[FFmpeg-devel] [PATCH] avformat/matroskadec: Parse encryption init info from streams.

[Jacob Trimble]

On Thu, Jul 12, 2018 at 5:05 PM Jacob Trimble <modmaker at google.com> wrote:
>
> Signed-off-by: Jacob Trimble <modmaker at google.com>
> ---
>  libavformat/matroskadec.c | 43 +++++++++++++++++++++++++++++----------
>  1 file changed, 32 insertions(+), 11 deletions(-)
>
> diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
> index 1ded431b80..bfef329e59 100644
> --- a/libavformat/matroskadec.c
> +++ b/libavformat/matroskadec.c
> @@ -2080,7 +2080,8 @@ static int matroska_parse_tracks(AVFormatContext *s)
>          int extradata_offset = 0;
>          uint32_t fourcc = 0;
>          AVIOContext b;
> -        char* key_id_base64 = NULL;
> +        char* key_id = NULL;
> +        int key_id_size = 0;
>          int bit_depth = -1;
>
>          /* Apply some sanity checks. */
> @@ -2133,14 +2134,8 @@ static int matroska_parse_tracks(AVFormatContext *s)
>                  if (encodings[0].encryption.key_id.size > 0) {
>                      /* Save the encryption key id to be stored later as a
>                         metadata tag. */
> -                    const int b64_size = AV_BASE64_SIZE(encodings[0].encryption.key_id.size);
> -                    key_id_base64 = av_malloc(b64_size);
> -                    if (key_id_base64 == NULL)
> -                        return AVERROR(ENOMEM);
> -
> -                    av_base64_encode(key_id_base64, b64_size,
> -                                     encodings[0].encryption.key_id.data,
> -                                     encodings[0].encryption.key_id.size);
> +                    key_id = encodings[0].encryption.key_id.data;
> +                    key_id_size = encodings[0].encryption.key_id.size;
>                  } else {
>                      encodings[0].scope = 0;
>                      av_log(matroska->ctx, AV_LOG_ERROR,
> @@ -2198,14 +2193,40 @@ static int matroska_parse_tracks(AVFormatContext *s)
>
>          st = track->stream = avformat_new_stream(s, NULL);
>          if (!st) {
> -            av_free(key_id_base64);
>              return AVERROR(ENOMEM);
>          }
>
> -        if (key_id_base64) {
> +        if (key_id) {
> +            AVEncryptionInitInfo *init_info;
> +            uint8_t *side_data;
> +            size_t side_data_size;
> +            const int b64_size = AV_BASE64_SIZE(key_id_size);
> +            char *key_id_base64 = av_malloc(b64_size);
> +            if (!key_id_base64)
> +                return AVERROR(ENOMEM);
> +            av_base64_encode(key_id_base64, b64_size, key_id, key_id_size);
> +
>              /* export encryption key id as base64 metadata tag */
>              av_dict_set(&st->metadata, "enc_key_id", key_id_base64, 0);
>              av_freep(&key_id_base64);
> +
> +
> +            /* Convert the key ID to a generic encryption init info */
> +            init_info = av_encryption_init_info_alloc(/* system_id_size */ 0, /* num_key_ids */ 1,
> +                                                      /* key_id_size */ key_id_size, /* data_size */ 0);
> +            if (!init_info)
> +                return AVERROR(ENOMEM);
> +            memcpy(init_info->key_ids[0], key_id, key_id_size);
> +            side_data = av_encryption_init_info_add_side_data(init_info, &side_data_size);
> +            av_encryption_init_info_free(init_info);
> +            if (!side_data)
> +                return AVERROR(ENOMEM);
> +            ret = av_stream_add_side_data(st, AV_PKT_DATA_ENCRYPTION_INIT_INFO,
> +                                          side_data, side_data_size);
> +            if (ret < 0) {
> +                av_free(side_data);
> +                return ret;
> +            }
>          }
>
>          if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC") &&
> --
> 2.18.0.203.gfac676dfb9-goog
>

Ping.