[FFmpeg-devel] [PATCH v6 3/9] avformat: add vvc raw demux

[Mark Thompson]

On 17/02/2021 01:51, Nuo Mi wrote:
> ---
>   libavformat/Makefile     |  1 +
>   libavformat/allformats.c |  1 +
>   libavformat/vvcdec.c     | 61 ++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 63 insertions(+)
>   create mode 100644 libavformat/vvcdec.c
> 
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index 10fee749c8..2b9d0eee7f 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -564,6 +564,7 @@ OBJS-$(CONFIG_VOC_MUXER)                 += vocenc.o voc.o
>   OBJS-$(CONFIG_VPK_DEMUXER)               += vpk.o
>   OBJS-$(CONFIG_VPLAYER_DEMUXER)           += vplayerdec.o subtitles.o
>   OBJS-$(CONFIG_VQF_DEMUXER)               += vqf.o
> +OBJS-$(CONFIG_VVC_DEMUXER)               += vvcdec.o rawdec.o
>   OBJS-$(CONFIG_W64_DEMUXER)               += wavdec.o w64.o pcm.o
>   OBJS-$(CONFIG_W64_MUXER)                 += wavenc.o w64.o
>   OBJS-$(CONFIG_WAV_DEMUXER)               += wavdec.o pcm.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index f837ddabc8..fb06723fb9 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -463,6 +463,7 @@ extern AVOutputFormat ff_voc_muxer;
>   extern AVInputFormat  ff_vpk_demuxer;
>   extern AVInputFormat  ff_vplayer_demuxer;
>   extern AVInputFormat  ff_vqf_demuxer;
> +extern AVInputFormat  ff_vvc_demuxer;
>   extern AVInputFormat  ff_w64_demuxer;
>   extern AVOutputFormat ff_w64_muxer;
>   extern AVInputFormat  ff_wav_demuxer;
> diff --git a/libavformat/vvcdec.c b/libavformat/vvcdec.c
> new file mode 100644
> index 0000000000..149f39f28e
> --- /dev/null
> +++ b/libavformat/vvcdec.c
> @@ -0,0 +1,61 @@
> +/*
> + * RAW VVC video demuxer
> + * Copyright (c) 2020 Nuo Mi <nuomi2021 at gmail.com>
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include "libavcodec/vvc.h"
> +
> +#include "avformat.h"
> +#include "rawdec.h"
> +
> +static int vvc_probe(const AVProbeData *p)
> +{
> +    uint32_t code = -1;
> +    int sps = 0, pps = 0, irap = 0;
> +    int i;
> +
> +    for (i = 0; i < p->buf_size - 1; i++) {
> +        code = (code << 8) + p->buf[i];
> +        if ((code & 0xffffff00) == 0x100) {
> +            uint8_t nal2 = p->buf[i + 1];
> +            int type = (nal2 & 0xF8) >> 3;
> +
> +            if (code & 0xc0) // forbidden_zero_bit and nuh_reserved_zero_bit
> +                return 0;
> +
> +            if ((nal2 & 0x7) == 0) // nuh_temporal_id_plus1
> +                return 0;
> +
> +            switch (type) {
> +            case VVC_SPS_NUT:       sps++;  break;
> +            case VVC_PPS_NUT:       pps++;  break;
> +            case VVC_IDR_N_LP:
> +            case VVC_IDR_W_RADL:
> +            case VVC_CRA_NUT:
> +            case VVC_GDR_NUT:       irap++; break;
> +            }
> +        }
> +    }
> +
> +    if (sps && pps && irap)
> +        return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg

How well does this test fully distinguish from previous standards using the same start code style?

(Can I have an H.264 or H.265 raw stream which passes this test?  Can an H.266 stream ever pass the test for those codecs, implying we need to update them?)

> +    return 0;
> +}
> +
> +FF_DEF_RAWVIDEO_DEMUXER(vvc, "raw VVC video", vvc_probe, "h266,266,vvc", AV_CODEC_ID_VVC)
> 

- Mark