[FFmpeg-devel] [PATCH 2/9] avformat/aviobuf: check if requested seekback buffer is already read

Marton Balint cus at passwd.hu
Wed Sep 30 00:10:14 EEST 2020


Existing code did not check if the requested seekback buffer is
already read entirely. In this case, nothing has to be done to guarantee
seekback.

Signed-off-by: Marton Balint <cus at passwd.hu>
---
 libavformat/aviobuf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 9675425349..d94be478ac 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -999,6 +999,9 @@ 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;
 
+    if (buf_size <= s->buf_end - s->buf_ptr)
+        return 0;
+
     buf_size += s->buf_ptr - s->buffer + max_buffer_size;
 
     if (buf_size < filled || s->seekable || !s->read_packet)
-- 
2.26.2



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