avformat/mxfdec: Fix av_log context

Fixes: out of array access
Fixes: mxf-crash-1c2e59bf07a34675bfb3ada5e1ec22fa9f38f923

Found-by: Paul Ch <paulcher@icloud.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
static int mxf_get_sorted_table_segments(MXFContext *mxf, int *nb_sorted_segments, MXFIndexTableSegment ***sorted_segments)
{
    int i, j, nb_segments = 0;
    MXFIndexTableSegment **unsorted_segments;
    int last_body_sid = -1, last_index_sid = -1, last_index_start = -1;

    /* count number of segments, allocate arrays and copy unsorted segments */
    for (i = 0; i < mxf->metadata_sets_count; i++)
        if (mxf->metadata_sets[i]->type == IndexTableSegment)
            nb_segments++;

    if (!nb_segments)
        return AVERROR_INVALIDDATA;

    if (!(unsorted_segments = av_calloc(nb_segments, sizeof(*unsorted_segments))) ||
        !(*sorted_segments  = av_calloc(nb_segments, sizeof(**sorted_segments)))) {
        av_freep(sorted_segments);
        av_free(unsorted_segments);
        return AVERROR(ENOMEM);
    }

    for (i = j = 0; i < mxf->metadata_sets_count; i++)
        if (mxf->metadata_sets[i]->type == IndexTableSegment)
            unsorted_segments[j++] = (MXFIndexTableSegment*)mxf->metadata_sets[i];

    *nb_sorted_segments = 0;

    /* 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->body_sid == last_body_sid && s->index_sid >  last_index_sid ||
                 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->body_sid == best_body_sid && s->index_sid <  best_index_sid ||
                 s->body_sid == best_body_sid && s->index_sid == best_index_sid && s->index_start_position <  best_index_start ||
                 s->body_sid == best_body_sid && s->index_sid == best_index_sid && 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;
            }
        }

        /* no suitable entry found -> we're done */
        if (best == -1)
            break;

        (*sorted_segments)[(*nb_sorted_segments)++] = unsorted_segments[best];
        last_body_sid    = best_body_sid;
        last_index_sid   = best_index_sid;
        last_index_start = best_index_start;
    }

    av_free(unsorted_segments);

    return 0;
}

static int mxf_get_sorted_table_segments(MXFContext *mxf, int *nb_sorted_segments, MXFIndexTableSegment ***sorted_segments)
{
    int i, j, nb_segments = 0;
    MXFIndexTableSegment **unsorted_segments;
    int last_body_sid = -1, last_index_sid = -1, last_index_start = -1;

    /* count number of segments, allocate arrays and copy unsorted segments */
    for (i = 0; i < mxf->metadata_sets_count; i++)
        if (mxf->metadata_sets[i]->type == IndexTableSegment)
            nb_segments++;

    if (!nb_segments)
        return AVERROR_INVALIDDATA;

    if (!(unsorted_segments = av_calloc(nb_segments, sizeof(*unsorted_segments))) ||
        !(*sorted_segments  = av_calloc(nb_segments, sizeof(**sorted_segments)))) {
        av_freep(sorted_segments);
        av_free(unsorted_segments);
        return AVERROR(ENOMEM);
    }

    for (i = j = 0; i < mxf->metadata_sets_count; i++)
        if (mxf->metadata_sets[i]->type == IndexTableSegment)
            unsorted_segments[j++] = (MXFIndexTableSegment*)mxf->metadata_sets[i];

    *nb_sorted_segments = 0;

    /* 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->body_sid == last_body_sid && s->index_sid >  last_index_sid ||
                 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->body_sid == best_body_sid && s->index_sid <  best_index_sid ||
                 s->body_sid == best_body_sid && s->index_sid == best_index_sid && s->index_start_position <  best_index_start ||
                 s->body_sid == best_body_sid && s->index_sid == best_index_sid && 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;
            }
        }

        /* no suitable entry found -> we're done */
        if (best == -1)
            break;

        (*sorted_segments)[(*nb_sorted_segments)++] = unsorted_segments[best];
        last_body_sid    = best_body_sid;
        last_index_sid   = best_index_sid;
        last_index_start = best_index_start;
    }

    av_free(unsorted_segments);

    return 0;
}
