[FFmpeg-devel] [PATCH v2 3/4] avformat/movenc: fix writing reserved bits in EC3SpecificBox

[Baptiste Coudurier]

> On Jun 5, 2025, at 5:14 PM, James Almer <jamrial at gmail.com> wrote:
> 
> As described in section F.6.1 from ETSI TS 102 366.
> 
> Found-by: nyanmisaka
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
> libavformat/movenc.c         | 2 +-
> tests/ref/fate/copy-trac3074 | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/libavformat/movenc.c b/libavformat/movenc.c
> index 5941f82521..7bcdc2463d 100644
> --- a/libavformat/movenc.c
> +++ b/libavformat/movenc.c
> @@ -618,7 +618,7 @@ static int mov_write_eac3_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *tra
>         put_bits(&pbc, 3, info->substream[i].bsmod);
>         put_bits(&pbc, 3, info->substream[i].acmod);
>         put_bits(&pbc, 1, info->substream[i].lfeon);
> -        put_bits(&pbc, 5, 0); /* reserved */
> +        put_bits(&pbc, 3, 0); /* reserved */
>         put_bits(&pbc, 4, info->substream[i].num_dep_sub);
>         if (!info->substream[i].num_dep_sub) {
>             put_bits(&pbc, 1, 0); /* reserved */
> diff --git a/tests/ref/fate/copy-trac3074 b/tests/ref/fate/copy-trac3074
> index 53ba27e920..9ed42c8d8d 100644
> --- a/tests/ref/fate/copy-trac3074
> +++ b/tests/ref/fate/copy-trac3074
> @@ -1,5 +1,5 @@
> -36fcc0a62695bcf93068fcfe68283ee9 *tests/data/fate/copy-trac3074.mp4
> -334016 tests/data/fate/copy-trac3074.mp4
> +5b4a3ed9de3b2a92e5dcb127bca12e68 *tests/data/fate/copy-trac3074.mp4
> +334015 tests/data/fate/copy-trac3074.mp4
> #tb 0: 1/48000
> #media_type 0: audio
> #codec_id 0: eac3

Looks good, you might wanna update the size of the buffer too in this commit, 
or do it in the atmos patch I guess

— 
Baptiste