avformat/format: av_register_output_format() and av_register_intput_format() that work in O(1) time

Reviewed-by: Stefano Sabatini
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2013-12-08 02:29:28 +01:00
parent ec464c9683
commit 49f10c9cb1

View File

@ -33,6 +33,9 @@ static AVInputFormat *first_iformat = NULL;
/** head of registered output format linked list */
static AVOutputFormat *first_oformat = NULL;
static AVInputFormat **last_iformat = &first_iformat;
static AVOutputFormat **last_oformat = &first_oformat;
AVInputFormat *av_iformat_next(AVInputFormat *f)
{
if (f)
@ -51,20 +54,22 @@ AVOutputFormat *av_oformat_next(AVOutputFormat *f)
void av_register_input_format(AVInputFormat *format)
{
AVInputFormat **p = &first_iformat;
AVInputFormat **p = last_iformat;
format->next = NULL;
while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
p = &(*p)->next;
last_iformat = &format->next;
}
void av_register_output_format(AVOutputFormat *format)
{
AVOutputFormat **p = &first_oformat;
AVOutputFormat **p = last_oformat;
format->next = NULL;
while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
p = &(*p)->next;
last_oformat = &format->next;
}
int av_match_ext(const char *filename, const char *extensions)