[libav-stable] [libav-devel] [PATCH] prores: Add a codepath for decoding errors

Sean McGovern gseanmcg at gmail.com
Thu Jan 9 01:41:49 CET 2014


On Thu, Oct 10, 2013 at 2:41 AM, Luca Barbato <lu_zero at gentoo.org> wrote:

> ---
>
> Since Kostya wanted me to.
>
>  libavcodec/proresdec.c | 71
> +++++++++++++++++++++++++++++---------------------
>  1 file changed, 42 insertions(+), 29 deletions(-)
>
> diff --git a/libavcodec/proresdec.c b/libavcodec/proresdec.c
> index 5687231..db998fa 100644
> --- a/libavcodec/proresdec.c
> +++ b/libavcodec/proresdec.c
> @@ -369,10 +369,10 @@ static inline void decode_dc_coeffs(GetBitContext
> *gb, int16_t *out,
>  /**
>   * Decode AC coefficients for all blocks in a slice.
>   */
> -static inline void decode_ac_coeffs(GetBitContext *gb, int16_t *out,
> -                                    int blocks_per_slice,
> -                                    int plane_size_factor,
> -                                    const uint8_t *scan)
> +static inline int decode_ac_coeffs(GetBitContext *gb, int16_t *out,
> +                                   int blocks_per_slice,
> +                                   int plane_size_factor,
> +                                   const uint8_t *scan)
>  {
>      int pos, block_mask, run, level, sign, run_cb_index, lev_cb_index;
>      int max_coeffs, bits_left;
> @@ -390,13 +390,13 @@ static inline void decode_ac_coeffs(GetBitContext
> *gb, int16_t *out,
>
>          bits_left = get_bits_left(gb);
>          if (bits_left <= 0 || (bits_left <= 8 && !show_bits(gb,
> bits_left)))
> -            return;
> +            return AVERROR_INVALIDDATA;
>
>          run = decode_vlc_codeword(gb,
> ff_prores_ac_codebook[run_cb_index]);
>
>          bits_left = get_bits_left(gb);
>          if (bits_left <= 0 || (bits_left <= 8 && !show_bits(gb,
> bits_left)))
> -            return;
> +            return AVERROR_INVALIDDATA;
>
>          level = decode_vlc_codeword(gb,
> ff_prores_ac_codebook[lev_cb_index]) + 1;
>
> @@ -408,22 +408,24 @@ static inline void decode_ac_coeffs(GetBitContext
> *gb, int16_t *out,
>          out[((pos & block_mask) << 6) + scan[pos >> plane_size_factor]] =
>              (level ^ sign) - sign;
>      }
> +
> +    return 0;
>  }
>
>
>  /**
>   * Decode a slice plane (luma or chroma).
>   */
> -static void decode_slice_plane(ProresContext *ctx, ProresThreadData *td,
> -                               const uint8_t *buf,
> -                               int data_size, uint16_t *out_ptr,
> -                               int linesize, int mbs_per_slice,
> -                               int blocks_per_mb, int plane_size_factor,
> -                               const int16_t *qmat, int is_chroma)
> +static int decode_slice_plane(ProresContext *ctx, ProresThreadData *td,
> +                              const uint8_t *buf,
> +                              int data_size, uint16_t *out_ptr,
> +                              int linesize, int mbs_per_slice,
> +                              int blocks_per_mb, int plane_size_factor,
> +                              const int16_t *qmat, int is_chroma)
>  {
>      GetBitContext gb;
>      int16_t *block_ptr;
> -    int mb_num, blocks_per_slice;
> +    int mb_num, blocks_per_slice, ret;
>
>      blocks_per_slice = mbs_per_slice * blocks_per_mb;
>
> @@ -433,8 +435,10 @@ static void decode_slice_plane(ProresContext *ctx,
> ProresThreadData *td,
>
>      decode_dc_coeffs(&gb, td->blocks, blocks_per_slice);
>
> -    decode_ac_coeffs(&gb, td->blocks, blocks_per_slice,
> -                     plane_size_factor, ctx->scantable.permutated);
> +    ret = decode_ac_coeffs(&gb, td->blocks, blocks_per_slice,
> +                           plane_size_factor, ctx->scantable.permutated);
> +    if (ret < 0)
> +        return ret;
>
>      /* inverse quantization, inverse transform and output */
>      block_ptr = td->blocks;
> @@ -468,6 +472,7 @@ static void decode_slice_plane(ProresContext *ctx,
> ProresThreadData *td,
>              }
>          }
>      }
> +    return 0;
>  }
>
>
> @@ -560,6 +565,7 @@ static int decode_slice(AVCodecContext *avctx, void
> *tdata)
>      int y_data_size, u_data_size, v_data_size, a_data_size;
>      int y_linesize, u_linesize, v_linesize, a_linesize;
>      int coff[4];
> +    int ret;
>
>      buf             = ctx->slice_data[slice_num].index;
>      slice_data_size = ctx->slice_data[slice_num + 1].index - buf;
> @@ -631,24 +637,31 @@ static int decode_slice(AVCodecContext *avctx, void
> *tdata)
>      }
>
>      /* decode luma plane */
> -    decode_slice_plane(ctx, td, buf + coff[0], y_data_size,
> -                       (uint16_t*) y_data, y_linesize,
> -                       mbs_per_slice, 4, slice_width_factor + 2,
> -                       td->qmat_luma_scaled, 0);
> +    ret = decode_slice_plane(ctx, td, buf + coff[0], y_data_size,
> +                             (uint16_t*) y_data, y_linesize,
> +                             mbs_per_slice, 4, slice_width_factor + 2,
> +                             td->qmat_luma_scaled, 0);
> +
> +    if (ret < 0)
> +        return ret;
>
>      /* decode U chroma plane */
> -    decode_slice_plane(ctx, td, buf + coff[1], u_data_size,
> -                       (uint16_t*) u_data, u_linesize,
> -                       mbs_per_slice, ctx->num_chroma_blocks,
> -                       slice_width_factor + ctx->chroma_factor - 1,
> -                       td->qmat_chroma_scaled, 1);
> +    ret = decode_slice_plane(ctx, td, buf + coff[1], u_data_size,
> +                             (uint16_t*) u_data, u_linesize,
> +                             mbs_per_slice, ctx->num_chroma_blocks,
> +                             slice_width_factor + ctx->chroma_factor - 1,
> +                             td->qmat_chroma_scaled, 1);
> +    if (ret < 0)
> +        return ret;
>
>      /* decode V chroma plane */
> -    decode_slice_plane(ctx, td, buf + coff[2], v_data_size,
> -                       (uint16_t*) v_data, v_linesize,
> -                       mbs_per_slice, ctx->num_chroma_blocks,
> -                       slice_width_factor + ctx->chroma_factor - 1,
> -                       td->qmat_chroma_scaled, 1);
> +    ret = decode_slice_plane(ctx, td, buf + coff[2], v_data_size,
> +                             (uint16_t*) v_data, v_linesize,
> +                             mbs_per_slice, ctx->num_chroma_blocks,
> +                             slice_width_factor + ctx->chroma_factor - 1,
> +                             td->qmat_chroma_scaled, 1);
> +    if (ret < 0)
> +        return ret;
>
>      /* decode alpha plane if available */
>      if (a_data && a_data_size)
> --
>


Oops, ignore previous, it's a revert of this one that causes the tests to
succeed again.

-- Sean McG.
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