avcodec/adts_parser: allow passing a pre allocated AACADTSHeaderInfo to avpriv_adts_header_parse()

Code freeing the struct on failure is kept for backwards compatibility, but
should be removed in the next major bump, and the existing lavf user adapted.
Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/adts_header.c

@@ -32,6 +32,8 @@ int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr)
     int size, rdb, ch, sr;
     int aot, crc_abs;
 
+    memset(hdr, 0, sizeof(*hdr));
+
     if (get_bits(gbc, 12) != 0xfff)
         return AAC_AC3_PARSE_ERROR_SYNC;
 

libavcodec/adts_parser.c

@@ -47,24 +47,30 @@ int avpriv_adts_header_parse(AACADTSHeaderInfo **phdr, const uint8_t *buf, size_
 {
 #if CONFIG_ADTS_HEADER
     int ret = 0;
+    int allocated = 0;
     GetBitContext gb;
 
     if (!phdr || !buf || size < AV_AAC_ADTS_HEADER_SIZE)
         return AVERROR_INVALIDDATA;
 
-    *phdr = av_mallocz(sizeof(AACADTSHeaderInfo));
+    if (!*phdr) {
+        allocated = 1;
+        *phdr = av_mallocz(sizeof(AACADTSHeaderInfo));
+    }
     if (!*phdr)
         return AVERROR(ENOMEM);
 
     ret = init_get_bits8(&gb, buf, AV_AAC_ADTS_HEADER_SIZE);
     if (ret < 0) {
-        av_freep(phdr);
+        if (allocated)
+            av_freep(phdr);
         return ret;
     }
 
     ret = ff_adts_header_parse(&gb, *phdr);
     if (ret < 0) {
-        av_freep(phdr);
+        if (allocated)
+            av_freep(phdr);
         return ret;
     }