[FFmpeg-devel] [PATCH 1/2] avformat/mov: fix frag_index.current out of sync

[Steven Liu]

Zhao Zhili <quinkblack at foxmail.com>于2022年7月31日 周日01:15写道：

> From: Zhao Zhili <zhilizhao at tencent.com>
>
> frag_index.current is used by cenc_filter, and is updated inside
> mov_read_moof. It can out of sync regarding to mov_read_packet.
>
> Partly fix ticket #9807.
> ---
>  libavformat/mov.c | 27 ++++++++++++++++++++++++++-
>  1 file changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index a09a762d91..ce12a9e4f1 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -7095,6 +7095,31 @@ static int cenc_decrypt(MOVContext *c,
> MOVStreamContext *sc, AVEncryptionInfo *s
>      }
>  }
>
> +static MOVFragmentStreamInfo
> *get_frag_stream_info_from_pkt(MOVFragmentIndex *frag_index, AVPacket *pkt,
> int id)
> +{
> +    int current = frag_index->current;
> +
> +    if (!frag_index->nb_items)
> +        return NULL;
> +
> +    // Check frag_index->current is the right one for pkt. It can out of
> sync.
> +    if (current >= 0 && current < frag_index->nb_items) {
> +        if (frag_index->item[current].moof_offset < pkt->pos &&
> +            (current + 1 == frag_index->nb_items ||
> +             frag_index->item[current + 1].moof_offset > pkt->pos))
> +            return get_frag_stream_info(frag_index, current, id);
> +    }
> +
> +
> +    for (int i = 0; i < frag_index->nb_items; i++) {
> +        if (frag_index->item[i].moof_offset > pkt->pos)
> +            break;
> +        current = i;
> +    }
> +    frag_index->current = current;
> +    return get_frag_stream_info(frag_index, current, id);
> +}
> +
>  static int cenc_filter(MOVContext *mov, AVStream* st, MOVStreamContext
> *sc, AVPacket *pkt, int current_index)
>  {
>      MOVFragmentStreamInfo *frag_stream_info;
> @@ -7102,7 +7127,7 @@ static int cenc_filter(MOVContext *mov, AVStream*
> st, MOVStreamContext *sc, AVPa
>      AVEncryptionInfo *encrypted_sample;
>      int encrypted_index, ret;
>
> -    frag_stream_info = get_frag_stream_info(&mov->frag_index,
> mov->frag_index.current, st->id);
> +    frag_stream_info = get_frag_stream_info_from_pkt(&mov->frag_index,
> pkt, st->id);
>      encrypted_index = current_index;
>      encryption_index = NULL;
>      if (frag_stream_info) {
> --
> 2.34.1
>

https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=7071

What about this patch to fix this ticket？

>
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