[FFmpeg-devel] [PATCH] avcodec/mpeg4videodec: Use more specific error codes

[James Almer]

On 3/10/2018 2:34 PM, Michael Niedermayer wrote:
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavcodec/mpeg4videodec.c | 100 +++++++++++++++++++++++----------------------
>  1 file changed, 51 insertions(+), 49 deletions(-)
> 
> diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
> index 19210d97fe..1357b357a8 100644
> --- a/libavcodec/mpeg4videodec.c
> +++ b/libavcodec/mpeg4videodec.c
> @@ -448,7 +448,7 @@ int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
>  
>      /* is there enough space left for a video packet + header */
>      if (get_bits_count(&s->gb) > s->gb.size_in_bits - 20)
> -        return -1;
> +        return AVERROR_INVALIDDATA;
>  
>      for (len = 0; len < 32; len++)
>          if (get_bits1(&s->gb))
> @@ -456,7 +456,7 @@ int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
>  
>      if (len != ff_mpeg4_get_video_packet_prefix_length(s)) {
>          av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
> -        return -1;
> +        return AVERROR_INVALIDDATA;
>      }
>  
>      if (ctx->shape != RECT_SHAPE) {
> @@ -468,7 +468,7 @@ int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
>      if (mb_num >= s->mb_num || !mb_num) {
>          av_log(s->avctx, AV_LOG_ERROR,
>                 "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
> -        return -1;
> +        return AVERROR_INVALIDDATA;
>      }
>  
>      s->mb_x = mb_num % s->mb_width;
> @@ -597,7 +597,7 @@ static inline int mpeg4_decode_dc(MpegEncContext *s, int n, int *dir_ptr)
>  
>      if (code < 0 || code > 9 /* && s->nbit < 9 */) {
>          av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
> -        return -1;
> +        return AVERROR_INVALIDDATA;
>      }
>  
>      if (code == 0) {
> @@ -620,7 +620,7 @@ static inline int mpeg4_decode_dc(MpegEncContext *s, int n, int *dir_ptr)
>              if (get_bits1(&s->gb) == 0) { /* marker */
>                  if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)) {
>                      av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
> -                    return -1;
> +                    return AVERROR_INVALIDDATA;
>                  }
>              }
>          }
> @@ -664,7 +664,7 @@ static int mpeg4_decode_partition_a(Mpeg4DecContext *ctx)
>                      if (cbpc < 0) {
>                          av_log(s->avctx, AV_LOG_ERROR,
>                                 "mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
> -                        return -1;
> +                        return cbpc;

get_vlc2() seems to return -1 on error, so nothing really changes with
this. Same with every other similar call, just hardcode
AVERROR_INVALIDDATA as well instead.