Marth64: > 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 <mart...@proxyid.net> > --- > libavformat/subtitles.c | 24 ++++++++++++++++-------- > libavformat/subtitles.h | 2 +- > 2 files changed, 17 insertions(+), 9 deletions(-) > > diff --git a/libavformat/subtitles.c b/libavformat/subtitles.c > index 3413763c7b..4742ca0667 100644 > --- a/libavformat/subtitles.c > +++ b/libavformat/subtitles.c > @@ -21,6 +21,7 @@ > #include "avformat.h" > #include "subtitles.h" > #include "avio_internal.h" > +#include "libavutil/avassert.h" > #include "libavutil/avstring.h" > > void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb) > @@ -111,15 +112,20 @@ AVPacket > *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q, > { > AVPacket **subs, *sub; > > + if (!event) > + av_assert1(len == 0);
av_assert1(event || len == 0) will make the assert message more meaningful and saves a line. > + > 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 */ > > @@ -133,14 +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; > } > diff --git a/libavformat/subtitles.h b/libavformat/subtitles.h > index 88665663c5..ad6b96ca6a 100644 > --- a/libavformat/subtitles.h > +++ b/libavformat/subtitles.h > @@ -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 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".