From 0dd7b8232d38317abc195edc48434ac1fd3e80fd Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Fri, 16 Oct 2020 16:33:23 +0200 Subject: [PATCH] avcodec/movtextenc: Don't presume every style to have a font Fixes segfaults in the absence of fonts; this can happen because the file didn't contain any or because the allocation of the font-string failed. Reviewed-by: Philip Langdale Signed-off-by: Andreas Rheinhardt --- libavcodec/movtextenc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c index 81e8c2e802..dcdbf16e08 100644 --- a/libavcodec/movtextenc.c +++ b/libavcodec/movtextenc.c @@ -298,10 +298,14 @@ static int encode_sample_description(AVCodecContext *avctx) // is avaiable in the ASS header if (style && ass->styles_count) { // Find unique font names - av_dynarray_add(&s->fonts, &s->font_count, style->font_name); - font_names_total_len += strlen(style->font_name); + if (style->font_name) { + av_dynarray_add(&s->fonts, &s->font_count, style->font_name); + font_names_total_len += strlen(style->font_name); + } for (i = 0; i < ass->styles_count; i++) { int found = 0; + if (!ass->styles[i].font_name) + continue; for (j = 0; j < s->font_count; j++) { if (!strcmp(s->fonts[j], ass->styles[i].font_name)) { found = 1;