Pad the extradata in the AAC ADTS to AudioSpecificConfig bitstream filter.

Originally committed as revision 20541 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/aac_adtstoasc_bsf.c

@@ -84,7 +84,7 @@ static int aac_adtstoasc_filter(AVBitStreamFilterContext *bsfc,
             buf      += get_bits_count(&gb)/8;
         }
         avctx->extradata_size = 2 + pce_size;
-        avctx->extradata = av_malloc(avctx->extradata_size);
+        avctx->extradata = av_mallocz(avctx->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
 
         init_put_bits(&pb, avctx->extradata, avctx->extradata_size);
         put_bits(&pb, 5, hdr.object_type);