On Wed,  8 Jan 2014 03:25:38 +0100, Luca Barbato <[email protected]> wrote:
> From: Tomas Härdin <[email protected]>
> 
> Such files have IndexTableSegments which when parsed cover EditUnit ranges
> like this:
> 
>  [0,1)
>  [249,250)
>  [249,377)
>  [0,249)
> 
> where each interval is
> 
>  [IndexStartPosition, IndexStartPosition + IndexDuration)
> 
> This would be reduced to a sparse index like:
> 
>  [0,1), [249,250)
> 
> instead of the full range:
> 
>  [0,249), [249,377)
> 
> Sample: http://streams.videolan.org/issues/7302/TimeCode_HD.mxf
> Signed-off-by: Luca Barbato <[email protected]>
> ---
>  libavformat/mxfdec.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> index 7bca23d..2fc31bf 100644
> --- a/libavformat/mxfdec.c
> +++ b/libavformat/mxfdec.c
> @@ -980,19 +980,23 @@ static int mxf_get_sorted_table_segments(MXFContext 
> *mxf, int *nb_sorted_segment
>      /* sort segments by {BodySID, IndexSID, IndexStartPosition}, remove 
> duplicates while we're at it */
>      for (i = 0; i < nb_segments; i++) {
>          int best = -1, best_body_sid = -1, best_index_sid = -1, 
> best_index_start = -1;
> +        uint64_t best_index_duration = 0;
>  
>          for (j = 0; j < nb_segments; j++) {
>              MXFIndexTableSegment *s = unsorted_segments[j];
>  
>              /* Require larger BosySID, IndexSID or IndexStartPosition then 
> the previous entry. This removes duplicates.
>               * We want the smallest values for the keys than what we 
> currently have, unless this is the first such entry this time around.
> +             * If we come across an entry with the same IndexStartPosition 
> but larger IndexDuration, then we'll prefer it over the one we currently have.
>               */
>              if ((i == 0     || s->body_sid > last_body_sid || s->index_sid > 
> last_index_sid || s->index_start_position > last_index_start) &&
> -                (best == -1 || s->body_sid < best_body_sid || s->index_sid < 
> best_index_sid || s->index_start_position < best_index_start)) {
> +                (best == -1 || s->body_sid < best_body_sid || s->index_sid < 
> best_index_sid || s->index_start_position < best_index_start ||
> +                (s->index_start_position == best_index_start && 
> s->index_duration > best_index_duration))) {
>                  best             = j;
>                  best_body_sid    = s->body_sid;
>                  best_index_sid   = s->index_sid;
>                  best_index_start = s->index_start_position;
> +                best_index_duration = s->index_duration;
>              }
>          }
>  
> -- 
> 1.8.5.1
> 

Wow, this format really is insane.

The patch looks fine.

-- 
Anton Khirnov
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