[FFmpeg-devel] [PATCH 2/2] avformat/mxfenc: fix DNxHD GC element_type

[Matthieu Bouron]

On Tue, Dec 14, 2021 at 04:27:43PM +0100, Nicolas Gaullier wrote:
> The values for the essence element type were updated in the spec
> from 0x05/0x06 (ST2019-4 2008) to 0x0C/0x0D (ST2019-4 2009).
> 
> Fixes ticket #6380.
> 
> Thanks-to: Philip de Nier <philip.denier at bbc.co.uk>
> Thanks-to: Matthieu Bouron <matthieu.bouron at gmail.com>
> 
> Signed-off-by: Nicolas Gaullier <nicolas.gaullier at cji.paris>
> ---
>  libavformat/mxfenc.c      | 9 ++++++++-
>  tests/ref/lavf/mxf_opatom | 2 +-
>  2 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/libavformat/mxfenc.c b/libavformat/mxfenc.c
> index 512baa45d3..bae41a774d 100644
> --- a/libavformat/mxfenc.c
> +++ b/libavformat/mxfenc.c
> @@ -32,6 +32,7 @@
>   * SMPTE 379M MXF Generic Container
>   * SMPTE 381M Mapping MPEG Streams into the MXF Generic Container
>   * SMPTE 422M Mapping JPEG 2000 Codestreams into the MXF Generic Container
> + * SMPTE ST2019-4 (2009 or later) Mapping VC-3 Coding Units into the MXF Generic Container
>   * SMPTE RP210: SMPTE Metadata Dictionary
>   * SMPTE RP224: Registry of SMPTE Universal Labels
>   */
> @@ -182,7 +183,7 @@ static const MXFContainerEssenceEntry mxf_essence_container_uls[] = {
>        mxf_write_cdci_desc },
>      // DNxHD
>      { { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x0A,0x0D,0x01,0x03,0x01,0x02,0x11,0x01,0x00 },
> -      { 0x06,0x0E,0x2B,0x34,0x01,0x02,0x01,0x01,0x0D,0x01,0x03,0x01,0x15,0x01,0x05,0x00 },
> +      { 0x06,0x0E,0x2B,0x34,0x01,0x02,0x01,0x01,0x0D,0x01,0x03,0x01,0x15,0x01,0x0C,0x00 },
>        { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x0A,0x04,0x01,0x02,0x02,0x71,0x01,0x00,0x00 },
>        mxf_write_cdci_desc },
>      // JPEG2000
> @@ -2674,6 +2675,12 @@ static int mxf_init(AVFormatContext *s)
>  
>          memcpy(sc->track_essence_element_key, mxf_essence_container_uls[sc->index].element_ul, 15);
>          sc->track_essence_element_key[15] = present[sc->index];
> +        if (s->oformat == &ff_mxf_opatom_muxer && st->codecpar->codec_id == AV_CODEC_ID_DNXHD) {
> +            // clip-wrapping requires 0x0D per ST2019-4:2009 or 0x06 per previous version ST2019-4:2008
> +            // we choose to use 0x06 instead 0x0D to be compatible with AVID systems
> +            // and produce mxf files with the most relevant flavour for opatom
> +            sc->track_essence_element_key[14] = 0x06;
> +        }
>          PRINT_KEY(s, "track essence element key", sc->track_essence_element_key);
>  
>          if (!present[sc->index])
> diff --git a/tests/ref/lavf/mxf_opatom b/tests/ref/lavf/mxf_opatom
> index b818f26c36..e34cf2559e 100644
> --- a/tests/ref/lavf/mxf_opatom
> +++ b/tests/ref/lavf/mxf_opatom
> @@ -1,3 +1,3 @@
> -e558e50a94d88762e07ab8149aced7b9 *tests/data/lavf/lavf.mxf_opatom
> +aab6397829bd90f0c77a3f9fde53bb9c *tests/data/lavf/lavf.mxf_opatom
>  4717625 tests/data/lavf/lavf.mxf_opatom
>  tests/data/lavf/lavf.mxf_opatom CRC=0xf55aa22a
> -- 
> 2.34.0

LGTM, thanks.

Matthieu

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