@@ -21,6 +21,7 @@
#include "avformat.h"
#include "subtitles.h"
#include "avio_internal.h"
+#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/mem.h"
@@ -112,15 +113,19 @@ AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
{
AVPacket **subs, *sub;
+ av_assert1(event || len == 0);
+
if (merge && q->nb_subs > 0) {
/* merge with previous event */
int old_len;
sub = q->subs[q->nb_subs - 1];
old_len = sub->size;
- if (av_grow_packet(sub, len) < 0)
- return NULL;
- memcpy(sub->data + old_len, event, len);
+ if (event) {
+ if (av_grow_packet(sub, len) < 0)
+ return NULL;
+ memcpy(sub->data + old_len, event, len);
+ }
} else {
/* new event */
@@ -134,14 +139,16 @@ AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
sub = av_packet_alloc();
if (!sub)
return NULL;
- if (av_new_packet(sub, len) < 0) {
- av_packet_free(&sub);
- return NULL;
+ if (event) {
+ if (av_new_packet(sub, len) < 0) {
+ av_packet_free(&sub);
+ return NULL;
+ }
+ memcpy(sub->data, event, len);
}
- subs[q->nb_subs++] = sub;
sub->flags |= AV_PKT_FLAG_KEY;
sub->pts = sub->dts = 0;
- memcpy(sub->data, event, len);
+ subs[q->nb_subs++] = sub;
}
return sub;
}
@@ -112,7 +112,7 @@ typedef struct {
/**
* Insert a new subtitle event.
*
- * @param event the subtitle line, may not be zero terminated
+ * @param event the subtitle line (not zero terminated) or NULL on not yet available event
* @param len the length of the event (in strlen() sense, so without '\0')
* @param merge set to 1 if the current event should be concatenated with the
* previous one instead of adding a new entry, 0 otherwise
If ff_subtitles_queue_insert() were given a NULL buffer with 0 length, it would still attempt to grow the packet or memcpy depending on if merge option is enabled. In this commit, allow passing a NULL buffer with 0 length without attempting to do such operations. This way, if a subtitle demuxer happens to pass an empty cue or wants to use av_get_packet() to read bytes, there are no unnecessary operations on the packet after it is allocated. Signed-off-by: Marth64 <marth64@proxyid.net> --- libavformat/subtitles.c | 23 +++++++++++++++-------- libavformat/subtitles.h | 2 +- 2 files changed, 16 insertions(+), 9 deletions(-)