);
> +    if (res < 0) {
> +        log_encoder_error(avctx, "Error finding the size of HDR10+");
> +        return res;
> +    }
> +
> +    uint8_t *hdr_plus_buf;
> +    // Extra bytes for the country code, provider code, provider oriented code and app id.
> +    const size_t hdr_plus_buf_size = payload_size + 6;
> +    hdr_plus_buf = av_malloc(hdr_plus_buf_size);
> +    if (!hdr_plus_buf)
> +        return AVERROR(ENOMEM);
> +
> +    uint8_t *payload = hdr_plus_buf;
> +    bytestream_put_byte(&payload, ITU_T_T35_COUNTRY_CODE_US);
> +    bytestream_put_be16(&payload, ITU_T_T35_PROVIDER_CODE_SMTPE);
> +    bytestream_put_be16(&payload, 0x01); // provider_oriented_code
> +    bytestream_put_byte(&payload, 0x04); // application_identifier
> +
> +    res = av_dynamic_hdr_plus_to_t35(hdr_plus, &payload, &payload_size);
> +    if (res < 0) {
> +        av_free(hdr_plus_buf);
> +        log_encoder_error(avctx, "Error encoding HDR10+ from side data");
> +        return res;
> +    }
> +
> +#if AOM_IMAGE_ABI_VERSION < 8

This can be removed. configure requires libaom >= 2.0.0; in that
version AOM_IMAGE_ABI_VERSION is 9.