AVFilterFormats *ff_merge_samplerates(AVFilterFormats *a,
AVFilterFormats *b)
{
AVFilterFormats *ret = NULL;
if (a == b) return a;
if (a->nb_formats && b->nb_formats) {
MERGE_FORMATS(ret, a, b, formats, nb_formats, AVFilterFormats, fail);
} else if (a->nb_formats) {
MERGE_REF(a, b, formats, AVFilterFormats, fail);
ret = a;
} else {
MERGE_REF(b, a, formats, AVFilterFormats, fail);
ret = b;
}
return ret;
fail:
if (ret) {
av_freep(&ret->refs);
av_freep(&ret->formats);
}
av_freep(&ret);
return NULL;
}
AVFilterChannelLayouts *ff_merge_channel_layouts(AVFilterChannelLayouts *a,
AVFilterChannelLayouts *b)
{
AVFilterChannelLayouts *ret = NULL;
if (a == b) return a;
if (a->nb_channel_layouts && b->nb_channel_layouts) {
MERGE_FORMATS(ret, a, b, channel_layouts, nb_channel_layouts,
AVFilterChannelLayouts, fail);
} else if (a->nb_channel_layouts) {
MERGE_REF(a, b, channel_layouts, AVFilterChannelLayouts, fail);
ret = a;
} else {
MERGE_REF(b, a, channel_layouts, AVFilterChannelLayouts, fail);
ret = b;
}
return ret;
fail:
if (ret) {
av_freep(&ret->refs);
av_freep(&ret->channel_layouts);
}
av_freep(&ret);
return NULL;
}
AVFilterFormats *ff_merge_formats(AVFilterFormats *a, AVFilterFormats *b,
enum AVMediaType type)
{
AVFilterFormats *ret = NULL;
int i, j;
int alpha1=0, alpha2=0;
int chroma1=0, chroma2=0;
if (a == b)
return a;
/* Do not lose chroma or alpha in merging.
It happens if both lists have formats with chroma (resp. alpha), but
the only formats in common do not have it (e.g. YUV+gray vs.
RGB+gray): in that case, the merging would select the gray format,
possibly causing a lossy conversion elsewhere in the graph.
To avoid that, pretend that there are no common formats to force the
insertion of a conversion filter. */
if (type == AVMEDIA_TYPE_VIDEO)
for (i = 0; i < a->nb_formats; i++)
for (j = 0; j < b->nb_formats; j++) {
const AVPixFmtDescriptor *adesc = av_pix_fmt_desc_get(a->formats[i]);
const AVPixFmtDescriptor *bdesc = av_pix_fmt_desc_get(b->formats[j]);
alpha2 |= adesc->flags & bdesc->flags & AV_PIX_FMT_FLAG_ALPHA;
chroma2|= adesc->nb_components > 1 && bdesc->nb_components > 1;
if (a->formats[i] == b->formats[j]) {
alpha1 |= adesc->flags & AV_PIX_FMT_FLAG_ALPHA;
chroma1|= adesc->nb_components > 1;
}
}
// If chroma or alpha can be lost through merging then do not merge
if (alpha2 > alpha1 || chroma2 > chroma1)
return NULL;
MERGE_FORMATS(ret, a, b, formats, nb_formats, AVFilterFormats, fail);
return ret;
fail:
if (ret) {
av_freep(&ret->refs);
av_freep(&ret->formats);
}
av_freep(&ret);
return NULL;
}
AVFilterFormats *ff_merge_formats(AVFilterFormats *a, AVFilterFormats *b)
{
AVFilterFormats *ret = NULL;
if (a == b)
return a;
MERGE_FORMATS(ret, a, b, formats, format_count, AVFilterFormats, fail);
return ret;
fail:
if (ret) {
av_freep(&ret->refs);
av_freep(&ret->formats);
}
av_freep(&ret);
return NULL;
}