[FFmpeg-devel] [PATCH] avformat:matroskadec: use a define to mark the EBML length is unknown

[Paul B Mahol]

On 2/23/19, Steve Lhomme <robUx4 at ycbcr.xyz> wrote:
> From: Steve Lhomme <robux4 at ycbcr.xyz>
>
> ---
>  libavformat/matroskadec.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
> index 5aa8a105dc..0e3a6890c1 100644
> --- a/libavformat/matroskadec.c
> +++ b/libavformat/matroskadec.c
> @@ -68,6 +68,8 @@
>
>  #include "qtpalette.h"
>
> +#define EBML_UNKNOWN_LENGTH  UINT64_MAX /* EBML unknown length, in uint64_t
> */
> +
>  typedef enum {
>      EBML_NONE,
>      EBML_UINT,
> @@ -869,7 +871,7 @@ static int ebml_read_length(MatroskaDemuxContext
> *matroska, AVIOContext *pb,
>  {
>      int res = ebml_read_num(matroska, pb, 8, number);
>      if (res > 0 && *number + 1 == 1ULL << (7 * res))
> -        *number = 0xffffffffffffffULL;
> +        *number = EBML_UNKNOWN_LENGTH;
>      return res;
>  }
>
> @@ -1049,7 +1051,7 @@ static int ebml_parse_id(MatroskaDemuxContext
> *matroska, EbmlSyntax *syntax,
>              break;
>      if (!syntax[i].id && id == MATROSKA_ID_CLUSTER &&
>          matroska->num_levels > 0                   &&
> -        matroska->levels[matroska->num_levels - 1].length ==
> 0xffffffffffffff)
> +        matroska->levels[matroska->num_levels - 1].length ==
> EBML_UNKNOWN_LENGTH)
>          return 0;  // we reached the end of an unknown size cluster
>      if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32) {
>          av_log(matroska->ctx, AV_LOG_DEBUG, "Unknown entry 0x%"PRIX32"\n",
> id);
> @@ -1201,7 +1203,7 @@ static int ebml_parse_elem(MatroskaDemuxContext
> *matroska,
>              MatroskaLevel *level = &matroska->levels[matroska->num_levels -
> 1];
>              AVIOContext *pb = matroska->ctx->pb;
>              int64_t pos = avio_tell(pb);
> -            if (level->length != (uint64_t) -1 &&
> +            if (level->length != EBML_UNKNOWN_LENGTH &&
>                  (pos + length) > (level->start + level->length)) {
>                  av_log(matroska->ctx, AV_LOG_ERROR,
>                         "Invalid length 0x%"PRIx64" > 0x%"PRIx64" in
> parent\n",
> @@ -1610,7 +1612,7 @@ static int
> matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska,
>              ret = AVERROR_INVALIDDATA;
>          } else {
>              level.start  = 0;
> -            level.length = (uint64_t) -1;
> +            level.length = EBML_UNKNOWN_LENGTH;
>              matroska->levels[matroska->num_levels] = level;
>              matroska->num_levels++;
>              matroska->current_id                   = 0;
> @@ -1620,7 +1622,7 @@ static int
> matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska,
>              /* remove dummy level */
>              while (matroska->num_levels) {
>                  uint64_t length =
> matroska->levels[--matroska->num_levels].length;
> -                if (length == (uint64_t) -1)
> +                if (length == EBML_UNKNOWN_LENGTH)
>                      break;
>              }
>          }
> --
> 2.18.0
>
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>

lgtm