[FFmpeg-cvslog] avcodec/avpacket: Respect payload offset in av_grow_packet

Andriy Lysnevych git at videolan.org
Thu Jun 2 01:43:20 CEST 2016


ffmpeg | branch: master | Andriy Lysnevych <andriy.lysnevych at gmail.com> | Wed May 25 17:56:21 2016 +0300| [2fe04630e7d9c32fcab847b482998fa9fa7224d8] | committer: Michael Niedermayer

avcodec/avpacket: Respect payload offset in av_grow_packet

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2fe04630e7d9c32fcab847b482998fa9fa7224d8
---

 libavcodec/avpacket.c |   28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
index bcc7c79..8988ca2 100644
--- a/libavcodec/avpacket.c
+++ b/libavcodec/avpacket.c
@@ -110,24 +110,38 @@ int av_grow_packet(AVPacket *pkt, int grow_by)
 {
     int new_size;
     av_assert0((unsigned)pkt->size <= INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE);
-    if (!pkt->size)
-        return av_new_packet(pkt, grow_by);
     if ((unsigned)grow_by >
         INT_MAX - (pkt->size + AV_INPUT_BUFFER_PADDING_SIZE))
         return -1;
 
     new_size = pkt->size + grow_by + AV_INPUT_BUFFER_PADDING_SIZE;
     if (pkt->buf) {
-        int ret = av_buffer_realloc(&pkt->buf, new_size);
-        if (ret < 0)
-            return ret;
+        size_t data_offset;
+        uint8_t *old_data = pkt->data;
+        if (pkt->data == NULL) {
+            data_offset = 0;
+            pkt->data = pkt->buf->data;
+        } else {
+            data_offset = pkt->data - pkt->buf->data;
+            if (data_offset > INT_MAX - new_size)
+                return -1;
+        }
+
+        if (new_size + data_offset > pkt->buf->size) {
+            int ret = av_buffer_realloc(&pkt->buf, new_size + data_offset);
+            if (ret < 0) {
+                pkt->data = old_data;
+                return ret;
+            }
+            pkt->data = pkt->buf->data + data_offset;
+        }
     } else {
         pkt->buf = av_buffer_alloc(new_size);
         if (!pkt->buf)
             return AVERROR(ENOMEM);
-        memcpy(pkt->buf->data, pkt->data, FFMIN(pkt->size, pkt->size + grow_by));
+        memcpy(pkt->buf->data, pkt->data, pkt->size);
+        pkt->data = pkt->buf->data;
     }
-    pkt->data  = pkt->buf->data;
     pkt->size += grow_by;
     memset(pkt->data + pkt->size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
 



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