[FFmpeg-cvslog] lavf: simplify handling of offset in av_probe_input_buffer()

[Anton Khirnov]

ffmpeg | branch: release/1.1 | Anton Khirnov <anton at khirnov.net> | Mon Jan 13 11:55:18 2014 +0100| [e38c62fe0c24ae4d138f4eff8b91db996a8b7e1d] | committer: Anton Khirnov

lavf: simplify handling of offset in av_probe_input_buffer()

(cherry picked from commit c1868e7ee7b07b40a0fe15f50df89fe499a01a50)

Signed-off-by: Anton Khirnov <anton at khirnov.net>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e38c62fe0c24ae4d138f4eff8b91db996a8b7e1d
---

 libavformat/utils.c |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index b0bfea2..fb6606b 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -357,7 +357,7 @@ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
                           const char *filename, void *logctx,
                           unsigned int offset, unsigned int max_probe_size)
 {
-    AVProbeData pd = { filename ? filename : "", NULL, -offset };
+    AVProbeData pd = { filename ? filename : "" };
     unsigned char *buf = NULL;
     int ret = 0, probe_size;
 
@@ -372,16 +372,14 @@ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
     if (offset >= max_probe_size) {
         return AVERROR(EINVAL);
     }
+    avio_skip(pb, offset);
+    max_probe_size -= offset;
 
     for(probe_size= PROBE_BUF_MIN; probe_size<=max_probe_size && !*fmt;
         probe_size = FFMIN(probe_size<<1, FFMAX(max_probe_size, probe_size+1))) {
         int score = probe_size < max_probe_size ? AVPROBE_SCORE_MAX/4 : 0;
         int buf_offset = (probe_size == PROBE_BUF_MIN) ? 0 : probe_size>>1;
 
-        if (probe_size < offset) {
-            continue;
-        }
-
         /* read probe data */
         buf = av_realloc(buf, probe_size + AVPROBE_PADDING_SIZE);
         if ((ret = avio_read(pb, buf + buf_offset, probe_size - buf_offset)) < 0) {
@@ -394,7 +392,7 @@ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
             ret = 0;            /* error was end of file, nothing read */
         }
         pd.buf_size += ret;
-        pd.buf = &buf[offset];
+        pd.buf       = buf;
 
         memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);