avcodec/dvbsubdec: Support computing clut only once

This avoids crafted files from consuming excessive resources recomputing the clut after each pixel change

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2021-03-04 14:22:31 +01:00
parent 46c4f39307
commit 7b4510d2a8
2 changed files with 6 additions and 3 deletions

View File

@ -293,6 +293,8 @@ Enabled by default.
@table @option
@item compute_clut
@table @option
@item -2
Compute clut once if no matching CLUT is in the stream.
@item -1
Compute clut if no matching CLUT is in the stream.
@item 0

View File

@ -823,7 +823,7 @@ static int save_subtitle_set(AVCodecContext *avctx, AVSubtitle *sub, int *got_ou
memcpy(rect->data[0], region->pbuf, region->buf_size);
if ((clut == &default_clut && ctx->compute_clut == -1) || ctx->compute_clut == 1) {
if ((clut == &default_clut && ctx->compute_clut < 0) || ctx->compute_clut == 1) {
if (!region->has_computed_clut) {
compute_default_clut(ctx, region->computed_clut, rect, rect->w, rect->h);
region->has_computed_clut = 1;
@ -979,7 +979,8 @@ static void dvbsub_parse_pixel_data_block(AVCodecContext *avctx, DVBSubObjectDis
}
}
region->has_computed_clut = 0;
if (ctx->compute_clut != -2)
region->has_computed_clut = 0;
}
static int dvbsub_parse_object_segment(AVCodecContext *avctx,
@ -1737,7 +1738,7 @@ end:
#define OFFSET(x) offsetof(DVBSubContext, x)
static const AVOption options[] = {
{"compute_edt", "compute end of time using pts or timeout", OFFSET(compute_edt), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DS},
{"compute_clut", "compute clut when not available(-1) or always(1) or never(0)", OFFSET(compute_clut), AV_OPT_TYPE_BOOL, {.i64 = -1}, -1, 1, DS},
{"compute_clut", "compute clut when not available(-1) or only once (-2) or always(1) or never(0)", OFFSET(compute_clut), AV_OPT_TYPE_BOOL, {.i64 = -1}, -2, 1, DS},
{"dvb_substream", "", OFFSET(substream), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 63, DS},
{NULL}
};