| Message ID | 20200916192118.22135-1-onemda@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [FFmpeg-devel] avformat/aviobuf: fix broken logic in ffio_ensure_seekback() | expand |
| Context | Check | Description |
|---|---|---|
| andriy/default | pending | |
| andriy/make | success | Make finished |
| andriy/make_fate | success | Make fate finished |
Paul B Mahol: > This removes big CPU overhead for demuxing chained ogg streams. > > Signed-off-by: Paul B Mahol <onemda@gmail.com> > --- > libavformat/aviobuf.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c > index a77517d712..c27d564602 100644 > --- a/libavformat/aviobuf.c > +++ b/libavformat/aviobuf.c > @@ -999,7 +999,7 @@ int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size) > int filled = s->buf_end - s->buffer; > ptrdiff_t checksum_ptr_offset = s->checksum_ptr ? s->checksum_ptr - s->buffer : -1; > > - buf_size += s->buf_ptr - s->buffer + max_buffer_size; > + buf_size += (s->buf_end - s->buf_ptr) + max_buffer_size; > > if (buf_size < filled || s->seekable || !s->read_packet) > return 0; > Wouldn't it actually be enough to check whether buf_size < filled (which should probably be renamed to available) without adding anything to buf_size at all (at least not before doing the check)? (Btw: avio_seek() does not always perform seeks within the buffer, even when it could: It doesn't do so if the direct flag is set and if there is a seek function; but does the existence of the latter really imply that the stream is actually seekable?) - Andreas
diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c index a77517d712..c27d564602 100644 --- a/libavformat/aviobuf.c +++ b/libavformat/aviobuf.c @@ -999,7 +999,7 @@ int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size) int filled = s->buf_end - s->buffer; ptrdiff_t checksum_ptr_offset = s->checksum_ptr ? s->checksum_ptr - s->buffer : -1; - buf_size += s->buf_ptr - s->buffer + max_buffer_size; + buf_size += (s->buf_end - s->buf_ptr) + max_buffer_size; if (buf_size < filled || s->seekable || !s->read_packet) return 0;
This removes big CPU overhead for demuxing chained ogg streams. Signed-off-by: Paul B Mahol <onemda@gmail.com> --- libavformat/aviobuf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)