[FFmpeg-devel] [PATCH] libavformat/movenc: Support encryption of H265 stream in AnnexB format

[Вадим Бездушный]

Ping.

This change is quite simple and should be quick to review. Feel free to ask
any questions

On Mon, 1 Mar 2021, 14:54 Vadym Bezdushnyi, <vadim.bezdush at gmail.com> wrote:

> Add an ability to accept H265 AnnexB stream at encryption
> similar to how its done for H264 AnnexB stream.
>
> Steps to test:
>
> 1. Create h265 test files - mp4 and h265 AnnexB streams:
> ffmpeg -f lavfi -i testsrc=duration=10:size=640x480:rate=30 -c:v hevc
> input_h265.mp4
> ffmpeg -f lavfi -i testsrc=duration=10:size=640x480:rate=30 -c:v hevc
> -bsf:v hevc_mp4toannexb input_h265.h265
>
> 2. Encrypt and decrypt files. Put appropriate input file name here:
> input_h265.mp4 or input_h265.h265
> ffmpeg -i input_h265.h265 -vcodec copy -acodec copy -encryption_scheme
> cenc-aes-ctr \
>  -encryption_key 00000000000000000000000000000000 -encryption_kid
> 00000000000000000000000000000000 \
>  encrypted_h265.mp4
> ffplay -i encrypted_h265.mp4  -decryption_key
> 00000000000000000000000000000000
>
> Signed-off-by: Vadym Bezdushnyi <vadim.bezdush at gmail.com>
> ---
>  libavformat/movenc.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/libavformat/movenc.c b/libavformat/movenc.c
> index 545b0885ae..0433968cd2 100644
> --- a/libavformat/movenc.c
> +++ b/libavformat/movenc.c
> @@ -5685,7 +5685,15 @@ int ff_mov_write_packet(AVFormatContext *s,
> AVPacket *pkt)
>                  return ret;
>              avio_write(pb, reformatted_data, size);
>          } else {
> -            size = ff_hevc_annexb2mp4(pb, pkt->data, pkt->size, 0, NULL);
> +            if (trk->cenc.aes_ctr) {
> +                size = ff_mov_cenc_avc_parse_nal_units(&trk->cenc, pb,
> pkt->data, size);
> +                if (size < 0) {
> +                    ret = size;
> +                    goto err;
> +                }
> +            } else {
> +                size = ff_hevc_annexb2mp4(pb, pkt->data, pkt->size, 0,
> NULL);
> +            }
>          }
>      } else if (par->codec_id == AV_CODEC_ID_AV1) {
>          if (trk->hint_track >= 0 && trk->hint_track < mov->nb_streams) {
> @@ -5727,6 +5735,9 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket
> *pkt)
>              if (par->codec_id == AV_CODEC_ID_H264 && par->extradata_size
> > 4) {
>                  int nal_size_length = (par->extradata[4] & 0x3) + 1;
>                  ret = ff_mov_cenc_avc_write_nal_units(s, &trk->cenc,
> nal_size_length, pb, pkt->data, size);
> +            } else if(par->codec_id == AV_CODEC_ID_HEVC &&
> par->extradata_size > 21) {
> +                int nal_size_length = (par->extradata[21] & 0x3) + 1;
> +                ret = ff_mov_cenc_avc_write_nal_units(s, &trk->cenc,
> nal_size_length, pb, pkt->data, size);
>              } else {
>                  ret = ff_mov_cenc_write_packet(&trk->cenc, pb, pkt->data,
> size);
>              }
> @@ -6711,7 +6722,8 @@ static int mov_init(AVFormatContext *s)
>
>          if (mov->encryption_scheme == MOV_ENC_CENC_AES_CTR) {
>              ret = ff_mov_cenc_init(&track->cenc, mov->encryption_key,
> -                track->par->codec_id == AV_CODEC_ID_H264, s->flags &
> AVFMT_FLAG_BITEXACT);
> +                (track->par->codec_id == AV_CODEC_ID_H264 ||
> track->par->codec_id == AV_CODEC_ID_HEVC),
> +                s->flags & AVFMT_FLAG_BITEXACT);
>              if (ret)
>                  return ret;
>          }
> --
> 2.30.0
>
>